Evolution Final

What are the four experimental design considerations? (4)

1. defining effective control groups is critical 2. all treatments MUST be handled alike 3. Randomization 4. large sample sizes

What is the theory of Special Creation in general?

big blanket theory, takes faith based systems with creation story and folds them together under one umbrella, explains how all species we have came to be

What are premutations?

premutations are when you have sections of the genetic code that are more susceptible to mutations, they are primed for mutations, one reason for this is the section being GC rich

what are the different reasons and ways that sexual dimorphisms can arise, generally? (3)

sexual selection natural selection intrinsic reasons

What are some important considerations when considering traits and adaptations? (3)

1. differences among populations are not always adaptive, they might be but we dont KNOW until we collect data and analyze it, you know.. do actual science, dont just make assumptions 2. not all traits are adaptations, maybe its just a trait that has nothing to do with fitness, not all traits affect fitness! Dr. steffenson's hair color does not affect his fitness 3. not every adaptation is perfect! adaptations are relative to one another, they only have to be better than other options, it could be a horrible trait to have that just happens to be better than the other options, thus it is adaptive but not necessarily "good" to have

What are Darwin's postulates? (4)

1. individuals have variation 2. differences must be heritable 3. differential surviving/reproduction 4. successful b/c of the variant traits inherited

What are the stages of speciation?

1. start off with a single variable population, needed because if everyone is the same then microevolution cant happen because natural selection has nothing to act on and preferentially select for, and thus speciation cant occur either 2. distinguishable but still interbreeding subpopulations, still some gene flow 3. distinct populations with limited interbreeding ie even less gene flow 4. eventually different, differences appear each the two populations, one population moves in one direction for a trait, while the other moves in a different direction for a trait, and eventually! because of this divergence, we now have reproductively isolated populations and thus two distinct species

What is the 1st stage of speciation? and more importantly give an example of it

1. start off with a single variable population, needed because if everyone is the same then microevolution cant happen because natural selection has nothing to act on and preferentially select for, and thus speciation cant occur either an example of variation in a single population is the Sticklebacks which are tiny little fish the sticklebacks' has gill rakers that are hair like structures which are used to make sure that the food they are eating isn't clogging their respiratory surfaces by scraping across their gills to clean them out so when the gill rakers were measured, they found that the gill rakers size differed based on the sticklebacks' food preference so if the food they were eating were large then the gill rakers were smaller and thicker while if the food was smaller the gill rakers were longer and skinner and more hairlike to form these meshlike structure

What is the history of evolutionary theory in the public eye? What was the big court trial? What was the deal, and who was involved? what was the verdict and punishment and overall end consequence?

1925 Scopes Trial John T. Scopes was highschool biology teacher in tennessee, there was the Butler Act at the time which made it ilegal to teach evolution in public schools, so he looked into the evolutionary theory and natural selection and thought it made a lot of sense and should teach it to his kids, the majority of kids had no issue with it, but one kid told his parents what they were learning in class and it got out of control, Scopes was brought to trial for violating the Butler Act, Clarence Darrow was his defense attorney, William Jennings Brian was prosecutor, Verdict of trial was that he was guilty and fined 100 dollars equivalent of 1800 dollars in todays money, but no jail time, he paid the fine and several years got supreme court to overturn verdict but was never reimbursed, Butler Act was declared unconstitutional in 1967 by supreme court based on the separation of church and state

What is the 2nd stage of speciation? and more importantly give an example of it

2nd stage of speciation is that there are subpopulations, within a larger species population, that preferentially breed with members of their subpopulation Sticklebacks in locations that are connected but slightly segregated from one another, Robert's Creek and Robert's Lake, the creek runs into the lake Creek sticklebacks much larger than the lake sticklebacks the creek fish had very small rakers, and lake fish had very big rakers, so theres variability, differences between populations, and it turns out they preferentially breed with their more similar sticklebacks, so its still one population but they are somewhat subdivided, they still interbreed though

What is the 3rd stage of speciation? and more importantly give an example of it

3rd stage of speciation - distinct populations with limited interbreeding In Canada, 2 populations of sticklebacks, Benthic (lake bottom) and limnetic (open water, higher up in water column) populations so theres variation in size, and they will breed with one another, but they tend not to, it is extremely limited Benthic individuals are big with small rakers because they are eating really big food, invertebrates at bottom of lake Limnetic individuals are small and have big rakers that create meshlike structure so they can filter tiny particulate out of water so they mate occasionally but the offspring compete poorly with the purebreds because the purebreds are specialists for a particular food source while the mixed offspring are generalists which cant really compete with the specialists for a particular food source

What is the 4th stage of speciation? and more importantly give an example of it

4th stage of speciation - distinct populations with complete reproductive isolation in Akkeshi Bay, Japan Sea 2 populations of sticklebacks, one closer to shore and one more out to sea they have similar lifestyles and diets, but differences in armor, mating, behavior, genetics, and sex chromosomes the two populations hybridize very rarely and the male hybrids are always sterile

What is genetic drift? how is population size, genetic drift, and hardy-weinberg predicted genotype frequencies related to one another?

A change in allele frequencies caused by random events genetic drift is the change in allele frequencies due to random chance, its effects on allele frequencies are most pronounced in smaller populations, so as you increase the population size being affected by genetic drift the allele and genotype frequencies will get closer and closer to the predicted hardy-weinberg frequencies you can never get rid of genetic drift, and you cannot predict what it will do ie whether it will increase or decrease an allele cause it can do both, but you can predict its strength ie how much it is going to do its thing whether it is increasing or decreasing an allele frequency

what is a shared character? what is a derived character? what is a shared derived character?

A shared character is one that two lineages have in common a derived character is one that evolved in the lineage leading up to a clade and that sets members of that clade apart from other individuals A shared derived character is a characteristic or trait that two lineages share, which has evolved leading up to their clade

All the following are types of traits that evolutionary biologists might study in regard to natural selection except: A. traits acquired during the lifetime of the lifetime of an organism B. physical characteristics of an organism C. behavioral traits D. genetics characters

A. traits acquired during the lifetime of an organism because individuals dont evolve, it has to be over generational time or its not evolution, this would be example of environmental variation because its acquired during lifetime of organism, this heredity value would be close to 0

In looking at a group of fence lizards after ten generations, which level of speciation would you predict to be the most prevalent? A. Variation in a single popuation B. Subpopulations that interbreed C. Distinct populations with limited interbreeding D. Distinct populations with complete reproductive isolation

A. variation in a single population

What is an experimental study involve/include? First - whats the general explanation they are seeking to answer in the experiment involving tetriphid flies and jumping spiders? Who was the person who tested this question and when? How did they do it?

An experimental study involve/includes: a control group, an experimental group, and you are manipulating something in the experimental groups that you can then compare to your control group so first.. the general explanation they are testing in the experiment is that the coloration of the wings of the tetriphid flies and the wing-waving behavior they have are meant to look like a courtship ritual in jumping spiders, so question is: are the flies actually mimicing the leg-waving display of the jumping spiders (that are their predators)? Green et al in 1987 tested this question by coming up with 3 specific hypotheses: 1. flies use markings and displays for own courtship 2. flies mimic jumping spiders to deter nonspider predators (in this environment nobody messes with jumping spiders) 3. flies mimic jumping spiders to deter jumping spiders Green for his experiment then broke the flies up into 5 groups each with different treatment: 1: tetriphid fly control (has wing pattern and wing-waving behavior) 2. tetriphid fly Sham treatment, where they cut wings off and then glued them back on, (another control group to be used as comparison in the future treatments where we are cutting wings off, so we know that any changes arent coming about from wing cutting) 3. tetriphid fly with housefly wings group (cut their wings off and glued different fly wings on that lack the marking pattern) 4. house fly with tetriphid fly wings glued on group 5. untreated control house fly group what they found was that the jumping spiders retreated from flies with marked wings and waving display (groups 1 and 2), and either stalked and attacked or attacked and killed all the other groups, other predators attacked and killed the flies regardless of wing markings and waving displays so the wing marking and waving display do appear to be adaptive

Natural selection ______. A. Works on populations, but its long-term effect is rendered on individuals B. works on individuals, but its long term effect is rendered on populations C. can only work on populations of genetically identical individuals D. works regardless of the amount of genetic variability in populations E. none of the above

B. works on individuals, but its long-term effect is rendered on populations

Darwin studied and wrote extensively about artificial selection, which is similar to natural selection, except that ________. A. natural selection works toward a specific goal B. artificial selection relies on preexisting variations in populations; natural selection does not C. aritificial selection prodcues varieties that would be less likely favored in nature D. artificial selection produces varieties of less interest to humans than natural selection

C. artificial selection produces varieties that would be less likely favored in nature so artificial selection can produce traits that are selected by natural selection but it doesn't have to

What are homoplasies? what causes homoplasies? how do homoplasies affect trees and how do we deal with this?

Convergence and Reversals are/can lead to homoplasies homoplasies confound trees, they are typically referred to as "noise" in the data of our outgroup and parsimony analyses we deal with the noise from homoplasies by analyzing as many independent characters as possible to minimize the affect of convergence and reversals, but it doesnt get rid of the homoplasies and there are other considerations like money and time to consider when adding traits to minimize the effects another way to reduce homoplasies if adding independent characters and if adding an outgroup doesnt help reduce homoplasies, then normally adding another outgroup is a good way to reduce the effects of homoplasies

The transition fossil archaeopteryx shows a combination of traits consistent with the hypothesis that it shared a common ancestor with_______. A. dinosaurs and batds B. hippos and whales C. reptiles and birds D. dinosaurs and birds E. birds and mammals

D. dinosaurs and birds

What are the different models for mate choice? (5) whats the acronym?

DGHRP 1. direct benefits model 2. good genes model 3. handicap hypothesis 4. runaway selection model 5. preexisting sensory bias

Give an overview of the history of natural selection leading to the modern synthesis Who came up with natural selection before Darwin? Who came up with natural selection at the same time as Darwin? who were the three guys who were involved in the formulation of natural selection?

Darwin did not come up with evolution but he did formalize the mechanism of Natural Selection as a driver of evolution Natural Selection was pitched before Darwin, W.C. Wells in 1813 wrote an article on human appearance and disease resistance, in which he wrote how people who survived disease better than others would pass that on and the next generation would survive better Alfred Russel Wallace discovered and formulated Natural Selection at the same time but independently of Darwin, Wallace did his stuff in indonesia Darwin didnt know anything about genetics, Mendel figured out monogenic inheritance patterns, his work was left in trunk in bottom of monastery, and his work was rediscovered after his death and people realized he was right Scientists agreed on evolution but not the mechanism, we could create fire far sooner before we figured out what was actual happening in the fire

What did darwin formalize? what does his theory basically say? what is the coolest thing about his book regarding its acceptance?

Darwin formalized the theory of natural selection basically what his theory said was that species are the products of descent with modification from a common ancestor coolest thing about his book was how quickly it spread across the globe and gained acceptance by scientific community, happened within 10 years

What did Darwin study using Artificial Selection? whats the difference between artificial selection and natural selection? How many species of dogs are there?

Darwin studied domestication of Dogs and he was a freak for Pigeons, he realized that if he only mates the pigeons with the most desirable traits then the next generation has more individuals with that trait artificial selection is when the people are deciding which genes are desirable and selectively breed the individuals with the desired traits to increase the frequency of these traits in the future generations, these traits do not to be natural occurring or normally advantageous in terms of darwinian fitness in the natural populations ie genetic engineering counts as artificial selection Natural selection is when environmental factors such as food availibility and type, and predators put pressures on individuals of a population and cause certain individuals with heritable traits that are advantageous to reproduce, survive and more importantly reproduce more because of those traits and thus the frequency those traits increase in the future generation of offspring there is only 1 species of dog, the different breeds of dogs simply the kind of variation that can be present within a population of the same species

Explain the problem in Darwin's Postulates that he pointed out and who figured out/solved the problem of: Age of the Earth

Darwin was kept up at night by the Age of the Earth, because if its only 6000 years old then theres no way his theory could be correct, he even looked at Lord Kelvin's calculations but even 20 million years would not be enough time either, even though kelvin would have been correct in predicting age of earth based on the sun if he had known that its energy was based on fusion instead of combustion, kelvin used the wrong constant, but he was soooo close to being right but now that we know the earth is around 4.6 billions years old we know that is more than enough time for all the variation we see on earth to have occurred

what was the cool and useful thing that darwin did when he first put forward his theory of evolution DWM? What are some problems with Darwin's postulates?

Darwin when he wrote his theory, pointed out all the things he didnt understand and that didnt add up with his theory which is useful since lots of times scientists just assume the working theory is correct and dont question it The problems he pointed out were: 1. source variation 2. inheritance patterns 3. Age of the Earth

Testing Darwin's Postulates: what are darwin's four postulates? How is that related to what Peter and Rosemary grant studied ie What did Peter and Rosemary Grant study and find?

Darwin's four postulates: 1. variation of traits in population 2. traits are heritable 3. differential survival/reproduction of individuals 4. individuals survive/reproduce more based on the variation they inherited from their parents peter and rosemary grant studied darwin's finches, there are 13 species and each one is found independently on a different island of the galapagos the beaks of the different species of finches have clear differences, ie variation in population, and the variation of beak shape and size reflects the diversity of food present on the islands

What is an example of microevolution that was shown in NATURAL populations?

Descent with Modification evidence from Natural Populations Frank's et al. 2007 studied field mustard (Brassica rapa) which is an annual plant; in the mid 90's there was a monsoon season during an El Nino year where it rained much longer than usual, deep into late spring, and then in 2000's there was a big drought where the rains ended very early so because plants are growing in the spring time and using the rains to drive that growth to eventually be able to breed and produce offspring, the plants during the El Nino large rainy season kept growing longer and waited to reproduce ie they flowered much later in the year while in the drought year, the opposite happened they flowered and reproduced much earlier, the hybrids of the 90's rainy season and 2000's drought season showed an intermediate flowering time so natural populations can have variation and they can produce changes across generational time

Evolution by natural selection ______. A. requires that multiple unverified assumptions are made before it can be considered a viable explanation B. is only a theory and therefore not testable C. can be tested experimentally D. can be test observationally E. Both C and D

E. Both C and D

In response to an overabundance of cheetah predators in the environment, the average speed of thompson's gazelles in the population increases between successive generations. This process is referred to as ______. A. Macroevolution B. Sequestration C. Speciation D. Coalescence E. Microevolution

E. Microevolution

What is a sister species in the context of phylogenetic trees?

