evolution final exam
A quick refresher: what is the frequency of the red allele in this population? - 14/20 - 10/20 - 6/20 - 10/10
14/20
You conduct a truncation selection experiment to determine the heritability of height in a group of plants. You determine that the average height of the original population is 6m. You then choose a group of individuals to breed, with the average height of breeders equal to 9m. In your second generation, you measure an average height of 8m. What is the response to selection? - 2m - 0.66m - 1m - 3m
2m
How many genotypes are in this population? -1 -2 -3 -4
3
Which node indicates the common ancestor of amphibians and coelacanths? - 3 - 4 - 1 - 2
3
Flip again. What's the probability of getting heads? - 30% - 40% - 50% - 60%
50%
Flip it again, what's the probability of getting heads? - 30% - 40% - 50% - 60%
50%
Imagine you flip a normal coin. What's the probability of getting heads? - 30% - 40% - 50% - 60%
50%
What is the heterozygosity of this population? - 6/10 - 4/10 - 2/10 - 6/20
6/10
If the starting frequency of the A allele in a population is 0.6, what is the probability of the allele going to fixation? - 30% - 40% - 50% - 60%
60%
What are the eye colors of the two black boxes? - brown, blue - brown, brown - blue, blue - blue, brown
- brown, blue
Which male obtained the most nests on his territory? - shortened - control - elongated
elongated
Which of these are central components of evolutionary theory? - all are components of evolutionary theory - all species share common ancestors - species change over time - species are well-suited to their environments
- all are components of evolutionary theory
Which observation(s) are evidence for particulate inheritance vs. blending? - F2 generations have parental and intermediate phenotypes - F1 generations have intermediate phenotypes - Alleles at different loci sort independently - phenotypic variation is influenced by the environment
- F2 generations have parental and intermediate phenotypes
Adaptations are: - traits organisms acquire to enhance their fitness - traits that always increase fitness in all populations - any aspect of the phenotype - a trait associated with the highest relative fitness in a particular environment
- a trait associated with the highest relative fitness in a particular environment
What pattern is shown in this figure? - descendant (post-drought) plants flower earlier than ancestral plants - ancestral (pre-drought) plants flowered earlier than descendant plants - there is no difference in flowering time between pre- and post-drought flowering time
- descendant (post-drought) plants flower earlier than ancestral plants
Why can't 100% environmentally determined traits evolve by selection? - evolution by selection is change in allele frequencies over time and there are no alleles in these traits - they are too variable and selection would be ineffective - offspring don't resemble parents in environmental traits.
- evolution by selection is change in allele frequencies over time and there are no alleles in these traits
Which statement correctly describes how mutations and natural selection interact? - mutations randomly generate genetic variants, and natural selections acts on those variants - mutations generate deleterious mutations that are then always removed from the population by natural selection - the environment stimulates mutations, on which natural selection then acts - mutations generate beneficial variants for the organisms, and natural selection acts on those variants
- mutations randomly generate genetic variants, and natural selections acts on those variants
Which is NOT true about how complex and novel traits typically evolve: - new, complex structures typically appear full formed via mutations of large effects - complex structures can evolve via many intermediate stages - structures that serve one function are frequently co-opted for a new function - gene duplications and gene sharing enable evolution of novel traits at the molecular level
- new, complex structures typically appear full formed via mutations of large effects
is language heritable? - yes - no
- no
Which pair of species diverged most recently? - tapirs and rhinos - tapirs and horses - elephants and hyraxes - cetaceans and pigs
- tapirs and rhinos
Do most genotypes show a similar relationship between leaf are and light intensity? - yes, most genotypes have the largest leaf area at intermediate light intensity - yes, most genotypes have the smallest leaf area at the highest light intensity - yes, most genotypes have the largest leaf area at the highest light intensity - no, all genotypes show a different relationship between light intensity and leaf area.
- yes, most genotypes have the largest leaf area at intermediate light intensity
In a population under Hardy-Weinberg equilibrium, you measure the frequency of of the aa genotype (the blue line in the figure above) to be 0.4. What is the approximate frequency of the Aa heterozygote? You may eyeball this on the figure. - 0.8 - 0.3 - 0.2 - 0.5
0.5
In a population under Hardy-Weinberg equilibrium, you measure the frequency of p (or A or A1) to be 0.3. Based on the figure above, what is the frequency of q (or a or A2)? - 0.5 - 0.8 - 0.4 - 0.7
0.7
Which trees are equivalent? - 1&3 - 2&4 - 3&4 - 1&2 - 2&3
1&2
Which trees are equivalent? - 1&2, 3&4 - 1&3, 2&4 - 1&3 only - 1,2 & 4
1&3, 2&4
In lava fields, which allele do you hypothesize will lead to higher viability: A or a? - A - a
A
Cospeciation due to an arms race occurs because - speciation is more likely in allopatry - arms races speed up the accumulation of differences among populations - speciating is a good way to escape parasite pressure - A and B
A and B
Studies of punctuated equilibrium suggest that: - rates of speciation vary widely through time - rates of speciation may not vary that much through time, but our ability to detect speciation events is biased to make it look like rates... - there is not enough information to determine how speciation rates vary over time - A and B
A and B
The concept of heterochrony allows us to: - think about development with an evolutionary framework - compare the time at which traits appear during development in ancestors and descendants - construct a phylogeny based on when traits appear during development - A and B
A and B
Which is an example of adaptive introgression? - There is strong selection against interbreeding - A few beneficial loci move across a hybrid zone - Traits involved in species recognition become more divergent in sympatry - Two differentiated populations collapse due to extensive hybridization
A few beneficial loci move across a hybrid zone
The interaction between bacteria and mold in leafcutter ant nests is best described as a: - A competitive relationship - A mutualistic relationship - A predator-prey relationship - A host-parasite relationship
A host-parasite relationship
A locus is: - A location on the genome - A particular genotype - different genetic variables - a particular phenotype
A location on the genome
The incorporation of phospholipids into simple lipid membranes provides evidence for: - Waste transport across membranes - A mechanism of cell division - A lipid bilayer surrounding all cells - A mechanism of selection on cell size
A mechanism of selection on cell size
The cinereous mourner mimicking a caterpillar is an example of: - A non-poisonous species mimicking a poisonous species - A poisonous species mimicking a non-poisonous species - A poisonous species mimicking a poisonous species - A non-poisonous species mimicking a non-poisonous species
A non-poisonous species mimicking a poisonous species
What is an adaptation? - Traits that are acquired during an organisms lifetime - Major modifications to the population average of a trait - Traits that always increase fitness in all populations - A trait associated with the highest relative fitness in a given environment
A trait associated with the highest relative fitness in a given environment
Is the A1 allele favored over the A2 allele in this environment? -no -yes -A1 and A2 have the same fitness
A1 and A2 have the same fitness
Based on the phenotypes you observe below, which genotype will have the highest viability in lava fields? - AA - Aa -aa - AA and Aa will have the same fitness, higher than aa
AA and Aa will have the same fitness, higher than aa
Which of these mutations in the third codon position results in a non-synonymous change? - AAU>AAG - GCA>GCC - UCU>UCA - CCU>CCC
AAU>AAG
When you knock out the Abd-A gene, your organism develops walking legs where it normally develops backwards walking legs, and anchoring legs where it should develop swimming legs. - Abd-A is needed to develop backwards walking legs and swimming legs - Abd-A is needed to develop walking legs and anchoring legs - Abd-A turns on a different part of the body unrealted to legs - Abd-A is needed to develop walking legs only
Abd-A is needed to develop backwards walking legs and swimming legs
When should females mate multiply? - To replenish sperm stores - All are correct - To avoid harassment by males - To gain indirect genetic benefits
All are correct
Why might traits that act as proxies for direct benefits evolve? - So females can efficiently evaluate the benefits provided by that male - All are correct - So males can avoid costly fights they might lose - So males can quickly assess the competitive ability of their rivals
All are correct
Which of these are central components of evolutionary theory? - Species change over time - Species are well-suited to their environments - Species share common ancestors - All of the above
All of the above
Heterochrony describes: - Differences in developmental timing between ancestors and descendent species - All of these - Changes that affect the timing of onset of somatic traits - Changes that affect the time of onset of reproductive traits
All of these
Which of these was a challenge for Darwin to explain under his theory of evolution? - Structures of seemingly no importance - Complex structures such as eyes - Elaborate traits with no fitness advantage - All of these were challenges for Darwin to explain
All of these were challenges for Darwin to explain
You notice that your dog wags his tail constantly, but you can't imagine what the fitness benefit of this behavior might be. What is an alternative explanation for the high frequency of tail wagging in dogs? - Alleles associated with wagging behavior are in linkage disequilibrium with a locus under selection - Alleles associated with wagging behavior are in linkage equilibrium with loci under selection - Alleles associated with wagging behavior are in regions of high recombination - Alleles associated with tail wagging behavior are subject to background selection
Alleles associated with wagging behavior are in linkage disequilibrium with a locus under selection
What two factors can most rapidly facilitate cospeciation? - Coevolutionary arms races and asexual reproduction - Allopatry and long generation times - Sympatry and coevolutionary arms races - Allopatry and coevolutionary arms races
Allopatry and coevolutionary arms races
Why does conflict occur among parents and offspring? - Parents want to invest more resources into their own fitness than their offspring's fitness - Certain offspring are more valuable to parents than others - Offspring want parents to save resources to invest in future broods - An individual offspring wants parents to invest more resources in them than is optimal for parents
An individual offspring wants parents to invest more resources in them than is optimal for parents
An allele is: - Any part of the DNA sequence that varies between individuals - a gene - a particular phenotype - a particular genotype
Any part of the DNA sequence that varies between individuals
Why would molecular mutualisms be favored in a closed system? - Molecular mutualisms should not be favored in a closed system - A closed system results in natural selection for self-sacrifice and loss of individuality - Any sacrifices a molecule makes to its own replication to benefit replication of another molecule are regained through the closed system - A closed system means products of replicators diffuse away
Any sacrifices a molecule makes to its own replication to benefit replication of another molecule are regained through the closed system
Can evolution produce any phenotype? - yes, given enough time, any phenotype is possible - no, adaption is constrained by physical laws - no, adaptation is constrained by available genetic variation - B & C
B&C
