BIO II CH 19-22

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

Competition for mates

True or false: Since the Cambrian period, biological diversity has greatly decreased around the globe.

False; Biological diversity has greatly increased as species have evolved to utilize vacant niches.

True or false: Natural selection is the same as evolution.

False; Evolution is change in a population over time. Natural selection is one of the processes that can bring about evolution.

True or false: Organisms that are more closely related have accumulated a greater number of genetic changes.

False; The opposite is true; the more closely related organisms are, the less their genetic difference.

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

False; since females and males invest resources differently, they often also have very different reproductive strategies.

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

False; there are many types of organisms that have been modified by artificial selection, including many plants such as corn, strawberries, etc.

True or false: All organisms have become perfectly adapted to their environment in the course of evolution.

Fasle; Natural selection can only work on the variation that is present within a population, so some organisms are not perfectly adapted.

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

Female choice of males based on certain characteristics

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

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

The great diversity of alpine buttercups in New Zealand may be attributed to which of the following? The founder effect Periodic isolation Habitat fragmentation due to changes in water levels Formation of new islands due to volcanic activity

Periodic isolation

Industrial melanism

Phenomenon in which darker individuals come to predominate over lighter ones

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

True; 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.

True or false: The fossil record is able to show evidence of mass extinctions.

True; Changes in the levels of biodiversity are seen in the fossil record and can show periods of mass extinctions.

True or false: Darwin's theory of evolution is not accepted by everyone, especially in the general public.

True; Darwin's theory is often the subject of controversy, and it is not accepted by everyone.

Select all of the following that contributed to the adaptive radiation of Darwin's finches on the Galápagos Islands. Allopolyploidy Repeated instances of gene flow from the mainland Vacant ecological niches Lack of many types of mainland birds Geographic isolation

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

How often do fossils form?

Very rarely

Sympatric species that show behavioral isolation avoid mating with members of the wrong species in a variety of ways, including differences in:

Visual signals Sound production Chemical signals: pheromones Electrical signals: electroreception

Artificial selection

Who/whatever is doing the breeding is selecting the specific traits that will show up in the offspring

Subspecies

Within a single species, individuals in populations that occur in different areas may be distinct from one another

In what type of selection does a breeder select for desirable characteristics in organisms?

artificial selection

A process that can drive adaptation to minimize competition for resources among sympatric species is called polyploidy. hybrid sterility. character displacement. reinforcement isolation.

character displacement.

The great diversity observed in the _____ fishes in Lake Victoria is an example of adaptive radiation.

cichlid

When a female mates with multiple males, not every male's sperm has an equal chance to fertilize an egg; in these cases, we observe sperm _____ between males.

competition

Gene flow can be both ____ and ____.

constructive, constraining

When two species from different lineages independently evolve similar characteristics because they occupy similar environments, we observe ______. artificial selection homologous structures vestigial traits convergent evolution

convergent evolution

The plant shown in the figure (teosinte) has been modified through artificial selection over many years to become what we know today as

corn

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

What term quantifies reproductive success of a phenotype?

fitness

The Biological Species Concept

focuses on ability to exchange genes

Organisms that are transitional between hoofed mammals and whales, between reptiles and mammals, between apes and humans, and between fish and tetrapods are all examples of ______ that have been discovered. living organisms endemic species organisms thought to have been extinct fossil intermediates

fossil intermediates

Changes in allele frequencies that result from the colonization of a new location by a small group of individuals from a larger population

founder effect

Changes in genetic variation that occurs when a new population is established by a very small number of individuals from a larger population

founder effect

The population is dependent on whatever was there to begin with (pioneer species)

founder effect

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

Prevention of _____ fusion acts as a reproductive isolating mechanism because sperm from one species is unable to successfully fertilize the egg of another species.

gamete

Prevention of gamete fusion:

gametes of one species function poorly with the gametes of another species or within the reproductive tract of another species

In incompletely reproductively isolated populations, _____ _____ decreases genetic distinctiveness between the populations when hybrids are produced and reproduce with members of either population.

gene flow

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

The drifting of gametes or immature stages of plant/marine animal from one place to another is an example of

gene flow

The mating of individuals from adjacent populations is an example of

gene flow

When an animal physically moves into a new population, that is an example of

gene flow

In populations that are incompletely reproductively isolated, speciation is countered by hybrid inviability. mechanical isolation. gene flow. reinforcement. hybrid infertility.

gene flow.

Because of ____ ____, even a harmful allele that is selectively disadvantageous can increase in frequency in a small population.

genetic drift

Dependent on small populations (small gene pools) and allele frequency may change by chance alone

genetic drift

The fewer individuals in the population, the bigger effect a ____ ____ can have on that population

genetic drift

What evolutionary mechanism results in random changes in allele frequencies from one generation to the next?

genetic drift

Which agent of evolutionary change can lead to complete allele loss within the population?

genetic drift

Consider two populations of the same plant species - population A and population B 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. This is an example of

genetic drift reinforcing natural selection.

