21. Evolution

How were cereal grains, such as wheat and barley, primarily spread outside their natural habitats during early human history?

Which of the following were the first living organisms on Earth?

How might changes to Hox genes have contributed to the Cambrian explosion?

Which of the following best explains why asteroids and comets differ in composition?

Which of the following is an adaptation that helps animals survive in the alpine biome?

Which of the following is a key characteristic that distinguishes modern birds from reptiles?

Which of the following statements about altruism in the context of evolution and natural selection is accurate?

Which event directly led to a significant decrease in the human population of Europe during the 14th century?

Darwin originally defined evolution as __________.

Which of the following is a key observation that must be explained in a unifying theory about life?

The scala naturae, or scale of nature, is based on the ideas of __________.

At the time Darwin voyaged on HMS Beagle, the popularly accepted theory in Western culture that explained the origin of Earth's plants and animals held that the various species __________.

Carolus Linnaeus is considered to be the founder of __________, and he __________.

The modern idea of extinction as a common occurrence in Earth's history was first proposed in the early-19th-century writings of __________.

Lyell's principle of uniformitarianism __________.