The camera-type eyes of octopuses are very complicated and have many of the same features as the camera-type eyes of vertebrates. Yet, the eyes of invertebrates and vertebrates are not homologous. This situation is an example of
The four-chambered hearts of birds and the four-chambered hearts of mammals evolved independently of each other. If one were unaware of this independence, then one might logically conclude that
d. the common ancestor of birds and mammals had a four-chambered heart.
Some claim that the birds should continue to be placed in a class (Aves) separate from the Reptilia, despite evidence from molecular systematics indicating a close relationship between birds and crocodiles. Their claim is based on the extent of the adaptations that birds have undergone for flight. The logic of their claim is most similar to that found in which statement?
b. Humans should be placed in their own order because no other member of the order Primates features so many modifications for bipedalism.
Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their
e. homologous genes that are highly conserved.
Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of homology?
d. Dogs and wolves shared a common ancestor very recently.
Which combination of the following species characteristics would cause the greatest likelihood of fossilization in sedimentary rock?
e. I, II, III, and V
The ostrich and the emu look very similar and live in similar habitats, however they are not very closely related. This is an example of
b. convergent evolution.
Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). The morphological similarities of these two species must therefore be due to
d. convergent evolution.
The correct sequence from the most to the least comprehensive of the taxonomic levels listed here is
b. kingdom, phylum, class, order, family, genus, and species.
If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
e. D and F
On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?
c. He would have placed them in more species than modern botanists do.
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?
b. a node where two twigs diverge
based rate of evolutionary change on the assertion that most genetic mutations in populations are neither harmful nor helpful and therefore are not influenced by natural selection
B. Charles Darwin
Generally, within a lineage, the largest number of shared derived characters should be found among two organisms that are members of the same
Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2?
Ultimately, which of these is the basis for both the principle of maximum parsimony and the principle that shared complexity indicates homology rather than analogy?
c. the laws of probability
If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of advanced molluscs (such as squids), then
b. ancestral versions of this protein assemblage were either less functional, or had different functions, than modern prokaryotic flagella.
If the prokaryotic flagellum developed from assemblages of proteins that originally were not involved with cell motility but with some other function instead, then the modern prokaryotic flagellum is an example of a(n)
If one organ is an exaptation of another organ, then what must be true of these two organs?
b. They are homologous organs.
Which of the following examples would be most likely to result in macroevolution?
a. a change in a regulatory gene, which has a major and adaptive impact on morphology
An organism has a relatively large number of Hox genes in its genome. Which of the following is not true of this organism?
b. It must have multiple paired appendages along the length of its body.
Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of
A hypothetical mutation in a squirrel population produces organisms with eight legs rather than four. Further, these mutant squirrels survive, successfully invade new habitats, and eventually give rise to a new species. The initial event giving rise to extra legs would be a good example of
d. changes in homeotic genes.
Many species of snakes lay eggs, but in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth is an example of
c. species selection.
In the 5-6 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. That these traits were common to both species is most easily explained by which of the following?
a. species selection
The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that
d. in particular environments, similar adaptations can be beneficial in more than one species.
In certain motile prokaryotes, dozens of different proteins comprise the motor that powers the prokaryotic flagellum. The motor has a complicated structure, and its various proteins interact to carry out its function. Based on Darwin's explanation for the existence of human eyes, how would he probably have explained the existence of such motors?
e. He would have proposed that less complicated, but still functional, versions (though maybe with a different function) had existed in ancestral prokaryotes.
Which of the following is a way that allopolyploidy can most directly cause speciation?
b. It can overcome hybrid sterility.
A new plant species formed from the hybridization between a plant with a diploid number of 16 and a plant with a diploid number of 12 would probably have a gamete chromosome number of
Plant species A has a diploid number of 28. Plant species B has a diploid number of 14. A new, sexually reproducing species C arises as an allopolyploid from hybridization of A and B. The diploid number of C would probably be
Two closely related populations of mice have been separated for a long period by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?
c. They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.
As a result of deforestation, the number of different habitats in a particular locale declines while, at the same time, the rate of cladogenesis in a particular lineage of animals in this locale increases. Choose the feature that most likely accounts for this observation.
e. increased sexual selection
What kind of speciation has occurred in this example, and what has driven it?
b. sympatric speciation, habitat differentiation
According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that
d. speciation occurred rapidly in geologic time.
