• 1. What were the chances of the girls being born with the coloring they had? • 2. How many eggs and sperm were used in this scenario?

• 3. What does this mean about the kinds of genes the father has?

• 4. Will the girls act the same?

• 5. Could the twins with darker skin have a white child when they are adults?

The image shows the evolution of a species of fish. a few fish from a population developed different social behaviors and evolved into different species. two fish according to the image, the fish underwent . the new species of fish had mating seasons that were different from that of the original fish. because of the differences in mating seasons, the fish underwent reproductive isolation. this mode of isolation would be .

Babies with very low or very high birth weight are less likely to survive. observe a graph of the data.

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.