Bio II - Test 1

allopolyploidy

a more common type of polyploid speciation, which may happen when two species hybridize. The resulting offspring, having one copy of the chromosomes of each species, is usually infertile because the chromosomes do not pair correctly in meiosis. However, such individuals are often otherwise healthy and can reproduce asexually.

stasis

a period of time during which little evolutionary change occurs

Haplodiplontic

a phenomenon occurring in certain organisms such as wasps, wherein both haploid (male) and diploid (female) individuals are encountered

mass extinction

a relatively sudden, sharp decline in the number of species; for example, the extinction at the end of the Cretaceous period in which the dinosaurs and a variety of other organisms disappeared

inheritance of acquired characteristics

a rival theory to Darwin, by Jean-Baptiste Lamarck, also known as Lamarckism; the theory, now discounted, that individuals genetically pass on to their offspring physical and behavioral changes developed during the individuals' own lifetime. For example, Lamarck proposed that ancestral giraffes with short necks tened to stretch their necks to feed on tree leaves, and this extension of the neck was passed on to generations, leading to the long-necked giraffe. But it is not created by experience, but is the result of pre existing genetic differences among individuals.

Sporangia

a structure in which spores are produced

cladistics

a taxonomic technique used for creating hierarchies of organisms that represent true phylogenetic relationship and descent

disassortative mating

a type of nonrandom mating in which phenotypically different individuals mate more frequently

postzygotic isolating mechanisms

a type of reproductive isolation in which zygotes are produced but are unable to develop into producing adults; these mechanisms may range from inviability of zygotes or embryos to adults that are sterile

frequency-dependent selection

a type of selection that depends on how frequently or infrequently a phenotype occurs in a population. This favors certain phenotypes depending on how commonly or uncommonly they occur. The change in frequencies themselves lead to the changes in fitness of the different phenotype.

Autopolyploidy

all of the chromosomes may arise from a single species. This might happen, for example, due to an error in cell division that causes a doubling of chromosomes. Such individuals, termed tetraploids because they have four sets of chromosomes, can self-fertilize or mate with other tetraploids, but cannot mate and produce fertile offspring with normal diploids.

the process of descent with modification from common ancestry results in...

all species being related in this branching, hierarchical fashion, and their evolutionary history can be depicted using branching diagrams or phylogenetic trees

gene pools

all the alleles present in a species

pleiotropy

alleles affect multiple aspects of phenotype & effects can place limitations on how phenotype can be altered.

reproductive isolating mechanisms

any barrier that prevents genetic exchange between species.

what are the five agents of evolutionary change

any of these may bring about changes in allele to genotype proportions - mutation - gene flow - nonrandom mating - genetic drift in small populations - the pressures of natural selection

artificial selection

change in the genetic structure of populations due to selective breeding by humans. Many domestic animal breeds and crop varieties have been produced through artificial selection

pheromones

chemical substance released by one organism that influences the behavior or physiological processes of another organism of the same species. Pheromones serve as sex attractants, as trail markers, and as alarm signals.

polyploidy

condition in which one or more entire sets of chromosomes is added to the diploid gamete

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime.

conditions 1 and 2

cladogram

depicts a hypothesis of evolutionary relationships. Species that share a common ancestor, as indicated by the possession of shared derived characters, are said to belong to a clade.

example of oscillating selection

during drought conditions versus during wet conditions. the medium ground finch of the Galápagos Islands. In times of drought, the supply of small, soft seeds is depleted, but there are still enough large seeds around. Consequently, birds with big bills are favored. However, when wet conditions return, the ensuing abundance of small seeds favors birds with smaller bills.

when equilibrium is not present, this is a sign that...

evolution has/is occurring

hardy-weinberg predictions can be applied to data to find evidence of ________ processes

evolutionary

clades

evolutionary units and refer to a common ancestor and all of its descendants.

positive frequency-dependent selection

favoring common forms, it tends to eliminate variation from a population. -Effect: tends to eliminate variation from a population -ex) predators don't always select common individuals, "oddballs" stand out.

the strength of selection should change through time as a result of....

frequency-dependent selection

the hardy-weinberg principle allows prediction of _________ ___________

genotype frequencies

what is an effect of oscillating selection

if selection repeatedly oscillates in this fashion, the effect will be to maintain genetic variation in the population.

homoplasy

in cladistics, a shared character state that has not been inherited from a common ancestor exhibiting that state; may result from convergent evolution or evolutionary reversal. The wings of birds and of bats, which are convergent structures, are examples.

Symplesiomorphies

in cladistics, another term for a shared ancestral character state.

plesiomorphies

in cladistics, another term for an ancestral character state

character states

in cladistics, one of two or more distinguishable forms of a character, such as the presence or absence of teeth in amniote vertebrates.

polarize

in cladistics, to determine whether character states are ancestral or derived.

Polyphyletic

in phylogenetic classification, a group that does not include the most recent common ancestor of all members of the group.

monophyletic

in phylogenetic classification, a group that includes the most recent common ancestor of the group and all its descendants. A clade is a monophyletic group

Paraphyletic

in phylogenetic classification, a group that includes the most recent common ancestor of the group, but not all its descendants.

Stomata

in plants, a minute opening bordered by guard cells in the epidermis of leaves and stems; water passes out of a plant mainly through the stomata

Gametophyte

in plants, the haploid (n), gamete-producing generation, which alternates with the diploid (2n) sporophyte "gamete plant"

reinforcement

in speciation, the process by which partial reproductive selection between populations is increased by selection against mating between members of the two populations, eventually resulting in complete reproductive isolation.

synomorphy

in systematics, a derived character that is shared by clade members

agent of evolutionary change: nonrandom mating

it does not alter allele frequency because it does not change the reproductive success of individuals, but rather changes with whom they mate. reduces the proportion of heterozygotes. ex) inbreeding is the most common form. This is why populations of self-fertilizing plants consist primarily of homozygous individuals

In _______ frequency-dependent selection, rare genotypes should become increasingly common, and their selective advantage will decrease correspondingly

negative

one important result of mass extinctions...

not all groups of organisms are affected equally. One hypothesis suggests that survivors were those animals that could shelter underground or in water, and that could either scavenge or required little food in the cool temperatures that resulted from the blockage of sunlight.

Instantaneous speciation through polyploidy

occurs when an individual is born that is reproductively isolated from all other members of its species. In most cases, a mutation that would cause an individual to be greatly different from others of its species would have many adverse side effects due to the many pleiotropic effects of most genes, and the individual likely would not survive. One exception often seen in plants, however, occurs through the process of polyploidy, which produces individuals that have more than two sets of chromosomes.

natural selection

occurs when some individuals are better suited to their environment than others. These individuals live longer and reproduce more, leaving more offspring with the traits that enabled their parents to thrive. In essence, genetic variation within a population provides the raw material on which natural selection can act thereby leading to evolution.

Diplontic

only the diploid stage is multicellular.

hardy-weinberg equation for allele frequency

p + q = 1

hardy-weinberg equation for genotype frequency

p2 +2pq +q2=1 - p2= frequency of AA(homozygous dominant) - 2pq= frequency of Aa (heterozygous) - q2= frequency of aa (homozygous recessive)

land plants ancestor traits

photosynthetic, multicellular, eukaryotes

industrial melanism

phrase used to describe the evolutionary process in which initially light-colored organisms become dark as a result of natural selection.

In _______ frequency dependence, the rarer a genotype becomes, the greater the chance it will be selected against.

positive

why is fitness usually measured as relative fitness

predicting fitness from a single component can be tricky because traits favored for one component of fitness may be at a disadvantage for others. As an example, in water striders, larger females lay more eggs per day. Thus, natural selection at this stage favors large size. However, larger females also die at a younger age and thus have fewer opportunities to reproduce than smaller females. Overall, the two opposing directions of selection cancel each other out, and the intermediate-sized females leave the most offspring in the next generation.

one consequence of mass extinction

previously dominant groups may perish, thus changing the course of evolution

Principle of parsimony

principle stating that scientists should favor the hypothesis that requires the fewest assumptions

techniques available to analyze variation at different levels

proteins, genes, and now genomes.

genetic drift

random fluctuation in allele frequencies over time by chance

negative frequency-dependent selection

rare phenotypes are favored by selection-thus, fitness has a negative relationship with phenotype frequency. Another cause is resource competition. -Effect: make rare alleles more common, thus maintaining variation

genetic variation

refers to the different alleles of genes found within individuals of a population.

relative dating

rock in lesser strata are generally older because of young rocks form on top of the older one

epistasis

select advantage of allele at one gene may vary between genotypes.

