bio ch 20-24

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For a gene with two alleles whose frequencies are p and q, the Hardy-Weinberg equation states that the genotypes that are possible for the population are p2 + 2pq + q2, which is equal to

(p + q)2.

Why is evolution considered a theory?

- because it helps explain a very wide range of observations -because it is supported by a large body of evidence

If the frequency of heterozygotes in a population of mice is 0.48 for a particular gene, what would be the frequency of heterozygotes in future generations if the population is in Hardy-Weinberg equilibrium?

0.48

In a population of seahorses, red seahorses on average produce 125 offspring and brown seahorses produce 75 offspring. What is the fitness of the brown phenotype?

0.6- Remember that the most fit phenotype is assigned a fitness value of 1. In this case the red seahorses will have a fitness of 1 and the brown seahorses will have a fitness of 75/125, or 0.6.

Consider a gene in a population of fruit bats. There are two alleles for this gene, A and a, that occur in a population with the frequencies 0.8 and 0.2, respectively. If the population is in Hardy-Weinberg equilibrium, what genotype frequencies will be observed?

0.64 AA, 0.32 Aa, and 0.04 aa

Consider a population with 100 cats. If 72 cats are black and 28 are white, what is the phenotypic frequency of black cats?

0.72

You are examining allele frequencies of a gene in a population of frogs. This gene has two alleles, T and t. If the frequency of the dominant allele (T) is 0.25, then the frequency of the recessive allele (t) is

0.75, .75, or 75%

The most fit phenotype is assigned a fitness value of ______.

1

The genomes of humans and chimps are different due to a number of insertions and deletions found in them. What is the percent of indels that are different between those two species?

1.5

Malaria is responsible for

1.7-2.5 million deaths each year

the feet of modern horses have ___ toe(s), early horses had _____ toes on their front feet and _____ toes on their hind feet.

1; 4; 3

Humans have a haploid chromosome number of _____ while all living great apes have a haploid chromosome number of _____. (Fill the blanks with numbers, do not spell them out.)

23; 24

In this example, six populations are currently under study. Four out of the six populations can interbreed with one another and produce fertile, viable offspring. Two of the populations can only form fertile, viable offspring with members of their own population. According to the biological species concept, how many species are present in this example? 2

3

The FOXP2 protein in mice and humans differs by only _____ amino acids, but the FOXP2 protein in chimps and humans differs by only _____ amino acids.

3; 2

In artificial selection experiments with corn plants that began in the 19th century, scientists have managed to increase oil content of corn kernels by

450%

The fossil record indicates that how many mass extinctions have occurred in the past?

5

The genome of P. falciparum appears to have about

5500 genes with those of related function clustered together

What proportion of insect species are beetles?

80%

Select all of the following that increase the chances of genetic drift in a population.

A few individuals of a population become isolated. A population becomes very small. Only a few individuals contribute gametes to the next generation.

What does a cladogram depict?

A hypothesis of evolutionary relationships

What are reproductive isolating mechanisms?

Barriers that prevent successful interbreeding among members of different species.

Why is it that some organisms do not appear to be perfectly adapted to their environment?

Because natural selection can only work on the variation present in a population.

Why does selection occur?

Because some individuals in a population possess more favorable phenotypes than others.

True or false: According to the fossil record, only two major mass extinctions have occurred in the past: one at the end of the Permian period and the other at the end of the Cretaceous period.

False- Five mass extinctions have occurred in the past. The one at the end of the Permian was the most severe and the one at the end of the Cretaceous is the most well-studied.

Which of the following processes are involved in making synthetic polyploids?

Crossing closely related plant species in the lab. Chemically inducting chromosome duplication in hybrids.

After a branch on a cladogram, each species will share a set of these characters that are not found in species below the branch point.

Derived

When populations are only partially reproductively isolated, which of the following may occur?

Despite prezygotic and postzygotic isolating mechanisms, some individuals may survive and reproduce.

How does artificial selection contradict the claim that selection can only produce minor evolutionary change?

Differences between breeds can be larger than differences between different genera of animals or plants.

Which of the following can be found when comparing genomes?

Differences in genes Differences in noncoding DNA Differences in the rate of genetic change DIfferences in whole DNA sequences

What type of evidence for evolution is provided by fossils?

Direct

Selection against intermediate-sized beaks in African black-bellied seedcracker finches is an example of which of the following?

Disruptive selection

Which type of selection acts to eliminate individuals which are intermediate on a phenotypic range?

Disruptive selection

Mechanisms that prevent formation of a zygote include ecological or environmental isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion.

Ecological Behavioral

Archaea are most closely related to

Eukarya

Which of the following are common misconceptions about evolution?

Evolution has not been demonstrated. Complex organs cannot be explained by evolution, but can be explained by intelligent design. A common misconception about evolution is that it violates the second law of thermodynamics.

Which of the following are common misconceptions about evolution that were traditionally thought to be revealed by the fossil records of horses.

Evolutionary change is constant through time. Natural selection is a progressive guiding force pushing evolution in a single direction.

What conclusion can be drawn from the observation that a population is not in Hardy-Weinberg equilibrium?

Evolutionary forces are affecting the population.

Which of the following is true of evolutionary forces in natural populations?

Evolutionary forces can alter allele frequencies in natural populations

Populations of a single species that are quite distinct from one another phenotypically may be connected by populations that have which characteristics?

Exhibit intermediate phenotypes

True or false: Recent findings suggest that there is no correlation between the prevalence of dark forms of moths and the pollution levels in an area.

False

True or false: The pace of speciation in most species is slow and gradual.

False

True or false: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts.

False- No, there are many types of organisms that have been modified by artificial selection, including many plants such as corn, strawberries, etc.

True or false: Genetic sequences are the only points of interest in the comparison of different genomes.

False- Other information, such as rate of change, is important as well.

What is synthesized in the apicoplast (and nowhere else in the cell) of the parasite P. falciparum?

Fatty acids

Which of the following is a driving force of intersexual selection?

Female choice of males based on certain characteristics

What term quantifies reproductive success of a phenotype?

Fitness

Which of the following statements about marsupials in Australia is true?

For many types of placental mammals found throughout the world, there is a strikingly similar marsupial mammal in Australia.

As the horse family fossil record became more complete, scientists realized that the evolution of horses was not linear, constant, and unidirectional. Why?

In some lineages completely opposite trends are observed The rates of evolution varied through time with long periods of little or no change Change often occurred simultaneously across the different lineages of the horse family

What type of sequences do scientists search for in the genome of distant human relatives such as pufferfish when trying to find clues about the causes of human diseases?

