Midterm 1 Flashcards by Bridgette Marie

1) Define biological evolution:
a. Any process by which populations of organisms change over time
b. Any change in the inherited traits of a population that occurs from one generation to the next
c. Change within a linage due to natural selection and other mechanisms
d. All of the above are possible definitions
e. None of the above is an appropriate definition

All of the above

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2) Explain why Theodosius Dobxhansky said that “nothing in biology makes sense expect in the light of evolution”.
a. He was an atheist
b. He was fascinated by the capacity for evolution to explain the diversity of life and its universal biological similarities
c. He wanted to explain the origin of life
d. All of the above
e. None of the above

b. He was fascinated by the capacity for evolution to explain the diversity of life and its universal biological similarities

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3) Why do baleen whales still have genes for building teeth?
a. These genes are now used to make baleen
b. Their ancestors had teeth and they inherited these genes from them, even though these genes no longer function
c. Their descendants might need teeth, so evolution keeps the genes around.
d. Evolution can’t take away genes, only add new ones
e. All of the above
f. None of the above

b. Their ancestors had teeth and they inherited these genes from them, even though these genes no longer function

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What makes hemagglutinin important in the evolution of the influenza virus?

a. It allows a virus to attack the red blood cells of its host
b. It is the basic building block of virus cell walls
c. It allows the virus to bind to the cells of its host
d. All of the above are true
e. Hemagglutinin is not important to viruses

It allows the virus to bind to the cells of its host

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Which of the following is a TRUE statement?

a. The ancestors of whales needed more food than could be found on land, so they evolved features that allowed them to survive.
b. Whales and humans share a common ancestor
c. Mutations always cause the improvement of a trait
d. Viruses mutate because they want to have the best adapted hemagglutinins throughout their evolution
e. All of the above are true statements
f. None of the above is a true statement

b. Whales and humans share a common ancestor TRUE

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Which of the following is NOT a place that scientists look for evidence of evolution?

a. The fossil remains of extinct animals
b. Comparison of homologous traits in various species
c. Change during an individual organism’s lifetime
d. Change in populations in the wild
e. None of the above (scientists look to all of these sources)

Change during an individual organism’s lifetime

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Which of these statements about phenotypes is TRUE?

a. Individuals that adjust their phenotypes in response to their environment cannot be favored by natural selection
b. Natural selection does not act on phenotypes
c. An individual’s behaviour is not part of its phenotype
d. An individual’s phenotype is a result of its genotype
e. Most phenotypes are perfectly adapted to their environments

d. An individual’s phenotype is a result of its genotype

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Why do scientists overwhelming accept the theory of evolution?

a. Because the theory has overwhelmingly evidentiary support
b. Because the theory explains and predicts independent lines of evidence
c. Because scientists have tests and retested predictions
d. Because a scientific theory is a comprehensive explanation of many diverse observations.
e. All of the above

All of the above

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What did early scientists learn from fossils?

a. The earth changes
b. The history of an area can be found in its rocks
c. Organisms different from current organisms once lived on the plant
d. Marine fossils can be found on mountain tops
e. All of the above
f. None of the above

All of the above

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10) Which of these statements is a concept found in George Buffon’s idea about evolution but, not in the way we understand evolution now?
a. Populations can change overtime
b. Life is divided into a number of distinct types that are not related to each other
c. Living things are made of the same particles found in rocks and water
d. Life took more than a few thousand years to evolve
e. All of the above
f. None of the above

b. Life is divided into a number of distinct types that are not related to each other

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What would Jean-Baptiste Lamarck and Charles Darwin have agreed upon?

a. One generation can pass on its traits to the next
b. Individual animals and plants can adapt to their environment
c. Life was driven from simplicity to complexity
d. Both a and b
e. All of the above
f. None of the above

One generation can pass its traits on to the next

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What is a correct definition of homology?

a. Common traits due to shared inheritance from a common ancestor
b. Common function of traits due to similar usage
c. Structure of lings that are common among all mammals
d. All of the above
e. None of the above

Common traits due to shared inheritance from a common ancestor

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What set Darwin and Wallace’s concept of natural selection apart from earlier ideas of evolution?

a. Their concept explains why organisms were related to each other
b. Their concept depended on a process that is observable
c. Their concept depended on the inheritance of characteristics from one generation to the next
d. Their concept suggested that change was very gradual
e. All of the above (all of these ideas were new).
f. None of the above (these ideas were shared by earlier views).

Their concept depended on a process that was observable

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Did Charles Darwin invent the Theory of Evolution?

a. Yes. On the Origin of Species outlines the theory of evolution as scientists understand it today
b. Yes. The theory of evolution is based entirely on natural selection, which was Darwin’s idea.
c. No. Natural selection and evolution were theories long before Darwin wrote On the Origin of Species
d. No. Darwin described a mechanism for evolutionary change, but natural selection is only a component of the theory of evolution.

