Oh, I'm so thirsty...those Neandertals sure have a lot of water...

Here's the main idea of this BBC story:

Scientists are increasingly convinced that tragedies in the deep past have shaped human evolution.

Well, that is certainly true. "Scientists" are increasingly convinced.

The story is about an ancient drought in Africa:

Scientists have identified a major climate crisis that struck Africa about 70,000 years ago and which may have changed the course of human history.
The evidence comes from sediments drilled up from the beds of Lake Malawi and Tanganyika in East Africa, and from Lake Bosumtwi in Ghana.
It shows equatorial Africa experienced a prolonged period of drought.
It is possible, scientists say, this was the reason some of the first humans left Africa to populate the globe.

The thing about these major environmental events in the past is that they clearly happened; their dramatic nature is why we know about them at all. And it seems churlish to point out that we actually have no evidence of a link between these massive environmental insults and human populations.

But it just doesn't make much sense.

The hypothesis is that a major drought in southeastern Africa effectively ejected some human populations from the continent into Eurasia, where they succeeded beyond anyone's wildest expectations. It's like the baby bird in a nest: all we needed was a little push, and we could fly!

Expressed that way, it isn't too hard to see the flaw: if humans could succeed in Eurasia after a drought forced them out of Africa, then they certainly could have succeeded there without any drought at all. The idea that they were "too comfortable" in their African homeland to move is just nonsensical -- if they were a successful population, then intrinsic population growth would force them to expand sooner or later anyway. If they were blocked from leaving Africa by ecological limits, then no drought would make them suddenly able to transcend those limits.

In other words, the drought is completely unnecessary to explain anything.

Notice how we never hear about the environmental catastrophes that didn't supposedly spur some kind of human migration. Like the last Yellowstone eruption. Now that would make a story.