Highly conserved sequences

Which are true of antibiotic resistance?

Increased resistance is due to selection. Resistance initially was due to a random mutation.

Why is the use of a molecular clock controversial?

It assumes that DNA divergence rates are constant over time.

Which of the following best distinguishes vestigial from homologous structures?

Homologous structures are functional, while vestigial structures have no function.

How are homologous and homoplastic traits different?

Homologous traits are inherited from a common ancestor; homoplastic traits are not.

Some stretches of an organism's genome do not appear to have any function. How does this affect the construction of phylogenies?

Homoplasy can be more common in these regions.

Which of the following statements are true of an outgroup?

It can be used to polarize characters. It it closely related to the group under study, but is not a member of the group.

What is the cause of the sixth mass extinction?

Human activity

What is one of the reasons for the much higher genome size of humans when compared to pufferfish?

Humans have many more introns which are also substantially larger.

Identify the feeding behavior and habitat of lions.

Hunt in groups in open grassland areas

Although the biological species concept can be useful when distinguishing among species, it is not as effective when pertaining to organisms that commonly undergo _____ with other species and produce viable offspring.

Hybridization

Why are giraffe necks not perfectly suited for their function?

Like all mammals, giraffes only have 7 vertebrae in their necks which limits their flexibility.

Which of the following statements about the reproductive strategies of males and females is true?

Males and females often have different reproductive strategies.

Review the following list of processes that can alter the genetic make up of a population. Which one is considered by scientists to be primarily responsible for evolution?

Natural selection

What process may lead to speciation when a population adapts to its environment in such a way that it becomes reproductively isolated from other populations?

Natural selection

Which evolutionary mechanism causes beneficial traits that are heritable to become more common in a population?

Natural selection

Why is the rate of evolution more rapid in segments of DNA that have no function?

Natural selection does not affect these DNA sequences.

Why are genome size and gene number not correlated?

Not all DNA is coding

If we find evidence that a population is experiencing changes in allele frequencies from one generation to the next, we say that this population is which of the following?

Not in Hardy-Weinberg equilibrium

What is meant by the term allopatric?

Occurring in geographically separated areas

What is a character state?

One of two or more variations of a character

We know that evolution is not a random process, but imagine for a moment that evolution is random. If so, which of the following would be true?

Organisms that are least adapted to their environment could have the highest fitness.

What is the difference between paleo and synthetic polyploids?

Paleopolyploids are ancient, while synthetic polyploids are generated by scientists in the lab.

Which of the following statements reflect similarities and differences between paralogues and orthologues?

Paralogues arise through duplication, while orthologues arise through speciation. Both orthologues and paralogues reflect homology.

Which species could be used as an outgroup for the trait of having lungs in this cladogram?

Shark

After generations of selective breeding, this animal has been made exceptionally tame.

Silver fox

What kind of data were first used to create phylogenetic trees?

Similarities in morphology

Which of the following most accurately describes the evolution of different characters?

Some characters evolve more rapidly than others.

which of the following most accurately describes the evolution of different characters?

Some characters evolve more rapidly than others.

How much genome size variation can be accounted for by polyploidy?

Some genome size variation

What is a potential problem with the PSC (phylogenetic species concept)?

Some species may be paraphyletic.

What types of species are most likely to be able to disperse to an island (choose all that apply)?

Species that fly Species that float Species that drift

Which type of selection favors individuals with intermediate phenotypes and selects against individuals with extreme phenotypes?

Stabilizing selection

When little or no evolutionary change in a species occurs for a long time, that time period is known as which of the following?

Stasis

Which of the following are findings of the 1000 Genomes Project?

Substantial differences in the amount of variation in different parts of the genome An average of about 24 to 30 alleles associated with known inherited disorders per individual A large number of SNPs among the different individuals (about 14 million)

Which of the following (choose all that apply) have been suggested as hypotheses that may explain industrial melanism?

Surfaces in polluted areas get darker due to soot deposition. Pollution has toxic effects on light-colored moths. Lichens decline due to pollution.

A phylogeny is a hypothesis about the evolutionary history of a species or a group of species. Classification does not necessarily refer to evolutionary history.

Systematics refers to the reconstruction and study of evolutionary relationships. Classifications do not always reflect evolutionary relationships (although biologists are always improving them in that respect).

If we consider all frogs and toads together, we are including numerous genera and families at once. Which would be the appropriate term to use for this group of beings?

Taxon

Which of the following statements best describes the evolution of HIV?

The AIDS virus evolves very rapidly, changing significantly even within a single host.

Which of the following is the habitat of the scrub oak in California?

The chaparral

If reproductive isolation is the criterion used to define species, then the process of speciation is equivalent to which of the following?

The evolution of reproductive isolating mechanisms

Which organism has been extensively used in the laboratory to show that selection can produce evolutionary change?

The fruit fly

The phenomenon that causes a single ancestral species to evolve into a wide array of descendant species with diverse habitats, forms, or behaviors that occurs often as a result of colonization of a new area is known as which of the following?

Adaptive radiation

What evolutionary process leads to the existence of groups of closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment?

Adaptive radiation

electroreception

African and South Asian electric fish independently have evolved specialized organs in their tails that produce electrical discharges and electroreceptors on their skins to detect them. These discharges are used to communicate in social interactions

How do postzygotic isolating mechanisms prevent successful interspecies hybridization?

Although fertilization is successful, the resulting hybrid is unable to develop or reproduce.

Which of the following best describes the general trend in global species diversity over time?

An overall increase, but with some some sharp declines occurring at certain times

How can natural selection play a role in speciation?

As species adapt to different environments, they can accumulate differences that lead to speciation.

Which evolutionary mechanism changes genotype frequencies but does not change allele frequencies?

Assortative mating

Match the different types of anatomical evidence for evolution to an example.

homology- vertebrate forelimbs embryonic development- lanugo vestigial structures- human coccyx

Because there are only four character states possible for any nucleotide base in DNA, the probability of _____ between two species is higher than if more character states were possible.

homoplasy

Survival is significantly lower in individuals who are _____ for the sickle cell allele because of the lethal effect of the alleles, but individuals that are _____ for the sickle cell allele are more resistant to malaria because only the blood cells containing the malaria parasite sickle and are filtered out by the spleen. Listen to the complete question

homozygous; heterozygous

When genes are transferred from one species to another, we say that _____ gene transfer has occurred, but in _____ gene transfer, genes are passed from generation to generation.

horizontal; vertical

Phylogenies provide information about

how evolution occurred. evolutionary relationships among species.

