The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.
A) having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild
B) paralogous genes can occur only in diploid species, thus they are absent from most prokaryotes
C) polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild
D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product

Question

Quizplus · Accepted Answer

Paralogous genes are genes that arise via gene duplication events within the same species, and thus the new copy is free to undergo modifications. These modifications can occur without affecting the original gene product. In contrast, orthologous genes are genes that speciate only after gene pools are isolated from each other, and thus the new copies that arise via speciation events share an ancestral relationship and cannot undergo modifications without losing the ancestral gene product.

The Reason That Paralogous Genes Can Diverge from Each Other