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

gradualism

Ernst Mayr defined species as:

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

In the laboratory setting, selection for a trait in fruit flies

has consistently lead to a strong, predictable evolutionary response

Homozygous

having two identical alleles of a particular gene or genes

A situation where individuals with two different alleles at a gene locus are favored over individuals with two of the same alleles at the locus is called ______ advantage.

heterozygous

Natural selection may be countered by mutations when mutation rates are _____ and by genetic drift when population sizes are _____.

high, small

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

higher susceptibility to disease in tomatoes

Structures with different appearances and functions that are all derived from the same body part in a common ancestor are called ______ structures.

homologous

Selection

individuals that have some sort of trait or behavior that is advantageous for their environment will produce more offspring

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

Regarding moths, the phenomenon where dark forms of individuals become more prevalent than light forms is known as _____ _____.

industrial melansim

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

In _____ selection, a small number of males may mate an inordinate number of times, while a large number of males rarely mate if they mate at all.

intrasexual

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

intrasexual

Disassortative mating

mates chosen based on dissimilarity to self

Assortative mating

mates chosen based on phenotypic similarity to self

A prezygotic isolating mechanism that physically prevents mating due to structures differences of reproductive organs is _____ isolation.

mechanical

The inability of different species to interbreed because of an incompatibility in reproductive organs is known as ____. temporal isolation ecological isolation hybrid inviability mechanical isolation behavioral isolation

mechanical isolation

Reproductive isolation

members of a species do not mate with each other or do not produce fertile offspring

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

minor species

Most phenotypes in nature are affected by

more than one gene.

Gene flow may:

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

Species concepts based on ______ do not apply to species that reproduce asexually. response to environmental changes nutrient usage reproductive isolation DNA sequence data

reproductive isolation

When members of populations do not mate with each other or cannot produce fertile offspring, they are undergoing anagenesis undergoing speciation reproductively isolated experiencing gene flow

reproductively isolated

Sexual selection often results in the evolution of features that increase the chance that a male will be chosen by a female (for example, bright plumage in many male birds); these features are known as _____ _____ characteristics.

secondary sexual

Galapagos finches with powerful thick beaks typically eat large ____.

seeds

The most powerful of the principle of agents of genetic change

selection

The theory of natural ________ as a mechanism of evolution was proposed by Charles Darwin.

selection

Assortative mating in plants is

self-fertilization

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

sexual

In many species of animals, males and females look very different as a result of sexual selection. These animal species exhibit which of the following?

sexual dimorphism

The amount of genetic variation present in naturally occurring populations is

significant

Features of fruit flies that have been selected for in laboratory experiments include body _____, eye _____, and growth rate, among others.

size color

Sexual selection

some individuals are more successful at attracting mates

Selection

some individuals leave behind more progeny than others, and the rate at which they do so is affected by phenotype and behavior

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

When members of two populations are completely reproductively isolated, they will remain two distinct _____ when they come into physical contact.

species

Behavioral isolation:

species differ in their mating rituals

Ecological isolation:

species occur in the same area, but they occupy different habitats and rarely encounter each other

Temporal isolation:

species reproduce in different seasons or at different times of the day

Mechanical isolation:

structural differences between species prevent mating

An example of recent experiments of evolution that have been conducted both in the lab and in the field are

studies of the guppy - Poecilia Reticulata.

What results in loss of genetic variability

survivors are random, so their genes/alleles are random and some alleles of the original population do not survive

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

sympatric

Species that occur in the same geographic area but are distinct species because they look different, utilize different parts of the environment, or behave differently, are polyploid species allopatric species sympatric species subspecies

sympatric species

If reproductive isolation is the criterion used to define species, then the process of speciation is equivalent to ____. the interaction between genetic drift and natural selection the evolution of reproductive isolating mechanisms the interaction between gene flow and natural selection

the evolution of reproductive isolating mechanisms

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.

The great diversity of Drosophila on the Hawaiian Islands may be attributed to ____. the formation of new islands by volcanoes the average temperature of the islands the annual rainfall of the islands the absence of predators

the formation of new islands by volcanoes

The change in allele frequencies that occur due to the colonization of a new location by a small group of individuals is called

the founder effect

Biogeography is the study of patterns of embryological development in vertebrates. the accumulation of molecular differences among a group of related organisms. the geographic distribution of modern and extinct species. homologous structures among different species.

the geographic distribution of modern and extinct species.

Epistasis

the interaction of genes that can suppress of the effect of one gene by another.

Because changes in traits are due to changes in alleles of a gene, the more distantly related two organisms are, the more different they are molecularly. the more equal they are molecularly. the less different they are molecularly.

the more different they are molecularly.

Fitness

the most fit phenotype is simply the one that produces, on average, the greatest number of offspring

Gene flow

the movement of alleles from one population to another

Pleiotropy

the production by a single gene of two or more apparently unrelated effects.

Prior to 1850, the melanic form of the peppered moth in Europe was ____ _____.

very rare

A _____ structure has no apparent function in a species, but is fully functional in the species' ancestors.

vestigial

Supporters of intelligent design cannot explain the presence of vestigial structures. imperfect adaptations. very complex structures.

vestigial structures imperfect adaptations

Some species have anatomical features that have no apparent function but resemble structures of their presumed ancestors; these anatomical features are called analogous structures. homologous structures. vestigial structures.

vestigial structures.

Which of the following drives intrasexual selection?

