A scientist measures the circumference of acorns in a population of oak trees and discovers that the most common circumference is 2 cm. What would you expect the most common circumference(s) to be after 25 generations of strong directional selection?

What is the missing step in this proof? scroll down to see the entire proof. u

The different forms of a gene for a given trait are called .

Which statements about the two fossil images are correct? 1. cave bears are ancestors of plateosaurus. 2. plateosaurus were present on earth before ostracoderms. 3. ostracoderms were the first to die. 4. plateosaurus died after the ostracoderms. 5. cave bears are the oldest fossils.