Question

Which statement describes the best evidence that two species share a recent common ancestor? NO LINKS NO NINKS

A) The species are about the same size.
B) The species eat the same type of food.
C) The species live in the same ecosystem.
D) The species have similar DNA sequences.

Answer 1

D.

Traits of two different organisms can be similar due to convergent evolution, that is, natural selection which favors the evolution of similar traits in species. The result of convergent evolution are analogous traits. These are traits which are similar but do not originate from a common ancestral trait. These can often be mistaken as homologous traits, which are traits that do originate from a common ancestor.

The take away here is that similarity of traits does not necessarily mean that two organisms shared a common ancestor.

However, by looking at the DNA sequences of the organisms we can determine if they truly shared a recent common ancestor or not.