Competition between males for females

During their study of medium ground finches, what were the Grants' findings regarding: (1) the amount of variation in beak depth among medium finches, and (2) the change in average beak depth from one year to another?

(1) great variation; (2) predictable change

Limitations to selection and what is can accomplish:

- Lack of genetic variation - Multiple phenotypic effects of alleles - Interactions between genes

Types of selection:

-Disruptive -Directional -Stabilizing

3 conditions for natural selection to occur and to result in evolutionary change:

-Variation must exist among individuals in a population -Variation among individuals must result in differences in the number of offspring surviving in the next generation -Variation must be genetically inherited

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. final form is attained greatest similarity is present different characteristics are lost or formed

1. greatest similarity is present 2. different characteristics are lost or formed 3. final form is attained

Autopolyploidy is when an individual has more than two sets of chromosomes as a result of which of the following? Hybridization between two species. Reproduction of a triploid individual. A cell division error in two species. A cell division error in a single species.

A cell division error in a single species.

What accurately describes sperm competition?

A female mates with multiple males and not every male's sperm has equal chances of fertilizing an egg.

What types of conditions may lead to adaptive radiation? A species occurs in an environment with few other species and many resources A duplication of chromosome sets via allopolyploidy Gene flow between previously isolated populations that are recently reconnected Formation of islands through volcanic activity and subsequent colonization

A species occurs in an environment with few other species and many resources Formation of islands through volcanic activity and subsequent colonization

Stabilizing selection

Acts to eliminate both extremes

Disruptive selection

Acts to eliminate intermediate types

Directional selection

Acts to eliminate one extreme

Which of the following are typical characteristics of all modern members of the horse family? Adapted to grasslands Except for horses, slow runners Fast runners Long legs Adapted to deserts

Adapted to grasslands Fast runners Long legs

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? Disruptive selection Adaptive radiation Character displacement Genetic drift Reinforcement

Adaptive radiation

What process led to the diversification of alpine buttercups in New Zealand? Hybridization Mass extinction Adaptive radiation Allopolyploidy Autopolyploidy

Adaptive radiation

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? Behavioral isolation Genetic drift Mechanical isolation Character displacement

Character displacement

Select all of the following that provide molecular evidence of evolution. All animals possess similar pattern formation genes. Whales have pelvic bones that resemble those of other mammals. Color vision genes are similar among relatives of humans. Humans have pharnygeal pouches during embryonic development.

All animals possess similar pattern formation genes. Color vision genes are similar among relatives of humans.

An increase in chromosome number due to hybridization of two species followed by doubling of the chromosome number in the hybrid offspring is a type of polyploidy called which of the following? Allopolyploidy Multiploidy Autopolyploidy Diploidy

Allopolyploidy

What condition is produced when two species hybridize and hybrid offspring have multiple sets of chromosomes? Allopatry Autopatry Autopolyploidy Allopolyploidy

Allopolyploidy

How do postzygotic isolating mechanisms prevent successful interspecies hybridization? Members of different species come into contact, but do not recognize one another as potential mates. Members of different species attempt to mate but are unsuccessful due to anatomical differences. The egg cannot be fertilized by sperm of another species following a successful mating attempt. Although fertilization is successful, the resulting hybrid is unable to reproduce.

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

Select the ways that polyploid individuals can arise. Hybridization of two allopatric species An error in cell division in a single species Geographic isolation of a single species followed by colonization by a different species Hybridization of two species followed by chromosome doubling

An error in cell division in a single species Hybridization of two species followed by chromosome doubling

Sympatric species

Are distinctive entities Are phenotypically different Utilize different parts of the habitat Behave separately

Select events that likely led to mass extinctions in Earth's evolutionary history. Asteroid collisions Predation by dinosaurs Global climate change Domination of Earth's environments by plants

Asteroid collisions Global climate change

The condition in which an individual has more than two sets of chromosomes due to a cell division error occurring in a single species is called which of the following? Unequal crossing over Autopolyploidy Crossing over Allopolyploidy

Autopolyploidy

What are reproductive isolating mechanisms? Procedures used in the study of courtship behavior in different species. Ways used by researchers to facilitate breeding of animals in captivity. Barriers that prevent successful interbreeding among members of different species. Techniques for isolating gametes and reproductive tissues for genetic analysis in order to identify species. Procedures used to study the embryonic development of different species.

Barriers that prevent successful interbreeding among members of different species.

Why is evolution considered a theory? Because it is an educated guess that explains the diversity of life. Because it helps explain a very wide range of observations. Because it can explain all observations in biology Because it is supported by a large body of evidence.

Because it helps explain a very wide range of observations. Because it is supported by a large body of evidence.

Why does selection occur?

