| A | B |
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| What type of population is most susceptible to loss of genetic variability as a result of genetic drift? | small populations |
| The number of individuals with a particular phenotype divided by the total number of individuals in the population is the | phenotype frequency. |
| When Darwin published his first book about evolution he included all of the following ideas except | the idea that species are permanent and unchanging. |
| The major idea that Darwin presented in his book The Origin of Species was that | species change over time by natural selection. |
| In a population with two alleles A and a the frequency of A is 0.2. Organisms that are homozygous for A die before reaching sexual maturity. In five generations what would be the frequency of individuals with aa genotypes? | greater than 0.64 |
| Anatomical structures that appear to be derived from a functional structure in an ancestor but that currently do not serve an important function are called | vestigial. |
| In a Hardy-Weinberg population with two alleles A and a that are in equilibrium the frequency of allele a is 0.7. What is the percentage of the population that is heterozygous for this allele? | 42 |
| Gene flow describes the | movement of genes from one population to another. |
| Natural selection acts | on phenotypes that are expressed. |
| You sample a population of butterflies and find that 42% are heterozygous for a particular gene. What would be the frequency of the recessive allele in this population? | Allele frequency cannot be estimated from this information. |
| Over millions of years plants and their pollinators have | coevolved. |
| Since natural resources are limited all organisms | must compete for resources. |
| The accumulation of differences between populations that once formed a single population is called | divergent evolution. |
| Natural selection is the process by which | organisms with traits well suited to their environment survive and reproduce more successfully than organisms less suited to the same environment. |
| Darwin thought that the animals of the Galápagos Islands were similar to those of the nearby coast of South America because | the animals’ ancestors had migrated from South America to the Galápagos Islands. |
| The process by which a population becomes better suited to its environment is known as | adaptation. |
| The occurrence of the same blood protein in a group of species provides evidence that these species | descended from a common ancestor. |
| Populations of the same species living in different places | become increasingly different as each population becomes adapted to its own environment. |
| Directional selection tends to eliminate | one extreme in a range of phenotypes. |
| The species of finches that Darwin observed differed in the shape of their beaks. According to Darwin all of these species probably | had a common ancestor. |
| In peas | a gene controls flower color such that R = purple and r = white. In an isolated pea patch there are 36 purple flowers and 64 white flowers. Assuming Hardy-Weinberg equilibrium what is the value of q for this population? |
| Which of the following is most likely a vestigial structure? | the human tailbone |
| According to Darwin evolution occurs | because of natural selection. |
| Darwin drew ideas for his theory from observations of organisms on | the Galápagos Islands. |
| Homologous structures in organisms provide evidence that the organisms | share a common ancestor. |
| A change in the frequency of a particular gene in one direction in a population is called | directional selection. |
| Scarcity of resources and a growing population are most likely to result in | increased competition. |
| The beak of a bird and the beak of a giant squid evolved independently and serve the same function. The beaks are | analogous structures. |
| 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 with Aa genotype? | 0.32 |
| The large brightly colored tail feathers of the male peacock are valuable to him because | they warn off potential competitors for mates. |
| Evidence that evolution occurs includes all of the following except | acquired characteristics. |
| Artificial selection has been used by humans to | speed up the process of divergent evolution. |
| The type of selection that may eliminate intermediate phenotypes is | disruptive selection. |
| The movement of alleles into or out of a population due to migration is called | gene flow. |
| In a population with two alleles A and a the frequency of a is 0.50. What would be the frequency of heterozygotes if the population is in Hardy-Weinberg equilibrium? | 0.50 |
| Speciation can occur as a result of geographic isolation because | populations that live in different environments may be exposed to different selection pressures. |
| The process in which two or more species become more adapted over time to each other’s presence is called | coevolution. |
| Natural selection is the only mechanism of evolution that will lead to | adaptation |
| Information on genetics and ____________________ now provide compelling evidence of evolution that was not available to Darwin. | biochemistry |
| Not all fossils of ____________________ organisms have modern counterparts. | extinct |