Intense _______ can remove variation from population faster than mutation can replenish it. Evolution is not possible w/out genetic variation.

selection

analogous

similarity of function and superficial resemblance of structures that have different origins. For example, the wings of a fly, a moth, and a bird are analogous because they developed independently as adaptations to a common function—flying.

natural selection occurs when...

some individuals are better suited to their environment than others. These individuals live longer and reproduce more, leaving more offspring with the traits that enabled their parents to thrive. In essence, genetic variation within a population provides the raw material on which natural selection can act thereby leading to evolution.

pseudogenes

sometimes called fossil genes because they are traces of previously function in genes, it is a copy of a gene that is not transcribed. It is actually quite common in the genomes of most organisms. When a trait disappears, the gene does not just vanish from the genome; rather, some mutation renders it inactive, and once that occurs, other mutations can accumulate.

agent of evolutionary change: genetic drfit

statistical accidents. the random fluctuation in allele frequencies increases as population size decreases. Can lead to the loss of alleles in isolated populations. Alleles that initially are uncommon are particularly vulnerable ex) For example, a small number of individuals are removed from a bottle. By chance, most of the individuals removed are green, so the new population has a much higher population of green individuals than the parent generation had.

homologous structures

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

Darwin's theory of evolution proposed...

that natural selection as the mechanism of evolution

gene flow

the basic unit of heredity; a sequence of DNA nucleotides on a chromosome that encodes a protein, tRNA, or rRNA molecule, or regulates the transcription of such a sequence. A very potent agent of change. Individuals or gametes move from one population to another ex) an animal physically moves from one place to another and survives to then mate successfully, the genetic composition of the receiving population may be altered

founder effect

the effect by which rare alleles and combinations of alleles may be enhanced in new populations. Sometimes one or a few individuals disperse and become the founders of a new, isolated population at some distance from their place of origin. These pioneers are not likely to carry all the alleles present in the source population. Thus, some alleles may be lost from the new population, and others may change drastically in frequency. In some cases, previously rare alleles in the source population may be a significant fraction of the new population's genetic endowment.

phylogeny

the evolutionary history of an organism, including which species are closely related and in what order related species evolved; often represented in the form of an evolutionary tree. Which represents a hypothesis about patterns of relationship among species.

fitness

the genetic contribution of an individual to succeeding generations. Relative fitness refers to the fitness of an individual relative to other individuals in a population. Fitness is a relative concept; The most fit phenotype is simply the one that produces, on average, the greatest number of offspring.

polymorphism

the occurrence of two or more clearly different morphs or forms, also referred to as alternative phenotypes, in the population of a species/

agent of evolutionary change: selection

the only agent that produces adaptive evolutionary changes. Natural selection can occur without producing evolutionary change; only if variation is genetically based will natural selection lead to evolution. The result of evolution driven by natural selection is that populations become better adapted to their environment. Many of the most dramatic documented instances of adaptation involve genetic changes that decrease the probability of capture by a predator. Selection also occurs to match climatic conditions, so that one allele is more common in northern populations over southern ones. Selection for pesticide and microbial resistance ex) The caterpillar larvae of the common sulphur butterfly Colias eurytheme usually exhibit a pale green color, providing excellent camouflage against the alfalfa plants on which they feed. An alternative bright yellow color morph is reduced to very low frequency because this color renders the larvae highly visible on the food plant, making it easier for bird predators to see them

The hardy-weinberg princple believes that

the original proportions of the genotypes in a population will remain constant from generation to generation, as long as the 5 assumptions are met

bifurcations

the part of a phylogenetic tree where it diverges.

heterozygosity

the presence of different alleles at one or more loci on homologous chromosomes

selection

the process by which some organisms leave more offspring than competing ones, and their genetic traits tend to appear in greater proportions among members of succeeding generations than the traits of those individuals that leave fewer offspring

evolutionary reversal

the process in which a species re-evolves that characteristics of an ancestral species, also has this effect.

systematics

the reconstruction and study of evolutionary relationships

Taxonomy

the science of classifying living things. By agreement among taxonomists, no two organisms can have the same name, and all names are expressed in Latin

heterozygote advantage

the situation in which individuals heterozygous for a trait have a selective advantage over those who are homozygous. Favors individuals with copies of both alleles, and thus works to maintain both alleles in the population. Some evolutionary biologists believe that heterozygote advantage is pervasive and can explain the high levels of genetic variation observed in natural populations. Others, however, believe that it is relatively rare.

oscillating selection

the situation in which selection alternately favors one phenotype at one time, and a different phenotype at another time. Environmental changes lead to the oscillation in selection.

Sporophyte

the spore-producing, diploid (2n) phase in the life cycle of a plant having alternation of generations "spre plant"

population genetics

the study of properties of genes in populations, an important consideration when it comes to evolution

agent of evolutionary change: mutatation

the ultimate source of variation. individual mutations occur so rarely that mutation alone usually does not change allele frequency much ex) a change in DNA

gradualism

the view that species change very slowly in ways that may be imperceptible from one generation to the next but that accumulate and lead to major changes over thousands or millions of years.

character displacement

this adaptation may be driven by the need to minimize competition for available resources with other species. In this process, termed character displacement, two reproductively isolated but ecologically similar species come into contact. Because the two species use the same resources, natural selection in each species favors those individuals that use resources not used by the other species. Because those individuals will have greater fitness, whatever traits cause the differences in resource use will increase in frequency (assuming that a genetic basis exists for these differences), and, over time, the species will diverge

biological evolution

through time, species accumulate differences; as a result, descendants differ from their ancestors. In this way, new species arise from existing ones. Descent with modification Evolution can result from any process that causes a change in the genetic composition of a population

what is one way to monitor how populations change through time?

to look at changes in the frequencies of alleles of a gene from one generation to the next. Natural selection, by favoring individuals with certain alleles, can lead to change in such allele frequencies, but it is not the only process that can do so. Allele frequencies can also change when mutations occur repeatedly, changing one allele to another, and when migrants bring alleles into a population. In addition, when populations are small, the frequencies of alleles can change randomly as the result of chance events. Often, natural selection overwhelms the effects of these other processes, but as you will see in this is not always the case.

land plant synapomorphies

uses chlorophylls a and b, cellulose cell wall, implications of this for cell division, starch as storage product, mostly terrestrial, all are evolutionary descended from a common ancestor (monophyletic)

some parts of the genome harbor much more ______ than other parts

variation

because most populations in nature will not fit all five assumptions of the hardy-weinberg equillibrium, the primary utility of this method is to determine...

whether some evolutionary process or processes are operating in a population and, if so, to suggest hypotheses about what they may be.

what are the five assumptions that must be met for the hardy-weinberg equilibrium will remain.

- No mutation takes place - No genes are transferred to or from other sources (no immigration or emigration takes place) - Mating is random (individuals do not choose mates based on their phenotype or genotype) - The population size is very large - No selection occurs

how can natural selection lead to speciation?

-As populations of a species adapt to different circumstances, they likely accumulate many differences that may lead to reproductive isolation. For example, if one population of flies adapts to wet habitats and another to dry areas, then natural selection will favor a variety of corresponding differences in physiological and sensory traits. These differences may produce ecological and behavioral isolation and may cause any hybrids the two populations produce to be poorly adapted to either habitat. -It may also act directly on mating behavior

Bryophytes

-Dominant gametophyte generation -Cannot grow tall because they lack a system to efficiently transport water -Bryophytes are the closest living descendants of the first land plants. Plants in this group are also called nontracheophytes because they lack the transport cells called tracheids. -Water and gas availability were limiting factors for early terrestrial plants. These plants likely had little ability to regulate internal water levels and tolerated desiccation, traits found in most modern (extant) mosses. -Have sexual reproduction -Live in damp areas, need water for reproduction -Have a photosynthetic gametophyte -Ex: Bryophytes are comprised of liverworts (phylum Hepaticophyta), mosses (phylum Bryophyta), and hornworts (phylum Anthocerotophyta). They are shown in the cladogram.