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

Which form of isolation occurs when differences in mating rituals, courtship songs, or chemical and electric communication prevent members of two different species from interbreeding? Mechanical Behavioral Temporal Gametic Habitat

Behavioral

A female bird refuses to mate with a male bird of another species because he does not perform the correct courtship ritual. This is an example of which of the following? Ecological isolation Hybrid inviability Temporal isolation Mechanical isolation Behavioral isolation

Behavioral isolation

_____ is the study of the geographic distribution of modern and extinct species.

Biogeography

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? General lineage species concept Ecological species concept Phylogenetic species concept Genetic species concept Biological species concept

Biological species concept

Behavioral isolation

Blue-footed boobies select mates after an elaborate courtship display They will not mate with other boobies

Which must be accounted for in any species concept? Connections between different populations of the same species Reproductive isolating mechanisms relevant to a geographic location Genetic differences with a single location on a chromosome Distinctiveness of species that occur together in a single location

Connections between different populations of the same species Distinctiveness of species that occur together in a single location

Which of the following would be molecular evidence of evolution? Conserved DNA sequences Similar biogeographical patterns of distribution Imperfect structures Transitional fossils

Conserved DNA sequences

_____ evolution happens when natural selection appears to have favored parallel adaptations in unrelated organisms that live in similar environments.

Convergent

Who mistakenly believed that evolution occurred at an extremely slow pace?

Darwin

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.

What type of evidence for evolution is provided by fossils?

Direct

What type of selection favors individuals with phenotypes toward one end of an array of phenotypes?

Directional

What type of selection often occurs in nature when the environment changes?

Directional selection

Produces excess of heterozygotes

Disassortative mating

Sympatric speciation can result from which type of natural selection that produces two different phenotypes in a population? Balancing selection Disruptive selection Directional selection Stabilizing selection

Disruptive selection

Which of the following best defines subspecies? Populations of the same species that differ in at least 50% of their features. Populations of the same species that can have intermediate features. Distinct populations of the same species that inhabit different areas. Populations of different species that can produce living (but not necessarily fertile) offspring.

Distinct populations of the same species that inhabit different areas.

Tigers and lions rarely successfully hybridize in the wild because of which reproductive isolating mechanism? Ecological isolation Temporal isolation Hybrid inviability Geographic isolation

Ecological isolation

Two species of oak (Quercus lobata and Q. dumosa) occur in California, but Q. lobata (the valley oak) is a tall tree that grows in fertile soils in open grassland and Q. dumosa is an evergreen shrub, which grows in less fertile soils on steep slopes. Hybridization is possible but rare. This is an example of which of the following? Mechanical isolation Geographical isolation Ecological isolation Temporal isolation Behavioral isolation

Ecological isolation

The idea that species can be defined based on how natural selection maintains their adaptation to their own environmental niche is known as which of the following? Ecological species concept Phylogenetic species concept Biological species concept Evolutionary species concept

Ecological species concept

The introduction of the Nile perch into Lake Victoria has led to which of the following? Extinction of cichlid species Sterility of cichlid species Hybridization of cichlid species Adaptive radiation of cichlid species

Extinction of cichlid species

Select all of the following organism transitions that are documented by the fossil record. Fish and tetrapods Peppered moths and finches Dinosaurs and birds Hoofed mammals and whales

Fish and tetrapods Dinosaurs and birds Hoofed mammals and whales

Which of the following statements about marsupials in Australia is true? Marsupial animals are unique and bear no similarities to any other mammals in the world. For many types of placental mammals found throughout the world, there is a strikingly similar marsupial mammal in Australia. A marsupial mouse is more closely related to a placental mouse than to a marsupial mole.

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

Which of the following is the most direct evidence for evolution? Homologous organs Darwin's finches Fossils Marsupials in Australia

Fossils

In what type of selection is a phenotype favored based on how common or uncommon it is?

Frequency-dependent selection

Speciation is more likely in geographically isolated populations because which of the following does not occur? Genetic drift Natural selection Gene flow

Gene flow

Gene flow can sometimes promote evolutionary change, but at other times it can constrain evolutionary change. How is that possible?

Gene flow can spread a beneficial allele or an inferior allele from one population to other populations.

For natural selection to occur, variation in traits must be which of the following?

Genetic and heritable

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? Gene flow Adaptive radiation Natural selection Genetic drift

Genetic drift

What did the scientists Godfrey Hardy and Wilhelm Weinberg explain?

Genetic variation in a population

The accumulation of small evolutionary changes at a relatively steady pace is known as which of the following? Stasis Adaptive radiation Gradualism Punctuated equilibrium Reinforcement

Gradualism

After Mendel's work was rediscovered, what scientists explained why a population doesn't always come to be composed solely of individuals with the dominant phenotype?

Hardy and Weinberg

In a large population that is not subject to mutation, migration, selection, or nonrandom mating, the proportions of genotypes are stable and the population is said to be in _____ - _____ equilibrium, named after the scientists who described this principle.

Hardy-Weinburg

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. Lake Victoria cichlids Caribbean Anolis lizards New Zealand buttercups Galapagos finches Hawaiian Drosophila

Hawaiian Drosophila

The not uncommon occurrence in natural settings of which of the following weakens the biological species concept? Natural selection Adaptation Mutation Hybridization

Hybridization

Which is left unexplained by the biological species concept, thereby weakening the concept? Hybridization in captivity Hybridization in natural settings

Hybridization in natural settings

Which of the following is an example of behavioral isolation? Two species of field crickets that mature and reproduce at different times of the year Differences in the body shapes of two species of dragonfly, preventing the male from clasping onto the female for successful copulation Successful mating between a donkey and a horse that results in the production of a mule, a sterile hybrid Inability of different species of meadowlarks to recognize each other as potential mates due to differences in their songs

Inability of different species of meadowlarks to recognize each other as potential mates due to differences in their songs

How does temporal isolation prevent successful interbreeding among members of different species? Differences in behavior prevent individuals of different species from recognizing one another as potential mates, so no gametes are exchanged. Mating is successful, but the resulting hybrid zygote is inviable. Anatomical differences prevent the formation of a zygote because gametes cannot be exchanged. Individuals of different species breed at different times of the day or year, preventing the exchange of gametes.

