Exam 20: Speciation and Macroevolution

The ranges of black bears and brown bears overlap. However, black bears spend most of their time in the woods and brown bears spend most of their time along the river. Which of the following best describes why black and brown bears do not interbreed?

The biological species concept declares an organism to be a separate species if it has undergone evolution long enough for the emergence of statistically unique traits.

In the example of the flicker hybrid zone, why does it appear that the flicker hybrids are in a stable hybrid zone?

Which model would predict the abrupt appearance of a new species in the fossil record, with little or no evidence of intermediate forms?

What characterizes hybrid breakdown?

Speciation is more likely to occur if the isolated population is large.

Having legs longer than your arms is an example of:

Which evolutionary process occurs when the hybrids in a hybrid zone are as fit as either of the parental populations?

Figure 20-2 In the accompanying figure, note the variation in these closely related birds. What does this illustrate?

Which mechanism would prevent interbreeding between two species of fish living in the same habitat?

Describe how continental drift resulting in Australia being isolated in the South Pacific contributed to biological species evolution.

An alloploid contains multiple sets of chromosomes from a single species.

Linnaeus' classification of plants and other organisms into separate species based on their visible structural differences, such as feathers or number of flower parts, is known as ______________.

An adult axolotl salamander ( Ambystoma mexicanum ) retains the juvenile characteristics of external gills and a tail fin. This is an example of what mechanism?

The evolutionary species concept states that for a population to be declared a separate species, it must:

How was the mechanism of sympatric speciation among hemp nettles in nature verified experimentally?

Which statement about allopolyploidy is FALSE?

What are the two major forces contributing to allopatric speciation?

Which describes the death of an interspecific embryo that failed to develop?

Gradualism is rarely observed in the fossil record because: