BIOL 1407 Lecture Exam #1 Question Bank

The most fit phenotype is assigned a fitness value of:

1.

One of the most important features of Galapagos finches is that the shape of their ________ is related to their ________ habits.

Beak; eating

Why does selection occur?

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

Identify the two main prezygotic isolating mechanisms between lions and tigers in India.

Behavioral Ecological

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.

Early horses inhabited woods areas where they probably browsed leaves and escaped predators by dodging through openings; this explains why those animals had ________ feet and __________ legs.

Broad; short

Sexual selection is a type of natural selection in which the evolution of certain traits is driven by which if the following types of competition?

Competition for mates.

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

Decreased.

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

Early embryonic similarities Homologous structures Vestigial structures

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

Fossils.

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.

Evolutionary change cannot occur in populations with no _______ variation.

Genetic.

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

Homologous; vestigial.

Homology vs. Embryonic Development vs. Vestigial Structures

Homology = Vertebrate Forelimbs Embryonic Development = Lanugo Vestigial Structures = Human Coccyx

What is the cause of the sixth mass extinction?

Human activity.

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/Mating

Choose all the components of fitness from the list below.

Individual survival, mating success, and production of viable, numerous offspring.

How does genetic drift affect allele frequencies?

It changes allele frequencies randomly.

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

It maintains genetic variation in a population.

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

It restricts genes flow.

B-Catenin, Bmp4, Ptchl, and Lbh are genes that determine the size and shape of the cichlid:

Jaw.

One of the most successful studies in showing evolution by natural selection is the one done by Peter and Rosemary Grant on the Galápagos Islands; scientists studied a hired that was referred to by the common name of ________ __________ finch.

Medium ground.

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 Members of two populations live in the same habitat, but they do not breed due to difference in their mating rituals Hybrid offspring have lower fitness than non-hybrid offspring, but some hybrids survive and reproduce

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

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

Typically, how are species on islands related to species in a nearby continent?

More closely.

What is the ultimate source of all new alleles?

Mutation.

_______ is the ultimate source of genetic variation.

Mutation.

Hybrid inviability and hybrid infertility are two examples of:

Postzygotic isolating mechanisms.

The amount of genetic variation present in naturally occurring populations is:

Significant.

In 1896, J.W. Tutt proposed that light colored moths were more visible to predators on:

Sooty trees that have lost their lichens due to pollution.

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.

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.

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?

3.

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.

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.

The term heterozygote _______ refers to situations in which heterozygotes are more fit than either homozygotes.

Advantage.

Select the observations that would indicate that a population is deviating from Hardy-Weinberg equilibrium.

Allele frequencies are changing between generations Genotype frequencies do not match those predicted by the Hardy-Weinberg equation based on existing allele frequencies

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

Allele frequencies.

How do postzygotic isolating mechanisms prevent successful interspecies hybridization?

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

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.

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

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

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 contrasting evolutionary change.

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

Artificial selection.

A seemingly important 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.

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.

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.

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.

According to the __________ species concept, species are distinguished by whether gene flow occurs between populations.

Biological.

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

Cats Pigeons Dogs Corn

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

Cattle Pigs Corn

When did humans begin to utilize artificial selection?

Centuries and millennia ago.

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

Character.

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.

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 Ana example of _________ evolution.

Convergent.

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

Convergent.

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

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.

What type of evidence for evolution is provided by fossils?

Direct.

Which type of selection favors individuals at one extreme of a phenotypic range who have greater reproductive success in a particular environment?

Directional selection.

Suppose that a population of finches migrated 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.

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

Directional.

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

Disruptive selection.

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

Disruptive.

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

Drift.

_________ isolation is another term for environmental isolation.

Ecological.

Organisms that are believed to share a common ancestor often show similarities in their early ________ development before diverging into varied forms.

Embryonic

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.

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

Evolutionary forces are affect the population.

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

Evolutionary forces can alter allele frequencies in natural populations.

Genetic variation is necessary for _______ change to occur.

Evolutionary.

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.

In natural populations, most genes:

Exhibit variation.

T/F: Within the same species, females and males usually employ the same reproductive strategy.

False

T/F: 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.

T/F: All species evolve over time either gradually or in a pattern predicted by the punctuated equilibrium model.

False.

T/F: Artificial selection has only recently become possible because of advances in our knowledge of genetics.

False.

T/F: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts.

False.

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

Finches; niches

What term quantifies reproductive success of a phenotype?

Fitness.

Which of the following statement at about marsupials in Australia is true?

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

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

Frequency-dependent.

Many laboratory experiments that test the hypothesis that selection can produce evolutionary change have been performed with Drosphilia melangester, known by its common name the _____________ _____________.

Fruit fly.

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

Gene flow Mutations Genetic drift Natural selection Nonrandom mating

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.

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

Gene flow.

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

Gene flow.

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

Genetic; nonrandom

Assortive mating changes ________ frequencies but does not change _________ frequencies.

Genotype; allele

Natural populations exhibit significant phenotypic and _________ variation.

Genotypic.

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

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

The concept of ________ suggests hat each new species evolved continuously over long spans of time.

Gradualism.

___________ and ________ __________ are two ends of the continuum of the pace of evolutionary change.

Gradualism; punctuated equilibrium

Developmental patterns seen in a group of organisms often reveal evolutionary relationships. Place the developmental descriptions in the order that they would occur in a group of related organisms, beginning with the earliest description at the top.

Greatest similarity is present Different characteristics are lost or formed Final form is attained

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 Drosophilia.

Consider a gene with the 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.

Which of the following best distinguishes vestigial from homologous structures?

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

Structures that are derived from a common ancestor but with different appearance and function are called _________ structures, while ___________ structures refers to structures that have little or no function but were functional in an ancestor.

Homologous; vestigial

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

Homologous; vestigial

The fossil record reveals that during the last 25 million years most of the lineages in the horse family have exhibited a rapid and substantial _________ in size.

Increase.

In certain areas of the world, populations of moths have been shown to change over the years with dark forms becoming more abundant than light forms; this phenomenon is called:

Industrial melanism.

The phenomenon, where dark forms of moths become more prevalent than light forms in industrialized areas, is known as __________ ____________.

Industrial melanism.

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.

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

Interspecies hybridization occurs in nature more often than was thought 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

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

Intrasexual.

Some critics of evolution claim that because complex cellular mechanisms (for example, blood clotting) are ________, the intricate machinery of the cell cannot be explained by evolution from simpler stages. But the argument ignores the fact that natural selection operates on _________.

Irreducibly complex; a system as a whole.

Reproductive __________ is the key to the process of speciation.

Isolation.

The teeth of modern members of the horse family are:

Large with a complex pattern of ridges.

Which of the following provide evidence that natural selection occurs in peppered moths?

Light moths become more abundant than melanic forms when clean air legislation is implemented Melanic moths become more abundant than light forms in polluted areas

J.W. Tutt proposed that ________ colored peppered moths were more visible to predators on trees without lichens.

Light.

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.

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

Mutations.

The observation that the relative frequencies of melanic to light peppered moths changes with the color is tree bark provided support for:

Natural selection

Evolutionary change within a population can result from which of the following?

Natural selection Migration Mutations

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

Natural selection.

The primary process responsible for evolution is _______ ________.

Natural selection.

What processes 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.

When a population is in Hardy-Weinberg equilibrium:

No natural selection is occurring.

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.

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.

Fitness is a measure of:

Number of offspring produced per mating Survival Mating success

What is meant by the term allopatric?

Occurring in geographically separated areas.

The feet of modern horses have ________ toe(s); in contrast, early horses had _________ toe(s) on their front feet and _________ toe(s) on their hind feet.

One; four; three

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.

The sex that is most choosy in selecting a mate is generally the sex that invests the most energy and time in producing and rearing offspring. Which of the following refers to the investment of time and energy?

