Bio 101: Unit 3 GRQ

mutualism

(+/+) both populations benefit ex. crocodiles/ bird

herbivory

(+/-) consumption of plant party or algae by an animal ex. caterpillars/ leaves

predation

(+/-) one species kills and eats another species ex. crocodiles/ fish

parasites or pathogens

(+/-) taking advantage of a host ex. heart-worms/dog salmonella/human

competition

(-/-) when populations of 2 different species compete for the same limited resources ex. squirrels/black bears- acorns

Fossils provide evidence for evolution, but so do homologies. Explain what homologies are and how they provide more evidence for shared ancestry?

- similarities resulting from common ancestry - different mammals are variations on an anatomical structure of an ancestral organism that over millions of years has become adapted to different functions

Why has using a morphological/archaeological approach to hypothesize a) what Canis species is most closely related to dogs and b) when dogs were domesticated proven difficult?

- skulls look similar spending on type of dog - bones say later but DNA says much earlier

In the nature versus nurture experiments with dog pups and wolf pups, what behavioral differences did the wolf pups exhibit as they grew older? What do the results of this experiment suggest about the influence of genetics versus environment and upbringing on where dogs come from?

- became more wolf-like and aggressive - genetics play a much bigger role than anything else in behavior

What happens to a population of insects (maybe cockroaches in a large apartment building) over time if the same pesticide is repeatedly applied for years and years? Explain your answer.

- becomes less and less effective - survivors who carry pesticide-resistant allele will carry gene onto offspring and become more frequent in population

What are "glutton" mice?

- no bacteria in them at all - eat 30% more than control mice and don't gain weight

In the experiment with the foxes, what trait was selected for when breeding one group pf foxes? What trait elected for in the other gourd of foxes? What does the outcome of this experiment suggest about where dogs come?

- non-aggressiveness/ aggressiveness - dogs come from friendly wolves

Describe gene flow and give it at least one example of it that you understand.

- the immigration or emigration of organisms between two populations - birds brought into low diversity area to make more genetic variation

Describe the cross fostering experiment the scientist conducted with the two groups of foxes. What happened to the aggressive fox pups in their experiment? How do these results support the findings of the previous experiment with the wolf and dog pups from question #5?

- they stayed aggressive - genetics plays a role in their behavior more than how they are raised

What is molecular systematics? What are the advantages of this approach to constructing phylogenetic trees over using physical characteristics?

- using DNA or other molecules to infer relatedness - use DNA analyses to assess relationships between groups of organisms that are so phylogenetically distant that structure similarities are absent

Describe the left gaze bias experiment. How does the left gaze differ when dogs encounter human faces compared to other dogs? How does this compare with humans that encounter other human faces? What hypothesis were the scientists testing with this experiment?

- we look to the left when we see a face (a person's right side of face) - dogs look to the left as well when looking at human faces but not other with dog faces - if dogs understand humans

What are some factors that may cause the composition of the microbial community in the intestine to be different from one individual to another?

- where you live - you mother - what you eat

What factors may have favored domestication of wolves by early human hunters? What advantages did this relationship provide for a) humans and b) wolves/dogs?

- work together in hunting - humans have a companion and wolves/dogs get constant source for food and housing

100 rabbits in a field. 50 are born in one month to these 100 rabbits. What is the net increase of rabbits per month?

.5

True or false, justify your answer. 1. Pesticide sprayed over and over causes some bugs to acquire a mutation in green that makes them resistant to the chemical. 2. Some bugs in the population may be resistant to pesticide even if there is no pesticide being sprayed.

1. False- a pesticide does not create new alleles that allow insects to survive. Rather the presence of the pesticide leads to natural selection for insects in the population that already have those alleles 2. True- trait is heritable

True or false, justify your answer. 1. Resistance to the pesticide DDT is always a good thing for the mosquito carrying it.

1. False- only good when DDT is in the environment

True or false? Then, explain your answer. 1. Polymers can't form without enzymes. 2. It is believed that DNA came first and then RNA

1. False- scientist have done studies that can get them to spontaneously bond 2. False- RNA came before DNA

What are the 3 KEY points emphasized about evolution by natural selection?

1. although natural selection occurs through interactions between individuals organisms and the environment, individuals do no evolve 2. natural selection can amplify or diminish only heritable traits 3. evolution is not goal directed; it does not lead to perfectly adapted organisms

What are four ways (i.e. concepts) to define a species?

