Conduction: I would explain why I think so, but I think the answer itself explains why well enough so that I don't exactly have anything to add
Answer:
Disruptive selection
Explanation:
Disruptive selection, also known as diversifying selection, describes changes in population genetics where extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups. In this more individuals acquire peripheral character value at both ends of the distribution curve.
Two amino acids can be joined by a protein.
Xylem, which is a dead cell that carries water in only one direction: up
Exposure to more radiation. Human made and from the sun.