Exam 15: The Origin of Species

The fossils of two adult birds are found in a nest containing several fossilized eggs.Physically,the bird fossils look very different from each other.What are scientists most likely to use to classify these species?

Sympatric speciation

The two squirrel species shown in the following figure arose from the same ancestor.The Kaibab squirrel lives on the north rim of the Grand Canyon and Abert's squirrel lives on the south rim.Which is the most likely explanation for their speciation?

Using reproductive isolation as a method of defining a species is NOT useful for

The experiment diagrammed in the following image could lead to the reproductive isolation of fruit fly populations.

Vertebrates are a group of related animals with a backbone.All vertebrates have basically the same eye structure.Therefore,the vertebrate eyes are

Two populations that are geographically isolated will always diverge into two species.

Currently,the biggest factor having an effect on polar bear evolution is

The death of zygotes produced by the mating of individuals of two different populations is an example of how ________ barriers can lead to reproductive isolation.

The following pictures show a shark,which is a fish,and a dolphin,which is a mammal.The similar body types of these two species are due to

Polyploidy can lead to

Adaptive radiation can only take place in the presence of reproductive isolation.

In the following figure,two populations of one species of fruit flies were raised for several generations on different nutrients (starch and maltose).Then the members of the two populations were reintroduced and the mating frequencies of flies from the two different populations were recorded.Which of the following is true?

Sympatric speciation can occur in the absence of geographic isolation.

The great diversity of life on Earth is caused by ________,the formation of new species.

Because alleles are only exchanged within species,each species is said to have a unique

Which of the following is an example of a postzygotic barrier?

The offspring of two individuals of different species that interbreed are known as ________.

Vestigial organs had a function in a previous ancestor but no longer have a function in the current species.

Mass extinctions frequently result in adaptive radiation because they lead to