1. biological concept: part of same species of they reproduce viable offspring 2. morphological concept: physical traits 3. ecological concept: adaptations to roles in community; i.e. what they eat, where they live 4. morphological concept: based on common ancestry (uses morphology,DNA, or other comparisons to examine similarities and differences)

True of false? 1. New alleles arise as organisms need them. 2. Evolution leads to organisms perfectly adapted to their environments 3. Evolution builds upon and modifies ancestral forms.

1. false 2. false 3. true

Aside from mutation and non-random mating (which have smaller effects) what are the three major mechanism leading to microevolution?

1. natural selection: a procession which individuals with certain inherited traits are more likely to survive and reproduce than are individuals that do not have those traits 2. genetic drift: a change int he even pool of a population due to chance 3. gene flow: the transfer of alleles from one population to another as a result of the movement of individuals or their gametes

1. Can individual organism evolve? 2. Can a population evolve? Explain your answers.

1. no 2. yes a change in the prevalence of certain heritable traits in a population over a span of generations is evolution

What are the four main stages that scientists hypothesize could have produced simple cells?

1. the abiotic (nonliving) synthesis of small organic molecules such as amino acids and nitrogenous bases 2. the joining of these small molecules into polymers, such as proteins and nucleic acids 3. the packaging of these molecules into "protocells" ,droplets with membranes, maintains an internal chemistry different form that of their surrounding 4. the origin of self-replacing molecules that eventually make inheritance possible

If a population is NOT evolving it would satisfy five conditions of genetic equilibrium (Hardy Weinberg non-evolution):

1. very large population: the smaller the population, the more likely that allele frequencies will fluctuate by chance from one generation to the next 2. No gene flow between populations: when individuals move into or out of populations, they add or remove alleles, altering the gene pool 3. no mutations: by changing alleles or deleting or duplicating genes, mutations modify the gene pool 4. Random mating: if individuals mate preferentially, such as with close relatives (inbreeding), random mixing of gametes does not occur, and genotype frequencies change 5. no natural selection: the unequal survival and reproductive success of individuals (natural selection) can alter allele frequencies

What year will the human population possibly "peak"?

2050

So, if a rabbit population, in which r=0.3 starts with 96 rabbits, what will the growth be in one month?

28.8

What percentage of the cheerio was digested by the Inuit mom? By the Argentinean mom? Why is there a difference?

98% 80% gut bacteria have different genes that make them create enzymes to break down different foods

What is the equation for exponential population growth?

G=rN

What is the equation for logistic growth?

G= rN*(K-N)/K

The visual in 14.3 is an excellent summary of the isolating mechanisms leading to reproductive isolation. List and and define each type and give an example that makes sense to you.

Pre-zygotic barriers 1. Habitat: lack opportunities to encounter each other (ex. one snake lives on land while other lives in water) 2. temporal: breeding at different times or season (ex. eastern skunk mates late winter and western skunk mates in fall) 3. behavioral: failure to send or receive appropriate signals (ex. one booby dances but other booby does other thing as sign to mate) 4. mechanical: physical incompatibility of reproductive parts (ex. one plant is pollinated by curved bill and other is pollinated with a straight bill) 5. gametic: molecular incompatibility of eggs and sperm or pollen and stigma (ex. Proteins on the rat sperm to not "fit" or bind with proteins on the mouse egg) Post-zygotic barriers 1. reduced hybrid viability: interaction of parental genes impairs the hybrid's development or survival (ex. salamander will be frail and not live long enough to mate) 2. reduced hybrid fertility: hybrids are vigorous but cannot produce viable offspring (ex. mules (horse and donkey) are sterile) 3. hybrid breakdown: hybrids are viable and fertile, but their offspring are feeble or sterile (ex. rice hybrids are fertile but their offspring are sterile)

True or false? A baby boom to a mother in Alaska would have a different gut bacteria than a baby born to a mom in Argentina.

True

Although scientists can't know how life began, they can test hypotheses about how organic compounds came to be on earth. Is there any scientific support the spontaneous synthesis of organic molecules on earth? That is, can experiments be done? Explain.

Yes, Stanley Miller did an experiments in 1953 that included an apparatus that combined water, NH3, CH4, H2, electrodes, etc. to represent how earth's atmosphere could've been

Define and give an example of co-evolution.

a series of reciprocal evolutionary adaptations in two species ex. passiflora produces toxic chemicals that protect its leaves from most insects, but Heliconius caterpillars have digestive enzymes that break down the toxins. Passiflora defenses evolve into producing yellow spots that look like Heliconius eggs. Females won't lay eggs here and less chance of being eaten.

