[csense]

But if the environmental challenge isn't quite so severe, some of that population might be able to survive. They'll pass on their genetic material to the next generation. That's the deal. If the environment changes very gradually, some version of the population might just make it, although each new generation is going to go through the filter of a changing environment.

But seasonal differences constitute significant environmental changes in a relatively short period of time. If evolution is true, then our earliest ancestors must have been subjected to such a rapidly changing environment, inferring that such adaptation has been present from the very beginning, and passed on to the subsequent diversity of species. This seems to conflict, or at the very least, fails to support, your proposal above.

What do you think about that?

[Coyoteman]

seasonal differences

What population you can imagine that is unable to cope with its own area's seasonal differences?