The primary difference between natural and artificial selection is

how the parents are chosen (by humans or because of their reproductive success)

Modern tobacco arose from the _____ of two Nicotiana species and subsequent genome _____. Listen to the complete question

hybridization or cross; duplication

Starting in 1850 when Europe become industrialized, the frequency of melanic forms of the peppered moth in populations ______ until they made up ______ of some population.

increased; almost 100%

There is about a 1.5% difference in the number of _____ and _____ between humans and chimps.

insertions; deletions

A common misconception among the general public is that the features of species can be scientifically explained by _____ design.

intelligent

According to the theory of blending Inheritance, offspring were expected to be phenotypically _____ relative to their parents, which would dilute any new genetic variants.

intermediate

Even though there are gaps in the fossil record, some of the most direct evidence for evolution comes from fossils called ______ fossils that illustrate how certain major transformations in life forms occurred. Select all that apply.

intermediate transitional

The phenotype frequency is calculated by dividing the total number of individuals with a particular phenotype by which of the following?

The total number of individuals in that population

What is the predicted response of transposons to genome shock caused by polyploidization?

They jump to a new position in the genome.

In a laboratory experiment, researchers placed guppies in three different types of pools: no predation, low predation, and high predation. Researchers hypothesized that predation is a selective force and that large, brightly colored guppies are more conspicuous to predators. Based on that, what would you predict the guppies will look like in the pool with high predation after 10 generations?

They should be smaller and not very brightly colored

Segmental duplication occurs when:

a block of genes is duplicated

What are some fossil findings in recent years that have bridged major gaps in our understanding of vertebrate evolution?

a four-legged aquatic mammal was discovered only recently that provides important insights concerning the evolution of whales and dolphins from land-dwelling, hoofed ancestors a fossil snake with legs has shed light on the evolution of snakes, which are descended from lizards that gradually became more and more elongated with the simultaneous reduction and eventual disappearance of the limbs. Tiktaalik, a species that bridged the gap between fish and the first land-living vertebrates

A population bottleneck could be caused by

a natural disaster.

HIV obviously descended from SIV. All strains of HIV are phylogenetically nested within clades of SIV strains, indicating that HIV is derived from SIV humans have acquired HIV from different host species.

a number of different strains of HIV exist, and they appear to represent independent transfers from different primate species. Each of the human strains is more closely related to a strain of SIV than it is to other HIV strains, indicating separate origins of the HIV strains.

The closest relative to HIV is

a virus that infects monkeys

Natural selection results in ______ in a population.

adaptations

The formation of small islands by volcanic activity and subsequent colonization may lead to _____ _____, evolution of a closely related group of species adapted to different parts of the environment.

adaptive radiation

The genome of P. falciparum proved very difficult to sequence because of its high proportions of _____ and _____ which made it difficult to distinguish one region of it one from another.

adenine; thymine

The term heterozygote _____ refers to situations in which heterozygotes are more fit then either homozygotes.

advantage

Today, fossils have been found that link

all major groups of vertebrates

gene pools

all of the alleles present in a species

The founder effect results in a new population which differs in _____ frequencies from its source population.

allele

Genetic variation in a population results from evolutionary forces that cause changes in

allele frequencies

geographically separated, or allopatric, populations appear much more likely to have evolved substantial differences leading to speciation

allopatric speciation as the primary means of speciation

The toads, Bufo woodhousei and Bufo americanus have overlapping ranges. They usually do not interbreed because B.______ breeds in rainwater puddles and B. _____ breeds in stream.

americanus; woodhousei

In genes that are epistatic in nature,

an allele's selective advantage may vary from one individual to another based on their genotype.

Suppose that a population of finches migrates to a small island where most of the seeds are large. On the island, birds with large beaks are more likely to survive, and over time, the mean beak size of the population increases. This is an example of a type of natural selection known as _____ selection.

directional

Examples from artificial selection clearly show that natural selection

can produce large differences between populations

Artificial selection clearly shows that selection ______ evolutionary changes, such that over millions of years, selection can produce the diversity of life on earth.

can produce significant

A variant of a trait used in cladistic analyses is known as a _____ state.

character

In cladistics, a(n) _____ is any aspect of the phenotype, including morphology, physiology, behavior, and DNA.

character

The process by which natural selection produces a divergence in traits and resource use among sympatric species is called _____ displacement.

character

When examining species, we can look at multiple aspects of the makeup of those organisms, from DNA to behavior. Any such feature that we examine is called a(n) ______.

character

The apicoplast is a _____-like structure found in the cells of P. falciparum.

chloroplast

In the chromosomes of humans, the rate of duplication is related to the number of genes such that

chromosomes with fewer genes have also had fewer duplications

A _____ is constructed by nesting clades characterized by shared derived characters.

cladogram

The type of diagram that represents hypothesized evolutionary relationships among taxa is called a ______.

cladogram

The process of categorizing species and determining where they belong in the taxonomic hierarchy is known as ______.

classification

Overall, the evolutionary changes observed in the fossil record of the horse family can be understood as adaptations to changes in global

climates

Many genes in plants and animals are found across many species and show high degree of similarity, i.e. they are highly

conserved

Sequences that are ______ between humans and distant relatives such as the pufferfish provide valuable information regarding how genes cause human diseases.

conserved

The ant-eaters in South America and the Australian echidna have similar snouts and tongues that they use to capture ants. This is an example of _____ evolution.

convergent

The similar shapes of fast swimming marine predators are an example of _____ evolution.

convergent

_____ evolution happens when two species from different lineages independently evolve similar characteristics because they occupy similar environments.

convergent

_____ selection favors individuals at one extreme of a phenotypic range. Those individuals usually have greater reproductive success in a particular environment

directional

The genomes of threatened species can be mined to find genes that will lead to _____ reduction in those species.

disease

Beaks in African black-bellied seedcracker finches are small or large, but not intermediate in size. This is an example of _____ selection.

disruptive

Pseudogenes are genes that

do not produce a functional product

Genetic _____ leads to random changes between populations that may result in reproductive isolation.

drift

Genome sequence for pathogens can help researchers find suitable _____ targets used to eliminate the pathogens without harming the human host.

drug

Both the genomes of closely and distantly related organisms are useful in medical research; the former because they can be used in designed _____ to identify gene function, the latter because _____ sequences provide clues about the causes of disease.

experiments; conserved

Because genes can be _____ differently, species with nearly identical genomes (such as humans and chimps), can look and behave very differently.

expressed or regulated

As a result of polyploidization, the _____ of genes can be changed.

expression

Species with nearly identical genomes can look and behave very differently due to differences in the

expression of their genes

True or false: Within the same species, females and males usually employ the same reproductive strategy.

false

True or false: Polyploidy accounts for all genome size variation.

false- Other factors, such as ncDNA, are incorporated also.