| Imagine that you are a paleontologist and you have found a dinosaur fossil that is intermediate in form between species. You would classify this fossil as a ____________________ fossil. | transitional |
| Anatomically similar structures inherited from a common ancestor are called ____________________ structures. | homologous |
| The snake pelvis is an example of a ____________________ structure. | vestigial |
| Any preserved trace of an ancient life form is a(n) ____________________. | fossil |
| A species that has disappeared permanently is said to be ____________________. | extinct |
| A heritable change in a species over time is called ____________________. | evolution |
| The process by which organisms with traits well suited to an environment survive and reproduce more successfully than organisms less suited for that environment is called ____________________. | natural selection |
| According to Darwin, the ____________________ limits the rate at which organisms survive and reproduce. | environment |
| ____________________ structures are similar because they originated in a common ancestor. | homologous |
| Closely related species show more ____________________ in nucleotide sequences than distantly related species. | similarities |
| ____________________ occurs as two or more species change over time due to each other’s influence. | coevolution |
| Scientists today use fossil evidence, anatomical evidence, DNA, and other molecular evidence to model ____________________, the relationships by ancestry among groups of organisms. | phylogeny |
| _________________________ is the study of evolution from a genetic point of view. | population genetics |
| A ____________________ shows that most members of a population have similar values for a given measurable trait. | bell curve |
| ____________________ results from flawed copies of individual genes. | mutation |
| Alternative versions of genes are called ____________________. | alleles |
| Allele ____________________ is determined by dividing the number of instances of a certain allele by the total number of alleles of all types in the population. | frequency |
| According to the ______________________________ principle, allele frequencies in a population tend to remain the same from generation to generation unless acted on by outside influences. | Hardy-Weinberg genetic equilibrium |
| The movement of individuals from one population to another is called ____________________. | migration |
| When there are only a few surviving individuals of a species, the species is vulnerable to extinction because there is little if any ____________________ on which natural selection can act. | genetic variability |
| ____________________ selection causes the range of phenotypes to become narrower, increasing the number of individuals with characteristics near the middle of the range. | stabilizing |
| Differences in physical characteristics between males and females of the same species may indicate that ____________________ selection is important in the species. | sexual |
| The key element in the biological concept of species is that individuals within a species can ____________________. | interbreed |
| When geographic isolation occurs, ____________________ flow between separated populations ceases, which can then lead to speciation. | gene |
| Reproductive isolation that occurs before fertilization is called ____________________ isolation. | prezygotic |
| Reproductive isolation that occurs after fertilization is called ____________________ isolation. | postzygotic |
| ____________________ is the hypothesis that evolution occurs at a constant rate. | gradualism |
| The group of living primates most closely related to humans are the African ____________________. | apes |
| The flattened faces of primates contribute to their ____________________ by increasing the degree of binocular vision. | depth perception |
| The group of primates that is divided into New World and Old World monkeys is collectively classified as ____________________. | anthropoids |
| Haplorhines include tarsiers, monkeys, and ____________________. | apes |
| Considering fossils ranging from early Australopithecus through the various Homo species (H. ergaster, H. erectus, and H. sapiens) a pattern of increasing ____________________ capacity emerges. | brain |
| The larger brains of primates require an extended period of infancy and childhood. This puts some species at higher risk of extinction because it is associated with a decreased rate of ____________________. | reproduction |
| In addition to the position of the foramen magnum of the skull, the other bone that would provide the most conclusive evidence of bipedalism in a fossil hominin is the ____________________. | pelvis |
| The discovery of fossilized australopithecine footprints by Mary Leakey is significant evidence indicating that Australopithecus walked ____________________. | upright |
| An anatomical feature that distinguishes humans from chimpanzees and enables humans to walk upright is a pelvis shaped like a ____________________. | bowl |
| The Australopithecus fossil known as “Lucy” displays a mosaic pattern of evolution. Its discovery is important because it indicates that it is possible for different parts of the body to evolve at different ____________________. | rates |