No. Darwin described a mechanism for evolutionary change, but natural selection is only a component of the theory of evolution.

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What evidence did Darwin use to predict the age of the Earth?

a. Darwin didn’t predict the age of the Earth
b. Darwin couldn’t predict the age of the Earth, because he didn’t understand radioactive decay.
c. Darwin used processes he could observe, such as erosion and sedimentation, to predict that the Earth must be hundreds of millions of years old.
d. It doesn’t matter, because Lord Kelvin refuted Darwin’s evidence

Darwin used processes he could observe, such as erosion and sedimentation, to predict that the Earth must be hundreds of millions of years old

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What is an isochron?

a. The ratio of rubidium (Rb) to strontium (Sr)
b. The half-life of an isotope
c. The slop of the line describing the ratio of 87Sr to 86Sr
d. A line on a graph of isotope ratios that indicates mineral samples formed at a similar time

A line on a graph of isotope ratios that indicates mineral samples formed at a similar time

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Which isotope would be useful for dating a fossil found in relatively recent sediments?

a. An isotope with moderately high probability of decay
b. An isotope with a low probability of decay
c. Rubidium
d. Strontium
e. Any unstable isotope would be useful

An isotope with moderately high probability of decay

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How did the fossils of the Burgess Shale form?

a. The animals fell to the bottom of a deep lake and over thousands of years turned to rock
b. The animals dropped into anoxic ocean depths and were covered by fine sediment
c. The animals were rapidly covered by ash falling from a volcano
d. Both a and b

The animals dropped into the anoxic depths and were covered by fine sediment

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How did scientists determine that Tyrannosaurus res could not run very fast?

a. They compared skeletal structures of T-rex to modern animals to determine the size of its muscles
b. They used living animals to test a model they had developed on the biomechanics of running
c. They used evolutionary theory to determine the most closely related organism to the T-rex
d. They developed a biomechanical model of running animals to determine how much force leg muscles of a given size could generate
e. All of the above

All of the above

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Which outcome would you predict if you could compare the isotopes of fossils of two species of human ancestors and found high ratios of carbon-13/carbon-12 in one and low ratios in the other?

a. The species with high ratios likely lived in grasslands
b. The species with high ratios likely preferred eating shrubby vegetation
c. The species with high ratios likely ate a mixed diet
d. It would depend on what kind of human fossils
e. All of the above
f. None of the above

The species with high ratios would likely ate a mixed diet

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What independent lines of evidence have scientists used to determine the history of life on Earth?

a. Zircons
b. Behaviour of living species
c. Fossilized dung
d. Oxygen isotopes
e. All of the above

All of the above

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Which group is not considered one of the major lineages of all living organisms?

a. Bacteria
b. Microbes
c. Archaea
d. Eukarya

Microbes

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) How can scientists determine that multicellular life arose more than once

a. Animals are more closely related to single-celled eukaryotes than to fungi
b. Fungi can produce multicellular structures
c. Bacteria live as multicellular groups called biofilms
d. Scientists have no idea if multicellular life arose more than once.

Animals are more closely related to single-celled eukaryotes than to fungi

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Define prokaryotes:

a. A descriptive grouping for microorganism that lack membrane-bound organelles
b. A grouping useful in the classification of earlier microbes
c. A grouping often used instead of Archaea
d. A single-celled eukaryote
e. A grouping to describe early fossils of plants

A descriptive grouping for microorganism that lack membrane-bound organelles

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) Why is a notochord an important adaptation for understanding the evolution of humans? a. The development of a notochord occurred in early fish b. A notochord is a backbone c. A notochord is a characteristic of chordates d. A notochord serves to distinguish the Ediacaran family from the trilobites.

A notochord is a characteristic of chordates

What allows us to know that synapsids were tetrapods? a. They lived on land b. They were dominant land animals c. They evolved to mammals d. They had four legs they used for walking e. All of the above

They had four legs they used for walking

Which of the term is not associated with treelike depictions of evolutionary histories known as phylogenies? a. Node b. Seed c. Branch d. Root

Seed

If you were looking at a phylogeny of living bird species, where could you find the name of a species on non-theropod dinosaur? a. At the tip of a branch, as an outgroup b. At the root of the tree c. Either a or b d. None of the above

At the tip of a branch, as an outgroup At the root of the tree Either A or B.