Either of the two descendant species formed when one species splits during evolution. Hence, the sister species (or sister group) is the one most closely related to any given species (or group), since both share an ancestral species (or group) not shared by any other species (or group)

what is the study the looked into sperm competition in fruit flies, who did it and when? what was the set up of experiment? what did they find?

Gage in 1991 with Mediterranean fruit flies idea was that increased ejaculate contributes to success he raised two sets of males, 1 set were raised by themselves and mate in private, the other set the males were raised in the company of other males and they mated in the presence of other males males raised in presence of rival had 2.5 times the volume of ejaculate, thus sperm competition, because they are producing more to increase their odds of fertilizing

What are some sexual reproduction asymmetries? (2)

Gamete energy cost - guys are cheap, eggs are insanely energetically costly to produce, meanwhile sperm cost almost nothing parental investment - in almost every species, females put in wayyyy more energy than males, so ultimately the more energy you put into your offspring the more successful they are BUT! at the same time, the more energy you put into offspring the lower the individual's remaining reproductive success parent offspring conflict is how the kid wants the parents to put all their energy into them and for their siblings to die, while the parents want to equally spread their energy across all the offspring

What is Geospiza fortis? why do we care about it? and what 3 things contribute to this reason for why we care about it? what does this thing eat and whats that significance?

Geospiza fortis is the medium ground finch we care about it because it is an ideal study population It is an ideal study population because there is very low immigration and emigration so static population, also the population is very low in size which is important because overtime researchers have tracked, banded, and collected data on every single bird for about 35 years, they also have a short generation time (4.5 year generations) which gives enough time to track and collect data from every single bird, but short enough that we track changes in the population over many generations the medium ground finches are primary seed eaters, ie primary food source is seeds

What is the hypothesis that explains why the flowers of the South African iris have white arrowheads on their petals, and who came up with it and when? What are some characteristics of the flower petals that led to the hypothesis? more importantly, How could we test this? what is this whole experiment and its conclusion an example of? explain why that thing is important

Hansen et al. 2002, came up with the nectar guide hypothesis to explain how the white arrowheads on the petals essentially are "nectar guides" and act as landing lights to guide pollinators to them especially since when you look at the arrowheads under a blacklight they glow in the frequency that the bees see in and act as an advertisement for the bees to come get their nectar How could we test this? Hansen did an EXPERIMENT in what they did was cover up the nectar guides with black ink, and see if more bees go to the ones with more nectar guides (control) vs the ones with covered up nectar guides (treatment group or experimental group) turns out there was fly preference difference for the type of pollinator that commonly go to these flowers, so the control flowers that had all of their nectar guides in tact, compared with our treatment groups that had all, most, or some of their nectar guides covered up, had a much higher percentage of pollinator visits so this shows that the reason these nectar guides had evolved were likely to help with pollination his whole experiment and its conclusion are an example of adaptive significance which is what is the trait USED for adaptive significance is important because apparently we as scientists assume that certain characteristics are adaptations without actually having tested it properly, especially to determine its function its one thing to determine whether a thing is adaptive or not, we just look to see if individuals with a certain trait survive/reproduce more than individuals without the trait and if they did then it is an adaptation but! the harder question is what is its adaptive significance which is basically what is the thing USED for

what is the name of the thing that causes trouble for phylogenetic trees? What are 2 things that cause issue

Homoplasies are similarity shared by two species that is not due to common ancestry, homoplasies can be caused by convergence and reversals Convergence - similarity between organisms that is not the direct result of shared phylogenetic history (and that may instead result from independent adaptations to similar environments), this can be remedied using DNA analysis as opposed to morphology Reversals - A derived trait can revert to an ancestral trait either through a mutation, or selection. Reversals provide misleading evidence about the order in a phylogeny and they can remove similarity that is caused by descent from a common ancestor (the reversal means that the two descendants of an ancestor do not share the derived trait) so if a species diverges from a common ancestor and has stayed constant since while another lineage underwent some transition that gives it spikes, down that lineage one of the branches undergoes a reversal and now that species has lost its spikes, so now it appears to be the same as the species that remained constant from the common ancestor and this similarity, ie homoplasy, can confuse when building the phylogenetic tree

What are the important patterns of genetic drift? (3) What are the key effects of genetic drift? (2)

Important patterns: the first important pattern is that each population has a unique evolutionary pathway, meaning there is a bunch of ways for each population to be randomly different from one another, ie each population is most likely going to be affected by genetic drift in a different way because it is random the second important pattern is that genetic drift is far more powerful in small populations, it can drastically shift allele frequency in a population size of 4 but in large populations of like 400 then its effects take on the appearance static on the line the last thing to recognize is that regardless of its strength, given enough time genetic drift can cause dramatic deviations in even large populations (strength is dependent on population size) Important Effects: 1. genetic drift also reduces genetic variation because it is pushing one of the alleles to fixation or loss, the speed of this pushing depending on the size of the population so genetic drift can often times work with natural selection in reducing genetic variation but it can also work against natural selection, sometimes it maintains genetic variation (making the frequency go back to 0.5), large scale trend it will reduce genetic variation but in the short run it can do anything, its a wild card 2. genetic drift also tends to reduce heterozygocity, heterozygocity is at a maximum when there are all heterzygotes in the populaiton when the allele frequencies are 0.5, so because genetic drift can increase or decrease an allele it decreases the chances of making a heterozygote, by reducing genetic diversity through genetic drift the heterzygocity also decreases

What is the example from class used to illustrate the situation in which we have a gene at a locus with two alleles, the wildtype dominant allele and a lethal recessive allele? so which genotypes will be normal and which will die? so we start off in this experiment with a population of all heterzygotes, thus what are the allele frequencies? so what do we expect to happen to the allele frequencies over generational time? what is the expected genotype frequencies if in hardy weinberg? but! based on the situation, what will the actual allele frequencies be and how do we solve for this? how does the dominance of an allele and the allele frequency affect the pattern of the allele frequency vs generational time graph ie whats the graph going to look like and why does it have this pattern? what factors of natural selection affect how quickly allele frequencies change?

In the example of Dawson flour beetles, we have a gene at a locus with two alleles, the wildtype allele and a lethal allele that is recessive the genotypes of homozygous wildtype and the heterozygotes will be normal while the homozygous lethal allele will die immediately so we start off in this experiment with a population of all heterzygotes, thus the allele frequencies are p = .5 (wildtype) and q = .5 (lethal) What we expect to happen to the allele frequencies over generational time is: Lethal allele is going to go down, and the wildtype will go up, the expected genotype frequencies if in hardy weinberg are p^2 = .25 ; 2pq = .5 ; q^2 = .25 but! based on the situation all the homozygous q individuals will die, so when we add this condition to the expected genotype frequencies by eliminating q^2 and then calculate the actual allele frequencies, they will be p = 0.67 and q = .33; solve for this by taking out q^2, so now new population that survives and reproduces is only p^2 and 2pq individuals so take new total of genotype frequencies (.75) and divide the p^2 and 2pq by the new total to get the new genotype frequencies then use p^2 + 2pq to get allele frequencies

so in an island and continent situation, we have a single locus with two alleles, and before migration the allele A has reached fixation on the island and the continent population is fixed for a so initially what are the genotype frequencies on the island and continent? 200 individuals from the continent migrate to the island (which originally had 800 individuals), what are the new genotype frequencies? (before they all mate) did the allele frequencies change? does this count as evolution? what are genotype frequencies after the mating on the island? thus, what is the genotype frequency pattern that is indicative of migration?

In the original population the island had allele frequencies of A = 1.0 and a = 0.0. So the predicted genotype frequencies would be AA = 1.0, Aa = 0.0, and aa = 0.0. If you compare these values to the post-migration genotypes frequencies of AA = 0.64, Aa = 0.32, and aa = 0.04, the post-migration population has fewer homozygotes overall (AA + aa = 1.0 before migration and AA + aa = 0.68 after migration) and more heterozygotes (Aa = 0.0 before migration and Aa = 0.32 after migration). the initial genotype frequencies on the island are: AA = 1.0 Aa= 0 aa = 0 the initial genotype frequencies on the continent are: AA = 0 Aa = 0 aa = 1.0 after 200 aa individuals from the continent migrate to the island that had 800 AA individuals, the new genotype frequencies are AA = .8 Aa = 0 aa = .2 the new genotype frequencies after mating on the island is: AA = .64 Aa = .32 aa = .04 thus the genotype frequency pattern that is indicative of migration is when after you have applied the situational condition (that is unknown at the time of solving the problem ie its what we are trying to figure out) then your final genotype frequencies have more heterozygotes and less homozygotes than you did originally

In this scenario, we are working in a mice model, we have one locus with two alleles: A and a. The copies of A turn into a by mutation at rate of 1/10,000 (which is still in the realm of possibility for mutation rates but it is literally one of thee highest possible mutation rates that is found only in viruses) first, whats the most common thing mutations do to alleles? second most common thing? least common thing? so if the alleles start off at: A = .9 a = .1 what are the predicted genotype frequencies if in HW? What would the allele frequencies change to?

In this scenario, we are working in a mice model, we have one locus with two alleles: A and a. The copies of A turn into a by mutation at rate of 1/10,000 (which is still in the realm of possibility for mutation rates but it is literally one of thee highest possible mutation rates that is found only in viruses) the most common thing mutations do is break the thing, second most common thing is that it does nothing, and the least common thing is that the allele gets more advantageous (something good happens) so if the alleles start off at: A = .9 a = .1 the predicted genotype frequencies are: AA = .81 Aa = .18 aa = .01 A = 0.9 - (0.0001 x 0.9) = 0.89991 a = 0.10009

Explain the problem in Darwin's Postulates that he pointed out and who figured out/solved the problem of: Inheritance Patterns what were the theories at the time and issues in those theories?

Inheritance Patterns problem: Darwin did not understand inheritance patterns and why they work the way they do, theories at the time were: blending inheritance lamarckism blending inheritance - the original parents are for example in the extremes of color, one really black another really white, and over time the offspring from original individuals end up looking more homogenous as some intermediate between white and black, but this means that variation over time disappears from population and thats not what happens, darwin didnt think that was what was happening lamarckism - as traits are used and disused, they change, he talked about giraffe necks, giraffes that need to constantly stretch to reach higher vegetation thus get longer necks, this is what Darwin thought might be happening but it is not how genetic inheritance works Darwin struggled with this, because of these theories were correct then his theory would not be correct

who, and when, did the example study that exemplifies a situation where there is zero parental care going on that still shows the asymmetry in reproductive success? what is the general scenario of the organisms in this study? what did they find when they analyzed the number of males, number of mates, and the number of offspring? what about in females? how is energy input in some way related to the amount reproductive success? how is number of mates related to number of offspring in males and females? so whats the upshot for the strength of sexual selection in the sexes? what does that specifically mean for heritable traits in the sexes?

Jones et al (2002) on newts so males gather in ponds and wait for females and once one wanders in a bunch of males and the female form the horrific mating ball after mating the females lays around 300 eggs, and then there is zero parental care, both the female and male just bail on the eggs the cost of the sperm and eggs are the entirety of parental investment in the offspring when they tracked the number of males, number of mates, and the number of offspring was that most males do not mate but the few males that do mate, produce a butt load of offspring in females, they are all successful and they all produce a butt load of offspring so basically, the females put in a bunch more energy but at the same time they are way more successful, so the amount of energy put in is in some way related to the amount of success in reproduction for males the number of mates really matters, and for females it doesnt really make a difference, there is no significant relationship the upshot is that sexual selection is a far more potent force in driving the evolution of males than it is for females, so because male traits matter for reproductive success the heritable traits associated with male success become more common tail crests in these newts are super sexy to females, they found that the males the reproduced more had larger tail crests, and it also helps them fight off competitors

What is Kin selection and a good example of it?

Kin Selection explanation is using the prairie dog alarm call example, one prairie dog puts itself at risk in order to alarm the colony that a predator is near and this makes sense because the goal of the organism is to reproduce so it can pass on genetic material, siblings and own offspring share 50% of genetic material, and siblings kids share 25% of my genetic material, so i could raise 1 kid of my own which has 50% of my genetic material or I could help raise 2 of my sibling's kids with each have 25% of my genetic material and I would be thus be equally successful evolutionarily, so it would better for the individual to help raise 3 of my siblings kids than to raise one its own, so the prairie dog screaming its head off tends to be very closely related to the individuals of the colony

what is the law that provides some evidence of macroevolution? Are there gaps in this evidence? who were 2 people who helped discover this evidence? What have humans done to the aforementioned law?

Law of succession - a pattern of correspondence, basically says that things that are alive in an area tend to look like the fossils of extinct things in that area Fossil record - which does not have "a bunch of gaps in it" it is in actuality incredibly complete William Clift (late 1700's) - he looked at Australian mammals and then dug and found a fossil that looked like the australian marsupials Darwin in South America saw armadillos running around and when he dug for fossils he found glyptodont fossils (massive extinct armadillos) so Clift and Darwin realized that extinct things looked similar to living things but with distinct differences, so evolution over time is causing some big differences but its ultimately coming from the same same ancestral thing people have, through traveling and bringing animals around with us, essentially destroyed the law of succession

What are the Hardy-Weinberg assumptions? (5) why do we use hardy-weinberg? What are the 2 conditions necessary for something to be in Hardy-Weinberg equilibrium?

MMRPS (mutation, migration, random mating, population is large, selection) 1. No mutation takes place. 2. No migration ie no genes are transferred to or from other sources (no immigration or emigration takes place). 3. Random mating is occurring 4. The population size is very large. 5. No selection occurs. We use Hardy-Weinberg as our null model, it is our baseline comparison through which we can whether evolution is happening or not happening and more specifically what mechanism is driving that evolution the two conditions of Hardy-Weinberg equilibrium are: 1. no change in allele frequencies over generational time 2. actual genotype frequencies match the predicted Hardy-Weinberg genotype frequencies

What are some differences between the theory of special creation and theory of descent with modification (DWM) ie what does DWM assert that the theory of special creation disagrees with? (5)

Microevolution - DWM says that small changes over generational time is occurin, example is beak size within darwinian finches is changing across generations, Special creation says species are immutable Speciation - DWM says that with enough microevolutionary events over time will lead to the arising of new species as ancestral species splits into two distinct species Macroevolution - DWM says that as speciation crops up then over enough time we can create massive changes like going from fish to tetrapods Species are derived from common ancestors - thus all species are related from original cell of life Age of Earth and Life - DWM says that they are far greater than 6000 years

What book did Charles Darwin write and when? What was discovered in 1908 and by whom? What was discovered in 1956 and by whom?