What is an expected outcome of negative frequency dependent selection? - Fixation of the more common allele in the population - Both alleles maintained in the population, with fluctuating frequencies - Both alleles are maintained in the population at constant frequencies - The dominant allele maintained in the population
Both alleles maintained in the population, with fluctuating frequencies
How do we know that the first ancestral cells to use DNA for storage gave rise to all other living things? - Because all examples of cells that use a different storage system are extinct - Because we can use phylogenetics to reconstruct the evolution of DNA - Because all living things use DNA for information storage - Because DNA is a more stable molecule than RNA
Because all living things use DNA for information storage
Why do we focus on averages across many individuals when we quantify viability selection at a particular locus? - Because many loci can affect fitness, and we need to average across many individuals to detect the impact of one particular locus - Because all loci affect fitness equally - Because selection acts directly on the genotype, not the phenotype - Because only one locus typically affects fitness, and we average across many individuals to detect its effect
Because many loci can affect fitness, and we need to average across many individuals to detect the impact of one particular locus
Why might horizontal gene transfer have been important to the evolution of early life? - It involves specialized and efficient organelles - Before the evolution of modularity, this was the primary way to exchange genetic information and organelles - Transduction can occur with only simple cells - It is a more efficient way to transmit genetic information than vertical transmission
Before the evolution of modularity, this was the primary way to exchange genetic information and organelles
Cooperation refers to a behavior that is: - Detrimental to both the actor and recipient - Beneficial for the actor but detrimental to the recipient - Beneficial for the recipient but detrimental to the actor - Beneficial for the actor and the recipient
Beneficial for the actor and the recipient
What are indirect benefits? - Benefits that increase a female's fitness - Benefits that increase the fitness of a female's offspring - Benefits that increase the fitness of a male - Benefits that increase the fitness of a female's daughters
Benefits that increase the fitness of a female's offspring
When we use parsimony to buid a tree based on molecular data rather than character data, we: - Can use the exact same approach, in which we treat nucleotide mutations across different sites as changes in the same character - Need to use a different approach, because DNA mutates and characters do not change - Need to use a different approach, since DNA and character data are fundamentally different - Can use the exact same approach, in which we treat nucelotide mutations at a particular site as changes in character state
Can use the exact same approach, in which we treat nucelotide mutations at a particular site as changes in character state
Extinction debt occurs because: - Clades that survive mass extinctions are able to speciate into open ecological niches - Mass extinctions are only responsible for 4% of all extinctions - Mass extinctions wipe out >75% of species - Clades that survive a mass extinction are unable to adapt to new ecological conditions and go extinct
Clades that survive a mass extinction are unable to adapt to new ecological conditions and go extinct
Based on the video about Australian fairy-wrens and bronze cuckoos, what would you hypothesize is the next step in this particular arms race? - Cuckoos match their eggs to those of the fairy wren host so they are less likely to be ejected - Cuckoos begin laying their eggs in fairy wren nests earlier so that their chicks learn fairy wren calls - Cuckoo chick begging calls evolve to mimic an entire fairy wren brood - Cuckoos evolve chick mimicry to look like fairy wren chicks
Cuckoos begin laying their eggs in fairy wren nests earlier so that their chicks learn fairy wren calls
What effect does inbreeding have on genotype frequencies? - Decrease heterozygosity only at loci involved in assortative mating - Increase heterozygosity at loci involved in assortative mating - Increase heterozygosity at all loci across the genome - Decrease heterozygosity at all loci across the genome
Decrease heterozygosity at all loci across the genome
Which is not a hypothesis for the retention of duplicate genes? - Duplicates may influence expression by increasing production of histones or rRNA - Paralogs may diverge because they divide the work of the previous gene - Duplicated genes produced twice as much gene product, which is beneficial - Duplicated genes may diverge and take on a new, related function
Duplicated genes produced twice as much gene product, which is beneficial
This figure shows reaction norms for the number of leaves on plants grown at different light intensities. What is the correct interpretation of this figure? - Each line is a genotype. The same genotype can produce different numbers of leaves in different light intensities. - Each line is a different light intensity. The number of leaves a plant produces in unpredictable based on light intensity - Each line is a genotype. The same genotype always produces the same number leaves, regardless of light intensity - Each line is a different light intensity. The same light intensity always causes plants to grow the same number of leaves.
Each line is a genotype. The same genotype can produce different numbers of leaves in different light intensities.
When do characteristics that unite species occur during development? - Middles of development - Early in development - It varies by species - Late in development
Early in development
Superhero movies like the X-Men series often refer to the next "step" or "stage" of human evolution. Why is this type of thinking incorrect? - Evolutionary steps are unconstrained by physical laws, and therefore unpredictable - Evolution is a completely random process, and it is therefore impossible to predict the next evolutionary step of human evolution - Evolution is not a directed process, and there are therefore no planned evolutionary "steps" - Evolutionary steps can only happen via mutations of large effect, which are comparatively rare
Evolution is not a directed process, and there are therefore no planned evolutionary "steps"
Why are males typically the more ornamented sex? - Male gametes are limited, so males must advertise their quality to choosy females - Males are always in higher condition than females - Males do not provide paternal care, so they have extra energy to allocate to becoming ornamented - Female gametes are limited, so males must compete to attract females or access females
Female gametes are limited, so males must compete to attract females or access females
How does anisogamy result in a skewed operational sex ratio? - Females invest more resources in reproduction and so are always ready to mate with the highest quality males - Males invest more time and resources in reproduction, so at any particular time point there are more females available to mate - Females invest more time and resources in reproduction, so at any particular time point there are more males available to mate - Males and females invest equally in reproduction, and so there are the same number of males and females typically available to mate
Females invest more time and resources in reproduction, so at any particular time point there are more males available to mate
Which is not a premating reproductive barrier? - Behavioral isolation - Temporal isolation - Gametic isolation - Habitat isolation
Gametic isolation
Which is correct about Darwin's views on natural and artificial selection? - He viewed them as essentially the same process, with only the selective agent differing - He viewed them as fundamentally different processes - He thought natural and artificial selection could produce new varieties, but not new species - He believed only artificial selection could produce new species
He viewed them as essentially the same process, with only the selective agent differing
Under Darwin's hypothesis of common ancestry of all living things, we would expect to observe: - Random and unpredictable relationships among species - Hierarchical clustering and a branching tree of life among all living things, wherein species that appear to be more similar are more likely to be closely related - Species independently progressing from simple to more complex over time - Hierarchical clustering among varieties, but no predictable clustering among species
Hierarchical clustering and a branching tree of life among all living things, wherein species that appear to be more similar are more likely to be closely related
Honeyguides and honeyhunters are an example of: - Honest signaling via mutual benefits - Honest signaling via handicaps - Enforcement of signal honesty - Parent-offspring conflict
Honest signaling via mutual benefits
Why are brood parasites an example of an evolutionary arms race? - The parasites benefit from the host, but the host is unaffected by the parasites - The parasites are driving their hosts to extinction - Hosts and parasites must constantly evolve in response to each other - The host and parasite both benefit from their interaction
Hosts and parasites must constantly evolve in response to each other
Reinforcement occurs when: - Hybrids are unfit, so there is selection for two divergent populations to interbreed and share adaptive loci - There is unrestricted gene flow between differentiated populations - Hybrids are unfit, so there is selection for two divergent populations to not interbreed with each other - Hybrids have high fitness, so there is selection for interbreeding on secondary contact
Hybrids are unfit, so there is selection for two divergent populations to not interbreed with each other
You are studying two species of snakes, and notice that the non-venomous species looks very similar to the venomous species, even though they are very distantly related. Why might this similarity be detrimental to the venomous species? - They have to compete for food with the non-venomous species - The non-venomous snakes are unlikely to cooperate to find food - They might accidentally mate with the wrong species - If predators learn that the non-venomous species is tasty, they are more likely to also try to eat the venomous species
If predators learn that the non-venomous species is tasty, they are more likely to also try to eat the venomous species
What is the difference between Fisherian runaway and good genes/handicap models of female choice? - In the runaway model the preferred trait is the only target of the preference, whereas in the handicap model, the preferred trait indicates some other preferred aspect of quality - In the runaway model traits are condition-dependent, but they do not need to be condition-dependent in the handicap model - In the handicap model traits confer a survival advantage, but not in the runaway model - In the runaway model the preferred trait advertises some aspect of male quality, whereas in the handicap model, the preferred trait only indicates attractiveness
In the runaway model the preferred trait is the only target of the preference, whereas in the handicap model, the preferred trait indicates some other preferred aspect of quality
This figure shows changes in heterozygosity and survivorship in Florida panther populations after the introduction of individuals from Texas. What pattern was observed? - Decrease in heterozygosity and increase in survivorship after introduction of Texas panthers - Decrease in heterozygosity and survivorship after introduction of Texas panthers - Increase in heterozygosity and survivorship after introduction of Texas panthers - Increase in heterozygosity and decrease in survivorship after introduction of Texas panthers
Increase in heterozygosity and survivorship after introduction of Texas panthers
What effect does migration have on genetic variation? - Decrease variation within populations, increase variation between populations - Increase variation within populations, decrease variation between populations - Increase variation within and between populations - Decrease variation within and between populations
Increase variation within populations, decrease variation between populations
This figure shows a regression of mean body mass between parents and offspring. What might you hypothesize about body mass based on this figure? - It has a high heritability and is weakly environmentally determined - It will likely exhibit a strong response to selection - It varies little between parents and offspring - It has a low heritability and is strongly environmentally determined