According to the concept of punctuated equilibrium,
c. a new species accumulates most of its unique features as it comes into existence.
Which of the following would be a position held by an adherent of the punctuated equilibrium theory?
a. A new species forms most of its unique features as it comes into existence and then changes little for the duration of its existence.
The origin of a new plant species by hybridization coupled with nondisjunction is an example of
b. sympatric speciation.
If these fly species lost the ability to fly independently of each other (the result of separate mutation events in each lineage), then the flightless condition in these species could be an example of
b. species selection.
In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition probably affected the ____ genes, making the initial mutants examples of ____.
c. Hox; complete metamorphosis
If the foods preferred by each species are found on different parts of the island, and if the flies mate and lay eggs on their food sources, regardless of the location of the food sources, then the speciation events involving these fly species may have been driven, at least in part, by which of the following?
e. habitat differentiation
If the males' halteres have species-specific size, shape, color, and use in courtship displays, and if the species' ranges overlap, then the speciation events may have been driven, at least in part, by which of the following?
d. sexual selection
Which of these events seem(s) to have occurred among the fly populations on the island?
e. 1, 2, and 3
Fly species W, found in a certain part of the island, produces fertile offspring with species Y. Species W does not produce fertile offspring with species X or Z. If no other species can hybridize, then species W and Y
e. A, B, and C
Which of these fly organs, as they exist in current fly populations, best fits the description of an exaptation?
Which of the following statements about speciation is correct?
e. Speciation is included within the concept of macroevolution.
Which of the following would be an example of macroevolution?
c. evolution of modern humans, Homo sapiens, from australopithecine ancestors
Males of one species sing only during rainy conditions; males of another species sing only when it is not raining.
Females of one species choose mates based on song quality; females of another species choose mates on the basis of size.
One species mates for two weeks in early April; another species mates for three weeks in early May.
Males of one species are too small to perform amplexus (an action that stimulates ovulation) with females of all other species.
This kind of isolation is most similar to which of the following reproductive isolating mechanisms?
d. habitat isolation
What is the mechanism for keeping the two frog species separate?
a. the postzygotic barrier called hybrid inviability
Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should
c. reinforce postzygotic barriers between horses and donkeys.
Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?
b. III only
Which graph best depicts the trends in genotypic frequencies that would be expected to occur over time?
b. graph B
If it should happen that some of these fleas develop a strong preference, instead, for cattle blood and mate only with fleas that, likewise, prefer cattle blood, it is possible that over time ____ will occur.
e. 1 through 5
Which example below will most likely guarantee that two closely related species will remain distinct biological species?
e. reproductive isolation from one another
The Hawaiian islands are a great showcase of evolution because of intense
b. adaptive radiation and allopatric speciation.
All of the following have contributed to the diversity of organisms on the Hawaiian archipelago except that
d. the islands are very young in geologic time.
What must have happened following the initial colonization event to account for the current situation?
d. 1, 3, and 4
A rapid method of speciation that has been important in the history of flowering plants is
Plant species A has a diploid number of 8. A new species, B, arises as an autopolyploid from A. The diploid number of B would probably be
Which of the following statements about species, as defined by the biological species concept, is (are) correct?
c. I and III
What is generally true of two sibling species?
a. They shared a common ancestor recently in evolutionary time.
Which of the various species concepts identifies species based on the degree of genetic exchange between their gene pools?
For which two species concepts are anatomical features the primary criterion for determining species identities?
d. 3 and 5
What type of reproductive barrier is most obviously separating these different species?
a. habitat isolation
Which of the following must occur during a period of geographic isolation in order for two sibling species to remain genetically distinct following their geographic reunion in the same home range?
d. reproductive isolation
two species of garter snakes live in the same region, but one lives in water and the other lives on land
mating fruit flies recognize the appearance, odor, tapping motions, and sounds of members of their own species, but not of other species
the scarlet oak is adapted to moist bottomland, whereas the black oak is adapted to dry upland soils
Cattle breeders have improved the quality of meat over the years by which process?
c. stabilizing selection
The allele that causes phenylketonuria (PKU) is harmful, except when an infant's diet lacks the amino acid, phenylalanine. What maintains the presence of this harmful allele in a population's gene pool?
b. stabilizing selection
Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform successful meiosis. Which statement about mules is true?
a. They have a relative evolutionary fitness of zero.
