Exam 14: How Evolution Works

Peppered moths in England evolved into a dark-colored form when soot darkened the bark of the trees they lived on and exposed the light-colored form to predation.However,air pollution control eventually restored the moths' habitat to its original condition.What would probably have happened to the peppered moth population if the light-colored alleles had been entirely lost from its gene pool during the period when dark-colored moths were selectively favored?

Evolution is

Plate tectonics causes the ________ of Earth's landmasses over geologic time.

The fossils of organisms that existed when the continents were connected are distributed across ________ continents than the fossils of organisms that evolved after the continents separated.

In ________ selection,success is related more to attracting a mate than to possessing adaptations that are beneficial for survival.

Cliff swallows in southwestern Nebraska are experiencing a new natural selection pressure;the swallows that are less agile are more likely to be killed by ________.

Nonheritable genetic variations typically account for only about 10 percent of the evolutionary change in a population.

The genus Lycopodium includes plants that evolved before the breakup of Pangaea.The genus Sequoiadendron (redwood trees)evolved after Pangaea split into separate landmasses.Which genus would you expect to have the widest distribution of living representatives across the modern continents?

Which of the following statements best describes what happens in gene flow?

The domestication of agricultural crops,such as corn and wheat,provides direct evidence for evolution.

It is quite common for species that are exposed to sexual selection to be sexually dimorphic.What best explains why the males of diverse species like the lion,elephant seal,and elk are so much larger than the females?

The need for new alleles to confront issues like environmental change has nothing to do with the specificity or rate of ________;the process is entirely random.

Suppose a population's gene pool consists of the A and a alleles in a ratio of 80:20.If the population has reached equilibrium,the next generation will consist of genotypes in a ratio of

Continental drift predicts that fossils of species that evolved after Pangaea split apart should be found on only one or a few present-day continents.

Species like the African cheetah,northern elephant seal,and Florida panther have all experienced a genetic bottleneck;what is the primary outcome of this experience?

As embryos,baleen whales have teeth and also have two nostrils directly above their mouth.Before birth,however,the teeth are reabsorbed,and the nostrils migrate and fuse to become the blowhole.What does this observation suggest about the ancestry of these whales?

Which of the following statements about the evolutionary relatedness of organisms is FALSE?

In genetic drift,the events that affect the survival and reproduction of individuals in a population occur

A study by Charles and Mary Brown has documented a reduction in the wing length of cliff swallows that live near busy roadways;the study proposes that the need to avoid being hit by cars is the evolutionary driving force for the change.How would you evaluate this hypothesis if wing length had also shortened in cliff swallow populations that live in the desert Southwest where traffic is virtually nonexistent?

Populations evolve over time because the individuals that form them are individually evolving.