It has a low heritability and is strongly environmentally determined
Why does the evolution of multicellular individuals present a challenge for natural selection? - Multicellularity selects against storage of large amounts of information - Economies of scale do not favor the specialization required for the formation of individuals - It is challenging to evolve mechanisms for individual cells to stay together after mitosis - Individual cells must give up their own reproduction to help the reproduction of other cells, which should be selected against
Individual cells must give up their own reproduction to help the reproduction of other cells, which should be selected against
Which one of these assertions is Darwinian and not Lamarckian? - Individuals better suited ti their environment reproduce more than others and pass beneficial characteristics to the offspring. - Individual organisms evolve because they need to survive or use new resources - an individual that acquired new characteristics in its lifetime is able to transmit them to its offspring - there is no extinction
Individuals better suited ti their environment reproduce more than others and pass beneficial characteristics to the offspring
Which of these assertions is Darwinian and not Lamarckian? - Individual organisms evolve because they need to survive or use new resources - Individuals better suited to their environment reproduce more than others and pass beneficial characteristics to their offspring - There is no extinction - An individual that acquired new characteristics in its lifetime is able to transmit them to its offspring
Individuals better suited to their environment reproduce more than others and pass beneficial characteristics to their offspring
Which is true about natural selection? - It acts on populations, leading them to evolve over time - It acts on individuals, leading populations to evolve over time - It causes individuals to evolve over time - It causes species to become more complex and sophisticated over time
It acts on individuals, leading populations to evolve over time
Why is language not heritable? - It has no genetic basis, and therefore cannot be passed from parents to offspring - It does not vary enough among individuals - It is not affected by the environment - Offspring do not resemble their parents
It has no genetic basis, and therefore cannot be passed from parents to offspring
Which is not true about the importance of heterochrony to our understanding of evolutionary development? - It incorporated evolutionary history by explicitly comparing ancestral and descendent species - It identified the key genes associated with the development of body plans - It focused on genetic changes - It recognized that traits associated with reproductive vs. somatic processes are fundamentally different
It identified the key genes associated with the development of body plans
Which is not true about horizontal gene transfer? - It is the transmission of genetic information directly between cells - It can occur when cells take up free-floating nucleic acids from the environment - "It explains why the universal common ""ancestor"" of all living things may have been a community of cells" - It is the mechanism by which offspring resemble their parents
It is the mechanism by which offspring resemble their parents
You hypothesize that female sticklebacks prefer males with red throats because red throats indicate a male's health. What observation would support your hypothesis? - Males lose their red throats after being infected with parasites, and females stop preferring those males - The sons of males with red throats also have red throats - Males lose their red throats after being infected with parasites, but females still prefer those males - Males do not lose their red throats after being infected with parasites because they are in high condition
Males lose their red throats after being infected with parasites, and females stop preferring those males
Which group on this tree is paraphyletic? - elephants and manatees - manatees, tapirs, and rhinos - tapirs, rhinos, horses - cetaceans, hippos, ruminants
Manatees, tapirs, and rhinos
Which process does not increase the likelihood of allopatric speciation: - Migration - Drift - Mutation - Selection
Migration
Which is not evidence that mitochondria and chloroplasts evolved via endosymbiosis? - Mitochondrial and chloroplasts can survive and reproduce outside of eukaryotic cells - Mitochondria and chloroplasts have their own DNA that is more similar to proteobacteria and cyanobacteria, respectively, than to eukaryotic DNA - Mitochondria and chloroplasts have their own ribosomes that are different from nuclear ribosomes - Mitochondria and chloroplasts are encolosed by two membranes
Mitochondrial and chloroplasts can survive and reproduce outside of eukaryotic cells
Homeotic genes are broadly conserved across animals because: - Different animal body plans develop in fundamentally different ways - There is extensive variation in animal body plans - Mutations in these genes have small phenotypic effects - Mutations in these genes often have large or lethal phenotypic effects
Mutations in these genes often have large or lethal phenotypic effects
One hypothesis for why postzygotic barriers occur is: - Individuals that breed at different times are unable to mate with each other - Genetic drift causes allele frequencies to differ between populations - Negative epistatic interactions occur between alleles that evolved on different genetic backgrounds - Beneficial alleles move between different genetic backgrounds
Negative epistatic interactions occur between alleles that evolved on different genetic backgrounds
Can evolution produce any phenotype? - No, adaptation is constrained by available genetic variation - No, natural selection is only effective in certain environments - Yes, any physical constraint can be overcome by mutations - Yes, given enough time, any phenotype is possible
No, adaptation is constrained by available genetic variation
Is mutation a strong force of allele frequency change over time? Why? - No, mutations do not change allele frequencies - No, it takes a very long time for mutation to lead to allele frequency change in the absence of selection - Yes, mutations cause rapid changes in allele frequencies in the absence of selection - Yes, mutations are the major driver of allele frequency change over time
No, it takes a very long time for mutation to lead to allele frequency change in the absence of selection
Does selection act to generate new species? - No, selection facilitates hybridization - Yes, selection prevents hybridization - No, species are typically by-products of evolutionary processes operating in isolation - Yes, biodiversity is beneficial so selection acts to generate new species
No, species are typically by-products of evolutionary processes operating in isolation
While walking outside, you notice a large, multi-species group of birds calling loudly and chasing a hawk. Are they behaving altruistically to help other birds in the area avoid predation? - Yes, natural selection has favored individuals that act for the benefit of the group in this example - Yes, they are helping other species of birds and therefore behaving altruistically - No, they are likely chasing the hawk away in their own self-interest, but other birds in the area happen to benefit from this behavior - No, they are likely related to most of the other birds and are gaining indirect genetic benefits
No, they are likely chasing the hawk away in their own self-interest, but other birds in the area happen to benefit from this behavior
You notice that in a forest there are green beetles and brown beetles. The green beetles are harder to see on leaves, and you hypothesize that they have evolved to be better adapted to their environment than brown beetles by natural selection. What is one piece of evidence that would support this hypothesis? - Brown beetles produce more offspring than green beetles - Offspring strongly resemble their parents (green beetles have green babies and brown beetles have brown babies) - Survival of green and brown beetles appears to be equal - Color is environmentally determined by diet, and changes over a beetles lifetime
Offspring strongly resemble their parents (green beetles have green babies and brown beetles have brown babies)
What does it mean for a trait to be condition dependent? - All males are able to express an elaborate trait - The trait only advertises male attractiveness - The trait evolves due to an arbitrary female preference - Only the highest-quality males have the resources to produce the most exaggerated versions of the trait
Only the highest-quality males have the resources to produce the most exaggerated versions of the trait
Which of these is NOT a component of natural selection as described by Darwin? - Individuals pass their variants on to their offspring - Survival and reproduction are non random: individuals carrying specific variations survive and reproduce the most - Individuals within species are variable - Organisms reproduce via sexual reproduction
Organisms reproduce via sexual reproduction
Who has higher relative fitness within its population, the brown mouse in population 1 or population 2? - Same fitness - Population 2 - No fitness - Population 1
Population 2
This figure shows: - Negative frequency dependent selection: fitness of P1 increases as it becomes more common - Negative frequency dependent selection: fitness of P1 decreases as it becomes more common - Positive frequency dependent selection: fitness of P1 increases as it becomes more common - Positive frequency dependent selection: fitness of P1 decreases as it becomes more common
Positive frequency dependent selection: fitness of P1 increases as it becomes more common
In which system would you hypothesize that reciprocity is most likely to evolve? - Moose, which are primarily solitary and rarely encounter other individuals - Primates that live for many years in complex social groups comprised of the same individuals - Locusts, which occur in large groups and live for a very short amount of time - Minnows, which live in large groups but seem to lack individual recognition capabilities
Primates that live for many years in complex social groups comprised of the same individuals
Which is not a feature of eusociality? - Cooperative rearing of young - Prioritizing direct over indirect fitness - Division of reproductive labor - Overlapping generations
Prioritizing direct over indirect fitness
You are studying a group of poison frogs, and realize that two individuals with almost identical bright coloration are actually two very different species. What the most plausible hypothesis for why these two poisonous species have evolved to look like each other? - Both species have convergently evolved to blend in with their surroundings - Genetic drift has led to convergence in color patterns in isolation - Producing similar warning coloration makes it easier for predators to remember to avoid them - Adaptive introgression has led to color pattern alleles being shared between species
Producing similar warning coloration makes it easier for predators to remember to avoid them
Which experimental result is evidence that natural selection can act on RNA? - An RNA fragment, when mixed with replicase enzyme and nucleotides, can create more copies of itself - The RNA molecule is less stable than DNA, leading to increased error rates - A 4000-base pair RNA fragment does not change in length over time - RNA fragments of intermediate length replicate most quickly and with the fewest errors, leading to increased frequency of intermediate-length fragments in experimental vials over time
RNA fragments of intermediate length replicate most quickly and with the fewest errors, leading to increased frequency of intermediate-length fragments in experimental vials over time
What effect does directional selection have on genetic variation within and between populations in different environments? - Reduces variation within populations, increases variation between populations - Increases variation within populations, decreases variation between populations - Reduces variation within and between populations - Increases variation within and between populations
Reduces variation within populations, increases variation between populations
