Richard Dawkins

And that's the difference in a dialect and a language.

Well, there are two species of frog in North America, Microhyla carolinensis on the east side and Microhyla olivacea on the west side.

And olivacea has a higher-pitched call.

So that's olivacea with a high-pitched call and carolinensis has a lower-pitched call.

There's not much difference between them.

Now, you might expect that if it was like, you might expect a climb that you would gradually get as you look from, these are very closely related species.

As you go from west to east, the call will get gradually deeper and deeper and deeper.

That's what you might expect.

The reverse happens.

It's a reverse climb.

As you get into a zone of overlap,

the Olivacea call goes up and the Pteranensis call goes down, so that these creatures are exaggerating the difference between them.

So in the zone of overlap, the difference between them is exaggerated compared to where they don't overlap.

This is equivalent to migrating into the Glasgow pub and attempting to do a Scott's dialect and being

And being hit.

And being jumped.

Yes.

And I think it's probably true.

I mean, Dobzhansky had this theory that when new species form, when an ancestral species diverges to form new subspecies,

and then new species.