On the Origin of Species by Means of Natural Selection (1859) Thomas Morgan identified chromosomes as the genetic material for inheritance Watson and Crick and Rosalyn Franklin figured out the double helical structure of DNA

What are some common modern day arguments against the theory of evolution? (3) Natural selection? Thermodynamics? Species?

One argument is: Natural selection is unscientific because it is not falsifiable and makes no testable predictions; this is so far from true, there are absolutely testable predictions like darwin's finches another: evolution violates the 2nd law of thermodynamics, natural processes tend to move toward state of greater disorder, but this law is only true when you do not put inputs into the system, this only applies to ISOLATED systems, there is no such thing as an isolated system Another: no one has ever seen a new species formed, so evolution is unproven we have seen new species formed, the different species of sticklbacks for example, and you do not "prove" anything in science you can only support for or against theories now even though we have seen new species formed, even if we hadnt this doesnt mean that it never happens, have you ever seen an atom? have you ever seen gravity? Should we throw out everything we know about chemistry? There are inferences in science, you see a bunch of evidence of something and you come up with an explanation for them all that accounts for the pattern you see and it is most likely absolutely true

What is reciprocal altruism and a good example of it?

Reciprocal altruism is done by vampire bats, its sort of a tit for tat exchange between individuals, the vampire bats have to drink blood every two days or they will starve because they have crazy fast metabolisms so basically reciprocal altruism in bats is shown when one vampire bat didnt get any food so I will vomit blood into the others mouth so it can eat and survive, now I lost my meal but the other bat gets to live and if tomorrow I dont get any blood then that vampire bat will reciprocate ie pay me back and give me its meal, I am not being nice to be nice though, I am being selfish by making sure that I am covered in case something bad happens to me

Explain what the Runaway Selection Model of mate choice? what is this also called?

Runaway Selection Model of Mate Choice basically explains what happens when the female preference is heritable and the trait that they prefer in males is also heritable, each of these two alleles has variation so some females dont care, some care little, and some care a whole lot; same with males, some dont have trait, some slightly have trait, and some are rocking the trait over generational time, the females that dont care reproduce randomly, but the ones that have the heritable preference will selectively choose the males with the trait, so the males with strong showing of the trait end up getting to mate more, thus in the next generation the preference and trait end up getting associated with one another but these alleles are still only in a subset of the population, however the frequency of the alleles did slightly shift, but then as the frequency of the alleles become higher the strength of the selection for the preference and the trait becomes exponentially higher each generation as the preference becomes stronger and more common in the population and the trait becomes more pronounced and common, until! the only ones who are successful are the males with extreme exaggerations of the trait and females with strong preferences the loci for the trait and preference are found in BOTH sexes but! they are only expressed in the appropriate sex this is called Fischers Runaway Selection

Who studied Begonia flowers and when? Whats the backround of the begonia flowers that relevant? what are the two hypotheses of how the female flowers will go about gaining their reproductive success in their particularly tricky way? How are Begonia flowers a good example of energetic constraints and tradeoffs?

Schemske and Argren in 1995 so the male and female begonia flowers are kind of competing with each other, the female flowers dont have pollen (thats where sperm is), so if insect pollinators are looking for pollen then they wouldnt visit females since they dont have any, but the females got tricky... the female flowers depend on mimicry for reproductive success, they try to look like male flowers the two hypotheses for the female flower mimicry of male flowers for reproductive success are: stabilizing selection hypothesis and directional selection hypothesis in the stabilizing selection hypothesis, the female flowers will aim to have the perfectly average male flower size, they will try to blend in by having the same size as the average male flower, because if they are too big or small then the pollinators are like... bro you look weird AF, im not pollinating you in the directional selection hypothesis, the female flower initially tries to have the average size of the male flowers but then theyre like.. if I look even more "male-like" then I'll get even MORE pollination they used artificial flowers to see which flowers the pollinators will prefer and it turned out that the number of pollination visits increased with flower size, but! in natural populations... there arent super massive flowers... becauseeee, of energetic tradeoffs so when they went out and looked at the size of flowers vs the number of flowers on each stem, they found an inverse relationship, as size of flower increases the number of flowers per stem decreased, this is CLASSIC Energetic Tradeoff of size vs number

Explain the problem in Darwin's Postulates that he pointed out and who figured out/solved the problem and how: Source of Variation

Source of Variation problem: darwin had no idea where the variation in populations came from, we also didnt know how the variation got from one generation to the next Morgan (early 1900's) used fruit flies, found chromosomes and found that they are transferred from one generation to the next and these things account for the physical characteristics

How does the study of the medium ground finch, Geospiza fortis, help support darwin's four postulates?

Supports Postulates: 1st postulate supported because within population there is variation, some individuals have relatively large beaks so they can eat large seeds and others have small beak for small seeds 2nd postulate: the variation of beak size is heritable, so what they did was calculate a regression, they took parent beak depth (plotted on x axis) and then plot the midoffspring beak depth on the y axis, so if the the beak depth is 100% genetic then the graph should be a perfect straight line with zero spread, but the graph of the finches beak size was not a perfect straight line because there is environmental variation in play, but the heritability value of the population is likely closer to 1 because the spread of the data points are pretty tight and close to being a positive linear correlation 3rd postulate: Individuals do vary in success at surviving and reproducing; there was a drought in 1978 that crashed the population, 84% died, because low amount of flowers and seeds 4th postulate: survival and reproduction of individuals was based on traits of finches they inherited from parents, drought changed number of type of seeds, soft seeds that are preferred get eaten first, once gone only hard Tribulus fruit was left over to eat and having a deep, narrow beak was best to eat the seed which caused the average beak depth after the drought to increase, but then! an El nino event in 1983 cause lots of rain, which caused small soft seeds abundance to increase again but the individuals with the big beaks previously selected for have trouble eating the small seeds, so now small beaks are selected for because the environmental pressures changed

How does migration or gene flow between a super large continent population and a small island affect the allele frequencies of each others' populations?

The super large continent population affects the allele frequency of the island a bunch because there is constant movement of alleles from the continent to the island so if you start off with only heterozygotes on the island but then you continually get an influx of homozygotes to the island, this will begin to drastic shift the allele frequencies on the island however the island does not really change the allele frequencies on the continent because there is no significant movement of individuals from the island to the continent, so migration of gene flow is approximately one way, from the continent to the island

What is the scientific theory that contradicts the theory of special creation's age of the earth? Who came up with it? What does it say?

Uniformitarianism was come up with by James Hutton (late 1700's), he basically said that sedimentary rock erodes very very slow, so if we back calculate based on the rate of geological processes like this, then it has to be wayyyyyy older than we thought, his assumption was that the erosion rates we see today were the same as they were far in the past

what are some questions that can be answered by phylogenies? dogs? clothes?

We answered canine transmissible venereal tumor (CTVT), we used phylogenetic trees to see if the contagious dog cancer CTVT could actually be transmissible between dogs or if the cancer is transmitted by a virus, if tumor can move from dog to dog then that means the dogs should be more closely related to one another than the tumors, if it is in fact a virus or mutagen that transmits/causes the cancer or the actual cancerous cells from one dog infecting and causing cancer in another dog so we did a phylogenetic tree to figure out how these tumors are transmitted We answered, when did humans start wearing clothes? we tracked neutral mutations to figure out longterm evolutionary trends, we assumed the number of neutral mutations since common ancestor is additive, and we know the mutation rate, then we can back calculate a divergence occurred, we did this with body lice vs head lice, to figure out when we started wearing clothes

What is the definition of a species? What is the biological species concept and who came up with it? Why is the biological species concept (BSC) useful ie where does the power of the biological species concept come from?

We dont know, there isnt one biological species concept - (most commonly used definition for species but that does not mean it is right) Ernst Mayr from 1942 species is a population of individuals in a localized area that are capable of breeding and producing fertile, viable offspring The power of the biological species concept comes from the fact that it lets the animals themselves to tell us whether they are the same species

When do we use observational studies? what is an example of an observational study with Garter snakes?

We use observational studies because sometimes experimental studies can be difficult or even immoral example of observational study is the Garter snake nighttime retreats observational study performed by Huey et al. in 1989 so the garter snakes are ectotherms thus they use environment to regulate their body temperature and want to keep the temperature within a CTmin and CTmax (critical temperature) outside of which they die and within which lies an optimal temperature range where their reproductive success is the best and they stay in this range by alternating between being exposed or hiding under rocks first they determined the snakes' lifetime reproductive success in different temperatures to determine their ideal temperature range which was 28-32 degrees then they hypothesized and tested whether the thickness of the rock is critical, and found that between small, medium, and thick rocks the temperature under the rock throughout the day between the 3 types differed substantially and that medium rock thickness coincided the most with the optimal temperature for the snakes finally they found that the selection of the rock type was adaptive as the 3 rock types are equally abundant at Eagle Lake, but the majority of the rocks that were chosen were of the medium variety

what was the experiment Weeks did after he found that the prior hypothesis was a bunch of bull? what did they find with regards to tickload and oxpecker presence? what else did Weeks track on the bison, what kind of experiment did he use here? sooooo after all this, what are these dang birds doing?

Weeks (2000) did an: Exclusion Experiment where they tracked things like tickload and earwax amount across different treatment groups in which 1 group of bison had oxpeckers on them and the other group had no oxpeckers as the birds were constantly scared away by grad students with tennis rackets they found that the tickload was random regardless of whether the oxpeckers were there or not, because if the oxpeckers were eating the ticks then when they are present the tickload should go down, BUT! that is not what they found; Oxpeckers had no discernable effect on hosts' tick loads Weeks did another Exclusion Experiment, tracking the number of wounds on the bison when there are Oxpeckers present and not present, and found that when the birds are present the number of wounds went up significantly He did the same thing with earwax, and found that when the Oxpeckers were scared away the amount of earway shot up significantly sooooo after all this, they found these dang birds were: it turns out that the birds preferred to only eat the adult female ticks that had already fed so that they ticks were thus big, juicy and delicious, but the birds left the juveniles and males It turns out the birds are actually PARASITIC, they open up wounds on the cattle to drink the blood, eat the earwax, and eat the hair follicles all to get the high protein content from these sources, and even when they do eat the ticks they wait till the ticks have fed first

What did William Paley come up with in 1802? What was the example he used? What was the essential argument of his example? what is the example used today? what are the major concerns in this example?

William Paley wrote and promoted treatise on special creation basically saying theres no way natural evolution is happening example he used was: imagine finding a watch on the beach, and from watch we see it is complex and precise, clearly a work of skilled craftsman, argument is that how can you find something complex and say that random changes lead to this complex item, in reality a skilled worker created complex, precise item and thats why it exists example used: vertebrate eye used now adays its the best eye and its so complex and ordered, claimed that theres no way it evolved by random mutations first major concern is: can random changes lead to order? yes absolutely, if the thing controlling the random changes is not random, ie natural selection is filtering the random mutations in a nonrandom way, 2nd concern: evolution predicts traits evolve in small increments, but what good is half a vertebrate eye? but yeah half a vertebrate eye can be advantageous if its better than other alternatives that are present, having a rudimentary eye is better than having no eye at all, yes complex traits can evolve if each intermediate is advantageous compared to the previous iteration

What was the extended evolutionary synthesis?

after the modern synthesis had altered Darwin's theories to incorporate knowledge of DNA, inheritance patterns, and genetics in general, we learned a whole lot more, such as epigenetics, multilevel selection, evo-devo theory, and all of that had to be integrated into evolutionary theory as well so in early 2000's they did the extended evolutionary synthesis, fancy name of integrating all new knowledge into darwin's works as we fill in previous gaps in knowledge

what is an example of an intrinsic reason that accounts for a sexual dimorphism?

an example of an intrinsic reason that accounts for a sexual dimorphism can be found in the hollyhock weevil the males and females have different roles in reproduction, so the female uses her crazy long probosis to drill into vegetation to lay her eggs under the epidermal layer of the vegetation and males dont have to do this, this is just an intrinsic difference between them that has nothing to do with sexual selection, but it does have to do with reproduction

What is an example of what happens to allele frequencies within a population when we have migration and natural selection occurring at the same time?

an example that shows how allele frequencies within a population change when we have migration and natural selection is water snakes of Lake Erie snakes on the mainland and an island, the snakes can range in appearance from strongly banded to unbanded uniform pattern so mainland is mostly banded snakes, which makes sense because the environment is highly heterogeneic cause has lots of moss and rocks and leaflets, so if you were one solid color you would show up better than if banded, but islands are limestone so having unbanded uniform color is better than being banded (different environments are selecting for different phenotypes and their corresponding genotypes/alleles) so the migration is trying to homogenize the populations on the different island as every generation we have individuals bringing the banded allele to the island but every generation the islands environment is selecting against that allele so our migration and natural selection forces are working in opposition to one another so the unbanded allele are being chosen for but because the we have the banded allele constantly being added to the population we never actually get rid of that variation, so the islands have quite an amount of variation within their populations due to the natural selection and migration forces opposing one another the result of migration and natural seleciton working in opposition to each other is that natural selection is preventing the allele frequency homogenation (preventing the islands from looking like the mainland population where there is only the banded allele) so the islands have quite amount of genetic variation in the population because of the effect of migration constantly reinforcing the banded allele that is simultaneously being stomped out as it is selected against by natural selection

What is darwinian evolution? explain darwinian evolution in depth

another way of saying natural selection, it follows his four postulates so we start with original individual this individual then has offspring, lets say 3, but the genetics that go to offspring might be slightly different from each other, on average we share about 50% of our genetic material with siblings, which is why we do not look exactly like our siblings then some of this variation is potentially good to have, and some bad, so these different offspring will survive and reproduce at different rates based on this heritable variation so now we have over time, the population changes and looks more like the variation that is advantageous, as the good stuff goes up in frequency and the bad stuff goes down in frequency

what is sexual dimorphism? whats an example that shows how males and females of a species can be different in multiple ways in iguanas? is sexual selection the only mechanism through which sexual dimorphism can arise? What is the example with the purple throated caribs?