Which is not evidence for the RNA world hypothesis? - All essential components of RNA were present on early earth - Ribonucleotides in RNA are derived from the deoxyribonucleotides of DNA - Ribozymes can catalyze reactions - RNA molecules catalyze reactions essential to all forms of life
Ribonucleotides in RNA are derived from the deoxyribonucleotides of DNA
You are curious about whether the number of leaves a plant produces is heritable. You have a population of plants with an average of 4 leaves per plant. You do an experiment where... - S = 5, r = 5, h2 =1/5, 20% of the variation in leaf number is due to genes - S = 5, r = 1, h2 =1/5, 20% of the variation in leaf number is due to genes - S = 4, r = 1, h2 =1/4, 25% of the variation in leaf number is due to genes - S = 5, r = 4, h2 =4/5, 80% of the variation in leaf number is due to genes
S = 5, r = 1, h2 =1/5, 20% of the variation in leaf number is due to genes
Which process cannot generate linkage disequilibrium? - Mutation - Drift - Migration - Sexual reproduction
Sexual reproduction
Transitional forms are: - Species exceptionaly adapted to their environments - Ecological analogues to other species - Groups that radiated on islands - Species with intermediate characteristics between major groups
Species with intermediate characteristics between major groups
Above is a phylogeny of several flowers in the genus Phlox. When you find all these flowers outside, you assume that red P. drummondii are more distantly related to the other species, because they are red but all other species are purple. However, when you build a phylogeny based on DNA sequence data, you find the above tree. Red color is therefore most likely to be a: - Analogy - Symplesiomorphy - Synapomorphy - Homoplasy
Symplesiomorphy
Late-phase expression of the Hox gene cluster d8-11 is is involved in the development of: - Drosophila antennae - Upper limb bones of tetrapods and fish fins - Tetrapod digits and distal fish fins - Mouse eyes
Tetrapod digits and distal fish fins
Which of these is not a testable, falsifiable hypothesis? - The COVID-19 pandemic is punishment for human destruction of the environment. - The diseas COVID-19 is caused by the coronavirus SARS-coV-2. - Transmission of the SARS-coV-2 virus occurs primarily through respiratory droplets. - The SRAS-coV-2 virus emerged from a single transmission from animals to humans, rather than many transmission events.
The COVID-19 pandemic is punishment for human destruction of the environment.
What is relative fitness? - The acquistion of beneficial characteristics that improve survival - The absolute number of offspring an individual produces - The ability of an individual to survive and reproduce in its environment - Only the strong survive
The ability of an individual to survive and reproduce in its environment
Which of these statements is NOT a conclusion of the Hardy-Weinberg model? - The allele frequencies in a population will not change only if the original allele frequencies are 60% and 40% - the allele frequencies in a population will not change only if the original allele frequencies are 60% and 40% - if the frequencies of alleles in a population are p and q and the q genotype frequencies are p2, 2pq, and q2 - the allele frequencies in a population will not change over time
The allele frequencies in a population will not change only if the original allele frequencies are 60% and 40%
For cooperation to evolve, you need: - The benefits of cheating and cooperating to be equal - The benefits of cooperation to be greater than the benefits of cheating - The costs of cooperation to be greater than the costs of cheating - The benefits of cooperation to be less than the benefits of cheating
The benefits of cooperation to be greater than the benefits of cheating
You notice that several closely related species of flowers all seem to be growing in the same area and producing flowers and pollen at the same time, but there does not seem to be any hybridization. Which is the most likely hypothesis for why this might be? - There is habitat isolation between the different floweres - The different flowers have different pollinators - There is temporal isolation between the different flowers - There is behavioral isolation between the flowers
The different flowers have different pollinators
If you remove the eyeless gene from a fly and instead insert a gene that causes eyes to develop in mice, what happens? - The flies develop normal fly eyes - The flies develop mouse eyes - The flies do not develop eyes - The flies develop legs instead of eyes
The flies develop normal fly eyes
A beneficial mutation arises on a chromosome in a population of individuals with no recombination.What will happen to the frequency of this haplotype over time? - There will be an increase in heterozygosity in the population - The haplotype of the entire chromosome will rise to fixation - The frequency of the haplotype will decrease over time - Alleles around the selected locus will rise to fixation
The haplotype of the entire chromosome will rise to fixation
What does a phylogeny illustrate? - The progression from more simple to more complex organisms - The end goal of natural selection - The hypothesized evolutionary relationships among groups of organisms - The confirmed evolutionary relationships among organisms
The hypothesized evolutionary relationships among groups of organisms
You are measuring tail length in a population of fish, and find that the population ranges in tail length from 2cm to 10cm. Individuals with long tails seem to have higher fitness. After observing the population for a few generation, you suddenly notice several individuals with 14cm tails. What is the most likely explanation for this observation? - Long tails are highly environmentally determined - An allele in linkage disequilbrium with a selected trait has caused long tails to increase in frequency - A beneficial mutation of large effect has led to long tails increasing in frequency - The long tails are due to latent variation that has been expressed in a novel haplotype you hadn't previously found
The long tails are due to latent variation that has been expressed in a novel haplotype you hadn't previously found
Why have mimics ""won"" the arms race in Batesian mimicry systems? - Mimics have the highest fitness when they are at high abundances in the population - Models eventually go extinct while mimics survive - The models may suffer increased predation if they exhibit a novel phenotype - Models evolve new phenotypes because the mimics are successful at copying them
The models may suffer increased predation if they exhibit a novel phenotype
What are the two variables that contribute to skew in the operational sex ratio? - The number of males vs. females available to mate and the quality of a male's territory - The number of males vs. females available to mate and the ability of males to monopolize access to females - The number of males vs. females available to mate and the strength of sexual conflict - The number of males vs. females available to mate and female choice for direct vs. indirect benefits
The number of males vs. females available to mate and the ability of males to monopolize access to females
What is heritability? - The total phenotypic variance - The sum of the variance due to genes and the variance due to the environment - The proportion of the total variance in a trait that is due to genes - The proportion of the total variance in a trait that is due to environment
The proportion of the total variance in a trait that is due to genes
Inclusive fitness refers to: - Kin selection - Direct fitness - Indirect fitness - The sum of direct and indirect fitness
The sum of direct and indirect fitness
If you find that the coefficient of linkage disequilibrium in your population is a large positive number, what might that mean? - There frequency of a particular haplotype is less common than expected under independent assortment - The frequency of a particular haplotype meets the expectations of independent assortment - There frequency of a particular haplotype is more common than expected under independent assortment - There is no linkage disequilibrium
There frequency of a particular haplotype is more common than expected under independent assortment
The figure above shows a phylogeny of the SARS-CoV-2 virus on the left, and the biogeography of transmission in early February on the right. Based on this figure, which is true about the status of the outbreak in North America in February? - There were two recognizable clades of the virus, and transmissions were coming in to North America from Europe and Asia - There were three recognizable clades of the virus, and transmissions were coming in to North America from Europe and Asia - There were three recognizable clades of the virus, and transmissions were coming in to North America only from Asia - There were three recognizable clades of the virus, and transmissions were coming in to North America only from Europe
There were three recognizable clades of the virus, and transmissions were coming in to North America from Europe and Asia
Which of these is a conclusion of the Hardy-Weinberg model? - If the allele frequencies in a population are given by A1 and A2, the genotype frequencies will be given by A12, 2A1A2, and A22 - These are all conclusions of the Hardy-Weinberg model - Allele frequencies in a population will not change over time if the assumption of random mating is met - If no other processes are operating, populations will reach Hardy-Weinberg Equilibrium in one generation
These are all conclusions of the Hardy-Weinberg model
Which is not a property of life? - Response to environmental stimuli - Maintenance of homeostasis - These are all properties of life - Growth and reproduction
These are all properties of life
Why is it best to build trees based on synapomorphies (shared, derived traits) if possible? - These traits are present in all descendants of a common ancestor and are absent in all non-descendant groups - These traits are present in all descendants and all ancestors of a group - These traits are absent in all descendants of a common ancestor and are present in all non-descendant groups - These traits are present in some, but not all, descendants of a common ancestor
These traits are present in all descendants of a common ancestor and are absent in all non-descendant groups
Why are traits that are only present in one species not useful for resolving trees under parsimony? - These traits require only one evolutionary step, and could therefore be produced by an evolutionary history - These traits require many evolutionary steps, and resolving the correct evolutionary history is too complex - These traits are not variable enough to accurately resolve evolutionary history - These traits are too variable to accurately resolve evolutionary history
These traits require only one evolutionary step, and could therefore be produced by an evolutionary history
What is a challenge for the evolution of mutualisms? - They are susceptible to cheaters - There are tradeoffs between direct vs. indirect fitness - Parents are more related to their siblings than to their offspring - Cooperation cannot evolve between different species
They are susceptible to cheaters
Which is not a function of homeotic genes? - They direct spatial development in plants - They are involved in proper ordering of the body plan - They code for fine-scale differences between closely related species - They encode transcription factors that bind to regulatory enhancers and guide development
They code for fine-scale differences between closely related species
In the phylogram above, what is true about strains with comparatively longer branch lengths? - They have slower rates of evolution, potentially due to longer generation times or weak selection - They have faster rates of evolution, potentially due to short generation times or strong selection - They have slower rates of evolution, potentially due to short generation times or strong selection - They have faster rates of evolution, potentially due to longer generation times or weak selection
They have faster rates of evolution, potentially due to short generation times or strong selection
Why are gar fish a useful study system for understanding the development of tetrapod limbs? - They are basal in the fish lineage - They exhibit early-phase expression of the Hox cluster associated with digit development - They have an extra whole genome duplication that has produced paralogs associated with limb development - They lack an extra whole genome duplications that is present in other Teleost fish
They lack an extra whole genome duplications that is present in other Teleost fish