Which is NOT a synapomorphy? a. The ability to swim in dolphins and sharks b. The production of milk in humans and cats c. The ability to fly in eagles and pigeons d. The laying of eggs with shells in snakes and lizards e. All of the above are synapomorphies

The ability to swim in dolphins and sharks

Which of the following is an example of homoplasy? a. The reversion of a derived character state to its ancestral state b. The independent origin of similar traits in separate lineages c. The evolution of winds in both birds and bats d. All of the above e. None of the above

All of the above

Why are bird feathers considered an exaptation? a. Because they are shared derived character found in most birds b. Becayse they are traits that have independently evolved into separate lineages c. Because they first evolved for functions other than flight d. Because they are an evolutionary reversal to an ancestral character state

Because they first evolved for functions other than flight.

) If two individuals mate, one of them heterozygous at a locus (one dominant and one recessive allele) and the other homozygous for a recessive allele at the same locus, what will be the outcome? a. The offspring will be either heterozygous, or homozygous, for the recessive allele b. The offspring will either be homozygous for the dominant allele, heterozygous, or homozygous for the recessive allele c. The offspring will not evolve, because they will carry the same alleles as the parents d. The recessive allele eventually will become dominant in the population e. None of the above

The offspring will be either heterozygous, or homozygous, for the recessive allele

The Hardy-Weinberg theorem is an important mathematical proof because a. It demonstrates that dominant alleles are more common than recessive alleles b. It demonstrates that in the absence of outside forces, allele frequencies of a population will not change from one generation to the next c. It demonstrates that heterozygotes are always better

It demonstrates that in the absense of outside forces, allele frequencies of a population will not change from one generation to the next.

Which population would be most likely to have allele frequencies in Hardy-Weinberg equilibrium? a. A population in a rapidly changing environment b. A population where immigration is common c. A large population that currently is not evolving d. A population that cycles between a very large and very small number of individuals

A large population that is currently not evolving.

A genetic bottleneck in a population often results in what? a. Loss of alleles b. Loss of genetic diversity c. An increase in genetic drift d. All of the above e. None of the above

All of the above

What do population geneticists mean when they refer to the fitness of an allele? a. The ability of the allele to survive in a population b. The contribution of an allele to the strength and over-all health of a genotype c. The contribution of an allele to a genotype’s relative success at producing new individuals d. Whether an allele is dominant or not e. Whether an allele is recessive or not

The contribution of an allele to a genotype's relative success at producting new indivduals

If a mutation that produces a new deleterious allele arises in a population, what will most likely happen to the frequency of that allele? a. It depends on that allele’s effect on the phenotypes – if the allele is recessive, it can remain at a low frequency within the population for a very long time b. It depends on the allele’s effect on the phenotypes – if the allele is recessive, drift will determine whether it persist in the population c. The allele will be rate enough that it almost never occurs in a homozygous state d. Deleterious alleles are always quickly purges from populations e. A, b, c

A, B, C

) If Cavalli-Sforza and colleagues had measured allele frequencies as 0.869 for the A allele and 0.131 for the A allele, how many homozygous genotypes should they have expected to find? Would they have considered the population to be at equilibrium? a. 9354 AA and 29 SS. No, they would not have considered the population to be at equilibrium b. 9354 AA and 211 SS. Yes, they would have considered the population to be at equilibrium c. 9354 AA and 211 SS. No, they would not have considered the population to be at equilibrium d. 2811 AA and 2993 SS. No, they would not have considered the population to be at equilibrium e. 9527 AA and 187 SS. No, they would not have considered the population to be at equilibrium

c. 9354 AA and 211 SS. No, they would not have considered the population to be at equilibrium

) What can measuring genetic distance, or Fst, tell scientists about a group of organisms? a. Whether groups have begun to diverge from each other b. Whether genes are under strong selection c. How barriers may be influencing gene flow d. All of the above e. None of the above

All of the above

Phenotypic traits often have a continuous distribution because a. They are a result of dominance interaction b. They are not related to genotypes c. They are influenced only by the environment d. They are often polygenic

They are often polygenic

The breeder’s equation incorporates two of the conditions Darwin identified that must be met for evolution by natural selection to take place. Which two? a. Greater survival (S) and reproduction (K) of phenotypes with specific alleles b. Variation in phenotypic traits (R) and heritability of additive alleles (h^2) c. Differences in phenotypes that influence the probability of survival or reproduction (S) and differences in phenotypic traits that must be at least partially heritable (h^2) d. Heritability of additive alleles (h^2) and the evolutionary response of the population (R) e. None of the above statements demonstrate evolution by natural selection

Differences in phenotypes that influence the probability of survival or reproduction (S) and differences in phenotypic traits that must be at least partially heritable (h^2)

How can scientists determine what constitutes a quantitative trait locus? a. They painstakingly examine the genotypes of hundreds of individuals and look for genes that are consistently similar b. They examine nucleotide sequences and count the repeated segments that they feel are important c. They hybridize species and compare how genetic markers recombine in the offspring d. They select for different traits in lineages of an organism, cross-breed the lineages for two generations, and search for genetic markers that are correlated with expression of the trait e. They map the genome and identify the distinct, short segments of DNA markers such as single nucleotide polymorphisms (SNPs), simple sequence repeats, and transposable elements.

