Y.E.C. Model: Was there rapid evolution and speciation post flood?

There seems to be a major point of disagreement amongst those proposing a Y.E.C. model of life's history. On the one hand, some propose wide spread and rapid evolution, including speciation (within "kinds") after the flood, while others deny that such things can happen. So, does the model require this speciation, especially considering that space on the Ark was limited? And how does it happen? Are beneficial mutations involved?Let's discuss the model, which seems to be in need of a major update.Anything relevant goes, including questions I like to ask like: how many giraffes were on the Ark and where did all the new Y-chromosomes come from?

Thread copied to the Y.E.C. Model: Was there rapid evolution and speciation post flood? thread in the Geology and the Great Flood forum, this copy of the thread has been closed.