In general, _____ are more likely to exhibit mate choice than _____.

females; males

Which of the following are reasons why island trees belong to plant families that typically do not have tree members (for example the sunflower family)?

Tree seeds rarely make it to isolated islands The tree niche is empty and so a flower can evolve through natural selection to be tree-like

Darwin's _____ likely evolved after an ancestral species colonized the Galapagos Islands and underwent character displacement as they adapted to the vacant ecological _____ available.

finches; niches

In _____ - _____ selection, the fitness of a phenotype depends on the proportion of individuals in the population that have that phenotype.

frequency dependent

Many of the laboratory experiments that test the hypothesis that selection can produce evolutionary change have been performed with Drosophila melanogaster, known by its common name the

fruit fly

Due to mutation without negative consequences, new character states may form more rapidly in regions of DNA that don't appear to have any

function

On occasion, the shuffling of parts of a gene due to a meiosis mistake can "land" the gene in a spot where it acquires a new

function or role

Promoting or constraining evolutionary change via the movement of beneficial or detrimental alleles into or out of a population is an effect of

gene flow.

In many cases, polyploidy induces the elimination of duplicated _____ or even whole _____

genes; chromosomes

A genome is the entire _____ sequence of an organism.

genetic

Evolution can result from any process that changes the ______ composition of a population.

genetic

Evolutionary change cannot occur in populations with no _____ variation.

genetic

the processes that lead to evolutionary change are mutations, natural selection, _______ drift, gene flow, and _____ mating.

genetic drift; nonrandom mating

The entire DNA sequence of an organism is called its

genome

Assortative mating changes ______ frequencies but does not change ______ frequencies.

genotype; allele

The accumulation of small changes at a relatively steady pace is known as

gradualism

The concept of _____ suggests that each new species evolves continuously over long spans of time.

gradualism

The idea that evolution occurs over time through the accumulation of small changes at a relatively steady pace is known as

gradualism

Many fishes that inhabit the sub-freezing Arctic and Antarctic waters posses antifreeze proteins; we now know that there are at least five different kinds of antifreeze protein genes that have evolved independently in different species to perform the same function. This is an example of:

convergent evolution

Structures that have evolved separately but look very similar exhibit _____ evolution; in contrast, structures that evolved through modification from a common ancestral trait are _____ structures.

convergent; homologous

Synthetic polyploids are created in the lab by _____ closely related plant species and then chemically inducing chromosome

crossing; doubling

Regarding the peppered moth, many studies have shown that in polluted areas, the ______ form of the moth is favored by natural selection, and in unpolluted areas, the ______ form of the moth is favored.

dark (melanic); light (peppered)

In the early 1850s, scientists noticed that the frequency of light colored peppered moths in polluted areas

decreased

biological species concept

defines species as " ... groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups."

Laboratory selection experiments have produced forms that cannot reproduce and thus would in nature be considered

different species

Evolutionary changes in the horse family can be related to changes in their habitat in North America (where most of the horse evolution has occurred); in particular, horse evolution was related to the widespread appearance of

grasslands

A type of sexual selection in which members of one sex, usually females, choose mates based on particular characteristics such as courtship songs is called

intersexual selection

_____ selection is a form of sexual selection based on same-sex competition usually involving males, in which the winner "gains" a mating partner.

intrasexual

One of the reasons for the large human genome is the presence of many relatively large _____ in our gene sequences.

introns

Because it favors those variations that lead to the highest reproductive fitness, natural selection:

is a non-random process

Darwin noted that _____ communities are often missing plants and animals typically found on continents.

island

Mechanisms that prevent genetic exchange between members of different species are termed reproductive _____ mechanisms and often play a role in plant and animal speciation. Listen to the complete question

isolating

Reproductive _____ is the key to the process of

isolation

Sometimes evolution can occur very rapidly and the number of derived shared characters can be small. In such cases, how is parsimonious analysis affected?

it can be inaccurate and misleading. similarity of species in this situation would more likely result from homoplasy than from inheritance from a common ancestor

A potential problem with the phylogenetic species concept is that

it may recognize even slightly differentiated populations as separate species.

β-catenin, Bmp4, PtchI, and Lbh are genes that determine the size and shape of the cichlid _____.

jaw

The human genome contains a

large amount of foreign DNA

The teeth of modern members of the horse family are

large with a complex pattern of ridges

Despite the _____ differences in their morphology and behavior, humans and chimps have accumulated _____ genetic differences since they last shared a common ancestor.

large; small

Evidence suggests that the human-specific mutations in FOXP2 gave early humans the ability to better use their brain to coordinate their _____ and _____, thus allowing them to speak.

larynx; mouth

Soon after it was established due to a founder effect, a population is expected to have (choose all that apply)

less genetic variation than the original larger population. different allele frequencies than the original larger population.

Peppered moths come in a variety of shades, from _____ gray with speckles to completely _____ (melanic).

light gray; black

Enzyme allele frequencies within a population may vary based on

location of the population.

What are the most likely fates of the duplicate gene after a gene duplication event?

lose function through mutation assume part of the function of the original gene gain novel function through mutation

Formation of a polyploid from two different species is usually followed by a rapid _____ of genes.

loss

what is a shared derived character for the group containing salamanders, lizards, tigers, gorillas, and humans?

lungs

Sequence analysis indicates that most of the transposon hitchhiking in the human genome seems to have occurred

many millions of years ago

Our genome carries how many transposons relative to the genomes of Drosophila, C. elegans or Arabidopsis.

many more

Aneuploids arise through mistakes in _____

meiosis

The jet black form of the peppered moth (Biston betularia) is also know as the _____ form.

melanic

Increased _____ may cause alteration of gene expression after polyploidzation.

methylation

The genome of a complex eukaryotic species normally evolves over

millions of years

A common criticism of evolution is that selection only produces ______ changes and cannot produce the variety of ______ documented in the fossil record.

minor; species

A _____ group includes its most recent common ancestor and all of its descendants, a _____ group includes its most recent common ancestor but not all of its descendants, and a _____ group does not include the most recent common ancestor of the organisms within the group.

monophyletic; paraphyletic; polyphyletic

The most commonly accepted hypothesis that explains industrial melanism and the reversal of industrial melanism is that

moths with coloration that matches their background are less susceptible to predation by birds

What is the ultimate source of all new alleles?

mutation

Changes in allele frequencies within a population may result from _____ which are changes in the nucleotide sequences of an organism's DNA.

mutations

Changes in allele frequencies within a population may result from _____, which are changes in the nucleotide sequences of an organism's DNA.

mutations

The primary process responsible for evolution is

natural selection

Antibiotic resistance in bacteria is an example of

natural selection.