Describe how patterns of early development provide evidence for evolution.

-Early embryonic development shows similarities in some groups -Embryos of different types of vertebrates, for example, often are similar early on, but become more different as they develop.

what is an effect and example of the heterozygote advantage

-Effect: natural selection actually tends to maintain variation in the population. -ex) sickle cell anemia in Africa, people who are heterozygous for the sickle cell allele (don't suffer from it) are much less susceptible to malaria.

working definition of land plants

-Green algae and the land plants shared a common ancestor -DNA sequence data are consistent with the claim that a single individual gave rise to all green plants -Fungi was essential to the colonization of land by plants, enhancing plants' nutrient uptake from the soil -Evolved from freshwater algae -Have adapted to terrestrial life -The haplodiplontic cycle produces alternation of generations

how did biogeographical studies provide further evidence of evolution?

-He noted that islands often are missing plants and animals common on continents, such as frogs and land mammals -those species that are present on islands often have diverged from their continental relatives and sometimes—as with Darwin's finches and the island trees just discussed—occupy ecological niches used by other species on continents. -island species usually are more closely related to species on nearby continents, even though the environment on continents and nearby islands often is not very similar.

Gymnosperms

-Plants with naked seeds -The most familiar gymnosperms are conifers (phylum Coniferophyta), which include pines, spruces, firs, cedars, hemlocks, yews, larches, cypresses, and others. Nearly 40% of the world's forests are composed of conifers. -Pollen (contains sperm)

Describe the effects of genetic drift on a population.

-Populations may diverge as a result of genetic drift. Random changes in small populations, founder effects, and population bottlenecks all may lead to changes in traits that cause reproductive isolation. -Given enough time, any two isolated populations will diverge because of genetic drift (remember that even large populations experience drift, but a lower rate than in small populations). In some cases, this random divergence may affect traits responsible for reproductive isolation, and speciation may occur.

explain the evolutionary significance of homologous and vestigial structures

-Suggest common derivation -As vertebrates have evolved, the same bones have sometimes been put to different uses. Yet the bones are still recognizable, their presence betraying their evolutionary past. -Natural selection has modified the same initial starting blocks to serve very different purposes -An excellent example of an imperfect design is the eye of vertebrate animals, in which the photoreceptors face backward, toward the wall of the eye. As a result, the nerve fibers extend not backward, toward the brain, but forward into the eye chamber, where they slightly obstruct light.

Angiosperms

-The dominant plant group on earth because of pollinators. Fertilization and seed dispersal with flowers and fruits. (esp. Co-evolution with animals) -The flowering plants -Vessels are a particularly efficient conducting cell type that is a common feature in angiosperms

Explain the possible outcomes when populations that are partially isolated become sympatric.

-When incompletely isolated populations come together, gene flow immediately begins to occur between them. Although hybrids may be inferior, they are not completely inviable or infertile. -When these surviving hybrids reproduce with members of either population, they will serve as a conduit of genetic exchange from one population to the other, and the two populations will tend to lose their genetic distinctiveness. -Thus, a race ensues: Can complete reproductive isolation evolve before gene flow erases the differences between the populations? The outcome depends on the initial conditions and the particular natural history of the species involved, but many experts consider reinforcement generally to be the less common outcome.

vestigial strucures

-a morphological feature that has no apparent current function and is thought to be an evolutionary relic; for example, the vestigial hip bones of boa constrictors. -Can be explained as holdovers from the past

Artificial selection though the phenotypes are ________, while in natural selection, the phenotypes are __________ by fitness.

-chosen -decided

sympatric speciation by disruptive selection

-disruptive selection can cause a population to contain individuals exhibiting two different phenotypes. -But before the two phenotypes could become different species, they would have to evolve reproductive isolating mechanisms. -For this reason, most biologists consider sympatric speciation of this type to be a rare event.

what problems to land plant adaptation solve?

-drying out; being able to move water around their system -obtaining water and nutrients; root system -dealing with gravity; having to have a support system (stem made of cellulose, trunks) -dispersing gametes; seeds

biological species concept (BSC)

-focuses on the ability to exchange genes. The concept that defines species as groups of populations that have the potential to interbreed and that are reproductively isolated from other groups. - defines species as groups of interbreeding populations that are reproductively isolated from other groups.

ferns

-have fronds that bear sori -seedless, vascular plant -water is necessary for fertilization. sperm are released on the underside of the gametophyte and swim in mois soil to neighboring gametophytes. spores are dipsered by wind -Have vascular tissue (xylem, tracheids) to allow them to grow bigger, so that they move water and food up into their systems

shared derived characters

-in cladistics, character states that are shared by species and that are different from the ancestral character state. -They are the only considerations of information in determining evolutionary relationships

Molecular clock

-in evolutionary theory, the method in which the rate of evolution of a molecule is constant through time -To make such estimates, the timing of one or more divergence events must be confidently estimated. For example, the fossil record may indicate that two clades diverged from a common ancestor at a particular time.

prezygotic isolating mechanisms

-prevent the formation of zygotes -Include ecological/environmental isolation, behavioral isolation (mating rituals/ pheromones), temporal isolation (breeding seasons), mechanical isolation, and prevention of gamete formation

ancestral traits

-similarity is distinguished among species that is inherited from the most recent common ancestor of an entire group. Ex: the presence of lungs in mammals is ancestral because it is also present in amphibians and reptiles and therefore prior to the common ancestor of mammals

allopatric speciation

-takes place when populations are geographically isolated -More likely to have evolved substantial differences leading to speciation. -Mayr made a strong case for allopatric speciation as the primary means of speciation

Phylogenetic species concept (PSC)

-the concept that defines species on the basis of their phylogenetic relationships -Moreover, they suggest that phylogenetic analysis is the way to identify such species. In this view, a species is a population or set of populations characterized by one or more shared derived character—the rationale being that the possession of a derived character implies a period of separate evolution.

sympatric speciation

-the differentiation of populations within a common geographic area into species. -occurs without geographic separation -Investigators have suggested that this could occur either instantaneously or over the course of multiple generations.

adaptive radiations

-the evolution of several divergent forms from a primitive and unspecialized ancestor. -Can result when a new trait, a key innovation, evolves within a species allowing it to use resources or other aspects of the environment that were previously inaccessible

convergent evolution

-the independent development of similar structures in organisms that are not directly related; often found in organisms living in similar environments. -caused by similar selective pressures

fossils

-the preserved remains of once-living organisms. They include specimens preserved in amber, Siberian permafrost, and dry caves, as well as the more common fossils preserved as rocks. -The process of fossilization occurs only rarely, only a very small fraction of the species that have ever existed are known from fossils.

biogeography

-the study of the geographic distribution of species. -Reveals that different geographical areas sometimes exhibit groups of plants and animals of strikingly similar appearance, even though the organisms may be only distantly related. -Instead, natural selection appears to have favored parallel evolutionary adaptations in similar environments. Because selection in these instances has tended to favor changes that made the two groups more alike, their phenotypes have converged.

rock fossils are created when three events occurs

1. The organism must become buried in sediment 2. Then the calcium in bone or other hard tissue must mineralize 3. Finally, the surrounding sediment must eventually harden to form rock.

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship

2 ---> 4 ---> 1 ---> 3

Arrange the following terms from most inclusive to least inclusive. 1. stomata 2. green plants 3. seedless vascular plants 4. ferns 5. tracheophytes

2, 1, 5, 3, 4

You want to study divergence of populations, and you need to maximize the rate of divergence to see results within the period of your grant funding. You will form a new population by taking some individuals from a source population and isolating them so the two populations cannot interbreed. What combination of characteristics would maximize your chance of seeing divergence in this study? 1. Choose a random sample of individuals to form the new population. 2. Choose individuals from one extreme to form the new population. 3. Choose a species to study that produces many offspring. 4. Choose a species to study that produces a few, large offspring. 5. Place the new population in the same type of environment as the source population. 6. Place the new population in a novel environment compared to that of the source population.