anytime we are talking about a difference between males and females within a species we are talking about sexual dimorphism, BUT! the difference does not necessarily have to be a physical difference, any difference counts as a sexual dimorphism, behavior is an example marine iguanas male marine iguanas weigh 2x as much as females, the males are also different behaviorally, the females all year hang out in groups just gabbin away with each other, meanwhile the males during the breeding season try to murder each other sexual selection is NOT the only mechanism by which sexual dimorphism can arise, Natural Selection can explain some cases as well, an example is the purple-throated carib (bird), natural selection led to ecological differences between the 2 sexes, so physical difference is that the males and females have different beak shapes due to their preferred food source, this arose basically because the males go after the preferred food source and eat all of it, so the females evolved over time different beaks for a different food source to the point where now they eat totally different things, this sexual dimorphism arose through natural selection and there is now an ecological difference between the sexes because of the niche the each fill from what they eat

What is: apomorphy plesiomorphy synapomorphy

apomorphy - (derived trait) A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms plesiomorphy - an ancestral trait that is homologous within a particular group of organisms but is not unique to members of that group (compare apomorphy) and therefore cannot be used as a diagnostic or defining character for the group, it can appear anywhere in a phylogenetic tree synapomorphy - a shared ("syn") apomorphy, a shared derived trait, that distinguishes and is shared by members of a monophyletic group, and can thus assumed to be present in their most recent common ancestor example- dogs belong to mammals thus share hair and lactation

What is the most famous transitional fossil? What is it between? When did it occur? Where was it found? What was the organism adept at? What traits does it have a mix of?

archaeopteryx - the transitional form between dinosaurs and modern day birds, occured about 150 million years ago, found fossil in modern day germany, it was adept at gliding, and it was a mix of bird and reptilian characteristics

What was the modern synthesis and how did it relate to and change Darwin's Theories?

at this point darwin's work was a little outdated, alot of the questions that darwin and his work put forward had been solved by now, this time was called the modern synthesis in the modern synthesis (mid 1900's) they took the information about genetics and patterns of inheritance and DNA and integrated it into darwin's theories, there is variation in populations which was changed to variation in populations as a result of mutations, variation has to be inherited changed to variation is passed down through chromosomes, they changed his statements slightly by integrating the new information, this was all called the modern synthesis

Inbreeding is not always as extreme as self-fertilization, such as in the otters where there genetic bottle neck led to regular animal inbreeding but not self fertilization, what was the difference between selfing and regular animal inbreeding? is inbreeding good or bad? what is inbreeding depression? How do we avoid inbreeding in natural settings?

both selfing and regular animal inbreeding will increase homozygotes and decrease heterozygotes, the difference between the two is the rates at which the change in genotype frequencies will occur, regular animal inbreeding does the same thing just at a slower rate whether inbreeding is good or bad depends, the reason why most people would say inbreeding is bad is because of inbreeding depression which is when you get bad recessives hidden in the heterozygotes of the population which through inbreeding making more homozygotes become more common in the population, this depresses the health of the population because you have more individuals out there with deleterious phenotypes from being homozygous for the deleterious recessives BUT! these deleterious recessives are now exposed to natural selection because they are no longer hidden in the heterozygotes which means these deleterious recessives now get selected against and thus weeded out of the population which causes the health of the population as a whole over time to increase! Thus, inbreeding is bad for individuals and even the population in the short-term but good in the long-term We avoid inbreeding in natural settings through: 1. mate choice - "not gonna happen cuz" 2. genetically controlled self-incompatibility - say you are capable of self-fertilization but you dont do it because it exposes you to inbreeding depression so youre like nah me not gonna happen 3. dispersal mechanism - a bird flys away from birth place, decreasing likelihood of breeding with close relatives

What is the comparative method of a study used for? what is an example of a study that uses the comparative method? What are the other things could account for the differences?

comparative method is used to study evolution of form and function Hosken (1998) was curious as to why some bats have bigger testes than others (form and function), and hypothesized that it was an adaptation for sperm competition they found that due to females having more mating opportunities in larger groups, the females end up mating with multiple males so the males only win if its their sperm that fertilizes the females' egg, so the strategy for males in large group is sperm competition in this case having large testes to eject more sperm they found that as the group size increased so did the average size of testes but there are other things that could account for this difference in size other than sperm competition such as: phylogenetic constraints phylogenetic constraints is basically when the relationship we think we find is not actually a true relationship between, in this case group size and testes size, but in fact it is a byproduct of evolution due to two groups of species inheriting traits from two common ancestors, thus we could have mistakenly said there is a relationship between testes size and group size based on the data from 6 species when there isnt actually one because in reality we were only comparing two common ancestors instead of 6 species, thus we are in effect drawing a best fit line to determine a relationship between two points thus it will have to be a line and thus make it seem like there is a relationship when there is not

which nucleotide is most susceptible to mutations? what can happen to it?

cytosine so there is spontaneous methylation going on in general, so when cytosine gets methylated and then also undergoes spontaneous deamination it turns into thymine

How can genotype-by-environment interaction play a part in evolution?

depending on the environmental pressures, the environment can select for certain characteristics to increase frequency of allele or in other pressures decrease the frequency of allele

How does the wild and domestic tomato relate to Artificial Selection, first what is the domestic tomato's scientific name? what is wild tomato scientific name? then explain differences in size and how did this come about, what mechanism of evolution and what is the gene being acted upon? and why would the natural fruit be the way it is as opposed to being like the domesticated fruit?

domestic - solanum lycopersicum wild - solanum pimpinellifolium domestic tomato is huge in comarison to wild tomato, its 15cm across and over 1 kg while wild is less than 1 cm across this happened through artificial selection, turns out there is a protein repressor for cell division, the fw2.2 protein, so if you are highly expressing this protein then your tomato will be small which is why the wild tomato is so small, because we cultivated tomatoes that have low production of the fw2.2 protein leading to massive fruit, the wild tomato is like this because of plant sex, the plant does not want to waste a bunch of resources in massive one tomato that only has so many seeds when it can produce a bunch of smaller tomatos to allow for greater seed dispersal as animals are forced to eat more of the smaller tomatos in order to get the same caloric intake as they would from just one big tomato

what is the example used for the situation in which the frequency of an allele actually determines how advantageous that allele is in the environment? if 80% of the popuation is one color and 20% is another color, which one has better reproductive fitness? why? what is the pattern of the allele frequency vs generational time graph of the situation when the frequency of the allele determines how advantageous that allele is in the environment? what is this kind of selection called? and what is the pattern it gives rise to called?

example study was done Gigord et al on Elderflower orchids and how their fitness is determined through pollination by bees, so the flowers are either yellow or purple it turns out that the yellow flowers are more frequent in the population than the purple flowers and that honey bees are stupid in that they have very low memory retention, bees like to pollinate these orchids but the yellow flowers dont have any nectar, so what happens is that as the bees fly around looking for nectar they end up alternating back and forth between the two kinds of flowers since after going to a yellow they are like these guys suck theres no nectar im going to a purple flower, but by the time they are done getting nectar from the purple flower they have forgotten they hate yellow flowers and end up going back to the yellow flowers, this is why they always alternate between the two flowers and thus visit each flower type an equal number of times (50% of the time), the flowers like this because when the bee visit them they get pollinated which is how they sexually reproduce, so essentially we can consider visits by a bee as equivalent with reproductive success aka darwinian fitness so if 80% of the population is purple and 20% is yellow then the yellow flowers have better reproductive fitness because if you have a less common color, and each color is being visited equally (50% of the time), then the individuals of the smaller population will get visited more often since the number of options for the bee to go to in that population is lower due to its smaller size, thus the fitness of the flowers increases and gets selected for as their population and thus allele frequency decreases or in the other way, the fitness of the flower decreases and it gets selected against as its allele frequency increases thus the pattern of the allele frequency over generational time graph has a pattern of the allele frequency bouncing back and forth between being more frequent and less frequent, because when the allele gets more frequent it starts to be selected against causing its allele frequency to go down below 0.5 but then once its below 0.5 it gets selected for causing its frequency to go back above 0.5 then it gets selected against again and its frequency goes back down again and so on and so on, But! as this goes on over generational time, as the the allele frequency bounces up and down it actually gets closer and closer to 0.5 i.e. the maxima and minima get smaller and smaller over the generations! this pattern gets reset at random points in time due to some environmental shift which causes the allele frequency of one of the alleles to spike again causing the damped oscillation pattern slowly drawing closer to 0.5 to start all over again (kinda looks like an ECG) this is called frequency-dependent selection which gives rise to the pattern of damped oscillation

for Chapter 10, one of the most important things is to be able to remember the general methods and thought processes as to how we can design experiments to test our different hypotheses Pay special attention to the types of experimental designs used in each case, especially whether they are experiments, observational studies, or comparative studies

for Chapter 10, one of the most important things is to be able to remember the general methods and thought processes as to how we can design experiments to test our different hypotheses Pay special attention to the types of experimental designs used in each case

What is BRCA1? what type of mutation is BRCA1?

gene that increases likely hood of developing breast cancer in women to 50% for heterozygous and 90% for homozygous it is an example of a mutation in the proofreading machinery of the cells that is used for DNA replication and this is one of the worst kind of mutations you can possible have

What would genetic drift due to variation of allele frequencies ACROSS different populations?

genetic drift because it is random would affect the different populations in different ways, genetic drift over a long enough time period fixes an allele in a population but because it is random the chances that it will fix the same allele in multiple populations are super low, so it decreases genetic variation within a population over long time periods but it increases genetic variation across populations thus it does NOT homogenize populations

How can we predict the probability of allele moving to fixation through genetic drift alone?

genetic drift is random but we can predict what it should do, we can predict the probability of which allele that genetic drift should move to fixation (We can predict what it SHOULD do, we cannot predict what it will do, same with flipping a coin) the probability of the allele drifting to fixation depends on its initial frequency, the probability of the allele drifting to fixation is exactly equal to that alleles initial frequency, because if you are randomly picking alleles to move to next generation then if that allele is more frequent then it is more likely to get picked to increase in frequency

What is the example of the handicap hypothesis of mate choice that exemplifies what it is well?

handicap hypothesis of mate choice example is the male peacocks tail feathers, which can weigh as much as the animal itself, thus if the males with super large tail feathers are still capable of surviving even while lugging their big butt around, then it is probably an indication that the male has some pretty good genes

in a situation of unstable equilibrium, what would the pattern of the allele frequency vs generational time graph look like if the heterzygotes still had lower fitness than both homozygotes (basis of unstable equilibrium) and one of the homozygotes had better fitness than the other? whats the example?

if the homozygotes have different fitnesses while both have better fitness than the heterozygotes, then it all comes down to the initial allele frequencies and the relative advantageousness of the allele, so the example used is a compound heterzygote situation with drosophila except this time the possible allele where one alllele version is a compound chromosome and the other is wildtype, so the heterozygote will still be strongly selected against giving us our unstable equilibrium, but this time being homozygous for the wildtype chromosome is much more advantagous than being homozygous for the compound chromosome so the determining factors for which allele is going to go to fixation is the starting allele frequency combined with the advantageousness of that allele, so basically the origin on the graph where the allele frequency will diverge will be higher up on the graph for the allele that is lethal because it needs to be at a much higher frequency in the population for equilibrium to be maintained because it is so deleterious, thus if its a graph of the allele frequency for the advantageous allele the point of divergence will be lower on the graph because it does not need to be as frequent in the population for the unstable equilibrium to be maintained this situation can also arise in less intense scenarios such as scenarios of speciation and subsequent hybridization, where the hybrids end up being generalists and less competitive for resources than the specialist populations that are forming the generalist hybrids by mating, and thus the heterozygote hybrids are being selected against just at a lower strength because being a heterozygote in this case doesn't cause instant death anymore it is just not as advantageous as being homozygous, so unstable equilibrium will still arise, it will just take longer for fixation and loss to take place

What would happen if we combine inbreeding with: natural selection genetic drift migration

if we combine inbreeding with natural selection then the inbreeding, by driving the population to be primarily consisted of homozygotes, is going to prime natural selection to be able to act that much stronger, inbreeding will increase the rate of allele frequency change through natural selection (unless the environment is selecting for heterzygote ie there is heterozygote overdominance going on in which case the two would be opposing one another) if we combine inbreeding with genetic drift it will most likely get rid of the heterozygotes at a faster rate, because inbreeding drives genotype frequencies towards homozygotes and genetic drift tends to reduce genetic variation and heterozygocity, but only potentially/probably because genetic drift is acting on alleles not genotypes and their associated phenotypes, so you genetic drift doesnt just get rid of the heterozygotes, what it would do instead is increase the frequency of one allele which depending on how that is done, it could increase homozygotes if it is converting one allele of a heterozygote to the other making it a homozygote but it could just as likely (because genetic drift is random) change the allele of a homozygote to another making it a heterozygote and now the two are in opposition to one another, however overall in long time period the genetic drift and inbreeding would be working together if we combine inbreeding with migration then how the two interact depends upon the genotypes of the continent population coming to the island, because if the continental population is homozygous then the inbreeding and migration would both be pushing towards homozygotes (especially of one particular type), but if the continental population is heterozygous then the two would be opposing one another as inbreeding drove the island population towards homozygotes and migration maintained the heterozygote frequency

in the situation of frequency-dependent selection, when do the frequencies reach the equilibrium frequency? if the two phenotypes based on the two different alleles have perfectly equal fitness, then what will the allele frequencies be? what will the graph that shows the relationship between reproductive success (fitness) and frequency of an allele look like? How is the equilibrium frequency depicted on the graph and where will it be when the two alleles have perfectly equal fitness? How is the equilibrium frequency shifted if the alleles do not have perfectly equal fitness and one of the alleles is now in general more advantageous than the other, but there is still frequency-dependent selection going on?

in frequency-dependent selection, the frequency is in equlibrium when both of the phenotypes have a fitness at 1 (which means neither good nor bad, its neutral with fitness of 1), if the two phenotypes based on the two different alleles have perfectly equal fitness, then the allele frequencies will be 0.5 at equilibrium in other words the equilibrium frequencies will be 0.5, the graph that shows the relationship between reproductive success (fitness) and frequency of an allele will have reproductive success (fitness) on the y-axis and frequency of the particular allele on the x-axis with a straight horizontal line at the fitness level of 1 to help denote where the shift from advantageous (above 1) to deleterious (below 1) will take place with the actual intersection of the this line and the data derived line denoting the equilibrium frequency for that allele the general trend of the lines on this kind of graph (in frequency dependent selection scenarios like this) will have the line starting from low frequency (to the left on x-axis) and the line at this point will have fitness above 1, then as the frequency increases (line moves to the right on x-axis) its related fitness will decrease (line moves down on y-axis); thus giving the line a negative slope, at the point at which the line hits the fitness level of 1 the allele frequency at that point of intersection between the the horizontal line and negative-sloped line will be the equilibrium frequency, so if both alleles have perfectly equal fitness then that intersection will occur at 0.5 on the x axis, but if the allele is advantageous then the point of intersection between the two lines will be at a point above 0.5 on the x-axis (further to the right) it is further to the right because the advantageousness of the allele is increasing the fitness so this needs to be counteracted by an increase in allele frequency (which decreases fitness) until the two counteracting forces perfectly balance each other out thus reaching equilibrium when the fitness of the allele equals 1 (which means the fitness of the other allele also equals 1); and if the allele is deleterious then the point of intersection between the two lines will be below 0.5 on the x-axis (further to the left)

in male-male competition, what do small males do and why? what is a good example of this?