Individuals of different species breed at different times of the day or year, preventing the exchange of gametes.

Fitness

Individuals with one phenotype leave more surviving offspring in the next generation than individuals with an alternative phenotype

Select the biogeographical observations about islands made by Darwin during his voyage around the world. Islands lack suitable habitat for the survival of many species of plants and animals. Island species have often diverged from their continental relatives. Islands are often missing plants and animals that are common on continents. Island species are usually most closely related to species on nearby continents. Island species are not closely related to species on nearby continents when the two environments are different.

Island species have often diverged from their continental relatives. Islands are often missing plants and animals that are common on continents. Island species are usually most closely related to species on nearby continents.

When heterozygous advantage exists, how would you describe the fitness of the heterozygous genotype?

It has higher fitness than either homozygote

What has been the general trend in biological diversity since the Cambrian period? It has decreased. It has remained stable. It has increased. It has oscillated.

It has increased.

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

It maintains genetic variation in a population.

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

Match marsupial mammals to placental mammals that look similar and occupy a similar niche. Lesser anteater Flying squirrel Wolf Numbat Thylacine Flying phalanger

Lesser anteater ---> Numbat Flying squirrel ---> Flying phalanger Wolf ---> Thylacine

Which of the following have been suggested as hypotheses that may explain industrial melanism?

Lichens decline due to pollution Toxic effects of pollution on light-colored moths Surfaces in polluted areas get darker due to soot deposition

Ecological isolation example:

Lions and tiger ranges overlap in India but they use different habitats

Select all of the following that support the pattern that selection favors light moths in pristine areas and dark moths in polluted areas.

Majerus' data Kettlewell's study Reversal of industrial melanism seen in Caldy Common Frequencies of moths sampled at a field station near Detroit

Select all of the following that are documented by the fossil record. How the first molecules formed Major mass extinctions in the past Successive evolutionary change Reproductive rates of different species Levels of biodiversity through time

Major mass extinctions in the past Successive evolutionary change Levels of biodiversity through time

Which of the following are reasons why the fossil record is incomplete? Many fossils occur in rocks that are inaccessible. Fossils can be destroyed before they are collected. Fossilizations only occur during mass extinctions. Organisms decay or are scavenged before forming fossils.

Many fossils occur in rocks that are inaccessible. Fossils can be destroyed before they are collected. Organisms decay or are scavenged before forming fossils.

Sharp declines in species diversity through time are called which of the following? Stasis Adaptive radiations Speciations Mass extinctions

Mass extinctions

Components of fitness

Mating success Production of viable, numerous offspring Individual survival

Postzygotic isolating mechanisms

Mechanisms that prevent development into an adult

Prezygotic isolating mechanisms

Mechanisms that prevent formation of a zygote

How does the biological species concept define a species? It combines ideas of several species concepts, resulting in one that considers reproductive isolation, evolutionary lineage, and ecological factors. Members of a species require the same set of habitat resources and have a similar influence on other species and the environment. Members of a species are defined based on the separate evolution of lineages over time. Members of a species are able to interbreed in nature and are reproductively isolated from members of other 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 cannot successfully hybridize in the wild or under artificial conditions. Members of different species may be able to successfully hybridize under artificial conditions, but don't do so in the wild. The ability to hybridize is irrelevant as long as the species use different ecological niches. Members of different species can successfully hybridize in the wild or under artificial conditions.

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

The 5 processes that lead to evolutionary change:

Mutation Gene flow Nonrandom mating Genetic drift Natural selection

According to the ecological species, what process maintains species distinctions? Reproductive isolation Ecological isolation Genetic drift Natural selection Geographic isolation

Natural selection

What is meant by the term allopatric? Occurring in the same habitat type, but in different areas Occurring in the same area Occurring in the same area, but in different habitats Occurring in geographically separated areas

Occurring in geographically separated areas

Which of the following statements about intrasexual selection (assume males are the competing sex) is true?

Often a few successful males may engage in an inordinate number of matings, while most males do not mate at all.

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? We would see improvements in organisms and processes from generation to generation. Gradual trends in the size of organisms would be linear. Organisms that are least adapted to their environment could have the highest fitness.

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

Why does polyploidy lead to sympatric speciation? Polyploidy accelerates the rate of genetic drift. Polyploid individuals are infertile. Polyploid individuals accumulate mutations more rapidly. Polyploid individuals cannot mate with normal diploid individuals.

Polyploid individuals cannot mate with normal diploid individuals.