What are the characteristics of lobed fin fishes? Are there any alive today?

a series of rod-shaped bones in their muscular pectoral and pelvic fins coelacanth, lungfish and tetrapods

What is demographic transition?

a shift from birth rates and death rates that are high but roughly equal to birth and death rates that are low but roughly equal

Natural selection is the only mechanism that consistently leads to ________ evolution. For each of the FIVE types of natural selection, a) define it, b) give at least one example of it that will help you understand and remember it, c) draw a graph if appropriate

adaptive

What types of cells did prokaryotic cells give rise to?

aerobic cells

If a population ecologist asks for your life history, what kind of information should you tell her?

age of first reproduction, the number of offspring and the amount of parental care given

How does homology in molecular biology support Darwin's idea that "all life forms are related"?

all forms of life use the same genetic language of DNA and RNA, and the genetic codes- how RNA triplets are translated into amino acids- is essentially universal

How is a community different from a population?

an assemblage of all the populations of organisms living close enough together for potential interaction

In module 36.11, it defines ecological footprint. What is this?

an estimate of the land and water area required to provide the resources an individual or a nation consumes and to absorb the waste it generates, of which carbon emissions are a major component

What is the most common ancestor for hawks and lizards?

ancestor 4

Early humans likely and pink skin with black fur, similar to chimpanzees for today. When the skin shed its fur, what would have likely happened to skin color?

became dark to protect from harsh UV rays

When a population goes from large to small, genetic drift is more pronounced in the small population. What are two major reasons that populations go from large to small?

bottleneck effect: genetic drift resulting from a drastic reduction in population size founder effect: genetic drift that occurs when a few individuals become isolated form a larger population and form a new population whose gene pool in not reflective of that of the original population

Referring to eating a cheerio (essentially plant seeds), what is the function of the bacteria that live in our intestines?

break down cheerio to help us digest it

What general defenses have evolve in prey against predators?

camouflage, mechanical defenses (sharp quills on porcupine) and chemical defenses (bitter taste of monarchs)

survivorship curves- what information can you learn by looking at one?

can compare species with widely varying life spans on the same graph

What is the difference between a density dependent and a density independent limiting factor?

density dependent: limting factors whose intensity is related to population density density independent: intensity is unrelated to population density

What is the relationships between developed vs. non-developed countries to this transition?

developed: have completed or are nearing completion non-developed: death rates have dropped, but high birth rates persist

How did she create different environments for the fruit flies and what did she find when she mixed the two different fruit fly groups together for mating?

different food sources (starch and maltose) "maltose" flies were more likely to mate with other maltose flies and starch flies were more likely to mate with other starch flies

Humans sweat to keep cool, what other strategies exist for hairier mammals to cool off?

dogs pant, many cat species are most active during cooler evening hours and many antelope can load off heat from the blood in their arteries to blood in small veins that has been cooled by breathing through the nose

Within a community, there are may be many species living in the same habitat. What is the word we use that differentiates each species unique ecological role?

ecological niche

What is a limiting factor? What does it do to growth?

environmental factors that restrict population growth

Diana Dodd's experiments with fruit flies demonstrated what principle of evolution?

evolution of reproductive isolation

When is it more appropriate to utilize mitochondrial DNA that to construct phylogenetic trees? Why?

evolves relatively rapidly and so can be used to investigate more recent evolutionary events

What kind of growth (exponential or logistic) is demonstrated by the human population?

exponential

disruptive selection

favors individuals at both ends of a phenotypic range over individuals with intermediate phenotypes ex. what sand and dark rocks blend for white and black mice

stabilizing selection

favors intermediate phenotypes ex. medium gray mice blend better into medium gray rock environment

Although lobed-fun fish were hypothesized to be ancestors to tetrapods, what evidence would scientist need?

fossil evidence of the transition

Darwin suggested that whales evolved from terrestrial (land-living) mammals but he did not have evidence. What kind of evidence do we have today that could answer this question? Was he right?

fossils showing a series of changes in a lineage of mammals adapted to a fully aquatic habitat yes

Module 19.4 tells us about an important adaption in vertebrate story, adapting form water to land. What are some of the challenges obstacles in moving from water to land?

gas exchange, water conservation, structural support, reproduction, sensory organs that worked in water had to be adapted or replaced by structures transmitted through air, new means of locomotion was required

What would happen to the cheerio if we didn't have bacteria in our intestine?

go right through us and gain nothing from it

As the resources get used up, what happens to the equation? That is, what happens to population growth as the population size approaches carrying capacity?

growth rate slows down to zero

Why do scientists think naked skin is an adaption related to the human behavior of hunting and eating meat for survival?

