Trek biology within canon is just terribly nutso right now. I mean, TOS wasn't actually bad for the time period it was done. But it's very clear that Naren Shankar, Andre Bormanis, and whoever else consulted for science in the TNG era just had no friggin idea how biology worked (Braga in particular - Genesis, Threshold, and Distant Origin were all embarassing). This isn't like the warp drives where they needed to invent weird technobabble to explain everything. They could have mined actual known concepts regarding how DNA works, the process of evolution, and paleontology and they just ignored it entirely.