The condition of having more than two sets of chromosomes is known as which of the following? Haploidy Polyploidy Diploidy Multiploidy

Polyploidy

What mechanism can cause immediate reproductive isolation and lead to sympatric speciation? Allopatry Adaptation to local environments Polyploidy Genetic drift

Polyploidy

Which of the following correctly links geographic isolation to speciation? Populations living in the same geographic area can undergo allopatric speciation Populations living in geographically separated areas can undergo sympatric speciation Populations living in geographically separated areas can undergo allopatric speciation

Populations living in geographically separated areas can undergo allopatric speciation

_____ isolating mechanisms prevent the proper functioning of hybrids, and _____ isolating mechanisms act to prevent the formation of hybrid zygotes.

Postzygotic prezygotic

Genetic drift

Random changes in the allele frequencies of a population over time

Incomplete reproductive isolation may become completely effective over time when natural selection acts upon less fit hybrid individuals. What is the name of this process? Character displacement Anagenesis Hybrid inviability Reinforcement Mechanical isolation

Reinforcement

Which of the following are correctly matched? Reinforcement: Decreases differences between populations Reinforcement: Increases differences between populations Gene flow: does not affect differences between populations. Gene flow: Increases differences between populations Gene flow: Decreases differences between populations

Reinforcement: Increases differences between populations Gene flow: Decreases differences between populations

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

Reproductive

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

Secondary sexual characteristics

Reasons why genetic variation within natural populations was a puzzle to Darwin and other scientists in the 19th century:

Segregation of alleles among progeny of hybrids was not understood. Genetic variants were expected to be diluted to the point of disappearing in future generations. Scientists thought that selection should always favor an optimal form.

Which of the following statements about adaptations that evolved through natural selection is true? Because of the limited genetic diversity in populations, natural selection can rarely produce a properly working adaptation to the environment. Some organisms do not appear to be perfectly adapted to their environment. All organisms are perfectly adapted to their environment.

Some organisms do not appear to be perfectly adapted to their environment.

Biological Species Concept

Species composed of populations whose members mate with each other and produce fertile offspring

What type of selection is the opposite of disruptive selection?

Stabilizing selection

What type of selection makes the intermediate (middle) more common by eliminating extremes (large and small)?

Stabilizing selection

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

Stabilizing selection

Within a species, distinct populations that occur in different areas may be classified as which of the following? Genera Allopatric species Subspecies Hybrids

Subspecies

What is the magnitude of change produced by artificial selection?

Substantial

What adds to a frequency of 1 (or 100%) for a particular gene in a population?

Sum of allele frequencies Sum of genotype frequencies

What describes the process of ones species splitting into two species without the species being geographically separated? Hybrid liability Allopatric speciation Hybridization Sympatric speciation

Sympatric speciation

If two sympatric species of trees release pollen at different times of the year, what type of prezygotic isolation keeps these two species reproductively isolated? Temporal Gametic Behavioral Ecological

Temporal

Much of the cichlid diversity in Lake Victoria has been decimated by the introduction of which of the following? The Nile perch African kudzu The pike cichlid South American nutria

The Nile perch

Directional Selection

The alleles will be removed of those that do not have the phenotypic traits

The biological species concept must account for two phenomena:

The distinctiveness of species that occur together at a single locality The connection that exists among different populations belonging to the same species

How does prevention of gamete fusion prevent interspecies hybridization? The hybrid embryo does not develop properly after fertilization. The egg cannot be fertilized, even if mating is possible. Members of different species come into contact, but are unable to mate because of anatomical differences. Members of different species come into contact, but do not recognize each other as potential mates.

The egg cannot be fertilized, even if mating is possible.

Natural selection

The environment selects who will survive

How does ecological isolation prevent successful interspecies hybridization? Gametes fail to fuse following a successful mating attempt Attempted mating is unsuccessful The parent species do not come into contact with one another Hybrid zygotes fail to develop properly

The parent species do not come into contact with one another

According to the fossil record, how did the skull of horses evolve, as animals started eating more grass about 35 million years ago? The skull's shape evolved such that it became strengthened over time. The skull became larger, but more delicate, as less strength is needed to chew on grass. The skull increased in size, but the thickness of bones remained relatively constant.

The skull's shape evolved such that it became strengthened over time.

What feature of horses has strengthened over time (as indicated by the fossil record) in order to deal with stress imposed by continuous chewing? Their tongues Their neck bones Their neck muscles Their skull

Their skull

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

What trend has been observed in the fossil record of horses regarding the length of their limbs? Overall the limbs have not changed much, only the size of the body. They have generally increased in length. They have generally decreased in their length.

They have generally increased in length.

True or false: In allopolyploidy, individuals have more than two sets of chromosomes from two species.

True

If organisms are distinct in one location, and populations of those organisms are reproductively connected by the breeding of individuals, we have the necessary components for ____. an ecological niche a species concept polyploidy evolution

a species concept

Galápagos finches supposedly underwent a(n) ______ after an ancestral population arrived on the islands about 2 million years ago and eventually evolved into a cluster of 14 species with different feeding adaptations.

adaptive radiation

The diversification of Drosophila species in the originally vacant niches and frequently isolated habitat patches of the Hawaiian Islands is an example of behavioral isolation gene flow reinforcement adaptive radiation

adaptive radiation

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

adaptive radiation

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 sympatric speciation hybridization concept reproductive isolation adaptive radiation

adaptive radiation

Artificial selection

any change initiated by humans

Natural selection favors characteristics that grant a survival advantage because these traits

are also likely to increase the likelihood of reproduction.