You notice that a group of sparrows seems to use the size of dark black patches on their chests to signal dominance. This is confusing to you, because it doesn't seem costly to produce these signals. Why don't low-quality males just cheat and produce a larger signal? - They aren't in good enough condition to produce the black patch - They use a different signal to indicate dominance - They will get beat up if they advertise above their status - Females don't like males with large black patches
They will get beat up if they advertise above their status
In scanning along a chromosome, you notice a region of very low heterozygosity in your study population. Why might this be? - This region has a high mutation rate - This region has a high recombination rate - This region is under selection - This region is highly differentiated between two populations
This region is under selection
Which is not evidence that toxins and toxin resistance are co-evolving in newts and gartner snakes? - Toxin production and resistance are not costly - The level of resistance in a population of snakes matches the level of toxicity in the newts - Toxin production and resistance are heritable - Toxin resistance has evolved multiple times independently
Toxin production and resistance are not costly
What are ring species? - Two reproductively isolated taxa coexisting in the same location - Two reproductively isolated taxa connected by a chain of intergrading populations around a geographic barrier - Two reproductively isolated taxa inhabiting different islands - Two reproductively isolated taxa distributed linearly across an ecological gradient
Two reproductively isolated taxa connected by a chain of intergrading populations around a geographic barrier
Why is sympatric speciation unlikely? - Very strong disruptive selection and complete cessation of migration is necessary among individuals living in the same location, which is unlikely - Directional selection is much more common than disruptive selection, and disruptive selection is therefore unlikely - Resource competition is required for the model but is rare in nature - It's unlikely that a situation with no geographic barriers will occur in nature
Very strong disruptive selection and complete cessation of migration is necessary among individuals living in the same location, which is unlikely
When do we expect the most rapid increase in the frequency of the dominant A allele? - When Aa and aa have lower fitness than AA - When Aa has the highest fitness - When Aa and AA have the same fitness, and aa has the lowest fitness - When aa and AA have the same fitness, and Aa has the lowest fitness
When Aa and aa have lower fitness than AA
When is it hard to evolve cooperation in the prisoner's dilemma? - When it benefits player 1 to cooperate and player 2 to defect - When cooperating has higher fitness than defecting - When it benefits player 2 to cooperate and player 1 to defect - When defecting always has a higher fitness than cooperating
When defecting always has a higher fitness than cooperating
When does Fisherian Runaway stop? - When the cost of the trait to survival is less than the benefit from mate choice - When the cost of the trait to survival is greater than the benefit from mate choice - When the cost of the trait to mate choice is less than the benefit from mate choice - When the cost of the trait to mate choice is greater than the benefit from survival
When the cost of the trait to survival is greater than the benefit from mate choice
Do fish have wrists? - Yes- whole gneome duplications have generated paralogs that express in the distal surface of the fish fin - No- development of fish fins and tetrapod limbs are regulated by different sets of enhancers and different Hox genes - Yes- homologous enhancers are involved in gene expression in tetrapod wrists and the distal surface of fish fins - No- non-homologous enhancers are involved in gene expression in tetrapod wrists and the distal surface of fish fins
Yes- homologous enhancers are involved in gene expression in tetrapod wrists and the distal surface of fish fins
The presence of the Denisovan EPAS1 gene in modern Tibetans is an example of - sympatric speciation - adaptive introgression - hybrid inviability - genetic swamping
adaptive introgression
All species concepts have flaws. When are most species concepts like to agree (delineate the same species boundaries), and when are they more likely to disagree? - agree between deeply diverged groups. disagree between recently diverged groups - agree between recently diverged groups, disagree between deeply diverged groups - agree between paraphyletic groups, disagree between monophyletic groups - agree between homoplasies, disagree between synapomorphies
agree between deeply diverged groups. disagree between recently diverged groups
The evolution of individuality likely required: - all of the above - cooperation among related cells - enforcement mechanisms to prevent cheating - differentiation of somatic and reproductive cells
all of the above
What should hosts do once cuckoos mimics their eggs? - develop vocal passwords that their chicks can learn while still in the egg - evolve individual-specific egg signatures - evolve chick recognition - all of the above
all of the above
Which statements about hybridization are true? - it is a form of migration that introduces new alleles and genetic variation into populations - it can lower the genetic fitness of parents if hybrid offspring are unfit - it can break up locally adapted linkage disequilibrium due to recombination - all of the above
all of the above
Why are island and endemic species more likely to go extinct? - population sizes are smaller on average - evolving in small communities means less exposure to predators and pathogens and thus greater susceptibility to perturbations - high levels of specialization may mean higher extinction risk if the environment changes - all of the above
all of the above
Why are there so many neutral variants in the genome? - all of the above - most of the genome is non-coding DNA, so mutations accumulate that dont have fitness consequences - mutations with large phenotypic effects are typically deleterious and are weeded out by natural selection - mutations in coding regions can be synonymous and not have phenotypic effects
all of the above
Why might there be a conflict if interest between parents and offspring? - offspring want parents to invest more resources in them than is optimal for their parents - parents must strategically allocate resources to current vs. future offspring - all offspring are equally valuable to a parent, but each individual offspring values itself more than its parent or siblings - all of the above
all of the above
Why might we see low heterozygosity in a population with millions of individuals? - all of the above - this population was started by a founder event - this population has recovered from a bottleneck
all of the above
Look at the highlighted section of this figure. What happens to variation in allele frequencies across generations? - allele frequency variation remains the same - allele frequency variation increases in magnitude - allele frequency variation decreases in magnitude - allele frequencies stop varying altogether
allele frequency variation increases in magnitude
In which scenario would you expect to find the lowest heterozygosity? - a large continental population - an island population - an insect population - an island population that has recently recovered from intensive hunting
an island population that has recently recovered from intensive hunting
Why would molecular mutualisms be favored in a closed system? - a closed system means products of replicators diffuse away - any initial sacrifice in fitness by replicator A is regained - resources can be transported across membranes -self-sacrifice is always favored by natural selection
any initial sacrifice in fitness by replicator A is regained
What is a locus? - a genotype - any location in the genome - a gene - an allele
any location in the genome
Why are island foxes an example of indirect drivers of extinctions? - because disruption of the ecosystem led to cascading impacts, culminating in near extinction - because endemic species usually have large population sizes and are more likely to decline - because an introduced disease nearly wiped them out - because a massive environmental catastrophe caused their populations to plummet
because disruption of the ecosystem led to cascading impacts, culminating in near extinction
Why might postmating barriers be important to the completion of speciation? - because if premating barriers fail, gene flow can still occur, but postmating barriers can completely stop gene flow - because if postmating barriers fail, gene flow can still occur, but postmating barriers can completely stop gene flow - because they operate before premating barriers - because they evolve before premating barriers
because if premating barriers fail, gene flow can still occur, but postmating barriers can completely stop gene flow
Why don't models outrun mimics? - they need to keep the same phenotype to maintain camouflage and avoid predators - because if they develop a novel phenotype, they are more vulnerable to predators - they are cooperating with the mimics to deter predators - they cannot produce enough toxins to outrun the mimics
because if they develop a novel phenotype, they are more vulnerable to predators
Why would genetic recombination reverse the ratchet? - because it removes chromosomes with deleterious mutations - because it reduces the frequency of mutation - because it generates new haplotypes with fewer deleterious mutations - because it increases the rate at which natural selection can purge deleterious mutations
because it generates new haplotypes with fewer deleterious mutations
Why are most mutations neutral or weakly deleterious? - because they have positive effects on fitness - because they have large effects on phenotypes - because mutations of large phenotypic effect are usually positive and favored by natural selection - because mutations with large phenotypic effects are usually strongly deleterious and are removed by natural selection
because mutations with large phenotypic effects are usually strongly deleterious and are removed by natural selection
Why does random mating not change allele frequencies under Hardy-Weinberg equilibrium? - because our model assumptions are violated - because our model assumes natural selection, which does not cause allele frequencies to change over time - because our model assumes mutations, which do not change allele frequencies over time - because our model assumes no mutation or natural selection, so random mating just reshuffles alleles each generation without increasing or decreasing the frequencies
because our model assumes no mutation or natural selection, so random mating just reshuffles alleles each generation without increasing or decreasing the frequencies
Why would we say that the extinction of the dinosaurs "paved the way" for mammals? - because the earth got colder and mammals are better suited to the cold - because the extinction of the dinosaurs removed competitors in opened up ecological niches, allowing for an adaptive radiation of mammals - because mammals are more fit than dinosaurs - because dinosaurs were big and physically getting in the way of mammals
because the extinction of the dinosaurs removed competitors in opened up ecological niches, allowing for an adaptive radiation of mammals
Why would a female preference for a trait that has no fitness value or benefit lead to that trait increasing in frequency in the population? - because males with that trait provide direct benefits to prospective females - because the trait is in linkage equilibrium with the preference - because the sons of males with the trait are attractive to females and have more reproductive success - because the daughters of males with the trait are attractive and have higher reproductive success
because the sons of males with the trait are attractive to females and have more reproductive success
Why are mutations at degenerate codon positions often considered "silent"? - because they have positive effects on fitness - because they have negative effects on fitness - because they are unlikely to affect the phenotype - because they lead to changes in the amino acid in a protein sequence
because they are unlikely to affect the phenotype
What happens to cell volume and relative fitness over time? - cell volume and relative fitness both increase - cell volume and relative fitness both decrease - cell volume increases but fitness decreases - cell volume decreases but fitness increases.
