Exam 13: How Populations Evolve

Examine the relationships between the elephants in the accompanying figure. Which pair is most closely related?

Which is a phenomenon that can result from directional selection?

The original source of genetic variation that serves as the raw material for evolution is ________.

The similarity of the embryos of chickens and humans is evidence of ________.

Years ago, farmers determined that suppressing flower development in the wild mustard plant gave rise to the plant we know as broccoli. This is an example of ________.

Scenario Over the past 60 years, many amphibian species have experienced significant population declines, and some species have become extinct. Scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. However, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. These global declines suggest widespread problems, including increased ultraviolet radiation, acid rain, and disease. In Switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. -When most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that ________.

Which statement about the voyage of the Beagle is TRUE?

Which explanation is most likely for a particular human population with a higher incidence of polydactyly (extra fingers/toes)than the human population as a whole?

Natural selection ________.

Natural selection generally results in ________.

Which is NOT a benefit of the understanding of evolution to understanding the field of biology?

Examine the evolutionary tree below. This tree tells us that the amnion is found in ________.