Much of the human genome is composed of

ncDNA

In _____ frequency-dependent selection, individuals whose resource requirements are rarer have fewer competitors for resources than individuals whose resource requirements are more common.

negative

When a population is in Hardy-Weinberg equilibrium

no natural selection is occurring.

As more genomes are being sequenced, we have realized that much of the genome of organisms is composed of Blank 1 of 1 DNA, also known as ncDNA.

noncoding or intron

Darwin's theory of evolution is

not accepted by everyone in the general public

In nature, mutation rates are usually ______ to maintain alleles that are not favored in a population by natural selection.

not high enough

OR genes is an abbreviation used for _____ _____ genes.

olfactory receptor

Which of the following describes the handicap hypothesis?

only genetically superior mates can survive with such a handicap.

Natural selection results in a population better adapted to its environment because

only individuals who are well adapted to the environment contribute their alleles to the next generation.

When considering that Earth is an _____ system, it is easy to see that evolutionary theory does not violate the second law of thermodynamics.

open

Ground finches with large bills are favored during times of drought, while ground finches with small bills are favored during times when water is abundant. This is an example of

oscillating selection

In cladistics, a(n) _______ is a taxon that is closely related to, but not a member of, the group whose evolutionary relationships are being studied.

outgroup

Which is a correct version of the Hardy-Weinberg equation for genotype frequencies in a population in equilibrium?

p2 + 2pq + q2 = 1

Two genes in the genome of an organism that have arisen through the duplication of a single ancestor gene are called _____, in contrast, _____ are genes in different species that are derived from the same common ancestral gene.

paralogues; orthologues

_____ are chemicals produced by a species that trigger a social response

pheromones

In the Arabidopsis genome, many of the unique "plant" genes are involved in _____ and the anatomy required to perform it.

photosynthesis

3814 gene families are shared by every plant, from the algae to grapes and corn.

photosynthetic anatomy

According to the _____ species concept, a population should be considered a separate species if it has been evolving independently of other groups of populations.

phylogenetic

Scientists can distinguish between competing hypotheses on the patterns of biological diversity through the use of _____ methods.

phylogenetic

When more than one process could have caused a pattern in biological diversity that is observed today, what methods do scientists use to distinguish between those competing hypotheses?

phylogenetic methods

Varieties of which of the following organisms are the result of artificial selection?

pigeons dogs cats corn

Economically important organisms that have been modified significantly through artificial selection include

pigs corn cattle

As a result of convergent evolution, many marsupial mammals of Australia look similar to _____ mammals found elsewhere and occupy a similar ecological niche.

placental

Malaria is caused by parasites in the genus _____; humans are typically infected through the bite of the malaria vector - mosquitoes in the genus _____.

plasmodium; anopheles

Some genes can affect multiple aspects of an organism's phenotype. This phenomenon is known as

pleiotropy

Unintentional selection can be the result of linkage and

pleiotropy

In chickens, the same gene that affects a hen's comb also affects the rate at which the hen lays eggs. Tis is an example of

pleiotropy.

Scientists have observed that light colored moths decrease in abundance in areas that are

polluted

The following diagram shows the average number of gene pairs (Y axis) over time (X axis, about 75 million years are represented). The red dots on the diagram represent

polyploidy events

the study of genetic variation within populations

population genetics

reproductively isolated

populations whose members do not mate with each other or who cannot produce fertile offspring; members of different species

The type of selection demonstrated in the figure showing a fish with a rare phenotype attracting the attention of a predator is called

positive frequency-dependent selection

In _____ isolating mechanisms a hybrid zygote is formed, but it is unable to survive or reproduce due to developmental or genetic problems.

postzygotic

Hybrid inviability and hybrid infertility are two examples of

postzygotic isolating mechanisms.

reproductive isolating mechanisms

prevent genetic exchange between species

Ecological isolation, behavioral isolation, and temporal isolation are examples of _____ isolating mechanisms.

prezygotic

Ecological isolation, behavioral isolation, and temporal isolation are examples of _____ reproductive , Incorrect Unavailable isolating mechanisms.

prezygotic

The formation of an interspecies hybrid zygote is prevented by _____ isolating mechanisms, whereas ______ isolating mechanisms prevent the successful development of hybrid zygotes once they are formed.

prezygotic; postzygotic

Molecular analysis of lactase DNA _____ in humans shows that genes for that enzyme have _____ evolved in Africa and Europe to produce the same result.

sequences; independently

Sexual selection favors traits that give males greater ability in mate competition, therefore males and females within the same species may exhibit different traits. This difference between the sexes of the same species is known as

sexual dimorphism

Derived characters are

shared with the most recent common ancestor of a group, but not with prior ancestors.

Barbara McClintock hypothesized that transposons could respond to genome _____ by jumping into a new position in the genome.

shock

Early systematics (before the advent of molecular sequencing) was based on overall _____ between species.

similarities

Single-base differences between individuals in a population are known as

single-nucleotide polymorphisms (SNPs).

Fast swimming marine predators such as dolphins, sharks, and tuna, have a _____ body shape that minimizes _____ in the water.

sleek; friction

The teeth of early members of the horse family (for example, Hyracotherium) were

small and relatively simple

Plasmodium falciparum, the organism that causes malaria, has a relatively

small genome

OR genes are responsible for our sense of

smell

Gene flow occurs only between populations that are in contact, however, and populations can become geographically isolated for a variety of reasons

speciation is much more likely in geographically isolated populations.

