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?
Of the following anatomical structures, which is homologous to the wing of a bat?
e. arm of a human
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.