Heterozygote advantage should be most closely linked to which of the following?
b. stabilizing selection
In equatorial Africa, all of the following factors contribute to keeping the sickle-cell allele at a high frequency in the population, except
E) frequency-dependent selection.
Which statement about variation is most true?
D) All new alleles are the result of nucleotide variability.
If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?
b. directional selection
What is true of the trait whose frequency distribution in a large population appears above? It has probably undergone
b. stabilizing selection.
If the unimodal distribution shown above becomes a bimodal distribution over time, then
B) a situation of balanced polymorphism may be produced.
If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring?
c. 2 and 3
Male satin bowerbirds adorn structures that they build, called "bowers," with parrot feathers, flowers, and other bizarre ornaments in order to attract females. Females inspect the bowers and, if suitably impressed, allow males to mate with them, after which they go off to nest by themselves. The evolution of this behavior is best described as due to
c. sexual selection.
In many animal species, mature males are much larger than mature females. This size difference can be attributed to
E) A, B, and C
Adult male vervet monkeys have red penises and blue scrotums. Males use their colorful genitalia in dominance displays wherein they compete with each other for access to females. The coloration of the male genitalia is best explained as the result of ____, and specifically of ____.
C) sexual selection; intrasexual selection
Which of the following is most likely to have been produced by sexual selection?
A) a male lion's mane
When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of
e. frequency-dependent selection.
Female wasps, which are protected by the use of a painful stinger, often make their presence conspicuous by rapidly moving their usually long antennae. These wasps are often mimicked by flies with short antennae who give the appearance of rapidly moving long antennae by waving their forelegs in front of their bodies. Which of the following statements concerning this behavior is not consistent with current evolutionary theory?
D) Given enough time, these flies will develop longer antennae and become perfect mimics.
The same gene that causes various coat patterns in wild and domesticated cats also causes the cross-eyed condition in these cats, the cross-eyed condition being slightly maladaptive. In a hypothetical environment, the coat pattern that is associated with crossed eyes is highly adaptive, with the result that both the coat pattern and the cross-eyed condition increase in a feline population over time. Which statement is best supported by these observations?
b. Phenotype is often the result of compromise.
A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. That the actual forelimbs of these mammals do not seem to be optimally arranged is because
e. natural selection is generally limited to modifying structures that were present in previous generations and in previous species.
If one assumes that Hardy-Weinberg equilibrium applies to the population of colonists on this planet, about how many people will have attached earlobes when the planet's population reaches 10,000?
If four of the original colonists died before they produced offspring, the ratios of genotypes could be quite different in the subsequent generations. This is an example of
c. genetic drift.
A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of
a. a cline.
Which of the following is one important evolutionary feature of the diploid condition?
D) Diploid organisms express less of their genetic variability than haploid organisms.
The outcome of the conflict between bacteria and bacteriophage at any point in time results from
a. frequency-dependent selection.
Over the course of evolutionary time, what should occur?
d. Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that vary over time.
The Darwinian fitness of an individual is measured by
a. the number of its offspring that survive to reproduce.
If a phenotypic polymorphism lacks a genetic component, then
B) natural selection cannot act upon it to make a population better adapted over the course of generations.
When we say that an individual organism has a greater fitness than another individual, we specifically mean
that the organism
e. leaves more viable offspring than others of its species.
Which of the following statements best summarizes evolution as it is viewed today?
e. It is the differential survival and reproduction of the most fit phenotypes.
The higher the proportion of loci that are "fixed" in a population, the lower is that population's
D) A, B, and C
An African butterfly species exists in two strikingly different color patterns
D. disruptive selection
Fossil evidence indicates that horses have gradually increased in size over geologic time
B. directional selection
A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are relatively rare.
D. disruptive selection
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 not a requirement for maintenance of Hardy-Weinberg equilibrium?