in male-male competition, the larger males have a clear advantage, so the smaller males use alternative strategies to be successful coho salmon sneaker males are excellent example of alternative strategy users the males go out to sea to develop and then come back to stream to spawn so larger males are hooknoses and they return to spawn from the sea after 18 months smaller males are Jacks, and they return after 6 months so females nest and lay eggs, then the larger males, hooknoses, will fight each other to get closer to the female, but the Jacks dont play that game and instead sneak around and hide in the vegetation and then while the hooknoses are duking it out, they will dart for the eggs ejaculate and then go back to hiding, and this is super effective so for hooknoses, fighting is very effective, but they are terrible at sneaking Jacks use sneaking to increase their success

In marine iguanas, explain how natural selection and sexual selection interact on the males and females to determine their body sizes

in marine iguanas, medium body size is optimal because the iguanas if they get too big have more trouble swimming and fighting the waves and the energy required for metabolism with large body size becomes too much, but at the same time sexual selection is selecting for large males so sexual selection and natural selection balance each other out causing medium body size to be the ideal so when they gathered the body size data on male and female iguanas they found that the females were for the most part mostly at the optimal size for natural selection purposes, but the males had considerable number that were larger than the optimal size for natural selection because sexual selection is driving the males to get bigger to be able to fight for females, so basically the males are decreasing their survival fitness to increase their reproductive fitness the males claim sun basking areas (iguanas are reptiles and thus ectotherms) and fight off other male challengers from their sun bathing territory, thus territory holders are more attractive to females because they are winning physical contests (this is excellent example of the sexy sons hypothesis, females want sexy sons because in terms of lifetime reproductive success male offspring are preferable to female offspring specifically sexy male offspring because the sexier sons will be successful and thus be able to pass on the mom's traits the most) so ultimately, natural selection is a more potent force on females than males, because males have to balance the force of sexual selection (which is stronger on them) AND the force of natural selection

in random mating population, what happens when you have rare recessives? unless! what? what is a caveat for this pattern of rare recessive allele frequencies in a population with random mating?

in populations with random mating, the rare recessive alleles essentially hide in the phenotypes and stick around in the heterozygotes because the odds of creating a homozygote for the recessive allele is super low, because of its initial low frequency in the population and the fact that selection only acts on the phenotype, not the genotype unless! a caveat for this pattern of rare recessive allele frequencies in a population with random mating is that if the heterzygotes have different fitness than the homozygotes of the wildtype dominant allele, so if we are dealing with strict dominant and recessive alleles then the homozygous dominant wildtype will have the same fitness as the heterozygotes, but this obviously isnt always the case

How is the Preexisting Sensory Bias model of mate choice different from runaway selection? what usually happens in this model? What is the example of the Preexisting Sensory Bias model of mate choice that shows what is is well?

in runaway selection, the females were arbitrarily selecting a trait, but in this one its a little different, what happens the females are using a preexisting trait that already has purpose to make mate choices from the female usually evolves trait and then male uses the trait that the females have and then will hijack that for sexual selection purposes great example is water mites: so the water mites ambush their prey by staying in this net stance which is the ready to go stance they use to hunt by standing on four hind legs ready to pounce when a prey moves in front of them, this net-stance evolved because they are blind but because they are blind mating is difficult since they cant find each other, so males took advantage of preexisting trait of this net-stance and ambushing by trembling at the front legs of the females to get them to clutch on to them, as if they were prey, but then instead the two copulate

what are some other adaptations they found in the organisms other than producing more ejaculate in sperm competition? (5)

in sperm competition, adaptations other than increased ejaculation that have been observed are: 1. mate guarding 2. prolonged copulation (keep having sex even after ejaculation for a really long time) 3. copulatory plugs - garter snakes in the mating balls produce a substance that acts as cement to seal shut cloaca, spiders put pedipalp (the organ they squirt their sperm on to) into the females gonapore and then violently rip their limb off, leaving it in there to seal the opening shut 4. sperm scoops - what it sounds like, the male scoops out other males' sperm with his penis that is shaped like a scoop and then ejaculate his own goods in there 5. traumatic insemination - bed bugs, on copulatory organ they have essentially a hypodermic needle, to beat other sperm that the female has already taken up, the male will stab the female in the side with his penis and inject sperm into the body cavity and the sperm will swim through blood and burrow through ovary wall and fertilize the eggs first

What is a good example of the good genes model of mate choice? what did they find when collecting data on this example?

in the Pronghorn Antelope, males provide no direct benefit to females but males control harems, so the females use the size of the harem as a metric for how good the males' genetic material is since the males have to fight off male competitors trying to steal their harem there is lots of variance in harem size in nature, but the males with larger harem sizes hard a disproportionate number of offspring, because it is a snowball effect as the more females you have, the more females want to be in your harem, which leads to more females wanting to be in the harem, etc.

What is an example of a behavior in nature that is clearly not for the "good of the species"? explain why it happens

infanticide is a clear example of individuals not working towards the "good of the species" infanticide is when you kill the young of your species, it is seen in male lions who will kill cubs in the pride why do they do this? they do this because the male sits there while females do all the work and hunting, what he does is he has sex and he fights off challengers, other males, who try to steal his pride, male lions need to have sex 1500 times to get a female pregnant so controlling reproductive access to females is critical from reproductive standpoint to male because thats only way they will ever get to have offspring, but when females are nursing cubs they cant reproduce, so when new male lion kicks the old one out the new male lion will kill the cubs because when the females are nursing they cant reproduce so that hurts the new lions chances for reproduction, so to free up the females for giving birth to his own kids he thus kills the cubs this is not good for the species, the only one who benefits is the new male lion

when males indirectly compete with each other they are doing something to make themselves stand out so that the female chooses them over the others, what is this called? what has this led to? what is quick example? what is study example, who did it, when, and on what? what was the set up? what was the metric they used in study that is important? what did they find?

intersexual selection the males advertise to the females and the females inspect the advertisements and choose the mate which has led to the development of very elaborate courtship displays example is the jumping spider dance study example: Pryke and Andersson in 2005 with red-collared widowbirds the males have super long tails, the tails arent good for natural selection, but the females love it so the males have to balance natural selection and sexual selection so they captured males before they had claimed their nesting territories, and maintained the tail length of some and trimmed the tails of others, and attached feathers on to other making super long tails, they then calculated a body condition index in which they calculated a variable that does not change in relation to your physical resource acquisition and divide it by a variable that does, so example in birds they divide beak size by body mass found that short tails had significantly fewer active nests, control groups with maintained tail lengths attracted 3 times as many, and the ones with artificial super long tails had like 8 nests but just terrible body condition indexes, the super long tails were way to energetically costly to fly with

what are the two sexual selection outcomes?

intrasexual selection intersexual selection intrasexual selection is basically competition, typically between males; male-male competition occurs when individual males attempt to monopolize access to the females; examples are: a) combat but is not common because its too risky, its a last resort, but when it does happen then size matters, size of the animal itself matters most, even more than size of their weapons such as horns or antlers b) intersexual selection is when the male evolves traits under strong sexual selection pressures that make him all showy and beautiful

What is the realm of "creation science" that was come up with in late 1960s? What happened in later 1970's?

it was put forward alternative form of scientific theory of how the earth was formed and life started on this planet, they demanded equal time because it was an alternative theory of life, it was also deemed unconstitutional based on separation of church and state science does not say anything about religion, it only puts forward theory and supports it with evidence in late 1970's creation science was reformulated and creation and creator were dropped from theories to make it ok to be taught in classrooms, the theory of intelligent design was born now intelligent design was also deemed unconstitutional

How does leopard gecko sex determination work by genotype-by-environment interaction? What do we use to get a feel for how the environment affects the phenotype? what about the serotonin transporter gene? How does this relate to phenotypic plasticity?

leopard geck sex determination is driven by temperature that eggs are incubated in, so the Sox9 gene is turned on a sweet spot zone of temperature, at low temps no males, at high temps theres no males We use Reaction Norms to get a feel for the variability of the degree to which the eggs are influenced by the temperature ie environment, a graph of how the genotype is altered by the environment with the same genotype and we average all the lines to figure out the power of the environment to influence the genetic expression of a phenotype, the more straight the line the less influence the environment has on genetic expression depending on the allele of the serotonin transporter, the probability of a major depressive episode will be more or less influenced by the level of severity of childhood maltreatment, so like homozygous for "l" allele means that no matter the maltreatment you are just as likely to get depression, for homozygous S allele the individual gets drastically more likely to develop depression based on the severity of childhood trauma ie the phenotypic plasticity is higher for homozygous S because the environment is more able to affect genetic expression of a phenotype than when compared to homozygous l the type of allele has altered susceptibility to the environment, when the environment and genotype interact then the allele determines how steep the phenotype is influenced by the environment, this is the degree/severity of phenotypic plasticity

When is sperm competition the most common/strongest determining factor?

mating success is ultimately determined by which sperm actually fertilizes the egg and this sperm competition is the strongest when there is internal fertilization and the female mates with more than 1 male

what leads to speciation? what is necessary for the thing that leads to speciation to occur?

microevolution eventually leads to speciation microevolution requires variability in the population, that is heritable, upon which natural selection can act

So if we can produce changes over time, then things that used to useful and advantageous could become no longer useful, so what is this an example of? and give an example from natural populations

microevolutionary changes over time, not speciation yet though Vestigial structures - structures that at one point in time served a purpose but because these generations change over time and those changes can eventually crop up and amalgamate into bigger changes, what happens is that those structures dont disappear over night and you get left over vestigial structures example: wings on a brown kiwi, vestigial limbs on pythons

what does migration do to allele frequencies across/between different populations? what is an example of what migration does to allele frequencies across populations and what is particularly cool or useful about geologic islands? How are island populations going to differ from one another as they go from Young to Old and Why? What are FST values, how will these change between the young, intermediate, and old populations?

migration homogenizes allele frequencies across populations, in other words it tends to take individual populations and make them look more similar to one another an example of what migration does to allele frequencies across populations ie an example of migration homogenizing individual populations (making them look more similar to each other) is: study done by Giles and Goudet on Red Bladder Campions whose pollination is done by insects and found on an archipelago in Sweden, so whats cool about the island is that according to uniformitarianism and the fact that the archipelago are geologic islands making the islands different ages we can calculate how quickly the islands are forming and thus we know old the islands are, then we can correlate that with biological genetic processes, one of the reasons why islands are so crucial is because on continental populations everybody is mixing and we dont necessarily know what was happening in the past, but with islands we know exactly when the clock of these biological process began so seeds come to islands by wind and water, and then insect do the pollination, and gene flow occurs through wind, water, and insect pollination, all of which are thus random, and a few hundred years after populations of red bladder campions get established new invasive species get introduced and since the red bladder campions are total wusses they basically give up and die when in the face of competition, when new thing comes in the seedlings of the red bladder campions die and thus the populations go down so because young population are founded by chance transport of a few seeds, if we were to compare allele frequencies between young island populations (allele frequencies super variable) there should be quite a bit of variation between the populations intermediate populations should be more homogenous to each other, because the continent is continually sending out more seeds making all the populations look more similar to the continental population and thus to each other as well (migration making things look more similar over time, decreasing variability of alleles between populations) old populations do not exchange genes anymore because they stop producing pollen and seeds because now there is competitors around making them give up, so the old populations end up looking different again because each island has different environmental conditions selecting for different alleles, (because of selection the variability of alleles between populations begins to increase again) we calculate FST values which is measure that allows us to compare genetic variation between populations, they range from 0-1, values closer to 1 means there is more genetic variability between populations while values closer 0 means theres less genetic variability between populations so migration homogenizes (decreases variability between) different populations over time, but then natural selection increases variability between different populations because each island has a different environment and thus different selective forces

What is: monophyletic paraphyletic polyphyletic polytomy

monophyletic - a group of organisms that consists of all the descendants of a common ancestor. Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. paraphyletic - a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding a few—typically only one or two—monophyletic subgroups. The group is said to be paraphyletic with respect to the excluded subgroups polyphyletic - a set of organisms that have been grouped together but do not share an immediate common ancestor. The term is often applied to groups that share characteristics that appear to be similar but have not been inherited from common ancestors; these characteristics are known as homoplasies, and the development and phenomenon of homoplasies is known as convergent evolution. polytomy - a section of a phylogeny in which the relationships cannot be fully resolved to dichotomies, divergence of two branches, thus presenting an unlikely picture of many apparently simultaneous temporally based branches ex- deepest branch in reptilia is unclear

Explain the common misconceptions of Natural selection: what does natural selection act on and where are consequences seen? do individuals evolve? whats the relationship between environment and phenotype? compare/contrast if beak size is not heritable vs heritable. Is Natural selection forward looking? Is natural selection the same as perfection?

natural selection acts on individuals but the consequences are seen in populations individuals do not evolve! the populations evolve over generational time has the allele frequency in the population changes the environment can alter the phenotype but these changes are not heritable; so if beak size is not heritable then the parents do indeed survive and reproduce more, however it does not change the population of offspring because those traits were not passed down if beak size is heritable then the parents do survive/reproduce more and the population in future genertaion Natural selection is not forward looking! It is backward looking, the traits that increase in frequency are the traits that were advantageous to the parent generation, but if the environment is unstable (very heterogeneous) then the population will evolve in one direction, then backslide, and then another and backslide and ultimately nothing is really changing in the population over long time periods, so any results from selection are AT LEAST one generation behind, you cannot adapt to future conditions No natural selection is not the same and does not lead to perfect, the reason is because often times we are trying to optimize two different things simultaneously that are at odds with one another ie contradictory selection patterns

How do we tell if natural selection is responsible for the change in allele frequency with Hardy Weinberg? how is the genotype frequencies going to change, and the allele frequencies going to change during natural selection?? what is the pattern in the allele frequency vs generational time graph going to look like? what 2 main things determines how quickly it takes for one of the alleles to reach fixation or the equilibrium frequency? what are examples of the two factors that determine how alleles increase and decrease in frequency based on natural selection?

