Well, they would have in a manner of speaking, but from common ancestors representing *kinds* on the ark. Nobody is denying that variation within species happens. All you have to do is walk through a crowded mall at Christmastime.
It sure fits better with the sudden appearance of fully the formed species that the fossil record shows.
The label of *species* is too vague and too arbitrary to be of much use.
The word has cause communication failures in biology, fer sure.
Nothing can be effected, unless favourable variations occur, and variation itself is apparently always a very slow process. The process will often be greatly retarded by free intercrossing. Many will exclaim that these several causes are amply sufficient wholly to stop the action of natural selection. I do not believe so. On the other hand, I do believe that natural selection will always act very slowly, often only at long intervals of time, and generally on only a very few of the inhabitants of the same region at the same time. I further believe, that this very slow, intermittent action of natural selection accords perfectly well with what geology tells us of the rate and manner at which the inhabitants of this world have changed.
Pop quiz: Who wrote this? Who first proposed that evolutionary change would be intermittent?
How do you fit that into the fact that the fossil record also shows that these species are in no way contemporaneous?
The fossil record also shows that there were no mammals with wings or hoofs during the time of the dinosaurs, and dinosaurs did not live at the same time as tigers and lions and wolves or any other placental mammal, that introduction of placental mammals to Australia has been a recent development. That temperate (warm loving for those of you in Rio Linda) species used to inhabit Antarctica, but only archaic species. Do you recognize this salient feature that the fossil record also shows?