Exam 14: How Evolution Works

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?

Humans have a reduced tailbone and the muscles to move a tail.This evidence indicates that we descended from an ancestor that had a tail.

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

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.

Evolution is

Natural selection tends to

Genetic variation is based on

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?

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

Darwin's ideas about natural selection were immediately accepted; this shows that the scientific community recognizes and accepts correct ideas as soon as they are presented.

Humans have bred cows that are specialized for milk production by mating female cows that produce large quantities of milk with male cows whose mothers also produced large quantities of milk.This is an example of ________ selection.

Peppered moths are generally light in color and blend into the trunks of the trees they live on.Populations of peppered moths that are found in areas where soot has blackened the tree trunks are dark in color.This example demonstrates

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

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

Many organisms are darker on their dorsal surface and lighter on their ventral surface.They are difficult to see from both above and below because of this ________,which is called countershading.

Which of the following things is an example of gene flow?

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 ________.

One frequently observed example of evolution is

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?

Pangaea is