2, 3, and 6

Rank the following in order from most general to most specific: 1. gametic isolation 2. reproductive isolating mechanism 3. sperm-egg incompatibility in sea urchins 4. prezygotic isolating mechanism

2, 4, 1, 3

Rank the following one-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide. 1. insertion mutation deep within an intron 2. substitution mutation at the third position of an exonic codon 3. substitution mutation at the second position of an exonic codon 4. deletion mutation within the first exon of the gene

4, 3, 2, 1

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium? A. Plantae B. Fungi C. Animalia D. Protista

A and D

assortative mating

A type of nonrandom mating in which phenotypically similar individuals mate more frequently.

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 2 → 3 → 1 D) 2 → 4 → 3 → 1

A) 2 → 4 → 1 → 3

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? A) Characteristics acquired during an organism's life are generally not passed on through genes. B) Spontaneous mutations can result in the appearance of new traits. C) Only favorable adaptations have survival value. D) Disuse of an organ may lead to its eventual disappearance.

A) Characteristics acquired during an organism's life are generally not passed on through genes.

The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information? A) Postzygotic isolation exists between the two frog species. B) Prezygotic isolation exists between the two frog species. C) These two species are likely in the process of fusing back into one species. D) The hybrids form a separate species under the biological species concept.

A) Postzygotic isolation exists between the two frog species.

In a comparison of birds and mammals, having four limbs is _____. A) a shared ancestral character B) a shared derived character C) a character useful for distinguishing birds from mammals D) an example of analogy rather than homology

A) a shared ancestral character

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of _____. A) convergent evolution B) a synapomorphy C) homology D) parsimony

A) convergent evolution

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of _____. A) homology B) convergent evolution C) the evolution of common structure as a result of common function D) the evolution of similar appearance as a result of common function

A) homology

Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and then die. These two frog species separate by _____. A) reduced hybrid viability B) hybrid breakdown C) reduced hybrid fertility D) gametic isolation

A) reduced hybrid viability

In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In the western United States, pronghorns and cattle often associate with one another in the same open rangeland. Some of these fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood. The host mammal can be considered as the fleas' habitat. If this situation persists, and new species evolve, this would be an example of _____. A) sympatric speciation and habitat isolation B) sympatric speciation and temporal isolation C) allopatric speciation and habitat isolation D) allopatric speciation and gametic isolation

A) sympatric speciation and habitat isolation

Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus, _____. A) the allele's frequency should not change from one generation to the next B) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency C) two alleles are present in equal proportions D) individuals within the population are evolving

A) the allele's frequency should not change from one generation to the next

What evidence do paleobotanists look for that indicates the movement of plants from water to land? A) waxy cuticle to decrease evaporation from leaves B) loss of spores C) flowers and fruits D) remnants of chloroplasts from photosynthesizing cells

A) waxy cuticle to decrease evaporation from leaves

Coloration in the peppered moth (Biston betularia) is determined by a single gene with two alleles showing complete dominance. Dark moths are homozygous dominant or heterozygous for the gene, light moths are homozygous recessive. In a sample of 100 moths, you determine that 64 of the moths are dark. According to the Hardy-Weinberg rule, the expected frequency of the dominant allele is A. 0.4 B. 0.36 C. 0.6 D. 0.64

A. 0.4

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? A. Characteristics acquired during an organism's life are generally not passed on through genes. B. Spontaneous mutations can result in the appearance of new traits. C. Only favorable adaptations have survival value. D. Disuse of an organ may lead to its eventual disappearance.

A. Characteristics acquired during an organism's life are generally not passed on through genes.

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of _____. A. Homology B. convergent evolution C. the evolution of common structure as a result of common function D. the evolution of similar appearance as a result of common function

A. Homology

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct? A. In this wild mustard, there is enough heritable variation to permit these different varieties. B. Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics. C. Natural selection is rare in wild populations of wild mustard. D. In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.

A. In this wild mustard, there is enough heritable variation to permit these different varieties.

How would gene flow between two allopatric populations affect the chance of speciation? A. It would most likely decrease the chance of speciation B. It would probably increase the chance of speciation C. It would reinforce the separation of the species D. It would increase the likelihood of the development of post-zygotic isolating mechanisms

A. It would most likely decrease the chance of speciation

If we were able to provide a vaccine against malaria to everyone, what changes would you predict to the frequency of the sickle cell allele in the world's population? A. It would probably decrease. B. It would probably increase. C. No change; it would remain the same.

A. It would probably decrease.

What kind of barrier to gene flow has not been shown between the two Bombina species? A. Mechanical isolation. B. Habitat isolation. C. Behavioral isolation. D. Postzygotic barrier.

A. Mechanical isolation.

Which of the following innovations was not involved specifically in the highly successful colonization of land by aquatic plants? A. Photosynthesis B. Cuticle C. Roots D. Vascular tissue

A. Photosynthesis

The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information? A. Postzygotic isolation exists between the two frog species. B. Prezygotic isolation exists between the two frog species. C. These two species are likely in the process of fusing back into one species. D. The hybrids form a separate species under the biological species concept.

A. Postzygotic isolation exists between the two frog species.

Which of the following was a key innovation specifically involved in the evolution of large trees like giant redwoods? A. Vascular tissues B. Flowers C. Fruit D. Coevolution with birds and insects

A. Vascular tissues

Which of the following is an example of the founder's effect? A. a fertilized seed lands on a new island B. North American elephant hunter to almost extinction C. assortative mating D. a bee brings pollen from a different population

A. a fertilized seed lands on a new island

In a comparison of birds and mammals, having four limbs is _____. A. a shared ancestral character B. a shared derived character C. a character useful for distinguishing birds from mammals D. an example of analogy rather than homology

A. a shared ancestral character

In the Hardy-Weinberg equation, p and q are A. allele frequencies. B. genotypes. C. phenotypes. D. measures of fitness.

A. allele frequencies.

In most regions of Earth today, land flora consists predominantly of A. angiosperms B. gymnosperms C. ferns D. bryophytes

A. angiosperms

Which of the following pairs are the best examples of homologous structures? A. bat wing and human hand B. owl wing and hornet wing C. porcupine quill and cactus spine D. Australian mole and North American mole

A. bat wing and human hand

In studying the medium ground finch on Daphne Major, the Grants noted that each generation of finches had beaks A. best suited for their parents' environment. B. best suited for their current environment. C. smaller than those of the previous generation. D. larger than those of the previous generation.

A. best suited for their parents' environment.

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of _____. A. convergent evolution B. genetic drift C. homology D. artificial selection

A. convergent evolution

You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to _____. A. cross your flies with flies from another lab B. reduce the number of flies that you transfer at each generation C. transfer only the largest flies D. change the temperature at which you rear the flies

A. cross your flies with flies from another lab

In hybrid zones where reinforcement is occurring, we should see a decline in _____. A. gene flow between distinct gene pools B. Speciation C. the genetic distinctness of two gene pools D. mutation rates

A. gene flow between distinct gene pools

Adaptive radiation is best described as the existence of A. groups of closely related species recently evolved from a common ancestor. B. groups of distantly related species recently evolved from a common ancestor. C. groups of closely related species recently evolved from different ancestors through hybridization. D. individuals of closely related species that originated in different areas within diverse habitats, but that have rejoined as a single species.

A. groups of closely related species recently evolved from a common ancestor.

The biological species concept proposed by Ernst Mayr emphasizes all of the following except A. hybridization between different species. B. production of fertile offspring within the species. C. reproductive isolation from other species. D. interbreeding within the species.

A. hybridization between different species.

The origin of genetic variation is A. mutation. B. gene flow. C. genetic drift. D. natural selection.

A. mutation.

In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In the western United States, pronghorns and cattle often associate with one another in the same open rangeland. Some of these fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood. The host mammal can be considered as the fleas' habitat. If this situation persists, and new species evolve, this would be an example of _____. A. sympatric speciation and habitat isolation B. sympatric speciation and temporal isolation C. allopatric speciation and habitat isolation D. allopatric speciation and gametic isolation

A. sympatric speciation and habitat isolation

Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus, _____. A. the allele's frequency should not change from one generation to the next B. natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency C. two alleles are present in equal proportions D. individuals within the population are evolving

A. the allele's frequency should not change from one generation to the next

The term ʺhomoplasyʺ is most applicable to which of these features? A. the legless condition found in various types of extant lizards B. the 5-digit condition of human hands and bat wings C. the beta-hemoglobin genes of mice and of humans D. the basic skeletal features of dog forelimbs and cat forelimbs

A. the legless condition found in various types of extant lizards

All of the following describe members of a biological species except A. they have several isolated gene pools. B. they differ from other species in one or more characteristics. C. they can interbreed freely with each other. D. there is potential gene flow with each other.