Frequency-dependent selection favors phenotypes which ____.

are rare or common

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

artificial

In _____ selection, humans choose the parents of the next generation, while in _____ selection, organisms that survive and reproduce are those that pass their genes on.

artificial natural

A seemingly irreducible complex structure can evolve by natural selection because natural selection operates on each part of a system separately, not on system as a whole. as natural selection acts to modify a complex system, the system is functional at each evolutionary stage. even though it is very small, there is always a chance that all of the components of a complex system can evolve simultaneously.

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

Species concepts that define species based on whether or not they can interbreed with other species do not apply to asexual organisms. oak trees. mules. organisms that reproduce sexually.

asexual organisms.

Increases proportion of homozygous individuals

assortative mating

Some mass extinctions in Earth's past were likely caused by collisions with _____.

asteroids

Recent evolutionary studies have shown that Darwin was mistaken in his belief that evolution occurred ____.

at a very slow pace

Polyploidy that occurs in a single species and may be caused by an error in cell division is known as _____.

autopolyploidy

The reproductive isolating mechanism that prevents interspecies hybridization because members of different species do not recognize each other's courtship rituals is _____ _____.

behavioral isolation

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

biological

The _____ species concept defines a species as a group of populations whose individuals are able to interbreed, producing viable and fertile offspring.

biological

In mammals, the ______ is an example of a system that functions as a whole and has come to depend on elements that have been added over millions of years, such that the system could not function without each component. amino acid sequence of hemoglobin appendix ear wiggling muscles blood-clotting process

blood-clotting process

Occurs after event that causes population numbers to be drastically reduced

bottleneck effect

In artificial selection, the ______ selects individuals with desired characteristics to produce offspring, and in natural selection, the ______ selects which individuals will produce the most offspring.

breeder, environment

Examples from artificial selection clearly show that natural selection can produce large differences between populations cannot produce large differences between populations

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

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

cattle corn pigs

Sequences of the ______ suggest that cichlid fishes entered Lake Victoria about ______ years ago and subsequently underwent adaptive radiation, encouraged by dramatic changes in water level over the course of their evolution. protein hemoglobin; 2,000,000 cytochrome b gene; 200,000 cytochrome b gene; 2,000,000 protein hemoglobin; 200,000

cytochrome b gene; 200,000

Kettlewell's study, Majerus' study, and the reversal of industrial melanism on two continents all indicate indisputably that no mater how the agent of selection is acting, the _____ form of the peppered moth is favored in _____ habitats and the _____ form of the moth is favored in pristine areas.

dark polluted light

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

decreased

Scientists have observed that when air pollution is significantly reduced, the frequency of the melanic form of peppered moths

decreases

The number of species worldwide is greater than it has ever been. Unfortunately, this number is currently _____ due to _____ activity.

decreasing human

Recently, the number of species on Earth has been decreasing quickly because of human activities. decreasing steadily because of natural cyclic fluctuations. stabilizing following major fluctuations immediately after the Cretaceous mass extinction. increasing steadily as species adapt to vacant ecological niches.

decreasing quickly because of human activities.

Laboratory selection experiments have produced forms that cannot reproduce and thus would in nature be considered the same species hybrid species artificial species different species

different species

In many animals, selection has favored traits that confer greater ability in mate competition; as a result of such selection, one of the sexes —usually males—can look very different. This is known as sexual _____.

dimorphism

Changes the frequency of alleles in a gene pool population

disassortative mating

Scientists think that natural selection that results in a population containing individuals that exhibit two different phenotypes, also known as _____ selection, can eventually lead to sympatric speciation.

disruptive

Select all that apply Varieties of which of the following organisms are the result of artificial selection?

dogs pigeons cats corn

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

drift

Although the ranges of the toads Bufo woodhousei and B. americanus overlap in some areas, B. woodhousei breeds in streams whereas B. americanus breeds in rainwater puddles. Therefore, even though these two species can produce viable hybrids, they rarely do in nature due to temporal isolation prevention of gamete fusion hybrid inviability ecological isolation behavioral isolation

ecological isolation

The reproductive isolating mechanism that occurs when the ranges of two species overlap, but they rarely come into contact with one another because they utilize different habitats is _____ _____.

ecological isolation

One of the strongest lines of anatomical evidence of evolution is exhibited by patterns of ______ that are common to a group of related organisms. the loss of features size increases toe reduction embryological development

embryological development

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.

In all cases when scientists have performed artificial selection experiments on fruit flies, a strong and predictable _____ response has been observed.

evolutionary

If a population is not in Hardy-Weinberg equilibrium, then _____ _____ are operating.

evolutionary processes

Contrary to the claims by supporters of intelligent design, the fossil record shows that many complex features of species such as the bones in the mammalian ear have become irreducibly complex. evolved incrementally. no inefficient designs. no intermediates.

evolved incrementally.

In evolutionary time, sharp declines in species diversity are called mass _____.

extinction

Evolutionary biologists believe that even though they serve different functions, the forelimb of a frog and the forelimb of a bat share structural similarities and are derived from a common ancestor. This makes these forelimbs an example of analogous structures. convergent structures. homologous structures. vestigial structures.

homologous structures.