What types of conditions may lead to adaptive radiation?

species occurs in an environment with few other species and many available resources creation of new islands through volcanic activity catastrophic event leading to the extinction of most other species, a phenomenon termed mass extinction

_____ selection favors individuals with intermediate phenotypes and selects against individuals with extreme phenotypes.

stabilizing

A long period of little or no evolutionary change in a species is known as

stasis

Organisms that have had their genome sequenced and are closely related to humans can be used in _____ to identify gene function.

studies

Species that are _____ species can occur in the same location and are phenotypically different.

sympatric

_____ is the study of the evolutionary relationships among organisms.

systematics

The field of _____ involves the reconstruction and study of evolutionary relationships among organisms, whereas _____ uses that information to place organisms into taxonomic groups.

systematics; classification

A term used to indicate species or higher level groups, such as genera or families, is

taxa or taxon

The science of classifying organisms is termed

taxonomy

In frequency-dependent selection

the fitness of a phenotype depends on how common it is in the population

True or false: Genetic drift, mutations, and nonrandom mating are three agents that can act to produce evolutionary changes in a population.

true

True or false: It appears that polyploidy has occurred numerous times during the evolution of plants.

true

Artificial selection may result in traits that are

unintended undesirable intended desirable

Attempts to domesticate silver foxes by artificial selection resulted in the _____ selection of traits which produced silver foxes that were as tame as domestic dogs.

unintentional

The pace of evolution is ______.

variable

According to genome comparisons, the most likely hypothesis that explains why many microbes have a mix of bacterial and archaeal genes is

very high rates of horizontal gene transfer in the early history of prokaryotes

Prior to 1850, the melanic form of the peppered moth in Europe was:

very rare

Two types of structures in adult organisms that provide anatomical evidence for evolution are _____ and _____ structures.

vestigial and homologous

Which have genomes that can evolve in a matter of days?

viruses bacteria

Match the beak shapes of Galapagos finches to their feeding habits.

warbler finches- small narrow beaks ground finches- crushing beaks "vampire" finches- sharp beaks

The medium ground finch of the Galápagos islands feeds on small seeds, produced in abundance during _____ years.

wet

Fill in the blanks to complete the sentence. Early horses inhabited woody areas where they probably browsed leaves and escaped predators by dodging through openings; this explains why those animals had _____ feet and _____ legs.

wider feet; shorter legs

The short legs and broad feet of early horses made them well adapted to their habitat which was

wooded areas

As a result of epistasis, the selective advantage of an allele

would vary from one genotype to another.

Select all of the following that could cause evolutionary change by natural selection.

A moth that has a gene for cryptic coloration A plant with an enzyme that makes it disease-resistant

Select all of the following events that could lead to a population bottleneck.

A natural disaster such as an earthquake or flood An infectious disease that kills a large proportion of the population Human destruction of habitat

The diversification of Drosophila species in the originally vacant niches and frequently isolated habitat patches of the Hawaiian Islands is an example of which of the following?

Adaptive radiation

Why do humans have one fewer chromosome (when considering the haploid number) than great apes?

Because two medium sized chromosomes have fused together in humans.

The production of pheromones by an animal contributes to which of the following types of prezygotic isolating mechanisms?

Behavorial

The idea that species are defined based on the ability to interbreed with each other and exchange genes is the basis of which species concept?

Biological species concept

Kettlewell released peppered moths in Birmingham, a highly industrialized area, and Dorset, then an unpolluted wood. In which of the two areas did he recapture a higher proportion of dark moths?

Birmingham

According to the handicap hypothesis, why does a female benefit from choosing the male with the largest handicap?

By choosing males with a large handicap females ensure that their offspring will have genes that confer better survival chances despite the handicap.

How is a cladogram constructed?

By using shared derived characters are to construct clades within clades

Which of the following accurately describes the rates of variation in different parts of the human genome, as determined by the 1000 Genomes Project?

Certain parts of the human genome contain more variation than others.

Which of the following is a process in which natural selection favors individuals with traits that allow them to use resources differently than other individuals, and over time the species diverges in phenotype and resource use?

Character displacement

In a cladogram, what word describes an ancestral species and all of its descendants?

Clade

Which of the following are ways in which genome analysis is used to treat and prevent human diseases?

Comparing individual human genomes. Comparing the genomes of pathogens with those of its host. Comparing genomes between humans and closely related species.

The evolution of these organisms is an example of adaptive radiation because populations were isolated and adapted to newly formed islands or habitat patches formed by lava flows.

Hawaiian Drosophila

Which of the following is the most direct evidence for evolution?

Fossils

How did modern tobacco arise?

From a cross between two Nicotiana species with subsequent genome duplication

Speciation is more likely in geographically isolated populations because which of the following does not occur?

Gene flow

Which of the following agents of evolutionary change occurs when alleles move from one population to another?

Gene flow

Why do genomes evolve at different rates?

Generation times differ among taxa. Transposable elements commonly remodel the genomes of certain taxa.

How can model organisms such as the mouse be used to determine the cause of human diseases?

Genes shared by mice and humans can be studied in mice and the results can be applied to treat human diseases.

Evolutionary change is not caused by phenotypic variation if the phenotypic variation lacks which of the following?

Genetic basis

What process can promote speciation through random changes between isolated populations?

Genetic drift

Many 19th century scientists believed that natural selection always favored an optimal form, and therefore would tend to reduce or eliminate which of the following?

Genetic variation

To what degree are plant and animal genes conserved?

Great

How does natural selection affect allele frequencies?

It causes beneficial alleles to become more common. It causes detrimental alleles to become less common.

How does homoplasy affect cladistic analysis?

It causes organisms to seem closely related when they are not.

How has phylogenetic analysis been used in studies of the human immunodeficiency virus (HIV)?

It has revealed that HIV evolved from a simian virus. It has been used to track the transmission of the virus among individuals.

Which of the following are limitations of the biological species concept?

It is difficult to determine whether geographically isolated species would interbreed in nature as they do in artificial settings. Reproductive isolation cannot explain speciation in organisms that reproduce asexually. Interspecies hybridization occurs in nature more often than was thought.

By favoring different phenotypes at different times, oscillating selection acts in which way?

It maintains genetic variation in a population.

Which of the following statements are true regarding the use of the molecular clock?

It may be used to determine the timing of clade branching events for a particular molecule. The evolutionary changes in genes with a constant rate of change can be determined.

Geographic isolation can accelerate speciation due to which of the following reasons?

It restricts gene flow.

How has phylogenetic analysis led to a greater understanding of HIV and AIDS?

It revealed that multiple HIV strains arose independently from SIV. It revealed that humans have acquired HIV from multiple species.

Which of the following are true of the mass extinction that occurred at the end of the Permian period?

It was the most severe mass extinction. As many as 96% of all species went extinct.

Consider a gene with two alleles, one dominant, and the other recessive. If this population is in Hardy-Weinberg equilibrium with respect to this gene, what would happen to the dominant allele from generation to generation?

Its frequency will remain unchanged

Once the data are assembled, the first step in a cladistic analysis is to polarize the characters—that is, to determine whether particular character states are ancestral or derived.

Jaws

Which of the following is true about the reproductive strategies of males and females?

Males are selective in choosing a mate much less frequently than females.

How does the biological species concept define a species?

Members of a species are able to interbreed in nature and are reproductively isolated from members of other species.

Which of the following statements is true in regard to how scientists define species based on the biological species concept?

Members of different species may be able to successfully hybridize under artificial conditions, but don't do so in the wild.

Which of the following situations are consistent with partial reproductive isolation?

