For more information on the proposed rule, contact Lisa Satterfield, ASHA's director of health care regulatory advocacy, at lsatterfield@asha.org or Neela Swanson, ASHA's director of health care coding policy, at nswanson@asha.org.
The link is that it's genes that are evolving. Evolution refers to the changing of the genetic content of a genome. In other words, the genetic code says one thing; then it says something different. It is the accumulation of these changes that causes the origin of species. http://www.cabdirect.org/abstracts/19432...
Because of the latter, it is possible for divergent evolution to occur between two genes within a species. In the case of divergent evolution, similarity is due to the common origin, such as divergence from a common ancestral structure or function has not yet completely obscured the underlying similarity.