[John H K]

Well, obviously, you're not going to see a given species get pregnant, and give birth to a completely different species.

The human lifetime (and recorded human history, which is only about 6,000 years) is far too short to witness speciation of that nature.

Which, of course, gives rise to the idiocy of young-earth creationism.

[Truth666]

"you're not going to see a given species get pregnant, and give birth to a completely different species"
I don't mean that. I mean, like in the two cases presented so far (both by Mr. Bird) :
1 - Galapagos finches - geographical isolation would have been the cause for them do diverge from other finches that you still can observe now elsewhere ...

[Truth666]

"you're not going to see a given species get pregnant, and give birth to a completely different species"
I don't mean that. I mean, like in the two cases presented so far :
1 - Galapagos finches - geographical isolation would have been the cause for them do diverge from other finches that you still can observe now elsewhere 2 - white colored homo sapiens - moving out from Africa (where you still can observe the "descendants from the ones that dinn't move out") has been the cause of "losing pigmentation"