Parental investment.

In a classic experiment m, scientists selected for fruit flies with many bristles on their abdomen by:

Picking out and breeding the 20% of the population that had the greatest number of bristles.

In Northeastern South America, which of the following is the main predator in streams ground just below water falls?

Pike cichlids.

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

Placental.

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

Pleiotropy.

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

Pleiotropy.

Scientists had observed that light colored moths decrease in abundance in areas that are:

Polluted.

_________ 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.

Select the two main types of reproductive isolating mechanisms based on when they act relative to the production of a zygote.

Postzygotic isolating mechanisms Prezygotic isolating mechanisms

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

Postzygotic.

The formation of an inter species hybrid zygote is prevented by ____________ isolating mechanisms, whereas ___________ isolating mechanisms prevent the successful development of hybrid zygotes once they are formed.

Prezygotic; postzygotic

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 in viability and infertility are _________ isolating mechanisms.

Prezygotic; postzygotic

Why is the argument "proteins are too improbable" invalid?

Probability cannot be used to argue backwards.

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.

Gene flow may:

Reduce evolutionary change Promote evolutionary change Remove alleles from a population Introduce new alleles to a population

Relative Dating vs. Absolute Dating

Relative Dating = Rocks are dated based on their position Absolute Dating = Rocks are dated based on changes in their isotopic composition

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 bring plumage of a male paradise bird are all examples of which of the following?

Secondary sexual characteristics.

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

Secondary sexual characteristics.

Galapagos finches with powerful thick beams typically eat large:

Seeds.

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

_________ selection is a type of natural selection in which competition for mates drives the evolution of certain traits.

Sexual

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

Similar; friction

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

Small and relatively simple.

Genetic drift has a greater impact in which of the following?

Small populations.

What is the preferred food of the Galapagos medium ground finch?

Small, tender seeds.

The fossil record shows that early species of horses were generally _______ in size, but many images since about 30 million years ago exhibit substantial change toward _________ in size.

Small; an increase

Island species are usually most closely related to:

Species on nearby continents.

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

Stabilizing selection.

_________ 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.

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.

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

Sympatric.

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

The fruit fly.

The most fit phenotype produces, on average, which of the following?

The greatest number of surviving offspring.

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.

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

The medium ground finch.

What is gene flow?

The movement of alleles into it out of a population.

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

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

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

The rate at which new mutations occur is low.

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)?

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

For a population to be in Hardy-Weinberg equilibrium:

There must be no migration into it out of the population.

What can likely happen to uncommon alleles in small, isolated populations as a result of genetic drift?

They are likely to be lost.

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 similar, but their mating calls differ. How would you describe the existence of such similar species in the same location?

They are sympatric species.

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

They exhibit drab coloration.

What trend has been observed in the fossil record of horses regarding the length of their limbs?

They have generally increased in length.

Which of the following is true about transitional fossils?

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

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.

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

Transitional Intermediate

Fossils that contain characteristics of two separate groups of organisms are called __________ fossils.

Transitional/Intermediate

T/F: Darwin's theory of evolution is not universally accepted.

True.

T/F: Natural selection does not always produce perfectly working adaptations, because it can only work on the genetic variation present in a population?

True.

T/F: Populations of a single species that connect those that are more geographically separated are often intermediate phenotypically when compared to the separated populations.

True.

T/F: Some populations that are considered to be separate species can interbreed and produce fertile offspring.

True.

T/F: The Earth is currently experiencing a sixth mass extinction as a result of human activity.

True.

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

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

The intelligent design argument cannot explain the presence of:

Vestigial structures Imperfect adaptations

Warbler Finches vs. Ground Finches vs. "Vampire" Finches

Warbler = Small narrow beaks Ground = Crushing beaks "Vampire" = Sharp beaks

The evolution of members of the horse family is:

Well-documented by the fossil record.

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

Wooded areas.

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

Would vary from one genotype to another.