Members of two populations mate primarily with members of their own population, but occasionally hybridize. Hybrid offspring have lower fitness than non-hybrid offspring, but some hybrids survive and reproduce. Members of two populations live in the same habitat, but they do not breed due to differences in their mating rituals.

Early horses had four toes on the front feet and three toes on the hind feet, all encased in fleshy pads. What statement correctly describes how the toes have changed during the evolution of modern horses?

Modern horses have a single toe enclosed in a bony hoof.

Which of the following is not an example of convergent evolution?

Muscles that wiggle the ears of humans and other mammals

What can a duplicated gene do after gene duplication that will result in a novel trait?

Mutate without a detrimental effect on the organism

How does homoplasy arise in DNA sequences?

Mutation of the same nucleotide base occurs independently in two lineages.

Select all of the following processes that can cause changes in allele or genotype frequencies in populations.

Mutations Genetic drift Gene flow Natural selection Nonrandom Mating

The following graph plots the relationship between beak depth of medium ground finches and their offspring. What can you conclude from that graph (choose all that apply)?

Parents with small beaks tend to have offspring with small beaks Beak depth seems to be a genetically inherited trait Parents with large beaks tend to have offspring with large beaks

In Northeastern South America, which of the following is the main predator in streams found just below waterfalls?

Pike cichlids

The extinction of the dinosaurs led to adaptive radiation in what group of animals?

Placental mammals

The presence of three or more chromosome sets is called

Polyploidy

_____ is the state of a cell or organism having more than two paired sets of chromosomes.

Polyploidy

Which of the following correctly links geographic isolation to speciation?

Populations living in geographically separated areas can undergo allopatric speciation

Which type of selection favors common phenotypes and tends to eliminate variation?

Positive frequency-dependent selection

Choose all the components of fitness from the list below:

Production of viable, numerous offspring Individual survival Mating success

When constructing phylogenies, the assumptions of the principle of parsimony may be violated under what conditions?

Rapid evolution of characters

How has rock and fossil dating changed since Darwin's times?

Relative dating was used in the past; today we use absolute dating.

What type of isolation occurs when members of one species are unable to successfully interbreed with members of another species?

Reproductive

Which characteristic of cichlids enabled them in their evolutionary radiation?

Second set of functioning jaws

A deer's antlers, a ram's horns and the bright plumage of a male paradise bird are all examples of which of the following?

Secondary sexual characteristics

How is the size of a population related to the likelihood that the population will experience genetic drift?

The larger the population, the lower the chance of genetic drift is.

What appears to determine variations in the coloration, size and maturation of guppies in northeastern South American streams?

The location of streams relative to waterfalls

What is gene flow?

The movement of alleles into or out of a population.

Select the conditions that must be met for a population to be in Hardy-Weinberg equilibrium.

The population is very large. No new mutations occur. Mating is random.

Select all of the following that can result from assortative mating.

The proportion of heterozygotes in the population decreases. The proportion of homozygotes in the population increases.

When genotypes differ in their resource requirements, which genotype has an advantage (assuming different resource types are equally abundant)?

The rarer genotype

Outside of mass extinctions, how has the rate of speciation compared to the rate of extinction over the past 600 million years?

The rate of speciation has surpassed the rate of extinction.

What is fitness?

The relative likelihood that a genotype will contribute to the gene pool of the next generation

What is systematics?

The study of evolutionary relationships among organisms

Select all of the following that are true about SNPs.

These are defined as single-base differences between individuals that exist in the population at more than 1%, several million have been noted in the human genome.

In Michigan, two different species of gray treefrogs, Hyla versicolor and Hyla chrysoceles, can exist in the same pond at the same time. The two species are anatomically very similar, but their mating calls differ. How would you describe the existence of such similar species in the same location?

They are sympatric species.

How can pharmaceutical researchers use genome sequence information to create new drugs against pathogens?

They can search the pathogen genomes for genes that are suitable drug targets.

In many animals, structures used for fighting, such as horns, have evolved to be larger in males because of which of the following?

They confer an advantage in intrasexual competition

Which describes male guppies located below South American waterfalls where predation is high?

They exhibit drab coloration.

Which of the following is true about transitional fossils (choose all that apply)?

They illustrate how major transitions in life occurred. They help to fill in the gap in the fossil record between two separate groups.

Organisms that exhibit polyploidy have how many sets of chromosomes?

Three or more

Most of the species that we use as food do not look like their ancestral species anymore. How have humans achieved that?

Through artificial selection

Where has industrial melanism been observed?

Throughout Eurasia and North America

How has the fossil record changed since Darwin?

Today the fossil record is far more complete.

How are traits produced by convergent evolution different from homologies?

Traits produced by convergent evolution have not evolved from a common ancestral trait, while homologies have.

True or false: Populations of a single species that connect those that are more geographically separated are often intermediate phenotypically when compared to the separated populations.

True

True or false: Some populations that are considered to be separate species can interbreed and produce fertile offspring.

True Reason: However, they do not do so under natural conditions. An example is the tiglon, which is a hybrid of lions and tigers. It can be produced in captivity, but is not found to occur in the wild.

Which of the following is the cause of Chagas disease?

Trypanosoma cruzi, an insect-borne protozoan, kills about 21,000 people in Central and South America each year.

Select all of the following that contributed to the adaptive radiation of Darwin's finches on the Galápagos Islands.

Vacant ecological niches Lack of many types of mainland birds Geographic isolation

Select all of the following criteria that must be present for natural selection to occur and cause evolutionary change in a population.

Variation must result in differences in the number of offspring surviving in the next generation. Variation must have a genetic basis. Variation must exist among individuals.

Research regarding the pace of evolution in well-documented groups of species has shown that the pace of evolution does which of the following?

Varies depending on the group of species

How are genes transferred during vertical and horizontal gene transfer?

Vertical - from parents to offspring; horizontal - between different species

Which of the following are anatomical features that provide evidence for evolution?

Vestigial structures Early embryonic similarities Homologous structures

Sometimes two different species can hybridize. If the hybrid undergoes a genome duplication, the result is an organism called

an allopolyploid

Derived characters are only shared with the most recent common ancestor of a clade, whereas _____ characters are shared with the most recent common ancestor as well as earlier ancestors.

ancestral or plesiomorphic

A clade consists of a common _____ species and all of its _____ species.

ancestral; descendant

The duplication or loss of a single chromosome (instead of the entire genome) is called

aneuploidy

Consider two populations (population A and population B) of the same plant species and the gene Xx. Researchers discover that there is constant flow of the x allele from population B into population A. This allele happens to be detrimental to individuals in population A because of the local soil conditions. In this case gene flow

appears to be constraining evolutionary change.