They select for different traits in lineages og an organism, cross-breed the lineages for two generations, and search for genetic markers that are correlated with expression of teh trait

If the age of sexual maturation is a phenotypically plastic trait, what relationship(s) would you expect to find? a. Genotypes differ in age at which they reproduce b. Environmental conditions (such as nutrition) affects the age at which individuals begin reproducing c. Body size affects the age at which different genotypes reproduce d. All of the above e. None of the above

Environmental conditions (such as nutrition) affects the age at which individuals begin reproducing

Which of the following is an example of the process of evolution? a. A population of snowshoe hares having different frequency of alleles than the previous generation b. Tree dropping their leaves in the fall c. A man becoming immune to a strain of virus that caused him to have a cold when he was younger d. A female bird laying more eggs one season that she did three previous seasons combined e. All of the above are examples of the process of evolution

A population of snowshoe hares having different frequency of alleles than the previous generation

Which of the following statements about natural selection is true? a. Natural selection is the same as evolution b. Natural selection always results in reduced genetic variation c. Natural selection can have an evolutionary effect only if phenotypic differences are heritable d. Natural selection acts directly on genotypes e. Changes in allele frequencies can occur only because of natural selection

Natural selection can have an evolutionary effect only if phenotypic difference are heritable

For a gene with two alleles and p=02, the frequency of heterozygotes would be: a. 0.009 b. 0.42 c. 0.32 d. 0.49 e. Not enough information

0.32

The response of a quantitative character to selection depends on the heritability (h^2) of the character and the selection differential (S). Response (R) to selection will be greatest and selection, respectively, which of the following? R=h^2(5) a. 0.75; 4 b. 0.40; 2.5 c. 0.75; 2.5 d. 0.40; 4 e. 0.60; 4

0.75; 4

For a locus with two alleles, the maximum heterozygosity would be when: a. p=q b. p>q c. q>p d. p=0 e. q=0

p=q

The proportion of phenotypic variance that is due to additive genetic differences among individuals is referred to as: a. non-additive genetic components b. environmental variance c. broad sense heritability d. narrow sense heritability e. linkage disequilibrium

narrow sense heritability

Which of the following represents the phenotypic variance (Vp) in a phenotypic trait? a. VG+VA b. VA+VE c. VD+VE d. VG+VD e. VG+VE

VP=VG+VE

Which of the following involve assumption for the Hardy-Weinberg principle? a. Heterozygosity = 2pq b. q=1-p c. p^2+2pq+q^2=1 d. two or all of A, B, C e. none of A, B, C

two or all of A, B, and C.

The data from morality rate of offspring from marriage registered in 1903-1907 in Italian populations indicated that the offspring of related individuals have higher mortality rates. What is a likely cause of this inbreeding depression? a. Close relative are more likely to neglect their children b. Italian populations are more likely than other populations to have genetic disease c. Inbred individuals are more likely than other individuals to be homozygous for deleterious recessive alleles d. The offspring of close relatives are born at large size than other offspring e. Italians are more likely to mate with other Italians than with individuals of other nationalities

Inbred individuals are more likely than other individuals to be homozygous for deleterious recessive alleles

Differences in the number of mates or in the reproductive capacity of individuals of one sex can be explains by the concept of: a. Reproductive assurance b. Sexual selection c. An operational sex ratio d. Sex-role reversal e. Sperm competition

Sexual selection

A genetic polymorphism results in two different morphs in a population. With frequency-dependent selection, genetic variation is maintained because: a. One morph has a higher frequency when its rare b. One morph has a lower frequency when its rare c. One morph has a higher frequency when its common d. Two or all of A, B, C

Two or all of A, B, and C

The additive genetic variance of fiddler crab claws is 0.50, while the total phenotypic variance is 0.30. What is the heritability of this trait? a. 1.6667 b. 0.6 c. 0.625 d. 0.2 e. 0.5

1.6667

Artificial selection experiments almost always show a response to selection. What is the most likely explanation for this observation? a. Populations contain significant amounts of genetic variation b. Few traits are polygenic c. Laboratory populations often are inbred d. Mutations are rare e. Alleles are in lineage disequilibrium