natural selection can be seen with hardy weinberg by calculating expected genotype frequencies and comparing to actual genotype frequencies over generational time and so expected hardy weinberg will have no change over generations but if natural selection is occuring then one genotype will do better than the others based on it possessing an advantageous allele so there is going to be a 2 alleles at a single locus that account for differential survival between the different possible phenotypes p^2, 2pq, q^2 one of the genotype frequencies will do better thus increase in frequency, while the others will not do as well, so the allele frequency of one of the alleles is going to increase while the other is going to decrease; so strength of selective pressure is usually relatively weak and thus number of generations it takes for the change to occur is normally very long ie hundreds of generations or thousands before the advantageous allele reaches fixation or the equilibrium frequency, however ultimately the amount of time ie the number of generations it takes for the allele to reach fixation depends two things below the 2 things that determine how quickly an allele reaches fixation are: 1. the strength of selective pressure (usually pretty weak) based on environment and how advantageous allele is relative to other allele in that environment 2. the initial frequency of the advantageous allele example of how the strength of the selective force influences rate of evolution (change in allele frequency over generational time): HIV resistance allele is relatively high in european populations but infection rates of HIV in european populations is super low, so because the environment is providing a super weak selective pressure, the allele is not really being selected for and thus it is not noticeable or significantly increasing example of how the initial frequency of the advantageous allele and whether it is recessive or dominant influences how quickly the allele will increase over time: HIV resistance allele is subsaharan africa populations superrrr low and recessive, so even though there is a strong selective force, the allele frequency stays low because in order to actually get the advantage of the allele the person has to be homozygous for the allele, so since the allele is super low in frequency the odds of getting a homozygous individual that thus gets the advantage basically never happens, so most of the copies of the allele are in heterzygotes that dont get the advantage which means the copies are hidden from selection because we dont get the advantage phenotype and thus don't increase in frequency

Why is natural selection is not perfect or does not lead to perfection? MORE importantly, give an EXAMPLE

natural selection is not perfect because often times two different things are being optimized simultaneously and sometimes these things are at odds with one another ie there are contradictory selection patterns Example: Male mosquitofish gonopodium, they have a gonopodium which depending on how big it is, the females decide whether they want to mate with the male if they have a big gonopodium, but! a large gonopodium causes a problem for the fish because if its too big they cant swim right, so in order to reproduce they need a big gonopodium, but to survive they need a small gonopodium, natural selection is pushing the population to decrease the size of the gonopodium meanwhile sexual selection is trying to increase the size of it, so the two forces need to weighed at the same time

Is natural selection tinkering vs engineering? what does this mean, can it create diversity or does it work on extant variants? how does this relate to perfection? Is NS goal driven or progressive? can you optimize everything at once?

natural selection is tinkering it takes an individual and it is altering it just a little bit to make it survive a little better in the environment, it works on extant variants, it does not create variability it only acts on that variation, it is not perfection it is simply a better alternative in REACTION to the environment there is no goal, it is nonrandom but that does not mean it is progressive, in fact complex traits are often lost an example are tapeworms, they lost their digestive system because it helps them survive and reproduce in their environment where they are taking advantage of their hosts' digestive system you cant optimize all traits, typically one trait is focused on by natural selection to aid in survival/reproduction and it kind of ignores the others

How can we use nested traits to determine ancestral relationships?

nested traits we look at traits that are found inside of other traits to get a rough idea of when they evolved nested traits tend to be a fairly good way to figure out what things evolved in what order a thing that throws off the accuracy of using nested traits to determine evolutionary trends is convergent evolution, but its still a good quick and dirty way to identify whats happening in what order, then nested traits tend to work

Did we turn from allosaurus directly to archaeopteryx and from archaeopteryx to birds? What were some key transitional forms (5 in total, 3 between allosaurus and modern birds) and what were the transitions to get to each organism?

no there were a bunch of transitional forms between each one allosaurus (had down, fuzzy undercoating) to sinosauropteryx (had rudimentary feathers) to similcaudipteryx (had vaned feathers, tail feathers, and wings that were useless) to archaeopteryx (had flight feathers, and could glide) to modern bird (had reduced tail, tootless beak, powered flight)

How does nonrandom mating affect evolution and being in hardy-weinberg equilibrium? what does inbreeding do genotype frequencies ie what is the characteristic pattern of inbreeding that can be found in genotype frequencies?

non-random mating BY ITSELF does not cause evolution because it does not cause a change in allele frequencies, however! it DOES cause a change in genotype frequencies which essentially primes the population for evolution to occur through the other mechanisms, thus it has profound INDIRECT effects on evolution inbreeding is great way to look at nonrandom mating, it tends to reduce heterozygocity (very quickly) and increases the frequencies of homozygotes compared to what is expected under Hardy-Weinberg

what is the most extreme example of the sexual reproduction asymmetry type: parental investment?

orangutans the opposite sexes of orangutans HATE each other and only tolerate each other long enough for copulation which is about 15 minutes the moms have an 8 month gestation, nurse them for 3 years, and then protect them until the kids are 8 years old, on the other hand males only contribute semen, the males put in 15 minutes of energy while the females put in almost 9 years of energetic effort into their offspring

Sometimes we have trouble when trying to figure out phylogenetic trees especially when trying to group species by shared characters proves to be of little use, like if all the species have brown legs but there are no other nested traits, some possible explanations for this confusion is that some characters may have evolved independently, or some characters were lost, or both! or maybe reversals, and at the same time we have no idea what the common ancestor looked like, we are in a phylogenetic pickle now So how can we use outgroup analysis and parsimony analysis to make some sense of this

outgroup anaylsis is a way making inferences and assumptions about what the common ancestor looked like without knowing what it actually looked like we choose an outgroup, we know 3 species are closely related but specifics of sister species and divergence is unknown, so if we want to know how a trait evolved in our "ingroup" of our phylogenetic tree ie the 3 species we are curious about, we have to have a reference point, and normally this would be the common ancestor, but we dont know what it looked like here, we need to make a frame of reference, so we pick a species that is closely to the ingroup members we are investigating while making sure the ingroup species are more closely related to each other than the outgroup we can assume that the outgroup is what the common ancestor would have looked like if it hadnt changed the big assumption we make with outgroup is that the outgroup is constant since common ancestor we now have our frame of reference so we use parsimony analysis which is essentially occam's razor, the simplest explanation is probably correct so with our frame of reference we can then figure out the simplest relationship of species that leads to our 3 current extant species by coming up with 3 possible sister species relationship hypotheses and then for each trait individually in each hypothesis, figure out the simplest sequence of events necessary to develop that trait in that hypothesis, each simplest possibility of events counts as 1, if there are 2 equally likely sequences of events ie they have the same number of events to get to that trait in that tree, that counts as 2 then for each hypothesis, add up the number of simplest possible events that could take place, for one trait if there is only 1 sequence of events that is most simple then that counts as 1, if there are two sequences of events that are both equally simple ie to get to that trait the two sequences involve to evolutionary events then that counts as 2 and whichever hypothesis has the lowest number is the most parsimonious and is thus the most probably tree

How is the statement "selection does not act for the 'Good of the Species'" a misconception of Natural Selection? What is altruism in terms of evolution? What is an example of altruistic behavior in animals? What are the caveats/reasons that explain the existence the altruism? (2 reasons) (explanation of reasons is in next 2 flashcards) in either explanation for altruism, are the organisms working for the good of the species?

people try to argue against natural selection by saying it is not for "the good of the species" and this drives evolutionary biologists nuts because what is "the good of the species"? what does that even mean? Who the hell said that natural selection ever did work for the good of the species? organisms are just trying to survive and reproduce this has nothing to do with good of the species, they arent evolving to be better in the next environment with any sort of goal, evolution just happens as a consequence of the selection altruism, in the context of evolution, is the acting for the good of the species, doing something that is good for you siblings or offspring without a seeming benefit to yourself, It appears to be acting for "the good of the species" but it is actually not, now altruistic behaviors do occur but are very rare and there are selfish reasons for it: First off here's example of altruistic behavior: example - prairie dog alarm calls, a bunch of prairie dogs foraging and doing stuff but one prairie dog is just sitting and watching as a look out, and then a predator shows up and that prairie dog screams its ass off as a warning to everybody, but this is a super dumb move to make for the individual because it draws attention to the prairie dog Reasons why the prairie dog does it is are: Kin selection Reciprocal altruism in both of these, the individuals are not working for "the good of the species", they are being selfish its not truly altruistic, in the first I am helping me make sure my genetic material lives on through siblings and the second I am helping me by making sure that I am covered if something bad happens and I cant get food

The tobacco hornworm is a great example of what aspect of phenotypic plasticity?

phenotypic plasticity is the degree to which the organism can change its phenotype in response to its environment, with the same genotype still in play, but phenotypic plasticity itself is under pressures from natural selection the strength of phenotypic plasticity is ultimately a factor of how that gene is influenced by the environment but that gene can change also be influenced by the environment ie natural selection over time, leading to basically.. natural selection selects for how susceptible organisms are to natural selection the phenotypic plasticity of the hornworms was figured out, whether they change color in response to heat, and then they mated the high plasticity hornworms with each other and the low plasticity hornworms with each other and kept a control line with random mating and found that the degree of plasticity increased in the high plasticity line over generations and decreased in the low plasticity line over generations, ie one population became more susceptible to the environment as they were selectively bred to do so and the other population's phenotype became less susceptible to the environment as they were bred to do so

What is the primary way the new traits evolve? describe importance of the way new traits evolve to natural selection what does mutation produce for natural selection? what are the two ways new alleles are produce?

primary way that new traits evolve is mutations if we are talking about variability in the population that is heritable then we are talking about mutations, so natural selection cant necessarily act and make changes on variation that is caused by the environment because that variation does not go on to next generation, it must have variation that is heritable is genetic and thus a mutation mutation is what produced the raw material for the heritable variation that natural selection then acts upon so we produce new alleles through two things: random mutations sexual reproduction

What are some basic characteristics of evolutionary trees ie phylogenetic trees? (3)

roots - the original ancestral species from the most recent common ancestor was a part of, so like that little segment that is at the very beginning of the phylogenetic tree nodes - the most recent common ancestor from which there was so divergence that occurred and spawned new species down the branches of the tree, the points of intersection where lines split on phylogenetic trees transitions - the characteristics that cropped up on the branches of the phylogenetic tree that the species downstream all inherited as long as some other transition did not crop up and take its place, marked

What is an example of the Runaway Selection Model of Mate Choice?

runaway selection model of mate choice example is the stalk-eyed flies random mutation leads to males having longer eye stalks, the females respond to it and the longer eye stalks increase in frequency, the females that respond to the longer eye stalks increase in frequency, then progressively longer eye stalks and stronger preferences for them appear over generations until the little flies have crazy long eye stalks, this runaway selection continues until some limiting pressure curbs it over 13 generations; they grouped males with long stalks with random females and grouped males with short stalks to mate with random females then they found that even if you start randomly the females when given the choice end up preferring the males with the longer stalks

What is an example of microevolution, and thus Descent with Modification, that was shown in LAB populations?

selective breeding programs and experiments such as Garland's High Running Mating program for mice, where he tracked rotations of the mouse wheels to see which mice were high runners and which were not, he selectively bred the high runners with each other and in his control he randomly mated mice together, in just 24 generations the high runner population became significantly more active runners than the control group, about 3 times further on wheels every day this is an example of microevolution, it showed there was variation in the individuals of the original population, and that variation when under selective pressures cause changes in populations over time, since his experiments they found differences in genotype, physiology, and even morphology

selfing or self fertilization is the most intense form of inbreeding so say we start off with in HW with alleles A1 at 0.5 and A2 = 0.5 what are our genotype frequencies? if all the individuals do selfing, what are the new genotype frequencies? How do you solve for these frequencies?

selfing or self fertilization is the most intense form of inbreeding so say we start off with in HW with alleles A1 at 0.5 and A2 = 0.5 our genotype frequencies are: A1A1 = .25 A1A2 = .5 A2A2 = .25 if all the individuals do selfing, the new genotype frequencies are: A1A1 = .375 A1A2 = .250 A2A2 = .375 solved by using a punett square, all homozygotes give birth to same amount of homozygote offspring, but heterzygote parents give birth to 25% of homozygote, and 50% heterozygote so 25% times original 0.5 heterzygote parent frequency means there is additional 0.125 frequency of each homozygotes, and 50% of heterozygote offspring are heterozygotes as well so 50% times original 0.5 heterozygote frequency give 0.250 as left over heterozygote frequency in offspring generation if continued selfing through another generation gives rise to new genotype frequencies of: A1A1 = 468.5 A1A2 = 62.5 A2A2 = 468.5 we started off with 500 heterozygotes! so in just 3 generations of selfing, our allele frequencies did not change at all but the genotype frequencies have drastically changed! Inbreeding is a catalyst for changing allele frequencies but doesnt change them itself

How does sexual selection act on females and how is this similar and different from males? what is polyandry? Who, when, and what is the example study for polyandry?

sexual selection acts on both and males and females to make the sexes promiscuous and apparently true monogamy is very rare, so thats how they are similar polyandry is when females mate multiple times with multiple males Example study is: Hoogland et al 1998 using Prairie Dogs 65% of females mater with more than 1 male, which is not whats expected since we have found that after 1 mate the reproductive success for females barely increases at al, but! it turns out they mate with more because the probability of pregnancy with 1 male is about 92% but if they can get around 3 or so then that goes up to 100% and that difference is worth it for the females especially since they are only fertile in the year for a very short period of time, so they mate with as many males as possible to get that probability of getting pregnant up to 100, AND the litter size increases as number of mates increases which also is good for the female prairie dog, another speculation as to why they mate with more than 1 is that the more mates gives more genetic diversity among the pups which gives the moms genetic info better odds of surviving

Explain the example using flies and salt concentrations that shows how mutations drive evolution and how mutations with natural selection drive evolution?

