The graph shows the distribution of the weight of individual dogs in a population of dogs.

Answer the following questions using the axes provided.

a) Draw a possible curve for the population several generations later if the population has stabilizing selection.

b) Draw a possible curve for the population several generations later if the population has directional selection.

c) Draw a possible curve for the population several generations later if the population has disruptive selection.

d) How do these selective pressures affect the genetic variation in the population?

2 a) In what way is the genetic code in all organisms the same?

b) Humans and chimpanzees have very similar DNA. What does this say about these two species?

c) Did humans evolve from Neanderthals? Explain.

d) What other hominids evolved from the same common ancestor as humans?

e) Dolphins and porpoises are closely related species. Name three ways that you would be able to find evidence for this.

1) 2) 3)

3. For each environment below, describe why you think it would have a high or low rate of speciation.

A rugged mountain terrain A large, open forest An island in the ocean

4. A cladogram is shown below.

a) Why is the amoeba considered an out group in this cladogram?

b) What trait does a salmon have that an earthworm does not?

c) What does this cladogram tell you about the evolutionary relationship of the traits of jaws and limbs?

d) A squirrel glider is an organism with jaws, limbs, and hair. It does not use a placenta for reproduction. Where do you think this organism would belong in the cladogram?

5 a) How are bacteria and archaea similar?

b) How are they different?

c) Which are more closely related to complex organisms, bacteria or archaea? Explain.

6. Name three adaptations that helped plants survive on land, and describe how each of them helped.