Did MicroRNAs Shape the Cambrian Explosion?

The fossil record reveals a history of life characterized by the abrupt appearance of new species followed by no change and eventual extinction in most cases. Needless to say, abrupt appearances and no change is not exactly what evolution expected. Much of this was known in Darwin’s time and he figured that the fossil record was incomplete. Today such speculation doesn’t work anymore. The evidence reveals even more clearly this pattern of abrupt appearances followed by stasis. As one recent paper explained:   Read more