cell volume and relative fitness both increase
What is the definition of evolution? - change in allele frequences over time - resemblance of offspring and parents - survival of the fittest - acquistion of beneficial characteristics
change in allele frequencies over time
Which is not a key component of early evolutionary thinking? - One species turning into a different species - The progression from simple to more complex and sophisticated forms over time - change in genotypes over time - survival of the fittest
change in genotypes over time
What is evolution? - Changes in genotypes and phenotypes over time - survival of the fittest - the progression from simple to more complex and sophisticated forms over time - one species turning into a different species
changes in genotypes and phenotypes over time
Which taxa are sister on this tree? - arthropods and echinoderms - flatworms and sponges - nematodes and annelids - cnidarians and ctenophorans
cnidarians and ctenophorans
Which is not likely a cause of extinction of Neanderthals? - climate change - inbreeding - competitive exclusion by modern humans - confrontations with modern humans
confrontations with modern humans
What would you expect to happen to the length of RNA strands over the course of the experiment? - converge on a intermediate strand length - get longer with each transfer - get shorter with each transfer - strand length stays at 40000 base pairs across transfers
converge on a intermediate strand length
What effect does heterozygote advantage have an allele frequencies over time? - creates a stable polymorphism that maintains both alleles - causes the dominant allele to go to fixation - causes the recessive allele to go to fixation - randomly causes one allele to go to fixation
creates a stable polymorphism that maintains both alleles
In a scenario with recombination, what effect do selective sweeps have on genetic variation (heterozygosity) around a selected locus? - no effect on genetic variation - increase genetic variation - decrease genetic variation - create new haplotypes
decrease genetic variation
What effect does genetic drift have on heterozygosity (genetic variation) in populations? - increase heterozygosity - decrease heterozygosity - maintain same heterozygosity - impossible to determine
decrease heterozygosity
What effect does assortative mating have on genotype frequencies? - decrease heterozygotes - increase heterozygotes - no change in heterozygotes
decrease heterozygotes
What should you do if you know what your partner will do? - defect no matter what - cooperate if they cooperate, defect if they defect - defect if they cooperate, cooperate if they defect - cooperate no matter what
defect no matter what
Which hominins likely encountered each other? - homo ergaster and homo floresiensis - homo heidelbergensis and homo erectus - denisovans and Neanderthals - homo sapiens and homo ergaster
denisovans and Neanderthals
Chicks benefit more from food- so should they call honestly, or neg even when they're not hungry? - depends on the cost vs. benefits of begging - beg honestly, because if they beg for more than they need they can reduce the fitness of their siblings - beg dishonestly, because they are more related to themselves than their siblings so they should hoard more food
depends on the cost vs. benefits of begging
Why are predator-prey and host-parasite dynamics like the Red Queen scenario? - both species are benefitting from the dynamic, so they evolve to cooperate with each other - each species is evolving in response to each other, so the selective environments are constantly changing - these relationships are evolutionary unstable and therefore susceptible to cheating - interactions drive species to evolve towards more complex and sophisticated forms
each species is evolving in response to each other, so the selective environments are constantly changing
In which group is intrasexual selection stronger? - elephant seals, because only a few males are able to mate so there is intense competition and the evolution of competitive traits - elephant seals, because no paternal care means you need to find the best possible female to mate with to ensure your offspring survival - kittiwakes, because nest sites need to be aggressively defended from intruders - kittiwakes, because lots of energy is expended in raising chicks
elephant seals, because only a few males are able to mate so there is intense competition and the evolution of competitive traits
Which of these is NOT true: - experiments allow us to test hypothesis about evolution - similar phenotypic changes can arise independently in similar environments - evolution can be predictable and repeatable over time - evolution always produce identical results in similar environments
evolution always produce identical results in similar environments
Which is a synapomorphy (shared derived trait) in the Sauria? - extensive changes in skeleton - determinate growth - hole in skull below eye socket - hole in skull in front of eye socket
extensive changes in skeleton
What is the chance that an individual offspring has an A2A2 genotype? - fA2 x fA2 - fA1 x fA2 - fA2 fA1 + fA1fA2 - fA1
fA2 x fA2
What observation might support the hypothesis that neoteny occurs because it's safer to stay in the water? - predation rates are equivalent for salamanders in the water and on land - facultatively neotenous species stay in the water when the water level is stable and there are few predators in the ponds - facultatively neotenous species stay in the water when there are lots of competitors for resources - neoteny has only evolved in the lineage inhabiting the most unpredictable environment
facultatively neotenous species stay in the water when the water level is stable and there are few predators in the ponds
Under negative frequency dependence, a particular phenotype is - favored at high frequencies - favored at low frequencies - under constant directional selection - under heterozygote advantage
favored at low frequencies
What is a consequence of anisogamy? - females are very choosy about their males, and males evolve to be attracted to females - females and males both mate indiscriminately - females and males are both very choosy about who they mate with - males are very choosy about their mate, and females evolve to be attractive to males
females are very choosy about their males, and males evolve to be attracted to females
What is a testable hypothesis for why females produce more clutches and smaller offspring at the downstream site? - females have evolved to produce many small offspring downstream because the risk is too high. Having many offspring increases the likelihood - females upstream do not like to have many offspring, and so they choose to have fewer, larger offspring - females at the downstream site have brighter colors than females upstream because there is more food available
females have evolved to produce many small offspring downstream because the risk is too high. Having many offspring increases the likelihood
Under negative frequency dependence, what happens to the fitness of P1 as it becomes more common in the population? - fitness of P1 decrease - fitness of p1 increases - fitness of p1 stays the same - fitness of p1 is unpredictable
fitness of P1 decrease
Which is not a characteristic of early Homo species? - Bipedalism - tool use - fully developed language - control of fire
fully developed language
What will happen to genetic variation of there is a strong directional selection for a long time? What effect will that have on heritability? - genetic variation increases, heritability declines - genetic variation declines, heritability declines - genetic variation declines, heritability increases - genetic variation increases, heritability increases
genetic variation declines, heritability declines
You are examining genetic variation within a population and discover several regions of a chromosome with very low heterozygosity. What might you hypothesize is the cause? - positive selection led to selective sweeps in these regions - there are increased rates of recombination in these regions - these loci confer advantages in heterozygotes - the population is inbred
positive selection led to selective sweeps in these regions
Why would cells that are clones of each other be more likely to form multicellular clusters? - genetically related individuals cooperate because it can increase the survival of genes - cooperation is always favored by natural selection - multicellularity is beneficial and will be favored by natural selection - a by-product of physical proximity during in complete cell division and separation
genetically related individuals cooperate because it can increase the survival of genes
Why might a neutralist ague that genetic drift is a stronger evolutionary force than selection? - The frequency of non-neutral mutations is much higher than the frequency of neutral mutations - The frequency of netural mutations is much higher than the frequency of non-netural mutations - Neutral mutations are frequently under selection - Selection is ineffective at large population sizes
he frequency of netural mutations is much higher than the frequency of non-netural mutations
Male wil turkeys often form coalitions, where two mates will cooperatively court a female. However, only the more dominant of the two males ever seems to mate. Why? - he is learning courtship skills from the dominant male - helping doesn't have much of a cost to his fitness - he is related to the dominant male, and he gets more fitness by helping his mate than if the tried to court females on his own - he has no choice, because the dominant male restricts his behavior by not letting him mate
he is related to the dominant male, and he gets more fitness by helping his mate than if the tried to court females on his own
Hometic genes have shown us that: - every organism's body plan develops in a fundamentally different way - the mechanisms that organize animal body plans are broadly conserved across genes - mutations in Hox genes typically have small phenotypic effects - plant and animal body plans have evolved independently via different mechanisms
he mechanisms that organize animal body plans are broadly conserved across genes
Directional selection will result in the most rapid fixation of the dominant allele when - heterozygotes have lower fitness than the dominant homozygotes - heterozygotes have the same fitness as dominant homozygotes - both homozygotes have higher fitness than heterozygotes - heterozygotes have the highest fitness
heterozygotes have lower fitness than the dominant homozygotes
School size is the number of fish in a group. The plot at right shows school size for high, medium, and low predation sites. at which site is school size largest? - high predation - medium predation - low predation - no difference
high predation
What is the main difference between the handicap and runaway models? - in the handicap model, the preferred trait indicates another aspect of quality, when the runaway model the trait is the only target -in the handicap model, the preferred trait indicates the only target, when the runaway model the trait indicates another aspect of quality -in the handicap model, traits do need to be conditioned-dependent, but they must be condition-dependent in the runaway model -in the handicap model, traits and preferences are not in linkage disequilibrium, but they are in the runaway model
in the handicap model, the preferred trait indicates another aspect of quality, when the runaway model the trait is the only target
How should selection change the frequency of A over time? - increase the frequency of A - decrease the frequency of A - no change in frequency of A
increase the frequency of A
What happened to the probability of fixation of neutral mutations around the selected locus? - increased probability of fixation - decreased probability of fixation -no change in fixation probability - only increased probability of fixing non-synonymous mutations
increased probability of fixation
When there are more males than females in the mating pool, what happens to competition for mates? - increases - decreases - stays the same - depends on specific context