A. they have several isolated gene pools.

isotopic dating

At the time a rock forms, some elements exist as different isotopes. Over time the less stable isotopes is converted into the other isotope and the ratio of the two forms changes.

A hybrid zone is properly defined as _____. A) an area where the ranges of two closely related species overlap, but do not interbreed B) an area where mating occurs between members of two closely related species, producing viable offspring C) a zone where sterile hybrids form, kept separate by postzygotic barriers D) an area where members of two closely related species intermingle, but gene flow is prevented by prezygotic barriers

B) an area where mating occurs between members of two closely related species, producing viable offspring

The most direct ancestors of land plants were probably _____. A) kelp (brown alga) that formed large beds near the shorelines B) green algae C) photosynthesizing prokaryotes (cyanobacteria) D) liverworts and mosses

B) green algae

In the formula for determining a population's genotype frequencies, the "2" in the term 2pq is necessary because _____. A) the population is diploid B) heterozygotes can come about in two ways C) the population is doubling in number D) heterozygotes have two alleles

B) heterozygotes can come about in two ways

Stomata _____. A) occur only in angiosperms and define them as a monophyletic group B) open to allow gas exchange and close to decrease water loss C) occur in only mosses and ferns D) open to increase both water absorption and gas exchange

B) open to allow gas exchange and close to decrease water loss

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following terms best describes this situation? A) directional selection B) stabilizing selection C) disruptive selection D) sexual selection

B) stabilizing selection

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the estimated frequency of allele A in the gene pool? A. 0.25 B. 0.50 C. 0.75 D. 0.125

B. 0.50

Which of the following is not a defining characteristic of plants? A. Photosynthetic B. Aquatic C. Cell wall made of cellulose D. Eukaryotic

B. Aquatic

Why is the sickle cell allele so prevalent in some parts of the world? A. Carrying two copies of the allele causes sickle-cell disease, which provides a selective advantage. B. Carrying one copy of the allele protects against malaria, common in those parts of the world. C. The allele arose by mutation in those parts of the world and never spread elsewhere. D. The presence of malaria caused the mutation that created the allele.

B. Carrying one copy of the allele protects against malaria, common in those parts of the world.

Co-evolution between plants and their natural enemies is generally believed to have generated much of the Earth's biological diversity. A process analogous to co-evolution occurs in agricultural systems, in which natural enemies adapt to crop resistance introduced by breeding or genetic engineering. The plant Arabidopsis has evolved resistance to fungal pathogens by producing chitinase, an enzyme that degrades their cell walls. Some fungi, in response, have evolved proteins that act as competitive inhibitors of the chitinase. In this arms race the Arabidopsis then evolved changes in the amino acids present in the active site of their chitinase. Why would these amino acid changes help the plant? A. Binding to the active site causes allosteric regulation of the enzyme B. Competitive inhibitors bind to the active site C. Competitive inhibitors are non-reversible D. Feedback inhibition involves metabolic pathways with multiple enzymes

B. Competitive inhibitors bind to the active site

If sickle cell disease were caused by the presence of only a single copy of the sickle cell allele, what would you expect to happen to the frequency of the allele in places with a high incidence of malaria? A. Increase B. Decrease C. Remain the same

B. Decrease

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true? A. Each bird evolved a deeper, stronger beak as the drought persisted. B. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. C. Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. D. The frequency of the strong-beak alleles increased in each bird as the drought persisted.

B. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

Which of the following is false? A. Over the history of the Earth the overall trend is a steady increase in the number of species B. Mass extinctions appear to affect all types of species equally C. One of the extinctions resulted in a loss of half the species of plants and animals on Earth D. One of the mass extinctions may have been caused by an asteroid hitting Earth

B. Mass extinctions appear to affect all types of species equally

Which of the following agents of evolution adapts populations to their environments? A. Mutation B. Natural selection C. Gene flow D. Genetic drift

B. Natural selection

In an individual re-infected by different HIV strains during multiple sexual encounters while undergoing anti-viral chemotherapy, which of the following Hardy-Weinberg assumptions is not necessarily being violated during evolution by the virus population? A. No selection B. No assortative mating C. No gene flow D. No mutation

B. No assortative mating

The idea that speciation occurs in rapid bursts followed by long periods without change in species is called A. Reverse Selection B. Punctuated equilibrium C. Gradualism D. Mass extinction

B. Punctuated equilibrium

Most moss gametophytes do not have a cuticle and are 1-2 cells thick. What does this imply about moss gametophytes and their structure? A. They use stomata for gas exchange regulation. B. They can easily lose water to, and absorb water from, the atmosphere. C. Photosynthesis occurs only on the top of the gametophyte surface. D. They have vascular tissue in their leaves.

B. They can easily lose water to, and absorb water from, the atmosphere.

Darwin analogized the effects of evolution as the above-ground portion of a many-branched tree, with extant species being the tips of the twigs. The common ancestor of two species is most analogous to which anatomical tree part? A. a single twig that gets longer with time B. a node where two twigs diverge C. a twig that branches with time D. the trunk

B. a node where two twigs diverge

The fact that modern birds lack teeth, yet have genes which encode teeth is ____. A. consistent with intelligent design—evidence of a purposeful plan. B. consistent with evolutionary theory, but not with intelligent design. C. consistent with both theories. D. consistent with intelligent design, but not with evolutionary theory.

B. consistent with evolutionary theory, but not with intelligent design.

Stabilizing selection will __________ genetic diversity A. increase B. decrease C. not influence

B. decrease

Over several generations in a population, inbreeding tends to A. decrease the relative proportions of homozygotes. B. decrease the likelihood of heterozygotes. C. stabilize the balance of genotypes predicted by the Hardy-Weinberg equilibrium. D. All of the choices are correct.

B. decrease the likelihood of heterozygotes.

You discover a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, you notes the following characteristics: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to _____. A. mosses B. ferns C. gymnosperms D. flowering plants

B. ferns

Migration and hybridization between individuals of adjacent populations causes gene ______. A. blending B. flow C. mutation D. dominance

B. flow

To reproduce sexually, bryophytes, such as mosses, require A. small, non-showy flowers that are fertilized with pollen from another plant. B. free water external to the plant. C. high temperatures. D. insect pollination.

B. free water external to the plant.

When bird populations migrate and mix with populations that do not migrate, ________ will occur. A. gene blending B. gene flow C. mutation D. genetic drift

B. gene flow

In the formula for determining a population's genotype frequencies, the "2" in the term 2pq is necessary because _____. A. the population is diploid B. heterozygotes can come about in two ways C. the population is doubling in number D. heterozygotes have two alleles

B. heterozygotes can come about in two ways

Natural selection has favored the dark form of the peppered moth in areas subject to severe air pollution, perhaps because on darkened trees, moth-eating birds see them less easily. As pollution abated, the light forms increased in the population because A. light moths had lower fitness than dark moths. B. light moths were able to produce more offspring than dark moths. C. light moths were more genetically variable than dark moths. D. birds ate more light moths.

B. light moths were able to produce more offspring than dark moths.

A gene pool consists of all the alleles A. of an individual's genotype B. present in a specific population C. that occur in a species throughout its evolutionary existence D. that contribute to the next generation of a population

B. present in a specific population

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following terms best describes this situation? A. directional selection B. stabilizing selection C. disruptive selection D. sexual selection

B. stabilizing selection

Natural hybrids between distantly related animal species are typically A. more fit than their parents B. sterile C. creating lots of new species D. reducing the number of species

B. sterile

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of _____. A. how widely the organisms assigned to each are distributed throughout the environment B. their inclusiveness C. the relative genome sizes of the organisms assigned to each D. morphological characters that are applicable to all organisms

B. their inclusiveness

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime. A) Condition 1 only B) Condition 2 only C) Conditions 1 and 2 D) Conditions 2 and 3

C) Conditions 1 and 2

Liverworts, hornworts, and mosses are grouped together as the Bryophytes. What do they all have in common? A) They are all wind pollinated. B) They have very small flowers and seeds C) They all have vascular tissue. D) They require water for reproduction.