Most of the species that humans use as food have been modified through _____ selection.

artificial

The great variety of breeds of cats, dogs and other domestic animals have arisen through

artificial selection

The odd proportions of dachshunds have resulted from

artificial selection for dogs that could enter narrow badger holes

A seemingly irreducible complex structure can evolve by natural selection because

as natural selection acts to modify a complex system, the system is functional at each evolutionary stage.

The type of nonrandom mating in which phenotypically similar individuals mate is called _____ mating.

assortative

In _____, the genome of one species is duplicated because of a meiotic error leading to four copies of each chromosome, while _____ results from a hybridization of two species followed by genome duplication.

autopolyploidy; allopolyploidy

Polyploid individuals can arise in two ways. In _____, all of the chromosomes come from a single species and in _____ two species may hybridize.

autopolyploidy; allopolyploidy

The ______ species concept defines a species as a group of individuals that is able to interbreed, producing viable and fertile offspring.

biological

Genome sequencing has revealed many organisms that contain a mix of _____ and _____ genes.

bacterial; archaeal

When researchers raised guppies in laboratory pools with high levels of predation, the guppies in those aquariums

became smaller and drab in coloration as a result of natural selection after about 10 generations.

After a gene duplication event, which is not one of the most likely fates of the duplicate gene?

become a transposon

The following graph indicates the actual size of beaks of ground medium finches in a given year for almost two decades. Would you predict a span of wet years, a span of dry years, or a span of average years for the finches in the left box?

dry years What you should focus on is the change in beak size over time. In the left box there is a sharp increase of average beak size, therefore, you can conclude those years were dry.

In humans, the three most gene-rich chromosomes have undergone the highest amount of gene ______.

duplication

______ isolation is another term for environmental isolation.

ecological

We know that selection can occur based on climatic conditions, because biologists have found that

enzyme allele frequencies can vary with geographic latitude.

Regarding the three domains of life, current thought suggests that Archaea are more closely related to _____ than they are to _____

eukaryotes; bacteria

In theory, if mutation rates were high enough, alleles could be maintained in a population

even if the alleles are not favored by natural selection.

Genetic variation is necessary for _____ change to occur.

evolutionary

Phylogenies can be used to determine _____ relationships between species.

evolutionary

Gene duplication provides an opportunity for genes to _____ in their functions because after duplication a "backup" pair of genes is in place.

evolve

According to the phylogenetic species concept, a species is a population that

has evolved independently of other groups of populations

Consider a gene with two alleles, A1 and A2. If the fitness of A1A2 individuals is higher than the fitness of both A1A1 and A2A2, we are observing

heterozygote advantage.

The sickle-cell anemia allele is maintained at relatively high frequencies in some human populations because

heterozygotes for the disease allele are resistant to malaria.

Heterozygote advantage can maintain an allele that is deleterious when it is recessive because

heterozygotes have the highest fitness.

Artificial selection has resulted in all of the following outcomes in agriculture except

higher susceptibility to disease in tomatoes

_____ structures are those that are derived from the same body part in a common ancestor.

homologous

Similarities between species that occur because the species are derived from a common ancestor are referred to as

homologous traits

______ traits are derived from the same ancestral structure or source whereas _____ traits only appear similar, arising independently through convergent evolution.

homologous; homoplastic

The forelimbs of vertebrates are an example of _____, while the human appendix is an example of a _____ structure.

homologous; vestigial

There are two main types of reproductive isolating mechanisms, depending on whether or not a zygote is formed when two individuals attempt to mate. Behavioral, temporal, and mechanical isolation and prevention of gamete fusion are examples of _____ isolating mechanisms whereas hybrid inviability and infertility are _____ isolating mechanisms. Listen to the complete question

prezygotic; postzygotic

Current evidence suggests that the common ancestor of Bacteria and Archaea was most likely an early

prokaryote

The common ancestor of Bacteria and Archaea was most likely an early

prokaryote

Gene flow may (choose all that apply)

promote evolutionary change. remove alleles from a population. introduce new alleles to a population. reduce evolutionary change.

Genome comparisons aid conservation biology by

providing information on genes involved in diseases

When errors in meiosis rearrange parts of genes, the most common result is the appearance of a

pseudogene

Genes that do not produce a functional product are known as

pseudogenes

One consequence of mass extinctions is that dominant species may go extinct, allowing other species to undergo adaptive _____ to use the newly freed resources.

radiation

Because there is no natural selection against mutations in regions of DNA that are nonfunctional, evolution in those regions occurs more _____.

rapidly

industrial melanism

refers to the phenomenon in which darker individuals come to predominate over lighter ones

Match the type of rock dating with its description.

relative dating- rocks are dated based on their position absolute dating- rocks are dated based on changes in their isotopic composition

Evidence shows that polyploidy has occurred

relatively often during the evolution of plants.

Features that increase the chance that a male will be chosen by a female (for example, bright plumage in many male birds) are known as _____ _____ characteristics.

secondary sexual

According to some critics of evolution, natural selection can produce changes in a population, but it cannot cause substantial changes leading to

the formation of an entirely new species.

On a branching diagram, what does the joining of twigs and branches represent?

the joining of twigs and branches reflects the pattern of common ancestry back in time to the single common ancestor of all life

Peter and Rosemary Grant studied natural selection in Galápagos finches for more than 40 years; which species was the focus of their research?

the medium ground finch

New mutations are not a major factor affecting the allele frequencies in a population because

the rate at which new mutations occur is low

What is the main assumption behind the idea of a molecular clock?

the rate of evolution of a molecule is constant through time

On a branching diagram, where should existing species be placed?

the twigs of the tree represent existing species

Evolution is supported by a substantial body of evidence and explains a wide range of observations, thus it is considered a scientific

theory

For a population to be in Hardy-Weinberg equilibrium,

there must be no migration into or out of the population.

Complex characters, such as the ability to fly or the human eye, usually evolve

through a progression of gradual transitions, starting out as an adaptation for some other purpose

Most complex characters evolve

through a series of evolutionary transitions

The average number of gene pairs is shown here as the Y axis, while time is shown on the X axis. About 75 million years are represented. The arrows pointing to the blue line indicate

times of gene loss after polyploidy

In recent years, scientists have discovered remarkable fossils, such as a four-legged aquatic mammal and a snake with legs. These are examples of

transitional fossils

The relative amounts of _____ elements allows some genomes to evolve faster than others.

transposable

In very distant ancestor genomes several million years ago, sequence analysis suggests that human genome acquired most its

transposons


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