increases
Why does examining more loci give more resolution for detecting population structure? - looking at more loci increases your chances of detecting natural selection - looking at more loci increases your chances of identifying rare alleles than between populations - looking at more loci increases your chances of identifying genetic drift - looking at more loci increases your chances of detecting assortative mating
looking at more loci increases your chances of identifying rare alleles than between populations
Effective population size is reduced when populations are fragmented and can lead to an extinction vortex because: - individuals are not able to mate with each other due to isolation, making the number of breeding population smaller than total population - some individuals have many more offspring than others, making the total number of breeding individuals smaller than total population size - sex ratios are unequal, making the total number of breeding individuals smaller than total population size - effective population size is not reduced in fragmented habitat
individuals are not able to mate with each other due to isolation, making the number of breeding population smaller than total population
If you help your relatives increase their fitness, is that altruism? - yes, because you are sacrificing some of your own fitness - yes, because helping relatives is the right thing to do - no, because you are just helping further your own genes - it depends on how much you help vs. how related you are
it depends on how much you help vs. how related you are
Which is not true about horizontal gene transfer? - it is an important reason that offspring resemble their parents - it is the transmission of genetic information directly between cells - it has important implications for how we understand the phylogenetic tree of life - it can occur when cells take up free-floating nucleic acids from the environment
it is an important reason that offspring resemble their parents
Which is true about the evolution of multicellularity? - it always involves specialization and differentiation among cells - it is more likely to occur between genetically related cells - it is always favored by natural selection - it allows cells to become larger
it is more likely to occur between genetically related cells
Which is not a benefit of DNA compared to RNA as an information storage system? - it is more chemically stable - it is shorter and therefore replicates faster - it has lower mutation rates - it has better repair mechanisms
it is shorter and therefore replicates faster
This idea is: - lamarckian - darwinian - very reasonable - not sure
lamarckian
If you are a small gamete, what size gamete should you fuse with? - small - large
large
What is fitness at the genetic level? - passing on your own genes to your offspring - being the biggest, strongest individual in your population - having as many mates as possible - leaving as many copies of your genes in the next generation, regardless of who has them
leaving as many copies of your genes in the next generation, regardless of who has them
Say we measured heterozygosity in the langurs and compared it to expectations under a Wright-Fisher model with population size = 250. Would we expect Ho to be higher or lower than He - lower - higher - impossible to predict
lower
Which do you think are is not a predicted outcome of the Red Queen hypothesis? - oscillation in the relative frequency of asexual lineages within populations when parasites are present - time lags between the emerges of a host defense and the evolution of pathogen traits that counter that defense - correlation between parasite load and sexual reproduction - maintenance of linkage disequilibrium and co-adapted gene complexes in sexually reproducing hosts
maintenance of linkage disequilibrium and co-adapted gene complexes in sexually reproducing hosts
What effect will migration from the mainland have an allele frequencies on the island in this model? - make the island and mainland frequencies more similar - make the island and mainland allele frequencies more different - increase variation on the mainland - decrease variation on the island
make the island and mainland frequencies more similar
Why does sexual conflict occur? - males and females cooperate to maximize each other's reproductive fitness - males and females have similar reproductive strategies, with both mating multiply to maximize their fitness - males and females have different reproductive strategies, with males investing more resources in reproduction than females - males and females have fundamentally different reproductive strategies
males and females have fundamentally different reproductive strategies
If the goal is to have as many offspring as possible, what mating strategy should males pursue? What mating strategy should females pursue? - males mate with as many individuals, females choose mates carefully - females and males both mate with as many individuals as possible - females mate with as many individuals as possible, males choose mates carefully - males and females both choose mates carefully
males mate with as many individuals, females choose mates carefully
Which two groups diverged most recently on the second tree (B)? - monotremes and placentals - marsupials and placentals - marsupials and monotremes - placentals and squamate reptiles
marsupials and monotremes
What effect does migration have on variation within and among populations? - migration increases variation within populations and decreases variation between populations - migration decreases variation within populations and increases variation between populations -migration decreases variation within populations and between populations -migration increases variation within populations and between populations
migration increases variation within populations and decreases variation between populations
Where does most genetic variation occur in humans? Within populations, or between populations? - most variation occurs within populations, human are extremely genetically distinct - most variation occurs between populations-human populations are clearly genetically distinct
most variation occurs within populations, human are extremely genetically distinct
What is the only process that can introduce completely novel variation into populations? - migration - recombination - mutation - lateral gene transfer
mutation
AT high temperatures, what effect did most mutations in the heat shock protein have in fitness? - negative - positive -neutral
negative
At 25C (low temperature), what effect did most mutations in the heat shock protein have on fitness? - neutral - positive - negative
neutral
What pattern would you expect to observe if toxins and resistance are coevolving? - toxin and resistance levels are unrelated - predators become very resistant to toxins in case newts escalate toxin production - newts produce lots of extra toxins so predators know not to try to eat him - newts produce just enough toxins to deter a predator and predators are just resistant enough to eat newts
newts produce just enough toxins to deter a predator and predators are just resistant enough to eat newts
Are individuals in a by-product mutualism behaving altruistically? - no - they are acting selfishly, but cooperating is the strategy that most increases their fitness - yes - they are sacrificing their fitness for the good of the group - no - they are sacrificing their own fitness for a future payoff - no - they are freeloading the investment of other group members
no - they are sacrificing their own fitness for a future payoff
What effect does assortative mating have an allele frequencies? - no effect - increase - decrease
no effect
Is most communication honest? - no, because it is usually advantageous to manipulate signal receivers that have something that benefits you, even if it harms them - yes, because natural selection usually favors cooperation - yes, because most communication is between relatives that share a common trait - no, because communication systems are inefficient
no, because it is usually advantageous to manipulate signal receivers that have something that benefits you, even if it harms them
Is coat patterning a useful trait for building a phylogeny in the Felidae? - no, patterning is a homoplasy - yes, patterning is the divergent trait - no, patterning is a synapomorphy - yes, patterning is monophyletic
no, patterning is a homoplasy
Think about the patterns of genetic variation we have see so far in humans. Do you think racial classification based on phenotype generally accurately reflects variation... - no, there is often more genetic variation within and among populations of "race" than among populations of different races - no, there is no genetic variation among human populations - yes, genetic variation among populations clearly corresponds to phenotypic differences - yes, phenotypic differences among humans are clearly geographically structured and associated with genetic clusters
no, there is often more genetic variation within and among populations of "race" than among populations of different races
How should A change over time just under mutation? - not enough information to predict direction of change - increase the frequency of A - decrease the frequency of A - no change in the frequency of A
not enough information to predict direction of change
Which observation supports Mendel's inference that offspring must receive genetic material from both parents? - offspring in the F2 generation exhibit both parental phenotypes - F2 offspring only express one parental phenotype - offspring in the F1 generation do not exhibit both parental phenotypes - offspring in the F1 generation only exhibit dominant phenotypes
offspring in the F2 generation exhibit both parental phenotypes
Which node represents the common ancestor of mammals and lungfish? - teal node - purple node - orange node - green node
orange node
Big questions about the origins of life do not include: - origin of inorganic molecules - origin of complex organic molecules - origin of storage information systems - origin of cells
origin of inorganic molecules
What do we call a group composed of organisms sharing a common ancestor in which not all the descendants of the common ancestor are included? - analogues - paraphyletic - sister taxa - monophyletic
paraphyletic
What relationship do you see among spur length and pollinators, and how might this affect reproductive isolation? - no relationship between spur length and pollinators; unlikely that pollinators affect isolation - pollinators change as spur length increase; unlikely that pollinators affection isolation - pollinators change as spur length increase; differences in pollinators likely increase reproductive isolation - pollinators change as spur length increase; differences in pollinators likely decrease reproductive isolation
pollinators change as spur length increase; differences in pollinators likely increase reproductive isolation
Based on these figures showing allele frequency change over time, which population would you hypothesize is the smallest? - population A - population b - population c - impossible to determine
population A
A parent-offspring regression examines the correlation between the average trait value the parents to the average trait value in the offspring. What type of relationship would you...: - positive correlation between parent trait and offspring trait - negative correlation between parent trait and offspring trait - no correlation between parent trait and offspring trait - impossible to predict
positive correlation between parent trait and offspring trait
Methodological naturalism set the stage for the modern scientific method by: - stating that the earth changed gradually over time - seeking explanations for the natural world driven by physical laws - suggesting that animals struggle for existence - demonstrating that species are adapted to their environments
seeking explanations for the natural world driven by physical laws
How would you predict asexual vs. sexual lineages respond to new environments? - sexual linkages are able to adapt faster to new environments - asexual lineages are able to adapt faster to new environments - no difference in ability to adapt to new environments - speed of adaptation will depend on the specific environment