Populations contain significant amounts of genetic variation

Imagine a species distributed over a large geographic range containing a gradual environmental gradient and having different genotypes with greater fitness at opposite ends of the range. Which of the following patterns would you expect to find for the frequencies of genes over the entire range in the absence of gene flow? a. There will be a very gradual cline b. There will be a peak shift c. There will be a step cline d. One genotype will become fixed for the entire population e. Each genotype will be found at random frequencies at various points along the range

There will be a very gradual incline

``` Explain what is required for natural selection to occur. A) Heritable variation B) Fitness differences C) Mutation D) Random genetic drift E) A and B F) A and B and C G) A and B and C and D ```

Heritable variation | Fitness differences

Natural selection acts on existing traits that may increase fitness in new environments 1) True 2) False

True

``` The snow goose (Chen caerulescens) has both a blue and white morph. Inheritance is Mendelian: BB and Bb individuals are blue, while bb individuals are white. If 16 geese in a population of 100 are white and 84 are blue, how many of the blue geese would you expect to be carriers of the b allele (i.e., Bb heterozygotes)? HINT: BB and Bb = 84 blue geese bb = 16 white geese (p2 + 2pq) = 84/100 (q2 ) = 16/100 ``` Total = 100 a) 52 b) 48 c) 84 d) 36 e) 16

For a locus with 2 alleles, the maximum heterozygosity would be when: a) p = q b) p > q c) q > p d) p = 0 e) q = 0

p=q

Which of the following would define a polymorphic locus? a) p = 1.0 b) q = 0.0 c) p = q d) p + q = 1.0 e) more than one of a, b, c, d

p=q

For a gene with two alleles and p = 0.3, the frequency of heterozygotes would be: a) 0.09 b) 0.42 c) 0.21 d) 0.49 e) not enough information

0.42

Which of the following observations would not violate the assumptions of the Hardy-Weinberg principle? a. UV radiation induces new mutations at a high frequency. b. Individuals migrate from nearby populations but die prior to breeding. c. Cold tolerance differs by genotype, and the population experiences a frost. d. Inbreeding is present.

Individuals migrate from nerby populations but, die prior to breeding

You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate the percentage (%) of the "AA" genotype.

16%

What allelic frequency (p) will generate twice as many recessive homozygotes as heterozygotes? Hint: Freq. (AA) = p2 Freq. (Aa) = 2pq Freq. (aa) = q2 (recessive) twice as many recessive homozygotes as heterozygotes: q2 = 2 x (2pq) a) p = 0.2 b) p = 0.4 c) p = 0.8 d) p = 1.0

p=0.2

An allele with a frequency of q = 0.0001 is likely to be recessive and deleterious (harmful). True False

False

For a gene with two alleles and p = 0.2, the frequency of heterozygotes would be: a) 0.09 b) 0.42 c) 0.32 d) 0.49 e) not enough information

0.32

Which of the following observations would violate the assumptions of the Hardy-Weinberg principle? a. No mutation b. Individuals migrate from nearby populations but die prior to breeding. c. Cold tolerance differs by genotype, and the population experiences a frost. d. Random mating e. Population size is very large.

Cold tolerance differs by genotype, and the population experiences a frost

You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate the percentage (%) of the "Aa" genotype.

48%

An allele with a frequency of q = 0.0001 is likely to be recessive and deleterious (harmful). True False

False

Random mating can avoid the loss of genetic variation in small populations. True False

False

Inbreeding depression is likely caused by recessive deleterious mutations made homozygous. True False

True

A population with allele frequencies p = 0.30 and q = 0.70 has an inbreeding coefficient of F= 0.50. The observed frequency of heterozygotes is: (Note: F = (Hexp – Hobs)/ Hexp ) a) 0.500 b) 0.300 c) 0.105 d) 0.210 e) 0.700 f) none of the above

0.210

Migration and gene flow can change allele frequencies but not genotype frequencies. True False

False

Finite population size causes: a) allele frequencies to diverge among populations b) a reduction in heterozygosity c) random drift of allele frequencies d) an increase in homozygosity e) all of a, b, c, d f) more than one of a, b, c, d

all of a, b, c, d

Which of the following statements is (are) true: a) founder effect decreases genetic differentiation b) random genetic drift increases genetic differentiation c) migration with gene flow increases genetic differentiation d) founder effect results in decreased genetic variation

Random genetic drift increases genetic differentiation Founder effect results in decreased genetic variation

Which of the following represents the phenotypic variance (VP) in a phenotypic trait? a) VG + VA b) VA + VE c) VD + VE d) VG + VD e) VG + VE

VG+VE

In the experiment to test for natural selection in the Alpine Skypilot flower size, the treatments used to test the prediction were bumble bee pollinated at random and hand pollinated at random True False

