It's the way in which two identical cells can be made from an original.
You can use A.D for before his birth and B.C. for after.
Answer:Chromosones!
Explanation: Chromosones contain the DNA for your entire body.
<span>(decreased variation in tail feather color because no form of the trait is advantageous) Due to the fact that the tail color is no longer a necessity, so it will eventually stop being needed and variation will decrease.</span>