Chapter 15 FINAL!

How is a vestigial organ tied in with Lamarck's principle?

A vestigial organ is an organ that no longer has a function. Lamarck stated that structures that are not used are not passed on.

What is a vestigial organ? Give an example.

A vestigial organ is an organ, such as the human appendix, that is reduced in size and no longer has a function.

What is artificial variation?

Artificial Selection is the breeding of certain traits over other traits.

Describe three of Darwin's observations about animals in South America and on the Galápagos Islands.

Darwin observed fossils, some of which resembled living organisms and others that were unlike any organisms he knew; that organisms everywhere seemed remarkably well suited to their environments; and that similar organisms, such as tortoises, were different on each island.

How does Darwin's principle of descent with modification explain the characteristics of today's species?

Descent with modification explains why organisms living today may be different from their ancestors,for example, by having different structures.

How does the principle of modern descent with modification clash with the religious idea of fixity of species?

Descent with modification explains why organisms living today may be different from their ancestors. According to the bible, people and species were created by God.

What two ideas from geology were important to Darwin's thinking?

Earth is very old, and the same processes that shaped Earth millions of years ago continue in the present.

What is evolution? Why is evolution referred to as a theory?

Evolution, or change over time, is the process by which modern organisms have descended from ancient ones. Evolution is referred to as a theory because it is a well- supported explanation of phenomena that have occurred in the natural world.

Distinguish between fitness and adaptation. Give an example of each.

Fitness, the ability of an individual to survive and reproduce in its specific environment, occurs through ongoing adaptation. An example is an animal that survives through camouflage. An adaptation is any inherited characteristic that increases an organism's chance of survival. Examples include a porcupine's quills and a lion's teeth and claws.

List and explain at least 3 examples of artificial selection that take place in today's world.

Greyhounds, dachshunds, and corn. Greyhounds now have unusual swiftness in running. Dachshunds now have an unusually low and elongated bodies. Corn originally had seeds that came off the cob and dispersed into the surrounding environment.

Explain Lamarck's principle of use and disuse.

Lamarck said that structures that are used develop and are passed on to offspring, whereas structures that are not used are not passed on.

How is artificial selection dependent on variation in nature?

Nature provides the variation, and humans select the variations that are useful.

How do scientists use similarities in embryology as evidence for evolution?

That the species evolved from a common ancestor.

What types of evidence did Darwin use to support his theory of change over time?

The fossil record, geographic distribution of species, homologous structures, and similarities in embryology

What is being "selected for" in the process of natural selection?

The traits that help an organism survive in a particular environment