False

Stabilizing selection results in: a) an increase in the mean and the variance b) a decrease in the mean and the variance c) a decrease in the mean and an increase in the variance d) a decrease in the variance e) an increase in the variance

a decrease in variance

Selection where there is no change in the mean but an increase in the variance is referred to as: a) directional selection b) diversifying selection c) stabilizing selection d) disruptive selection e) more than one of a, b, c, d

more and one of a, b, c, d

A "common garden" is used to compare the genotypes of different phenotypes in a common environment True False

False

Genotype x environment interaction (G x E) involves: A) modification of the environment by the genotype B) natural selection favouring different phenotypes in different environments C) the expression of different phenotypes in different environments for a set of genotypes D) parallel reaction norms of each genotype in different enviroments E) all of the above

the expression of different phenotypes in different environments for a set of genotypes

The cost of males relates to understanding the adaptive significance of sex because: A) males take more energy to produce than females B) asexual females gain an advantage by not producing males C) males mate with asexual females D) males accumulate deleterious mutations E) all of the above

Asexual females gain an advantage by not producing males

Sexual reproduction is considered a paradox because: a) sexual reproduction is more costly than asexual reproduction b) sexual reproduction is more common than asexual reproduction c) asexuality can evolve from sexual species d) asexuality appears to be an evolutionary dead end e) two or three of a, b, c, d f) all of a, b, c, d

all of a, b, c, d

Darwin recognized that sexual selection was similar to natural selection except that it specifically involved: a) mating success b) asymmetry in reproductive investment between the sexes c) offspring survival d) trade-offs between reproduction and survival e) all of the above f) more than one of a, b, c, d

more than one of a, b, c, d

The asymmetry of investment in reproduction means that males should be choosy when selecting females as mates True False

False

change in the inherited traits of a population that occurs from one generation to the next (i.e., over a time period longer than the lifetime of an individual of the population)

biological evolution

refers to a chain of ancestors and their descendants. A lineage may be the successive generations of organisms in a single population, the members of an entire species during an interval of geological time, or a group of related species decending from a common ancestor

lineage

is a mechanism that can leave to evolution, whereby differential survival and reproduction of individuals cause some genetic types to replace (outcompete) others)

natural selection

characteristics are similar in two or more species because they are inherited from a common ancestor - Structural characters that are shared because they are inherited from a common ancestor

homologous

derived form of a trait that is shared by a group of related species (i.e., one that evolved in the immediate common ancestor of the group and was inherited by all its descendants).

Synapomorphy

are linages evolving through time that connect successive speciation or other branching events - A population may become subdivided into two populations that can no longer exchange genes, making it possible for them to diverge into two species

Branches

is a visual representation of the evolutionary history of populations, genes or species - Evolution of a lineage into branches

Phylogeny

are points in phylogeny where a lineage splits (a speciation event or other branching event, such as the formation of subspecies)

nodes

are the terminal ends of evolutionary tree, representing species, molecules, or populations being compared

tips

are nodes that occur within a phylogeny and represent ancestral populations or species - Located within the phylogeny representing ancestral populations or species that have long since disappeared

internal nodes

are single “branches” in the tree of life; each clade represents an organism and all its descendants.

clades

represent the branching pattern of evolution over time

Phylogenetic trees

describes a group of organisms that form a clade | - Group is made up of an organism and all its descendants

monophyletic

describes a taxon that does not include the common ancestor of all members of the taxon

Polyphyletic

describes a group of organism that share a common ancestor although the group does not include all the descendants of that common ancestor

Paraphyletic

are heritable aspects of organisms that can be compared across taxa

characters

are groups of organisms that a taxonomist judges to be cohesive units, such as a species or order

Taxa | Taxon

is a derived form of a trait that is shared by a group of related species (i.e., ones that evolved in the immediate common ancestor of the group and was inherited by all of its descendants).

Synapomorphy

are groups of organisms (i.e., a species) that are outside of the monophyletic group being considered. In phylogenetic studies, outgroups can be used to infer the ancestral states of characters

outgroups

describes a character state similarity not due to shared descent (e.g., produced by convergent evolution or evolutionary reversal).

Homoplasy

is the independent origin of similar traits in separate evolutionary lineages

Convergent evolution

describes the reversion of a derived character state to a form resembling its ancestral state

Evolutionary reversal

is a principal that guides the selection of alternative hypothesis; the alternative requiring the fewest assumptions or steps is usually (but not always) best. In cladistics, scientists search for the tree topology with the least number of character-state changes – the most parsimonious.

Parismony

describes an internal node of a phylogeny with more than two branches (i.e., the order in which the branchings occurred is not resolved)

Polytomy

is a trait that initially carries out one function and is later co-opted for a new function. The original function may or may not be retained.

Exaptation

is the study of the distribution of alleles within populations and the mechanisms that can cause allele frequencies to change overtime

Population genetics

) refers to the specific location of a gene or piece of DNA sequence on a chromosome. When mutations modify the sequence at a locus, they generate new alleles-variants of a particular gene or DNA region. Alleles are mutually exclusive alternative states for a genetic locus

Genetic locus (loci)

is an allele that remains in a population when all alternative alleles have disappeared. No genetic variation exists at a fixed locus within a population, because all individuals are genetically identical at that locus.

a fixed allele

is an event in which the number of individuals in a population is reduced drastically. Even if this dip in numbers is temporary, it can have lasting effects on the genetic variation of a population.

Genetic bottleneck

: is a type of genetic drift. It describes the loss of an allelic variation that accompanies founding of a new population from a very small number of individuals (a small sample of a much larger population). This effect can cause the new population to differ considerably from the source population

Founder effect

refers to the success of an organism at surviving and reproducing and this contributing offspring to future generations

Fitness

describes the success of the genotype at producing new individuals (its fitness) standardized by the success of other genotypes in the population (for example, divided by the average fitness of the population).

Relative fitness

is the condition when a mutation in a single gene affects the expression of more than one difference phenotypic trait.

Pleiotropy

occurs when a mutation with beneficial effects for one trait also causes detrimental effects on other traits

Antagonistic pleiotropy

refers to selection that decreases the frequency of alleles within a population. Negative selection occurs whenever the average excess for fitness of an allele is less than zero

Negative selection

is the type of selection that increases allele frequency in a population. Positive selection occurs whenever the average excess for fitness of an allele is greater than zero

Positive selection

takes place when rate genotypes have higher fitness than common genotypes. This process can maintain genetic variation within populations

Negative frequency-dependent selection

occurs when selection favors heterozygote individuals over either the dominant homozygote or the recessive homozygote.

Heterozygote advantage

describes the type of selection that favors more than one allele. This process acts to maintain genetic diversity in a population by keeping alleles at a frequencies higher than would be expected by chance or mutation alone.

Balancing selection

mathematical statements that have been proven based on previously established theorems and axioms. Theorems use deductive reasoning and show that a statement necessarily follows from a series of statements or hypothesis-the proof. Theorems are not the same as theories. Theories are explanations supported by substantial empirical evidence – the explanations are necessarily tentative but weighed by the quality of evidence that supports them.

Theorems

default hypothesis that there is no relationship between two measured phenomena. By rejecting this hypothesis, scientists can provide evidence that such a relationship may exist.

Null hypothesis

refers to the probability that two alleles at any locus in an individual will be identical because of common descent. F can be estimated for an individual, Fpedigree by measuring the reduction in heterozygosity across loci within the genome of that individual attributable to inbreeding, or it can be estimated for a population, by measuring the reduction in heterozygosity at one or a few loci sampled for many different individuals in a population.

Inbreeding coefficient (F)

is a reduction in the average fitness of inbred individuals. It arises because rare, recessive alleles arise in a homozygous state where they can detrimentally affect the performance of individuals.

Inbreeding depression

is a relatively new field of research that combines population genetics, landscape ecology, and spatial statistics.

Landscape genetics

refers to the occurrence of populations that are subdivided by geography, behaviour, or other influences that prevent individuals from missing completely. Population subdivision leads to deviations from Hardy-Weinberg predictions.

Population structure

is a measure of how different populations are from each other genetically. Genetic distance can inform population geneticists about levels of inbreeding within a population or about the historic relationships between populations or species.

Genetic distance

is a measure of genetic distance between subpopulations.

Fst

describes the movement, or migration, of alleles from one population to another

Gene flow

is the study of continuous phenotypic traits and their underlying evolutionary mechanisms.

Quantitative genetics

is a statistical measure of the dispersion of trait values about their mean

Variance

is the proportion of the total phenotypic variance of a trait that is attributable to genetic variance, where genetic variance is represent in its entirety as a single value (i.e., genetic variance is not broken down into different components).

Broad sense heritability (H^2)

is the proportion of the total phenotypic variance of a trait attributable to the additive effects of alleles (the additive genetic variance). This is the component of variance that causes offspring to resemble their parents, and it causes populations to evolve predictably in response to selection

Narrow sense heritability (h^2)

): is a measure of the strength of phenotypic selection. The selection differential describes the difference between the mean of the reproducing members of the population who contribute offspring to the next generation and the mean of all members of the population

Selection differential (S)

are stretches of DNA that are correlated with variation in a phenotypic trait. These regions contain genes that contribute to population differences in a phenotype

Quantative trait loci (QTLs)

involves scanning through the genomes of many different individuals, some with, and others without, a focal trait of interest, to search for markers associated with expression of the trait.

