Without Genetic Variation, Evolution Cannot Occur

Multiple Choice

Without genetic variation, evolution cannot occur. Sexual reproduction leads to increased genetic variation, but male bdelloid rotifers have never been observed. Which of the following are correct statements with regard to evolution in bdelloid rotifers?

A) As we learn more about bdelloid rotifers, we find males in more and more species.
B) Bdelloid rotifers gain genetic variation by absorbing DNA from the external environment.
C) Protists infect bdelloids and bring DNA from other rotifers with them.
D) Bdelloid rotifers have lost the ability to reproduce sexually only recently.