so Zhang et al inbred drosophila until they made genetically a pure generation, they then allowed a selective force to act upon this population, by rearing these flies populations in different salt concentrations from 1-6%, some survived up to 4% but all died at 5% then they used the survivors from the different salt concentration populations to be the founder for new populations so the only genetic difference between the different populations can come from mutations since they were all inbred initially so when they took individuals that were reared in low salt concentrations and placed them in 5% salt conc, a couple survived but the salt stressed lines that were bred in high salt concentrations, when placed in 5% salt concentration had for more individuals surviving, because there was a mutation for salt tolerance and then the selective forces from being reared in high salt concs selected for these mutations, the number of salt tolerant individuals was significantly greater thus number of individuals from the nonstressed fly lines that were tolerant to 5% salt was due to mutation while the number of individuals from the stressed fly lines that were tolerant to 5% salt, was due to mutation AND natural selection so when you add mutations and natural selection together, you shift the population much more rapidly, this is when the magic happens, these together are the biggest synergistic evolutionary driver

Without considering parental investment, why do females typically put in far more energy than males for sexual reproduction? what is the fancy word/name for one of the reasons for the difference in energy input for sexual reproduction? relative to basal metabolism, how costly is it for females and males to produce their gametes? what are females limited by energetically in sexual reproduction? what about males? how do these things play into how reproductively successful the different sexes are?

so parental care is rare but there is still an asymmetry in energy input for sexual reproduction because females' eggs are much larger than sperm and lots of times they are yolky, the yolk is used for energy and nutrition for the developing offspring, sperm comparatively cost almost nothing sperm are produced by the millions are still nowhere near as costly as an egg this difference in sizes of the gametes between sexes is called Anisogamy during the breeding season, females devote 3 times the energy to produce eggs relative to the amount of energy they use in just their basal metabolism sperm for males costs 1/1000th of the energy for their basal metabolism females are limited energetically in sexual reproduction by the number of eggs and the number of pregnancies males are limited by the number of female's he can copulate with so the reproductive success of the males steadily increases with number of mates meanwhile the females shoots up after 1 and then only very slightly increases with more mates

what is mutation selection balance? what is example scenario in which mutation selection balance is gonna be really high?

so selection typically eliminates bad mutations, but bad mutations are always cropping up, mutation selection balance is: the rate at which deleterious mutations crop up is equal to the rate at which natural selection is stomping them out of the population which sets a neutral tone for these mutations so theyre not negatively affecting population anymore mutation selection balance depends pretty much entirely on how deleterious the mutation is so if you have midly deleterious mutation the NS isnt going to get rid of it very fast but if its lethal then NS takes it out super fast so if mutation is pretty mild and the mutation rate is pretty high then the mutation selection balance (equilibrium frequency) is gonna be really high

what is an example of the subtype of genetic drift, the Founder Effect, ie who did the research and what organism were they looking at? how did the number of alleles on an island change as the islands got further away from the mainland? What would we expect the FST values to be and why?

so the individuals and the alleles they carry that make it to say an island by being blown there during a hurricane, made it there due to random chance, their alleles had nothing to do with them having been the ones to survive and make it to the island Tinghitella et al did research on polynesian field crickets which are native to islands in the pacific, they are not the best swimmers or flyers, so they made it to the islands is by hitching a ride on boats the number of alleles on an island decreases as the distance from the mainland increases so on mainland Australia there is a wide variety of alleles all at low frequencies, then as you get to further out on islands they have fewer alleles at higher frequencies the further out you go, the islands also have different alleles on each particular island due to random chance so if we look at the variability among the alleles between all the islands by looking at the FST values then we would expect the FST values of the islands to be close to 1 because of the randomness of which alleles get there causing a high amount of variation

What is the pattern of how allele frequencies change over generational time when heterozygotes have different fitness relative to the homozygous dominant alleles and homozygous recessives: so if we have allele V (viable) and allele L (lethal) at a single locus, which genotypes would we expect to live or die? How would we expect the allele frequencies to change over generational time, just based on the immediately above information? BUT! what is the pattern when the heterzygotes have better fitness than the two versions of homozygotes, and what is an example of this? what is this new pattern of when heterzygotes have better fitness than the homozygous individuals? so explain why we get this different pattern in allele frequencies when the heterzygotes are most advantagous while the wildtype homozygous individuals have relatively better fitness than the recessive lethal allele homozygous individuals at equilibrium, what does heterzygous overdominance maintain?

so when being a heterzygote is advantagous relative to being homozygous for either allele (when dealing with a single locus with two alleles) the pattern is: so VV and VL live while LL individuals die based on VV and VL individuals living and LL individuals dying, we would expect the V allele to rapidly increase in frequency because the odds of creating an LL individual that will die and get weeded out is high initially, but then it would level off at not quite fixation because the L allele is hiding in the heterzygotes phenotype (since you need homozygote of L for selection to act on) BUT! the pattern changes when heterzygotes have different fitness relative to the two options of homozygotes; an example done by Mukai and Burdock with Drosophila, they looked at allele V (viable) and L (lethal) allele; so at first the V allele goes up really quickly like we expect and then levels off, but the allele frequency at which it levels off in this case is lower than when dealing with the beetles with no difference in fitness between homozygous wildtype and heterozygotes; so when heterzygotes are more advantagous than either version of homozygote then the equilibrium frequency will be much lower because the wildtype dominant allele gets dragged down by the recessive lethal allele being artificially inflated due to the heterozygote being the most advantagous the new pattern we have when heterzygotes have better fitness than the two homozygous options is called, heterozygote superiority/overdominance because heterzygotes have better fitness than either homozygote, and the homozygote of wildtype does better than homozygote for lethal allele, the lethal allele frequency gets artificially inflated because of the overdominance of heterzygotes, ie the heterzygotes have the best fitness and the lethal allele is recessive, the lethal allele becomes more frequent because it is hiding in the phenotype of the advantagous heterozygous individuals at equilibrium, heterzygote overdominance maintains genetic diversity by allowing an artificially inflated amount of the recessive lethal allele to tag along with the dominant allele in the heterozygotes

What does the theory of special creation specifically say? (4)

species are immutable and unchanged since origin variation among individuals is thus extremely low if non existent all species are created independently and are thus genealogically unrelated to one another Earth and life are both relatively young, approximately 6000 years for catholics

a hypothetical population has two alleles for a gene: A and a. In a random sample of 100 individuals, 20 are homozygous for a, 20 are homozygous for A, and 60 are heterzygous. what is the frequency of A? Step 1- how do we get genotype frequencies? step 2- how do we get allele frequency of A from the just calculated genotype frequencies?

step 1: use information to get genotype frequencies, do this by taking number of individuals with each genotype and divide by total number of individuals so aa = 20/100 ; Aa = 60/100 ; AA = 20/100 so aa = .2 ; Aa = .6 ; and AA = .2 step 2: use equation p = p^2 + 1/2(2pq) so in this case A = .2 + (1/2)(60) thus A = 0.5

How can homology and nested traits be used to reconstruct ancestral relationships and macroevolutionary trends? what is structural homology? what is an example? what is a nonhomologous structure? what is an example? what is the cause of the similarities?

structural homology means there are structures that have an underlying ancestral relationship, example is vertebrate forelimbs where the structures look different but come from the same tissues during development due to them sharing an underlying ancestral relationship nonhomologous structures- structures of living things which are not related at all, but the structures look similar, example of this is shark and whale fins, the fins of both look similar but in reality are different so like a whale is mammal while a shark is a fish and whales have bone and sharks do not they have cartilage, these similarities are due to convergent evolution, which is when similar environmental pressures select for similar functional traits, even though the organisms dont share any recent common ancestry whatsoever, so this is why we need to be careful these two factors are why we need to be careful when determining ancestral relationships based on morphological structures

what is example of when the homozygotes have better fitness than the heterozygotes (so when heterozygotes are being selected against)? so when the heterozygotes are highly selected against, ie they immediately die, what is this situation called? what will the resulting pattern be in the frequency of alleles vs generational time graph? what is unstable equilibrium and how does it relate to the pattern in the frequency of alleles vs generational time graph? what is the time line involved in unstable equilibrium?

study done by Foster in Drosophila where you get a non-segregation during meiosis that results in compound chromosomes, the gametes created from individuals from with compound chromosomes can result in 4 different kinds, so when individuals with compound chromosomes mate, there are 16 different zygotes that can be made but only 4 of them are viable (1/4 of total), while 3/4 are inviable; so the researchers had two populations; 1 populations that had compound chromosome on 2nd chromosome c(2)c(2), and other population had compound chromosome on 3rd chromosome c(3)c(3) so each population is homozygous for their respective compound chromosome; and its important to note that you cant have individuals with a mix of compound chromosomes, so basically heterzygotes c(2)c(3) die for example offspring genotypes from mixing of populations is: c(2)c(2) = 0.25 c(2)c(3) = 0 c(3)c(3) = 0.25 so when the heterozygotes are highly selected against, ie they immediately die, this situation is called heterzygote underdominance the resulting pattern in the frequency of alleles vs generational time graph will be: essentially the exact opposite of heterzygote overdominance, so instead of maintaining genetic variation, in this scenario one of the alleles will go to fixation and other will be completely lossed thus reducing genetic variation in the population, so when the allele frequencies are plotted on the same graph the immediately diverge from each other with their origin at the initial allele frequencies unstable equilibrium is the type of equilibrium frequency behavior we have that results from intense heterzygote underdominance which is when heterozygotes get selected against and in this case that selection is super strong since heterozygotes immediately die, so if the two populations of homozygous compound chromosome individuals get mixed with equal numbers, initially the allele frequency for c(2) and c(3) will be the same (0.5), but then if any sort of shift occurs then the allele that had a higher initial allele frequency will immediately go to fixation while the other immediately goes to loss because when you have a higher frequency of individuals that are c(2)c(2) there is a higher chance these individuals will mate with each other to produce viable offspring which is why any shift causes super fast fixation; the fixation that results from unstable equilibrium occurs within like 10 generations, its as fast as evolution can possibly go

What is substitution in the context of evolution? what are the two leading theories that explain how we need to look at substitution in the context of evolution and what do they say?

substitution is the fixation of a new mutation in a population the two leading theories that explain how we need to look at substitution in the context of evolution are: Neutral Theory - pitched by Kimura in 1983, she said when we look at mutations we have 3 categories: good, bad, and neutral. If we look at the population as whole then we see that good mutations are super rare, most mutations of alleles are selectively neutral so we can predict the rate of evolution using the neutral mutation rate since they are not affected by natural selection or other forces of evolution so they are in a nice perfect bubble for us, we also have bad mutations in alleles but these are knocked out of the population very quickly by natural selection so we need to ignore these for evolutionary theory because they dont stick around long enough, thus the only thing we have to look at are neutral mutations, Kimura says that rate of neutral mutations is a better representation for the rate of substitution and thus evolution Selection Theory - pitched by Gillepsie in 1991, selection theory says that deleterious alleles are going to be eliminated by natural selection very quickly so we shouldnt look at them for evolution, neutral mutations shouldnt be looked at because they dont do anything for evolution and thus dont matter, and because natural selection is super important for evolution we should primarily focus on good mutations that are common enough to not be ignored and they are way too important to be ignored since they are what natural selection acts on, so thus the rate of substitution reflects what natural selection is doing in the population ie selecting for good

what does a synonymous substitution do? what does a non-synonymous substitution do? what is a nonsense mutation? what causes adermatoglyphia?

synonymous substitution is a silent mutation, it does not do anything non synonymous is a mutation that does something, it changes an amino acid, ie it is a missense mutation, can be as bad as indels depending on location a nonsense mutation is a premature stop codon, which is realllyyyyy bad adermatoglyphia is caused by a mutation in a splice site of an intron, causes there to be no fingerprints, normally intron mutations do nothing and exon mutations are much worse, but splice site mutations can also be real bad

How do you calculate the coefficient of variation? Why is the coefficient useful?

take the standard deviation of data set and divide it by mean of data set, this gives you the coefficient of variation the coefficient of variation is useful because it doesnt really make sense to compare the variation in height between people and the variation in height between dogs because its like comparing apples and oranges, when you calculate the coefficient of variation you are effectively standardizing your metrics by getting rid of the units which allows you to compare the "apples" and "oranges"

What is phenotypic plasticity?

the ability of an organism to change its phenotype in response to changes in the environment the genotype does not change but the genotype based on environmental factors can express multiple phenotypes

What is Darwinian fitness? how is it related to physical fitness? what is the study thats a good example of the relationship between the darwinian fitness and physical fitness?

the ability of an organism to survive and contribute genes to the next generation by having offspring, the traits that allow you to do this might be physical fitness but it doesn't have to be, darwinian fitness is not physical fitness, but physical fitness can be related to darwinian fitness genovart et al. 2010 did a study on seagulls, so seagulls have differing levels of physical fitness, but when a hunter comes at them with a shotgun the physical fitness does not really matter, they took data from hunters to see which individuals are being taken out ie skinny, normal, or buff seagulls, keep in mind that the seagulls being shot should be a random sample as the the one's who are killed are essentially whichever seagulls the hunter sees, ie the distribution of gulls killed by hunters should be a normal distribution, and it was At the same time, they looked at which seagulls would be killed by raptors, a predatory bird from the seagull environment, and the muscle condition now definitely played a roll in death rates of seagulls the seagulls who were buff were killed more compared to when killed by hunters, and the skinner gulls were killed more as well this implies that muscle condition plays some role, but it is not the only factor in the survival of the gulls

what is it going to look like if you have genetic drift and natural selection both acting on a population, what's the allele frequency graph over time going to look like if say we have a large population and the allele is advantageous? what is an example situation in which we are using a graph of heterozygocity over time and what is it going to look like that make it representative of an effective population size?

the allele frequency would increase, if its advantageous, at a rate (the slope of the line going to fixation) that is dependent on how advantageous the allele is, and then if genetic drift is acting weakly (due to large population size) then it will end up looking like a slightly staticy line with a positive slope, but if genetic drift is acting strongly then the staticyness is going to be far more drastic, but the line is still going to possess its positive slope so in a study population of fruit flies we have a population size of 16 which starts off as all heterozygotes, so on the graph it will start off at 0.5 heter0zygocity (which is the maximum of heterozygocity) and then the actual data showed that the heterozygocity decreased faster than it should, and the reason why it did this is because not everyone in the population is successful at mating, this mating section of the population that are successful is the effective population size so as a result the population does not act perfectly as a population of 16 because its effective population size is lower this thus causes genetic drift to act with greater strength on the population causing heterozygocity to decrease faster

Oxpeckers are the little birds that hang out on top of the water buffalo and bison in africa what was the conscensus as to why they hang out on top of the large mammals? was this true?! who tested the hypothesis and what did they find?