sexual linkages are able to adapt faster to new environments
What effect fo most mutations have on fitness? - positive - mutations are usually beneficial for fitness - negative - mutations are usually deleterious to fitness - neutral - mutations don't usually affect fitness - slightly negative and neutral - most mutations are neutral or slightly deleterious
slightly negative and neutral - most mutations are neutral or slightly deleterious
If you are a large gamete, what size gamete should you fuse with? - small - large
small
Will allele fix faster due to drift in large or small populations? - large - small - same rate - unpredictable
small
Here we see the correlation in phenotype (in this case, presence of clinical depression) in identical (MZ) vs. fraternal (DZ) twins. A larger correlation coefficient means twins are: - strong genetic component to depression - no relationship between relatedness and depression - strong environmental component to depression - equal environment and genetic components
strong genetic component to depression
Which type of mutation is least likely to have an effect on phenotype? - inversion - deletion - synonymous mutation - non-synonymous mutation
synonymous mutation
Why is genetic drift stronger in small populations? - small populations have less variation - the chances of a large change in allele frequency due to drift are greater when population size is small - the chances of a large change in allele frequency due to drift are greater when population size is large - the chances of large changes in allele frequency are greater when there is no natural selection
the chances of a large change in allele frequency due to drift are greater when population size is small
A haplotype is: - all alleles at a locus - the combination of alleles across multiple loci on both chromosomes in a diploid organisms - the combination of alleles present across multiple loci on a single chromosome gamete - the same thing as a genotype
the combination of alleles present across multiple loci on a single chromosome gamete
What is an assumption? - the predictions of a model - the conditions under which a model is true - a mathematical equation - a perfect prediction of reality
the conditions under which a model is true
A population of mice has brown or white fur, and blue or yellow eyes. White fur is under positive selection. If white fur and yellow eyes are in linkage disequilibrium, what pattern... - the frequency of yellow eyes increases - blue and yellow eyes maintain their frequencies in the population - the frequency of blue eyes increases - the frequency of yellow eye decreases
the frequency of yellow eyes increases
A consequence of Malthus's ideas that populations outstrip their available resources is that: - individuals will acquire heritable characteristics that help their offspring survive - the individuals best able to monopolize resources will survive - individuals vary within a population - individuals ressemble their parents
the individuals best able to monopolize resources will survive
There is a strong linkage disequilibrium when: - the observed frequency the AB haplotype is very different from the expected frequency - the expected and observed frequencies of the AB haplotype are very similar - the frequency of the A allele is high - the frequency of the AB haplotype is high
the observed frequency the AB haplotype is very different from the expected frequency
Which is NOT true about polygenic traits? - the phenotypes of offspring are completely unpredictable based on the genotypes of the parents - multiple genotypes can produce the same phenotype - phenotypic variation is continuous despite discrete Mendelian inheritance - F2 offspring exhibit a wide range of phenotypes intermediate between the parental types
the phenotypes of offspring are completely unpredictable based on the genotypes of the parents
Drift is a more important driver of allele frequency change that selection when: - the population is large and selection is weak - the population is small and selection is weak - the population is small and selection is strong - the population is large and selection is strong
the population is small and selection is weak
What is population genetics? - the study of natural selection and adaptation - the study of the effects of mutations on phenotypes - the study of genetic variation within individuals - the study of variation in allele frequencies over time and space within populations
the study of variation in allele frequencies over time and space within populations
We observe a plant with white and purple flowers. The white plant produces 100 offspring and the purple plant produces 20 offspring. What can we infer? - there is a selection coefficient of 0.5 against purple - there is a selection coefficient of 0.2 against purple, and the white allele will increase in frequency - there is a selection coefficient of 0.8 against purple, and the white allele will increase in frequency - there is a selection coefficient of 0.2 against white, and the white allele will increase in frequency
there is a selection coefficient of 0.8 against purple, and the white allele will increase in frequency
What might a challenge for the evolution of interspecific mutualism? - they are susceptible to cheating from one participant - they increase indirect fitness but not direct fitness - they require sophisticated communication systems - they cannot evolve from initially parasitic or neutral relationships
they are susceptible to cheating from one participant
Regulatory enchancers are important because: - they determine when a gene is turned on and at what level it is expressed at - they cause divergence in coding regions between species - they cause divergence in coding regions between species - plant and animal body plans have evolved independently via different mechanisms
they determine when a gene is turned on and at what level it is expressed at
Which is true about mass extinctions? - they typically result from catastrophic events - they are the major cause of all extinctions - they typically occur gradually over a longer period of time - they only affect species at the tips of phylogenetic trees
they typically result from catastrophic events
What happens to size/frequency of a preferred male trait over time? What happens to female preference for that trait? - trait becomes larger/more common, preference becomes stronger - trait becomes smaller/rarer, preference becomes weaker - trait becomes smaller/rarer, preference becomes stronger - trait becomes larger/more common preferences become weaker
trait becomes larger/more common, preference becomes stronger
What is true of active trends? - trait values are as likely to increase as decrease among different clades over time - trait values are constrained by a minimum or maximum value but increase or decrease among clades away from this boundary - trait values change in the same direction across clades over time - trait values do not change over time
trait values change in the same direction across clades over time
Which tree is more persimonious? - tree 1, because there are fewer branches - tree 1, because there are fewer changes in character state - tree 2, because there are fewer changes in character state - tree 2, because there are more changes in character state
tree 1, because there are fewer changes in character state
Endosymbiosis occurs when: - two cells have a parasite relationship and one begins exploiting the other - two cells have a mutualistic relationship and cannot survive independently - two cells have a mutualistic relationship and can survive independently - two cells exchange genetic material
two cells have a mutualistic relationship and cannot survive independently
In which kind of environment might sexual reproduction be favored? - constant environments, because organisms can quickly become optimized to the environment - constant environments, because linkage disequilibrium is maintained between beneficial alleles - unpredictable or variable environments, because related offspring can cooperate with each other - unpredictable or variable environments, because it is more likely that one or few offspring does well in the environment
unpredictable or variable environments, because it is more likely that one or few offspring does well in the environment
What are ecological analogues? - related species that exhibit different adaptations to similar environments - unrelated species that exhibit different adaptations to different environments - closely related species that exhibit similar adaptations to similar environments - unrelated species that exhibit similar adaptations to similar environments
unrelated species that exhibit similar adaptations to similar environments
Why might sympatric speciation be controversial and unlikely in nature? - resource competition is required for the model but is rare in nature - very strong disruptive selection and complete cessation of migration is necessary among individuals living in the same location - directional selection is much more common than disruptive selection, and disruptive selection is therefore unlikely - it's unlikely that a situation with no geographic barriers will occur in nature.
very strong disruptive selection and complete cessation of migration is necessary among individuals living in the same location
When does A1 increase most rapidly? - when A1 is dominant - when A1 is recessive - when A1 is incompletely dominant
when A1 is incompletely dominant
When would you expect the frequency of allele A to increase in frequency most rapidly? - when saa=0.8 and the u from A--> a is low - when saa=0.8 and u from A-->a is high - when saa = 0.5 and u from A-->a is high - when saa = 0.8 and the u from A--> a is low
when saa=0.8 and the u from A--> a is low
When does Fisherian Runaway stop/ - when the cost of the trait to survival is greater than the benefit from mating - when the cost of the trait to survival is less than the benefit from mate choice - when the cost of the trait to mate choice is greater than the benefit from survival - when the cost of the trait to mate choice is less than the benefit from mate choice
when the cost of the trait to survival is greater than the benefit from mating
When could reciprocity evolve? - when you are certain that you will interact with the other individual in the future and there is a way for you to get payback if they cheat - when you will never see the other individual again so they cannot punish you for cheating - when individual recognition is poor, so that everyone helps everyone just in case - when lifespans are very short, so helping is essential for increases reproductive success
when you are certain that you will interact with the other individual in the future and there is a way for you to get payback if they cheat
Can traits that increase male reproductive success but harm females (and vice versa) be selected? - yes, because all individuals are just increasing their own genetic fitness and the individuals they mate with don't share their genes - no, it would be maladaptive for male traits to harm females if females are producing their offspring - not sure
yes, because all individuals are just increasing their own genetic fitness and the individuals they mate with don't share their genes
Based on this tree, would you hypothesize that striped tails are homologous? - yes, straight tails form a monophyletic group - yes, stripes are the ancestral state of the whole group - no, stripes are paraphyletic - no, stripes probably evolved multiple times independently
yes, straight tails form a monophyletic group
What are the two costs of sex under the Maynard Smith model? - you only pass on 50% of your genes, and half of your offspring don't produce their offspring - you only pass on 50% of your genes, and it takes you a long time to find a mate - you reproduce slower, and half of your offspring dont produce their own offspring - you reproduce slower, and you only pass on 50% of your genes
you only pass on 50% of your genes, and half of your offspring don't produce their offspring
