Dr Mareike Janiak

I've heard of a moose getting stuck in an apple tree because it was trying to eat the fermenting apples.

There are stories about birds,

especially cedar waxwings that are birds that occur here in Canada.

They're known to eat these fermenting berries.

It's so widespread that I think there's safaris that actually use this and they're advertising.

Humans have a mutation in one of the genes that codes for a protein that breaks down ethanol or alcohol, as we commonly call it.

This mutation was not unique to humans, but it was actually shared with humans, chimpanzees and gorillas.

So that means it must have evolved in our common ancestor.

The idea is that our ancestors became more terrestrial, so they started moving on the ground more.

They were encountering fallen fruits more.

You know, once they've been there for a while, they start fermenting.

So by being able to digest and metabolize that ethanol that's found in these fruits, you're able to eat more of them without having really detrimental effects.

Yeah, that's roughly the idea.

And that's actually kind of what inspired our research.

So we actually looked across 85 different mammals, and we did find that other frugivores, so other fruit-eating mammals, didn't have the exact same change as humans, but they had other changes in the same location of that gene.

It said, it's impossible.

And the flaw in these was that they used the human ethanol metabolism efficiency in that calculation.

Which we know is very special.

When we started looking into this, we realised quickly that elephants actually have what we call a pseudogene, and that means it's not functioning anymore.

So we can definitely say that elephants don't have the same rate of ethanol metabolism that we do.