the consensus as to why they hang out on top of the large mammals was that they eat the ticks off of them and get a safe place to eat was this true?! this was not true... scientists got lazy and never tested this, we just assumed this for 3 decades and everyone was like yeah totally bro but it was... fake news, SAD Weeks (1999) went out and tested this through an OBSERVATIONAL study, ie all he did was watch, and he found little evidence to support the eating ticks hypothesis, but what weeks did find was: roughly 85% of the time, the birds were licking blood, probing ears for wax, and scissoring beaks through the bisons' hair AND the cattle actively try to shoo the birds away

what is the direct benefits model of mate choice? What is the example study, who did it and with what organism? whatd they track in the study and whatd they find?

the direct benefits model of mate choice is the gold digger model actual tangible resources increase fecundity, so females choose males that provide the most and best important resources such as food, or shelter example is Thornhill et al. with Scorpion Flies females choose males that bring the largest food items, so the males will bring nuptial gifts to entire females and theyre like you can eat this fly I caught while I have sex with you when they tracked the duration of copulation with nuptial prey size, they found that as the nuptial prey size increased so did the duration of copulation, up until a certain point because the female can only eat so much until she gets full, but with increased copulation time there is an increase in sperm transferred so finding a big nuptial gift is good for the males, it's also good for the females bc the bigger the nuptial gift the more eggs she can produce and increases her lifetime is also increased because foraging is dangerous and with the gift she doesnt have to spend as much time foraging now but at any 1 time only 10% of the males have large prey, so they end up being the serial killers of the insect world as they murder things and discard them until they get one that they think is large enough to get them sex with the female, so there is heavy selection for finding a large gifts through sexual selection which results in stealing behaviors in which the males mimic female behavior and then steal the other males' gifts

what does the energetic investment dichotomy normally cause/lead to? what are some things that this typically leads to?

the energetic investment dichotomy normally causes sexual selection to be strong force for one sex and weak for the other, typically strong on males and weak on females this typically leads to: 1. competition between the members of the sex subject to strong selection (due to their low energy input in sexual reproduction) 2. members of sex subject to weak selection (due to large amount of energy input in sexual reproduction) will be choosy

What is an example of a bottleneck effect from class? What was the problem that resulted from this bottleneck? What aspect of evolution did people use to fix the problem?

the florida panther was subject to a genetic bottleneck when a bunch of rich assfaces wanted to wear their fur, by 1995 there were only 12 left on earth, the problem that resulted from the bottleneck effect and subsequent inbreeding is that the remaining panthers were in super poor health the aspect of evolution they used to save the florida panther was migration/gene-flow (artificial migration), so specifically what they did was they brought in a bunch of genetic material from texas panthers to make hybrids

what does the good genes model of mate choice say? what are females in this model receiving? what is this model synonymous with?

the good genes model says that females are receiving more than just direct resources, they are receiving genetic material that is going to combine with their own which will contribute half of the genetic material for their offspring thus! they really want good genes; this model says that females are trying to get a metric for the quality of the males' genes which will go to be passed into the females' offspring females in this model are still receiving a benefit but it is indirect in the form of offspring fitness also synonymous with the sexy sons hypothesis - females want sexy sons because they will have more offspring which will lead to the females' genetic material being passed on at a greater rate

What happens if we have a situation where males put in more energy than the females? what is our example of this in fish?

the males end up being the picky ones and the females start competing with each other example is broad-nosed pipefish males provide all the parental care, and the females make eggs faster than the males can rear them so the males are the choosy ones males pick females based off arbitrary trait of being larger and having larger skin folds (runaway selection)

What do missing details in phylogenetic trees mean? what do we know about the timing of the transitions? what does the tree say about taxa? what is rare to know? whats an example of knowing? what is thus necesary and what is that based off of? Where do we get well established trees from?

the missing details, such as the evolution of the mane in lions, does not imply that evolution did not occur the timing of the transitions is not precisely known the tree can only speak about the taxa included in it it is rare to know evolutionary histories by direct observation such as with lineages in labs so it is necessary to make influences based on the data set and analysis techniques well established trees are generated from multiple data sets, a variety of analysis techniques, etc.

What is the other example, other than the yellow and purple Elderflower orchids, that depicts frequency-dependent selection? what is the allele frequency over generational time graph pattern look like for frequency-dependent selection?

the other example, other than the yellow and purple Elderflower orchids, that depicts frequency-dependent selection is a directionally jawed fish in south america, the fish can be either left or right jawed (their jaws are angled towards the right or left), the fish attack other fish and eat their scales, so when the right jawed fish is eating the scales on the left side of the prey fish in a high enough frequency, the prey fish begins shying away from that particular side and protecting that side more often, when the prey fish evolve this anti-predator behavior of protecting their left side (which evolves because the right jawed predator fish are too common) then the right jawed fish that has become too common decreases in fitness and its allele frequency goes down again while the left-jawed fish go up in frequency until their allele frequency goes above 0.5 at which point the prey fish begins protecting that side of their body which means now the left jawed fish are being selected against and now their allele frequency goes down, and so on, and so on thus the frequency dependent selection gives rise to our damped oscillation pattern in which the allele frequency is bouncing up and down, due to the higher allele frequency being selected against until it goes below 0.5 at which point it gets selected for and increases in frequency until it gets above 0.5 at which point it gets selected against again causing its allele frequency to go down again, and so on and so on with the allele frequency continually getting closer and closer to 0.5 ie the maxima and minima get smaller and smaller over generational time, this pattern gets reset at random points in time due to some environmental shift which causes the allele frequency of one of the alleles to spike again causing the damped oscillation pattern slowly drawing closer to 0.5 to start all over again (kinda looks like an ECG)

what are the three species that together show an example of a living transitional fossil?

the pacific leaping blenny (alticus spp.), a terrestrial fish little fish that climb around in inner tidal zone, so during high tide its underwater and in low tide its exposed to air, so during low tide they will be exposed to predators, to protect themselves from these predators they developed this little tail with a grabber that allows them to grab onto a rock and throw themselves through the air to avoid predators, it is a mostly horizontal movement Blenniella (aquatic) they do a similar thing to the alticus, except they are in the water, so instead of throwing themselves across rocks, they fling themselves in a mostly vertical movement out of the water to avoid predators Praealticus (amphibious) the transitional form between the alticus and blenniella, it is a living transitional fossil the ancestor of the terrestrial, alticus was probably fully aquatic, then we probably had a split in our lineage, because if blenniella evolved into alticus then there wouldnt be any blenniella left blenniella is still around is because it never went extinct, instead we had a split of behavior and anatomy such that praealticus and alticus came out of that split but that blenniella is still around

why are daphnia pulex cool to study for environmental variation of phenotype?

the phantom midge larvae are sea vampires but when the pulex realize the predator is nearby they have an inducible defense in response to a kairomone which is a chemical messenger in the environment that a prey can pick up on so that they are aware of the presence of a predator so what they do is grow neck teeth to protect themselves from the predator this is an example of phenotypic plasticity

So what things determine whether genetic drift or Natural selection is playing a predominant role in the change of allele frequencies over generational time?

the things that determine whether genetic drift or Natural selection is playing a predominant role in the change of allele frequencies over generational time are: 1. the size of a population 2. the strength of selection so like if an good allele pops up through a random mutation (genetic drift) but it is only present in 1 individual, then the odds of genetic drift eliminating that allele again is pretty high relative to if that is present in many individuals

Why are there tradeoffs in evolution?

there are energetic constraints that make it so that things cannot evolve optimal solutions to all selective challenges, thus there needs to be a tradeoff we've got to pick our battles

what are transitional forms and how do they relate to macroevolution?

transitional forms come from the idea that if we have a fossil organism that was around a long time ago and now we have something that is fairly different, there should have been something in between, because if we have microevolution building up over time then we should a progressive change and all the pieces in between that lead to the current species from the fossilized creature we have microevolution leading to speciation which all amalgamating for hundreds of millions of years ultimately leads to macroevolution, but there should be fossil evidence of all the in between steps from a fossil of a creature 300 million years ago till the creature that is alive now these in between stages of organisms in the long past and now are called transitional fossils

what are transitional fossils useful for?

transitional fossils are useful in determining the direction under which evolution goes, how did we get to where we are now, they are very useful in answering that question

in the Tungara frogs, females choose males based on what? what complicates the matter? so what does that mean that we have going on here?

tungara frogs so females choose mates based on the complexity of their songs, the more complex song the sexier the male frog complicating the matter is that unfortunately there are frog-eating bats that are also attracted to the frogs with more complex songs so what we have going on here is sexual selection and natural selection being in conflict with each other and thus some sort of tradeoff will need to be made

what are two reasons for why we can variation of traits in a population ie what is the equation that accounts for variation in a phenotype (Vp)? what are the variables that are involved in the equation? what are the possible values for the variables that determine the degree of heritability of each reason/factor for variability the population?

variation can be present for two reasons: Vp = Vg + Ve Vp = variation of phenotype variation of phenotype is made up of variation that is result of genetics and variation that is result of environment Ve = variation that is result of environment environmental - like working out and tanning getting you buff and tan, changing the phenotype but the genotype didnt change and thus the phenotype is not heritable Vg = variation that is result of genetics/genotype if variation of a phenotype is 100% due to environment then that means there is no heritability So a score of 0 for Vp means that we are 100% environmental, and a score of 1 means we are 100% genetic so ultimately if differences of alleles are inherited then what ever that trait is the offspring should resemble the adults in some way

How did we build the geologic time scale at first? what was the next kind of dating that we developed to build the geologic time scale?

we built the geologic time scale at first using relative dating, which is when we would find a fossil in a higher strata of rock relative to a fossil in a lower strata of rock, so the deeper fossil is thus older than the higher one the next kind of dating we used was radiometric dating which is when we use radioactive isotopes with a known, and constant, half life we can analyze the amount of say Carbon 14 which we only taken in when we are alive, and then after death the Carbon 14 begins to decay into nitrogen 14, so depending on the proportion of Carbon 14 to Nitrogen 14 we can calculate how much time has gone by using the half life period

site-directed mutagenesis of viruses how do this work and what does this allow us to see?

we take a virus, alter its code, and then inject it into a host, we alter the genome so that it causes really nasty mutations at a high rate so when we inject the virus into host, we are trying to hikack code of host so that we can increase the rate of mutations to much much faster than it would normally be this allows us to see the frequency in the different types of mutations ie whether they are lethal, neutral, where on the spectrum of bad but not lethal, or how good they are we were able to figure out, that when there are mutations, the majority do nothing, the next highest are bad news ranging from lethal to slightly bad, and only a tiny amount is good the faster the rate of generational time, the faster the rates of mutations, the faster the rate of evolution, also the smaller the genome code, the more likely you are to get these mutations propping up proportionately

What do we do in mutation accumulation experiments? What influences rate of mutation accumulation?

we take wildtype organism, grow them in optimal conditions and then compare the individuals from the optimal conditions to the wildtype still out in the wild, and then we can see what the rate of mutations are we look at the number of substitutions per base pair per generation size of genetic code and generation time influences the rate at which the accumulation of mutations occurs faster generation rate and smaller the genome, the more likely you are to build up bad mutations so basically the ratio of indels to substitutions typically increases the smaller the generational time and genome, so bacteria and viruses have ratios of indels to substitutions of like 1:1 indel to substitution and people have like 1:17 indel to substitution

the number of possible trees grows exponentially as the number of species involved increase in the phylogentic tree youre trying to create, so what do we use to deal with this?

we use super computers to calculate which is the most parsimonious tree as we get into like the 10 species range since there is over 34,459,435 possible trees for trees involving 10 species

so you have a mainland population with a bunch of different alleles that are all at low frequencies, and you have islands off the mainland population that get progressively further away from the mainland how would you expect the number of alleles on each island to change as you got further away and why? What would the FST value be for the island populations and why?

we would expect the number of alleles on each island to decrease as we got further away from the mainland because it is difficult for the alleles to get from one island to the next, the particular alleles that make it to each island is based on genetic drift (randomness) while simulatenously migration increasing the number of alleles on an island closer to the mainland while the further out islands are most likely getting their alleles from the islands in between them and the mainland which means the number of alleles will decrease as you get further out, it is possible that alleles from the mainland could get to the furthermost islands but this is less likely than them coming from closer islands the FST value ie the amount of variation between the island populations would be very close to 1 because the particular alleles at each island are determined through genetic drift (random chance)

Suppose you were a dog breeder who wished to reduce the incidence of Barking in an otherwise popular breed of dog. Design a strategy that would allow you to do this. What assumptions would you need to make, and what key elements would need to be in place to be successful?

we would need to know: barking would need to not be a learned behavior, the trait needs to be a heritable, genetic trait how I would get rid of barking, if controlled by genetics: find the dogs that are barking less, and they selectively breed the less barking ones, take the next generation and do the same thing, and eventually we would get our less barking breed

What are the common misconceptions of natural selection? (just list them) (explanation of each is not next flashcard)

what does natural selection act on and where are consequences seen? do individuals evolve? traits must be heritable! purely environmental variation does not lead to natural selection Is natural selection forward looking? Is natural selection the same as perfection?

what is important to consider when thinking about mutations?

what type of mutation is it? ie is it an indel or substitution? where is the mutation? ie is it in proof reading machinery gene or an intron?

what happens to the health of the population when we get rid of natural selection?

without natural selection to weed out the negative alleles from the population, the population's health steadily declines but once natural selection is reintroduced there is a rapid recovery in the health of the population so natural selection is actually very good for the population but can be pretty brutal to the individual

is fitness relative? what does that mean with regards to the cheetah example from class? what do darwinian fitness and natural selection lead to?

yes fitness is relative, we didnt need to be as fast as husein bolt, or faster than the cheetah, we just had to run faster than the person next to us, we dont have to be the fastest, we just cant be the slowest darwinian fitness and natural selection lead to adaptation, traits that confer a survival and reproduction advantage over the other traits that are possible in the population Natural selection is the only way that evolution can occur that produces adaptations, the other four mechanism change the allele frequency in the population but the individuals do not necessarily become better at surviving and reproducing in their natural environment

How do you account and fix the problem of phylogenetic constraints in a comparative experiment?

you account and fix the problem of phylogenetic constraints in a comparative experiment by using phylogenetically independent contrasts you assign your extant species and all the common ancestors a notation (some letter to denote that species) then create random mismatched pairs, some of which are closely related and some are not, then you make best fit lines between these pairs and then you shift all the pairs down to origin while maintaining the slopes of the lines between the pairs to reorient the data points in such a way that removes the effect of phylogeny because the pairings were random (independent of phylogeny) then! with your data points reoriented in a way that has accounted for the phylogenetic constraitns, you draw your best fit line