A) an increasing mutation rate
In which population is the frequency of the allele for brown feathers highest?
D. They are all the same.
In which population would it be least likely that an accident would significantly alter the frequency of the brown allele?
B. Population 2
The probability of a mutation at a particular gene locus is ____, and the probability of a mutation in the genome of a particular individual is ____.
B) low; high
Which factor is the most important in producing the variability that occurs in each generation of humans?
B) sexual recombination
In modern terminology, diversity is understood to be a result of genetic variation. Sources of variation for evolution include all of the following except
a. mistakes in translation of structural genes.
Which of the following chromosomal mutations can increase the mass of DNA present in an organism's genome, creating superfluous DNA that may undergo further changes producing entirely new genes?
Genetic recombination is a crucial process in evolution. This statement is supported by the continuous existence of which of the following in evolving populations?
E) A, B, and C
Which is true regarding genetic variation in prokaryotes, where cell reproduction occurs via binary fission?
D) Prokaryotic genomes can experience increased genetic variation via both mutation and genetic recombination.
In DNA molecules, A-T base pairs are held to each other by two hydrogen bonds, whereas the more stable G-C base pairs are held to each other by three hydrogen bonds. If DNA mutability increases as DNA stability decreases, then which of the five exons of a hypothetical gene should be most highly conserved over evolutionary time (assuming no selection and no transposition occurs)?
C) Exon C
What is true of retrotransposons that is not generally true of non-replicative transposons?
D) A, B, and C are true.
In which way(s) should retrotransposons affect the genome that non-replicative transposons do not?
E) Both B and C are true.
In a large, sexually reproducing population, the frequency of an allele changes from 0.6 to 0.2. From this change, one can most logically assume that, in this environment,
E) the allele reduces fitness.
The following important concepts of population genetics are due to random events or chance except
D) natural selection.
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.
If the frequency of a particular allele that is present in a small, isolated population of alpine plants should change due to a landslide that leaves an even smaller remnant of surviving plants, then what has occurred?
e. A, B, and C
Through time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing
e. gene flow.
What is the most important missing evidence or observation in Darwin's theory of 1859?
a. the source of genetic variation
Which hypothesis of inheritance, common at Darwin's time, caused many to question the ability of natural selection to bring about adaptation in populations?
b. blending hypothesis
Which definition of evolution would have been most foreign to Charles Darwin during his lifetime?
a. change in gene frequency in gene pools
Even in Darwin's time, the blending hypothesis was incompatible with observed facts. If the blending hypothesis were true, then what should one expect to observe over the course of generations?
c. Members of a breeding population should become more uniform in phenotype.
What is true of the modern evolutionary synthesis?
E) It exemplifies the tentative nature of scientific knowledge.
What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait (aa) has not changed over time?
B) The two phenotypes are about equally adaptive under laboratory conditions.
All of the following are criteria for maintaining Hardy-Weinberg equilibrium involving two alleles except
A) the frequency of all genotypes must be equal.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.7. What is the percentage of the population that is homozygous for this allele?
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?
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?
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?
Most copies of harmful recessive alleles in a sexual species are carried by individuals that are
D) heterozygous for the allele.
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?
E) greater than 0.64
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?
e. Allele frequency cannot be estimated from this information.
If there are 4,000 children born to this generation, how many would be expected to have AB blood under the conditions of Hardy-Weinberg equilibrium?
Which of the following is the best example of humans undergoing evolution, understood as "descent with modification"?
a. reduction in the amount and coarseness of body hair over millennia
Which statement best describes how the evolution of pesticide resistance occurs in a population of insects?
d. A number of genetically resistant pesticide survivors reproduce. The next generation of insects contains more genes from the survivors than it does from susceptible individuals.
DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. What would need to be true for pest eradication efforts to have been successful in the long run?
d. All individual insects should have possessed genomes that made them susceptible to DDT.
Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Maintaining resistance against the herbicide is metabolically expensive for the plants. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain?
d. 1, 3, and 6
If 3TC resistance is costly for HIV, then which plot (I-IV) best represents the response of a strain of 3TC-resistant HIV over time, if 3TC administration begins at the time indicated by the arrow?