C) They all have vascular tissue.

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? A) a temporal reproductive isolating mechanism B) a postzygotic isolating mechanism C) a behavioral reproductive isolating mechanism D) a gametic reproductive isolating mechanism

C) a behavioral reproductive isolating mechanism

The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and _____. A) an increasing number of infertile hybrids is produced over the course of the next one hundred generations B) no reproduction occurs in the hybrid zone C) an increasing number of viable, fertile hybrids is produced over the course of the next one hundred generations D) a decreasing number of viable, fertile hybrids is produced over the course of the next one hundred generations

C) an increasing number of viable, fertile hybrids is produced over the course of the next one hundred generations

The main role that humans play in artificial selection is to _____. A) create new species B) create genetic diversity C) choose which organisms live and reproduce D) perform artificial insemination

C) choose which organisms live and reproduce

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? A) temporal isolation B) behavioral isolation C) habitat isolation D) gametic isolation

C) habitat isolation

Genetic variation _____. A) is created by the direct action of natural selection B) arises in response to changes in the environment C) must be present in a population before natural selection can act upon the population D) tends to be reduced by when diploid organisms produce gametes

C) must be present in a population before natural selection can act upon the population

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that _____. A) the species is now extinct B) speciation occurred in one generation C) speciation occurred rapidly in geologic time D) the species will consequently have a relatively short existence, compared with other species

C) speciation occurred rapidly in geologic time

Which of these is a major trend in land plant evolution? A) the trend toward smaller size B) the trend toward a haploid-dominated life cycle C) the trend toward a diploid-dominated life cycle D) the trend toward larger stomata

C) the trend toward a diploid-dominated life cycle

A gene in humans has two alleles, M and N, that code for different surface proteins on red blood cells. If you know that the frequency of allele M is 0.2, according to the Hardy-Weinberg rule, the frequency of the genotype MN in the population should be A. 0.16 B. 0.2 C. 0.32 D. 0.64 E. 0.8

C. 0.32

In a hypothetical population of sawflies, 20 percent of the population is homozygous for allele A and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at this locus, what percent of the population is heterozygous? A. 10 percent B. 20 percent C. 35 percent D. 45 percent

C. 35 percent

Which of the following would most likely result in a bottleneck event A. A small population of geese migrates and joins a large flock of the same species. The two groups subsequently begin interbreeding. B. A mutation occurs in an individual poison ivy plant, doubling the number of seeds it produces. The mutation is inherited by future generations. C. A hurricane blows through a coastal swamp inhabited by an apple snail population. The hurricane drastically changes the hydrology of the swamp, killing 98% of the apple snails. D. Two populations of lizards were separated for many years by a river. The river's course has been diverted and migration between the two lizard populations can now occur.

C. A hurricane blows through a coastal swamp inhabited by an apple snail population. The hurricane drastically changes the hydrology of the swamp, killing 98% of the apple snails.

Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the Hardy-Weinberg model? A. A1 = 0.9997, A2 = 0.0003 B. A1 = 0.9800, A2 = 0.0200 C. A1 = 0.9700, A2 = 0.0300 D. A1 = 0.9604, A2 = 0.0392

C. A1 = 0.9700, A2 = 0.0300

A group of closely related species that has recently evolved from a common ancestor by occupying different parts of a habitat is an example of A. Sympatric speciation B. Hardy-Weinberg equilibrium C. Adaptive radiation D. Polyploidy

C. Adaptive radiation

In comparing artificial and natural selection, which of the following statements is true? A. Artificial selection is slower than natural selection. B. Artificial selection is reversible; natural selection is not. C. Artificial selection can produce maladaptive structures, natural selection cannot. D. Artificial selection cannot produce changes as large as changes produced by natural selection.

C. Artificial selection can produce maladaptive structures, natural selection cannot.

Closely related species that have different mating rituals are example of A. Ecological isolation B. Temporal isolation C. Behavioral isolation D. Mechanical isolation

C. Behavioral isolation

Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related tree frogs in South America. If reinforcement is occurring, what would you expect if you compare the calls of the two species in zones of sympatry versus zones of allopatry? A. Calls would be about the same in both areas. B. Calls would be more similar in areas of sympatry. C. Calls would be more different in areas of sympatry.

C. Calls would be more different in areas of sympatry.

If a person wanted flies with lots of bristles on their abdomens as pets, she could achieve this by only allowing the flies with the most bristles on their abdomens reproduce. What would this be an example of? A. Heterozygote advantage B. Natural selection C. Directional selection D. Stabilizing selection

C. Directional selection

Which of the following modes of selection arises when individuals at both extremes of the distribution have high fitness? A. Stabilizing selection B. Directional selection C. Disruptive selection D. Both a and b

C. Disruptive selection

Which of the following is not a prezygotic reproductive isolating barrier? A. Behavioral isolation B. Mechanical isolation C. Hybrid infertility D. Temporal isolation

C. Hybrid infertility

Which of the following changes over the past 50 years is probably having the most effect on changing (increasing or decreasing) human evolution rates? A. Sexual selection B. Increased mutation rates because of radiation leaks from nuclear reactors C. Increased migration between populations D. Decreasing population sizes leading to bottlenecks

C. Increased migration between populations

Which of the following statements about biological evolution is false? A. Species change over time. B. Natural selection produces changes in species. C. Individuals in a population evolve. D. Most populations are genetically diverse.

C. Individuals in a population evolve.

Which of the following is a true statement concerning genetic variation? A. It is created by the direct action of natural selection. B. It arises in response to changes in the environment. C. It must be present in a population before natural selection can act upon the population. D. It tends to be reduced by the processes involved when diploid organisms produce gametes.

C. It must be present in a population before natural selection can act upon the population.

Considerably more phenotypic variation exists in domesticated varieties of species like dogs and cabbages than exists in non-domesticated species like lions and maple trees. Which one of the following statements best explains why this is true? A. There is no selection and mating is random under domestication. B. During domestication, very high rates of mutation are induced. C. Many domesticated varieties would not survive in the natural world. D. Domesticated species exhibit "hybrid vigor" (heterosis).

C. Many domesticated varieties would not survive in the natural world.

Which of the following statements is false? A. Fitness is determined by the relationship between the phenotype and the environment. B. Both natural and sexual selection are non-random processes. C. Natural selection results in perfect adaptation. D. An increase in the number of hawks in the area would probably result in a decrease in the number of brightly colored male birds in the population over time.

C. Natural selection results in perfect adaptation.

A narrow hybrid zone separates the toad species B. bombina and B. variegata. What is true of those alleles that are unique to the parental species? A. Such alleles should be absent. B. Their allele frequency should be nearly the same as the allele frequencies in toad populations distant from the hybrid zone. C. The alleles' heterozygosity should be higher among the hybrid toads than in toad populations distant from the hybrid zone. D. Their allele frequency on one edge of the hybrid zone should roughly equal their frequency on the opposite edge of the hybrid zone.

C. The alleles' heterozygosity should be higher among the hybrid toads than in toad populations distant from the hybrid zone.

Which one of the following statements about the Lake Victoria cichlid fishes is false? A. The adaptive radiation of the almost 500 species of cichlid fish was very rapid and took place during the last 200,000 years. B. The adaptive radiation of the Lake Victoria cichlids may have resulted from a key evolutionary innovation. C. The diversity of the Lake Victoria cichlids continues today because the lake is devoid of predators. D. Many of the Lake Victoria cichlids have very specialized adaptations that allow them to occupy diverse habitats within the lake.`

C. The diversity of the Lake Victoria cichlids continues today because the lake is devoid of predators.

Which one of the following observations was not important in the studies done on the medium ground finch by Rosemary and Peter Grant to verify Darwin's selection hypothesis? A. Considerable variation existed in the bill size and shape in this finch. B. During the 30-year period of the study, the dryness of climate varied considerably. C. The medium ground finch showed assortative mating according to bill size and shape. D. Offspring were similar to parents in bill size and shape.