had to run a lot to get their food

Why pubic hair? Why armpit hair?

hair in the armpits and groin probably serves both to propagate pheromones (chemicals that serve to elicit a behavioral response from other individuals) and to help keep these areas lubricated during locomotion

Where ideally on a logistic growth curve do we want to keep population size for say fish that we hope to harvest for food yet not have go extinct?

half the carrying capacity

There is evidence that the composition of the intestinal microbial community can be changed as the example of a person moving from the US to Australia illustrated. Why is this exciting for scientist trying to find a cure for disease such a obesity?

have the potential to eliminate bacteria that cause obesity and other disease

Why do humans have hair on their heads?

help scheld against excess heat on the top of the head

heterozygote advantage

heterozygous individuals have greater reproductive success than either type of homozygote, with the rest that two or more alleles for a gene are painted int he population ex. sickle cell- one allele helps prevent malaria but two alleles you have sickle cell anemia

Compare and contrast homologous and analogous traits. Which of the two types of traits are utilized to construct phylogenetic trees? Why?

homologous: evolved from the same structure analogous: similar but not from ancestry homologous structures because they show ancestry of structures

What type of individual does each of these variables represent in the population? p2 2pq q2

homozygous dominant (AA) heterozygotes (Aa) homozygous recessives (aa)

What is different about human sweat compared to other animal swear and why is this an advantage for cooling, say when competing in a marathon against a horse?

in most species, sebaceous and apocrine glands are dominant, which produce sweat that is foamy, oily and thick its ability to dissipate heat is limited humans have glands that produce watery sweat

Did Darwin find as he traveled the world that species resembled each other more closely if they were geographically located near each other or of the two species lived in similar environments (possibly very far apart)? What is an example of this?

indicated that geographic proximity is a better predictor of relationships among organisms than similarity in environment ex. plants and animals living in temperate regions of South America have more closely resembled species living in tropical regions of that continent than species living in temperate regions of Europe

Why would a population gain or lose individuals?

individuals are born or immigrate into an area and others die or emigrate

sexual selection

individuals with certain traits are more likely than other individuals to obtain mates ex. more color on a male peacock

Give an example of an inherited phenotype vs. an acquired phenotype. Which is relevant to natural selection?

inherited: born with brown hair and crooked teeth acquired: dyed hair blonde and straightened teeth with braces inherited phenotypes are relevant for natural selection

If the Inuit and the Argentinean eat the same amount of cheerios, who will absorb more calories from the cheerios? How is this important in the context of obesity?

inuit mom eating the same as another person can actually make you gain weight depending on the type of gut bacteria you have

What does a geographical barrier do to gene flow?

isolates population and blocks gene flow, creating a new species over time (allopatric speciation)

How would you describe the exponential model as a curve plot? (Draw it)

j-shaped curve

Compare and contrast k-selecition and r-selection

k-selecition: the concept that in certain populations, life history is centered on producing relatively few offspring that have a good chance of survival r-selecition: the concept that in certain populations, a high reproduction rate is the chief determinant of life history

Beyond trying to determine when humans became furless, they are searching for genetics answers for how hairlessness is encoded in our genome. What kind of comparisons are they doing to search for these answers?

large scale comparisons of the sequences of DNA "code letters", or nucleotides, in the entire genomes of different organisms

Some mammals no longer have hair, because of one of three reasons, list an example animal next to each:

living underground: naked mole rats living in water: whales keeping cool because of large body size: elephants

Type III

low survivorship for the very young, followed by a period when survivorship is high for those few individuals who live to a certain age ex. produce very large numbers of offspring but provide little or no care for them at all

frequency-dependent selection

maintains two different phenotypic forms in a population ex. right or left mouthed fish

Look at Figure 13.5, which animal groups all have the shared characteristic of the amnion?

mammals; lizards and snakes; crocodiles; ostriches; and hawks and other birds

Define carrying capacity

maximum population size that a particular environment can sustain

If organic compounds did not originate on earth, what is an alternate hypothesis for who they arrived on earth?

meteorites

Darwin called evolution, "descent with __________" and unlike other who had thought of ideas similar to this, he proposed a scientific mechanism for his worked. What did he propose?

modification natural selection: as the descendants of a remote ancestor spread into various habitats over millions and millions of years, they accumulated diverse modification, or adapts, that fathom to specific ways of life in their environment

When using a molecular approach to construct phylogenetic trees, why might a phylogenetic tree look different than one constructed based on physical characteristics or a fossil record when comparing that same group species?