If two modern organisms are distantly related in an evolutionary sense, then one should expect that
b. they should share fewer homologous structures than two more closely related organisms.
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from the same embryonic tissues. How do biologists interpret these similarities?
d. A and C only
Human intestines are held in place by membranes called mesenteries. In bipedal humans, it would be logical for these mesenteries to be attached to the rib cage. Instead, they are attached to the backbone, as they are in quadrupedal mammals. Because of this arrangement, human mesenteries have a tendency to tear more often than mesenteries in other mammals, as frequently observed among truck drivers and jackhammer operators. The same evolutionary modification that causes increased susceptibility to torn mesenteries is responsible for
c. back and knee problems.
As adults, certain species of whales possess baleen instead of teeth. Baleen is used to filter the whales' diet of planktonic animals from seawater. As embryos, baleen whales possess teeth, which are later replaced by baleen. The teeth of embryonic baleen whales are evidence that
c. baleen whales are descendants of toothed whales.
Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
c. Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
b. All organisms use essentially the same genetic code.
What would be the best technique for determining the evolutionary relationships among several closely related species, each of which still contains living members?
e. DNA or RNA analysis
Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree?
e. DNA sequence evidence fully disagreed with morphological evidence.
Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would shed the most light on whether these structures are homologous or whether they are, instead, the result of convergent evolution?
b. The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.
Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails just as fish do, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are
e. B and C only
It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that
a. island forms and mainland forms descended from common ancestors.
Monkeys of South and Central America have prehensile tails, meaning that their tails can be used to grasp objects. The tails of African and Asian monkeys are not prehensile. Which discipline is most likely to provide an explanation for how this difference in tails came about?
The theory of evolution is most accurately described as
d. an overarching explanation, supported by much evidence, for how populations change over time.
Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of
b. the fossil record.
Which of the following events, as described here, is most in agreement with the idea of catastrophism?
d. the demise of the dinosaurs, and various other groups, by the impact of a large extraterrestrial body with Earth
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 would you use to correct this student's misconception?
a. Characteristics acquired during an organism's life are generally not passed on through genes.
"Improving the intelligence of an adult through education will result in that adult's descendants being born with a greater native intelligence." This statement is an example of
In the mid-1900s, the Soviet geneticist Lysenko exposed winter wheat plants to ever-colder temperatures, collected their seeds, and then exposed the seedlings to ever-colder temperatures. He repeated his attempts over the course of decades in an attempt to evolve cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of
Darwin had initially expected the living plants of temperate South America to resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explanation for this observation is most properly associated with the field of
Charles Darwin was the first to propose
d. a mechanism for evolution that was supported by evidence.
In evolutionary terms, the more closely related two different organisms are, the
c. more recently they shared a common ancestor.
Both Darwin's and Lamarck's ideas regarding evolution suggest which of the following?
e. The interaction of organisms with their environment is important in the evolutionary process.
Natural selection is based on all of the following except
e. individuals must adapt to their environment.
Which of the following represents an idea Darwin took from the writings of Thomas Malthus?
b. Populations tend to increase at a faster rate than their food supply.
Which statement about natural selection is most correct?
d. Well-adapted individuals leave more offspring, and thus contribute more to the gene pool, than poorly adapted individuals.
Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
a. 2, 4, 1, 3
If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of
b. the ability of populations to undergo modification as they adapt to a particular environment.
During drought years on the Galapagos, small, easily eaten seeds become rare leaving only large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, then what should one expect to result from natural selection?
d. More small-beaked birds dying than the larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.
Which of the following statements is not an inference of natural selection?
e. individuals must adapt to their environment.
Which of the following must exist in a population before natural selection can act upon that population?
a. genetic variation among individuals
In a hypothetical environment, fishes called pike-cichlids are visual predators of algae-eating fish, i.e., they locate their prey by sight. If a population of algae eaters experiences predation pressure from pike-cichlids, which of the following would least likely be observed in the algae-eater population over the course of many generations?
c. Female algae eaters may become larger, bearing broods composed of more, and larger, young.
A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. What inferences might you make about this population?
e. A, B, and C