Answer:
a change in allele frequencies in a breeding population over time
Step-by-step explanation:
Evolution is BEST explained by the appearance of a new species. There is much more going on. Evolution is bigger than just one individual so it can't be the changes in the DNA of an individual over his or her lifetime. While evolution is a process that occurs over a long period of time in its entirety, evolution can only be most specifically and most accurately explained by the changes in allele frequencies in a breeding population over time because the best changes are more likely to survive and reproduce ("survival of the fittest").
* please honestly rate how helpful that was... not really much of a biology buff so it would help me understand where i'm at