Fitness is

how many children you have, and how many children your children have

The primary difference between natural and artificial selection is

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

Postzygotic isolating mechanisms:

hybrid inviability or infertility

One reason why the fossil record is incomplete is that many fossils occur in rocks that are _____ to scientists.

inaccessible

The most common form of assortative mating in animals is

inbreeding (mating between relatives)

Over the last 55 million years, the limbs of animals in most lineages of the horse family have in _____ length.

increased

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 this argument ignores the fact that natural selection operates on ______. produced by a molecular clock; an isolated part of a system irreducibly complex; an isolated part of a system produced by a molecular clock; a system as a whole irreducibly complex; a system as a whole

irreducibly complex a system as a whole

The fact that rattlesnake venom initially evolved as digestive enzymes but now is essential to rattlesnake feeding is an example of how a seemingly ______ has evolved. irreducibly complex system unlikely fossil intermediate convergent set of traits unrelated group of species

irreducibly complex system

Because it favors those variations that lead to the highest reproductive fitness, natural selection is a non-random process. is a random process. proceeds according to an intelligent design.

is a non-random process.

Geometric growth

is increasing by a set percent until some outside factor limits growth

A characteristic that confers a survival advantage

is likely to also increase reproductive success and, as a consequence, favored by natural selection.

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

island

The diversity of Drosophila in Hawaii was aided by the formation of new _____.

islands

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

isolating

Reproductive _____ is the key to the process of speciation.

isolation

Geographic isolation can accelerate speciation because _____. it increases the level of genetic drift it restricts gene flow it counteracts the effect of natural selection it increases the level of mutation

it restricts gene flow

Emigration

leaving a population

The Grants were able to show that after dry years, when _____ seeds are produced, and smaller seeds are quickly eaten, the average beak depth of medium ground finches _____.

less increased

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

light

All modern members of the horse family are large, _____-legged, _____-running animals adapted to living in open _____.

long fast grasslands

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

Immigration

moving to a population

The ultimate source of genetic variation is

mutation

The significant changes illustrated by artificial selection provide strong support for the power of _____ selection.

natural

According to the ecological species concept, species distinctions are maintained by Darwin's mechanism for evolution, known as _____ _____.

natural selection

Multiple phenotypic effects of alleles, lack of genetic variation, and interactions between genes can all limit what _____ _____ can accomplish.

natural selection

What happens to the frequency of the individual alleles in nonrandom mating (both assortative and disassortative)

no change to individual allele frequency

When genetically similar individuals preferentially mate with each other, this is known as

nonrandom mating

Selection is ______, but genetic drift is _____.

nonrandom, random

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

not high enough

Fill in the blanks to complete the sentence. The Grants were able to show that the changes in beak depth they observed in finches were due to genetic differences by determining that the beak size of parents was similar to the beak size of their _____.

offspring

Sympatric speciation occurs when one species splits into two species because intermediate populations become extinct. one species becomes another species after colonizing an island. two populations are geographically isolated. one species splits into two species at the same location.

one species splits into two species at the same location.

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

open

A type of natural selection called _____ selection favors different phenotypes at different times and maintains _____ variation in populations.

oscillating, genetic

The great diversity of cichlids in Lake Victoria may be attributed to multiple colonization events by several ancestors. rampant autopolyploidy periods of isolation when water levels dropped multiple hybridization events

periods of isolation when water levels dropped

The frequency of melanic peppered moths has decreased in areas where _____ is removed from the air and environment.

pollution

If an individual has three or more sets of chromosomes, it is known as a(n) _____ individual.

polyploid

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

prezygotic postzygotic

If a gene has two alleles R and r, the frequency of the R allele is usually designated as p, and the frequency of the r allele is usually designated as

q

The process of fossilization occurs only _____.

rarely

When natural selection acts against hybrids and completes reproductive isolation, a process called _____ has occurred.

reinforcement

If two reproductively isolated populations re-establish contact, ______ will tend to increase differences between the populations, and ______ will tend to decrease differences between the populations. gene flow; reinforcement hybrid inviability; hybrid infertility hybrid infertility; hybrid inviability reinforcement; gene flow

reinforcement gene flow

The criticism that evolution violates the second law of thermodynamics and that life should become more disorganized not more organized is not taking into account that energy constantly enters the biosphere from decomposition. chemical reactions. the ocean. the Sun.

the sun

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

theory

If two species that have evolved over time to be completely reproductively isolated suddenly come into contact with one another, they will remain distinct species. they will hybridize, initiating gene flow and homogenizing the gene pools. they will hybridize, forming a third species.

they will remain distinct species.

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. keystone punctuated isotopic transitional

transitional

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

transitional fossils

Prezygotic isolating mechanisms:

•Ecological isolation •Behavioral isolation •Temporal isolation •Mechanical isolation •Prevention of gamete fusion

Conditions that must be met for a population to be in Hardy-Weinberg equilibrium:

•No mutation takes place •No genes are transferred to or from other sources (no immigration or emigration) •Random mating is occurring •The population size is very large •No selection occurs