What does it mean to say that a characteristic is heritable?

a. The characteristic evolves.

b. The characteristic can be passed on to offspring.

c. The characteristic is advantageous to the organism.

d. The characteristic does not vary in the population.

Could both the food competition hypothesis and the sexual competition hypothesis explain why giraffes have long necks? Why or why not?

You read a blog that states, 'A squid's eye has been perfectly designed to see in the dark depths of the ocean.' Draft a paragraph that responds to the blog's use of the phrase 'perfect design' by citing an example discussed in this chapter.

Some humans have genes that make them resistant to infection by HIV. Would human populations likely evolve differently in areas of the world where HIV infection rates are high? Explain your logic.

Explain the role of heritable variations in Darwin's theory of natural selection.

Which of the following is not consistent with evolutionary theory?

a. All living organisms share a common ancestor.

b. The environment affects which organism survives to reproduce.

c. Natural selection always favors the same traits, regardless of environment.

d. Humans are not necessarily the best adapted organisms.