C. The medium ground finch showed assortative mating according to bill size and shape.

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that includes species T, X, Y, and Z makes up A. outgroup. B. a monophyletic clade. C. a paraphyletic grouping. D. a polyphyletic grouping.

C. a paraphyletic grouping.

The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and _____. A. an increasing number of infertile hybrids is produced over the course of the next one hundred generations B. no reproduction occurs in the hybrid zone C. an increasing number of viable, fertile hybrids is produced over the course of the next one hundred generations D. a decreasing number of viable, fertile hybrids is produced over the course of the next one hundred generations

C. an increasing number of viable, fertile hybrids is produced over the course of the next one hundred generations

Plants, and their predecessors, green algae, do not all share the property of A. containing chlorophylls a and b, and carotenoids. B. containing cellulose-rich cell walls. C. containing a system of roots and stems. D. containing starch as the primary food storage product. E. forming a cell plate during cytokinesis.

C. containing a system of roots and stems.

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should _____. A. test whether other traits in these males are also adaptive B. look for evidence of hair in ancestors of tamarins C. determine if hair length is heritable D. test whether males with shaved heads are still able to mate

C. determine if hair length is heritable

A biologist doing a long-term study on a wild spider population observes increased variation in silk thickness. Which of the following could the spider population be experiencing? A. directional selection B. stabilizing selection C. disruptive selection D. genetic drift

C. disruptive selection

which of the following most favors a wider array of phenotypes? A. directional selection B. stabilizing selection C. disruptive selection D. guppies with pike cichlids and killifish E. guppies with killifish

C. disruptive selection

In experiments using artificial selection to change the light number of bristles in the fruit fly Drosophila, the resulting populations of flies A. showed stabilizing selection. B. showed disruptive selection. C. exhibited large changes in after only a couple dozen generations. D. were unable to interbreed with wild type flies.

C. exhibited large changes in after only a couple dozen generations.

The several hundred species of picture-winged fruit flies of the Hawaiian Islands are genetically very similar, yet they all differ markedly from their ancestral population in Asia. This is probably an example of A. sexual selection. B. directional selection. C. founder effect. D. gene flow.

C. founder effect.

A unique feature of angiosperms is A. roots B. seeds C. fruit D. pollen

C. fruit

The common housefly (Musca domestica) belongs to all of the following taxa. Assuming you had access to textbooks or other scientific literature, knowing which of the following should provide you with the most specific information about the common housefly? A. order Diptera B. family Muscidae C. genus Musca D. class Hexapoda E. phylum Arthropoda

C. genus Musca

After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island? A. evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks B. evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks C. increased variation in beak size and shape over time D. no change in beak size and shape over time

C. increased variation in beak size and shape over time

About 80% of the alleles present in thoroughbred horses can be dated back to 31 known ancestors from the late eighteenth century. As a result, one would expect A. low rates of mutation B. many polymorphic alleles C. little variation in physiology and behavior D. Hardy-Weinberg equilibrium

C. little variation in physiology and behavior

Compared with Hardy-Weinberg predictions, populations that have practiced assortative mating have A. fewer homozygotes. B. more heterozygotes. C. more homozygotes. D. more mutations.

C. more homozygotes.

Genetic variation _____. A. is created by the direct action of natural selection B. arises in response to changes in the environment C. must be present in a population before natural selection can act upon the population D. tends to be reduced by when diploid organisms produce gametes

C. must be present in a population before natural selection can act upon the population

The best classification system is that which most closely _____. A. unites organisms that possess similar morphologies B. conforms to traditional, Linnaean taxonomic practices C. reflects evolutionary history D. reflects the basic separation of prokaryotes from eukaryotes

C. reflects evolutionary history

Which of the following would be most useful in predicting the outcome of evolution in Mytai lisgorgeous? A. the strength of female preference for bright males. B. the frequency of the two genes in the population. C. the relative fitness of the genes which encode the bright and dull coloration. D. the intensity of hawk predation.

C. the relative fitness of the genes which encode the bright and dull coloration.

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals that are heterozygous for this allele? A) 0.02 B) 0.04 C) 0.16 D) 0.32

D) 0.32

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened? A) The herbicide company lost its triazine formula and started selling poor-quality triazine. B) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. C) Triazine-resistant pigweed has less-efficient photosynthesis metabolism. D) Triazine-resistant weeds were more likely to survive and reproduce.

D) Triazine-resistant weeds were more likely to survive and reproduce.

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake? A) directional selection B) disruptive selection C) a founder event D) a genetic bottleneck

D) a genetic bottleneck

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of _____. A) convergent evolution B) a homologous structure C) natural selection D) a vestigial trait

D) a vestigial trait

There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example? A) phylogenetic B) ecological C) morphological D) biological

D) biological

Darwin and Wallace were the first to propose _____. A) that evolution occurs B) a mechanism for how evolution occurs C) that Earth is older than a few thousand years D) natural selection as the mechanism of evolution

D) natural selection as the mechanism of evolution

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals that are heterozygous for this allele? A. 0.02 B. 0.04 C. 0.16 D. 0.32

D. 0.32

In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population? A. 0.36 B. 0.64 C. 0.75 D. 0.80

D. 0.80

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1. What is the frequency of individuals with AA genotype? A. 0.20 B. 0.32 C. 0.42 D. 0.81

D. 0.81

If the HIV mutation rate results in a 10-6 rate for resistance to a single drug, what would the mutation rate be for independent resistance to three different anti-viral drugs evolving simultaneously? A. 3x10-6 B. 1x10-9 C. 3x10-9 D. 1x10-18

D. 1x10-18

In a population of 200 individuals, 72 are homozygous recessive for the character of eye color (cc). One hundred individuals from this population die from a fatal disease. Thirty-six of the survivors are homozygous recessive. How many heterozygous individuals are expected in the new population? A. 16 B. 36 C. 40 D. 48

D. 48

Speciation appears to be reinforced mostly by? A. Gene duplication. B. Hybrid sterility. C. Geographical barriers. D. Behavioral isolation.

D. Behavioral isolation.

Lions and tigers can mate but in the wild they occupy different portions of the landscape (grasslands vs. forests), what force is maintain their genetic isolation? A. Temporal isolation B. Behavioral isolation C. Mechanical isolation D. Ecological isolation

D. Ecological isolation

The idea that reproductively isolated populations slowly accumulate differences until speciation occurs is called A. Reverse Selection B. Punctuated equilibrium C. Adaptive radiation D. Gradualism

D. Gradualism

Which of the following is thought to be the common ancestor of all land plants? A. Sponges B. Bacteria C. Ferns D. Green algae

D. Green algae

Hardy-Weinberg pointed out that the original proportions of the genotypes in a population would remain constant from generation to generation if certain assumptions are met. Which one of the following is not a Hardy-Weinberg condition? A. The population is very large. B. No gene flow occurs. C. No selection occurs. D. No polymorphic loci exist in the population.

D. No polymorphic loci exist in the population.

Within the life cycle of a pine, which of the following structures are haploid? A. Nucleus B. Tracheids C. Xylem D. Pollen grain

D. Pollen grain

Which eukaryotic kingdom is polyphyletic and therefore not acceptable, based on cladistics? A. Plantae B. Fungi C. Animalia D. Protista

D. Protista

____ would keep a population in Hardy-Weinberg equilibrium A. Gene flow B. Mutation C. Selection D. Random mating

D. Random mating

Which of the following most often involves polyploidy? A. Extinction B. Allopatric speciation in animals C. Adaptive radiation D. Sympatric speciation in plants

D. Sympatric speciation in plants

A pine forest covers a valley, and one of the inhabitants is a red squirrel species. A large volcanic eruption occurs and separates the valley with a huge lava flow that the squirrels cannot cross, thus producing two isolated populations of squirrels. What change needs to occur for the two populations of squirrels to become separate species? A. The two squirrel populations must eat distinct species of plants. B. The fur color of the two squirrel populations must become distinct. C. The two squirrel populations select mates using the same sexual behavior. D. The two squirrel populations become reproductively isolated.