Genome-wide association mapping (GWA)

refers to the pattern of phenotypic expression of a single genotype across a range of environments. In a sense, reaction norms depict how develops maps the genotype to the phenotype as a function of the environment.

Reaction norm

Homology can be used to show that species evolved from a common ancestor TRUE FALSE

True

Evolution increases adaptation TRUE FALSE

FALSE

Macroevolution is large changes within populations and species TRUE FALSE

FALSE

Sexual selection can explain the adaptive significance of sexual reproduction TRUE FALSE

FALSE

Directional selection decreases the variance of a trait TRUE FALSE

TRUE

The cost of producing males can explain the adaptive significance of sexual reproduction TRUE FALSE

FALSE

Evolution requires natural selection TRUE FALSE

FALSE

Random mating is required to calculate the Hardy-Weinberg portions (p^2 2pq q^2) TRUE FALSE

FALSE

Rare genetic disease could be maintained by mutation – selection balance TRUE FALSE

TRUE

Migration and gene flow homogenizes allele frequencies among populations TRUE FALSE

TRUE

The response to selection (R) predicts the selection differential (A) and the heritability (h^2) TRUE FALSE

FALSE

Random genetic drift decreases genetic variation within populations TRUE FALSE

TRUE

Random genetic drift increases genetic variation within populations TRUE FALSE

FALSE

A non-synonymous DNA nucleotide substitution can affect fitness. TRUE FALSE

TRUE

Homologous characters have a similar function TRUE FALSE

FALSE

With a large amount of phenotypic variation for a character and heritability = 0.8, directional selection will result in an increase in phenotypic variation TRUE FALSE

FALSE

Variation in mating success is generally greater in females than males TRUE FALSE

FALSE

Migration and gene flow between populations changes both allele and genotype frequencies TRUE FALSE

TRUE

Natural selection acts on individuals but its consequences affects populations TRUE FALSE

TRUE

A cline in allele frequency can be the result of natural selection and gene flow TRUE FALSE

FALSE

The response to selection (R) predicts the selection differential (S) and the heritability (h^2) TRUE FALSE

FALSE

The cost of producing males can explain the adaptive significance of sexual reproduction TRUE FALSE

FALSE

Directional selection can increase or decrease the mean of a trait in a population TRUE FALSE

TRUE

Natural selection can create new traits the increase fitness in new environments TRUE FALSE

TRUE

Mutation can result in evolution TRUE FALSE

TRUE

Heterozygosity is increased by random genetic drift TRUE FALSE

FALSE

Heterotic selection results in the fixation of heterozygotes in a population TRUE FALSE

TRUE

Mutations always cause the improvement of a trait TRUE FALSE

FALSE

Viruses mutate because they want to have the best adapted hemagglutinins throughout their evolution TRUE FALSE

FALSE

The ancestors of whales needed more food than could be found on land, so they evolved features that allowed them to survive. TRUE FALSE

FALSE

Natural selection acts on existing traits that may increase fitness in new environments TRUE FALSE

TRUE

Individuals that adjust their phenotypes in response to their environment cannot be favored by natural selection TRUE FALSE

FALSE

Natural selection does not act on phenotypes TRUE FALSE

FALSE

An individual’s behaviour is not part of its phenotype TRUE FALSE

FALSE

Most phenotypes are perfectly adapted to their environments TRUE FALSE

FALSE

Inbreeding is not a mechanism of evolution TRUE FALSE

TRUE

Inbreeding can affect the fitness of individuals, but it does not necessarily alter allele frequencies within a population TRUE FALSE

TRUE

Inbreeding depression is a concern of conservation biologists TRUE FALSE

TRUE

Inbreeding increases the probability that two alleles at any locus will be identical because of a shred common ancestor TRUE FALSE

TRUE

Narrow sense heritability includes only the epistatic effects of alleles TRUE FALSE

FALSE

Narrow sense heritability can be estimated by comparing quantitative trait loci among offspring using regression TRUE FALSE

FALSE

If rates of migration are high, then at equilibrium, Fst will be low. TRUE FALSE

TRUE

Gene flow causes populations to be similar while genetic drift causes populations to differ. TRUE FALSE

TRUE

Fst levels can be used to estimate migration rates. TRUE FALSE

TRUE

If rates of migration are low, then at equilibrium, Fst will be high. TRUE FALSE

TRUE

At equilibrium, Fst will be lower for large populations compared to small populations when Nm (number of migrants per generation)=2. TRUE FALSE

FALSE

An allele with a frequency of q = 0.0001 is likely to be recessive and deleterious (harmful). TRUE FALSE

FALSE