molecular biology has helped to extend systematics to that extremes of evolutionary relationships far above and below that species level, ranging from major branches of the tree of life to its finest twigs

Scientists found fossils of Eusthenopteron. Was it more fish-like or tetrapod-like and why? What features did it have?

more fish-like fins

Type I

most people survive to the older age intervals ex. mammals that usually produce few offspring but give them good care

What creates new alleles in a population?

mutations: accidental changes in the nucleotide sequence of DNA

balancing selection

natural selection maintains stable frequencies of two or more phenotypic forms in a population ex. If there are a lot of blue lizards, orange become more successful. Blue frequency drops. If there are a lot of orange lizards, yellow become more successful. Orange frequency drops. If there are a lot of yellow lizards, blue become more successful. Yellow frequency drops.

Why does interspecific competition (between species) negatively affect both species?

niches of two populations overlap and both populations need a reserve that is in short supply

Do any of these reasons fit with why humans have little hair?

our bare skin is related to staying cool

Who benefits in the parasite host relationship?

parasite

Who benefits in the predator prey relationship?

predator

What countermeasures have evolved in predators?

predators learn to associate these color patterns with undesirable consequences, such as noxious taste or a painful sting, and avoid potential prey with similar markings

Hair is a distinctly mammalian trait. What purpose does hair have for mammals?

provides insulation and protection against abrasion, moisture, damaging rays of sunlight and potentially harmful parasites and microbes

How is the per capital of increase for a population represented? How is it calculated?

r BR-DR/Total pop

What did Darwin learn about geology?

realized that natural forces gradually changed Earth's surface and that these forces still operate

We know microevolution is occurring f we see what changing over many generations?

relative frequencies of alleles in a population change

What shuffles alleles already existing in a population?

sexual reproduction

directional selection

shifts the overall makeup of the population by acting against individuals at one father phenotype extremes ex. ground is dark so dark mice fit better

define population density

the number of individuals of a species per unit area of volume

Humans cannot communicate with their fur but how do humans communicate with their skin?

social blushing, complex facial features, body paint, cosmetic tattoos, body postures and gestures

Tiktaalik was found much more recently...in 2006. Where was it in the lineage of transitional animals?

straddled the border between Panderichthys and Acanthostega

Type II

survivorship constant constant over the life span ex. observed in some invertebrates, lizards and rodents

In what ways are reptiles adapted to terrestrial life that amphibians are not?

terrestrially adapted egg, tough skin

They also found fossils of Ichthyostega. Was it more fish-like or tetrapod-like and why? What features did it have?

tetrapod-like ray-finned tail and flipper-like hind limbs

What is macroevolution, and how is it different from microevolution?

the broad pattern of changes in life of earth microevolution looks at small changes in populations

What is speciation?

the process by which one species splits into two or more species

define population distribution and describe 3 types of distribution patterns

the way individuals are spaced within their environment 1. clumped: individuals are grouped in patched 2. uniform: individuals are spread out evenly 3. random: individuals are spaced in an unpredictable way, without a pattern

In what ways are amphibians not completely adapted to life on land?

their eggs are not well protected against dehydration; many species have an aquatic larval form; their skin is not waterproof and must remain moist to permit gas exchange

When germ-free glutton mice are removed from their sterile environment, exposed to germs, and allowed to keep eating, what happens?

they gain weight

What information do phylogenetic trees depict? What types of characteristics can be utilized to construct phylogenetic trees?

to depict hypotheses about the evolutionary history of species homologous features

What was missing?

transition from fins to limbs

Prior to Darwin's trip around the world, what did religious scholars believe about Earth and the living species on it?

used biblical accounts to estimate the age of Earth at 6,000 years. Thus, the idea that all living species came into being relatively recently and are unchanging in for, dominated the intellectual climate of the western world at the time

When is it more appropriate to utilize DNA that codes for ribosomal RNA to construct phylogenetic trees? Why?

useful for investigating relationships between taxa that diverged hundreds of millions of years ago because ribosomal RNA changes relatively slowly

What are vestigial structures vestigial genes?

vestigial structures: remnants of features that served important functions int he organism's ancestors vestigial genes: genes that have lost their function

What is the advantage of breathing air rather than staying in war stagnant water?

warm stagnant water is low in oxygen

Define mutualism

when both populations benefit

Are wolves and dogs the same species? Why?

yes, because they can interbreed

Would there have been food available for tetrapods beginning to colonize land?

yes, in carboniferous swamp forests

Can speciation occur even if there is no geographical barrier?

yes, speciation can occur when accidents happen in cell division (tetraploids- 4n)