D. The two squirrel populations become reproductively isolated.

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened? A. The herbicide company lost its triazine formula and started selling poor-quality triazine. B. Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. C. Triazine-resistant pigweed has less-efficient photosynthesis metabolism. D. Triazine-resistant weeds were more likely to survive and reproduce.

D. Triazine-resistant weeds were more likely to survive and reproduce.

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake? A. directional selection B. disruptive selection C. a founder event D. a genetic bottleneck

D. a genetic bottleneck

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of _____. A. convergent evolution B. a homologous structure C. natural selection D. a vestigial trait

D. a vestigial trait

The gene pool includes A. all of the individuals within a population. B. all of the mutations within a population. C. all of the adaptations within a population. D. all of the alleles of genes within a population.

D. all of the alleles of genes within a population.

Geographical speciation is also known as A. reinforcement. B. sympatric speciation. C. Darwinian speciation. D. allopatric speciation.

D. allopatric speciation.

In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool. In the United States, the parasite that causes malaria is not present, but African-Americans whose ancestors were from equatorial Africa are present. What should be happening to the sickle-cell allele in the United States, and what should be happening to it in equatorial Africa? A. stabilizing selection; disruptive selection B. disruptive selection; stabilizing selection C. directional selection; disruptive selection D. directional selection; stabilizing selection

D. directional selection; stabilizing selection

Reproductive success of an individual is known as A. variation. B. microevolution. C. macroevolution. D. fitness.

D. fitness.

The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including those in their original homeland. Which of the following likely explains the genetic uniqueness of this population? A. population bottleneck and B. Hardy-Weinberg equilibrium heterozygote advantage and stabilizing selection C. mutation and natural selection D. founder effect and genetic drift

D. founder effect and genetic drift

Angiosperms are primarily characterized by all of the following except A. ovules are enclosed within other tissues at the time of pollination. B. a seed develops within a carpel. C. the ovary matures into the fruit. D. free water is required for pollination.

D. free water is required for pollination.

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing _____. A. nonrandom mating B. geographic isolation C. genetic drift D. gene flow

D. gene flow

Which of the following choices correctly presents only prezygotic isolating mechanisms? A. geographical isolation, ecological isolation, behavioral isolation, and hybrid sterility B. temporal isolation, mechanical isolation, hybrid adults die before mating, geographical isolation C. ecological isolation, geographical isolation, mechanical isolation, hybrid sterility D. geographical isolation, temporal isolation, behavioral isolation, mechanical isolation

D. geographical isolation, temporal isolation, behavioral isolation, mechanical isolation

The shape of the beaks of Darwin's finches and industrial melanism are often cited as examples of the process of ________ leading to evolutionary change. A. coevolution B. intelligent design C. founder effect D. natural selection

D. natural selection

Which of the following is not a reason that the Galapagos Islands and the Hawaiian Islands have so many endemic species of flies and birds? A. numerous islands in archipelago B. adequate distance between islands to allow divergence C. founder effect when islands are colonized D. numerous volcanic events separating birds on an island

D. numerous volcanic events separating birds on an island

All tracheophyte plants are characterized by all of the following except A. specialized conducting systems. B. waxy cuticle. C. stomata. D. seeds.

D. seeds.

Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by _____. A. a genetic bottleneck B. sexual selection C. habitat differentiation D. the founder effect

D. the founder effect

In England during the 1850's higher levels of industrial pollution darkened the trunks of trees found around industrial areas. What effect did this have on the local moth populations? A. Light winged moths became common B. Dark winged moths experienced less predation from birds C. Dark winged moths became more common due to camouflage D. A, B, C are all correct E. B & C are both correct

E. B & C are both correct

Which of the following is not required for evolution by natural selection? A. Time B. Variation C. Genetic inheritance D. Selection E. Sexual reproduction

E. Sexual reproduction

________________ suggests that evolutionary change occurs slowly through time and is not linked to speciation, whereas _________________ requires that phenotypic change occurs in bursts associated with speciation, separated by long periods of little or no change.

Gradualism punctuated equilibrium

_____________ features are derived from the same ancestral source; _____________ features are not

Homologous homoplastic

Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related but separate species of tree frogs in South America. What outcomes could possibly occur where the ranges of two species overlap? I) The species will interbreed, eventually fusing over time. II) A stable hybrid zone will form if hybrids are better adapted to the area of overlap than either parent species is. III) Species will continue to diverge and be isolated by behavioral or genetic mechanisms.

I, II, and III

_________ forms of fossils are often available to illustrate how the major transitions in life occurred to fill in missing gaps.

Intermediate

Order of heirarchy

Kingdom, Phylum, Class, Order, Family, Genus, Species -King Phillip came over from great Spain

components of fitness

Large males mate with many females, and small males rarely get to mate The number of offspring produced per mating is also important. Large female frogs and fish lay more eggs than do smaller females, and thus they may leave more offspring in the next generation. Fitness is a combination of survival, mating success, and number of offspring per mating.

Darwin's Theory of evolution

Natural selection produces evolutionary change when some individuals in a population possess certain inherited characteristics and then produce more surviving offspring than individuals lacking these characteristics. As a result, the population gradually comes to include more and more individuals with the advantageous characteristics. In this way, the population evolves and becomes better adapted to its local circumstances.

Evolution is not always divergent

Often, species evolve convergently because they use similar habitats, in which similar adaptations are favored. As a result, two species that are not closely related may end up more similar to each other than they are to their close relatives.

how does Phylogenetics help explain species diversification

One of the central goals of evolutionary biology is to explain patterns of species diversity: Why do some types of plants and animals exhibit more species richness—a greater number of species per clade—than others? Phylogenetic analysis can be used both to suggest and to test hypotheses about such differences.

_______________ ____________ can help determine whether structures are homologous or homoplastic.

Phylogenetic analysis

why is phylogenetics the basis of all comparative biology

Phylogenies not only provide information about evolutionary relationships among species, but they are also indispensable for understanding how evolution has occurred. By examining the distribution of traits among species in the context of their phylogenetic relationships, much can be learned about how and why evolution has proceeded.

Similarity may not accurately predict evolutionary relationships

Some will diverge more than others, and as a result, similarity is not necessarily a good predictor of how long it has been since two species shared a common ancestor

green algae

The green algae split into two major clades: the chlorophytes, which never made it to land, and the charophytes, which are a sister clade to all the land plants. Together charophytes and land plants are referred to as streptophytes

Homoplasy complicates cladistic analysis

The reason is that in some cases, the same character has evolved independently in several species. These characters would be categorized as shared derived characters, but they would be false signals of a close evolutionary relationship. In addition, derived characters may sometimes be lost as species within a clade re-evolve to the ancestral state.

Synapomorphy

a characteristic present in an ancestral species and shared exclusive (in more or less modified form) by its evolutionary descendants.

derived traits

a characteristic used in taxonomic analysis representing a departure from the primitive form Ex: the presence of hair is a shared derived feature of mammals.

stablizing selection

a form of selection in which selection acts to eliminate both extremes from a range of phenotypes. -Outcome: increase the frequency of the already common intermediate type. This selection is operating to prevent change away from this middle range of values. Does not change the most common phenotype of the population, but rather makes it even more common by eliminating extremes.

directional selection

a form of selection in which selection acts to eliminate one extreme from an array of phenotypes. -Outcome: the genes promoting this extreme become less frequent in the population and may eventually disappear.

disruptive selection

a form of selection in which selection acts to eliminate rather than favor the intermediate type. -Outcome example: populations of the African black-bellied seedcracker finch contain individuals with large and small beaks, but very few individuals with intermediate-sized beaks.

outgroup

a group of species that is closely related to, but not a member of. The outgroup species will not always exhibit the ancestral condition

Spores

a haploid reproductive cell, usually unicellular, capable of developing into an adult without fusion with another cell

punctuated equilibrium model

a hypothesis about the mechanism of evolutionary change proposing that long periods of little or no change (stasis) are punctuated by periods of rapid evolution

bottleneck effect

a loss of genetic variability that occurs when a population is reduced dramatically in size, most often by natural forces or changes in the environment

genotype frequencies

a measure of the occurrence of a genotype in a population, expressed as a proportion of the entire population, for example, an occurence of 0.25 (25%) for a homozygous recessive genotype