Name: The Risky Paleo Diets of Our Ancestors
Uploaded: 2021-05-03T14:13:31.000Z
Duration: 8 min 25 s
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In 1973, a fossil hunter discovered the partial skeleton of a female Homo erectus in the Koobi

The specimen dated to 1.6 million years ago; today she's known as KNM-ER 1808.

Her skeleton was pretty complete, given its age, including parts of her skull, limbs,

And the anthropologists who studied her remains quickly noticed that there was something strange

The texture of her bones was coarse, with patchy areas of new bone growth.

That coarse layer was evidence that something had seriously disrupted the normal functioning

This would've been very painful, and ultimately, fatal.

But what could have caused this condition?

Oddly enough, it looks like it might've been something she ate.

The researchers who originally studied the bones considered several possibilities, and

But, they eventually settled on one that's pretty uncommon these days: an overdose of

While Vitamin A is usually good for us, helping us with color vision and healthy immune systems,

in high doses it can cause toxicity and a painful death.

We're talking peeling skin, gastrointestinal problems, and an increased risk of seizures,

And those original researchers thought that the most likely way that this poor Homo erectus

got ahold of that much vitamin A was by eating the livers of carnivores.

Now, like us, our hominin ancestors could - and did - eat pretty much everything.

But the downside of this is that it comes with serious risks - as that Homo erectus

We can track our history of eating just about anything back through the fossil record and

see the impact it's had on our evolution.

And when we do, we see that our adventurous eating habits allowed us to expand our diets,

and enabled us to live almost everywhere.

So the fact is, there's never been just one paleo diet.

But throughout time, part of the secret to our success as a species has been our early

- and sometimes fatal - experimentation with food.

A taste for meat was probably disastrous for that Homo erectus in Kenya, but it's been

Our early hominin relatives, like Australopithecus anamensis and Paranthropus boisei, probably

Likewise, our closest living relatives, chimpanzees and gorillas, eat lots of what we consider

“low quality” foods - things that aren't calorie-dense, like grasses, leaves and unripe

And they only get small amounts of animal protein from insects and the occasional bit

But we think meat and other “high quality” foods, like fat and bone marrow, probably

became a bigger part of the diet early in the history of our genus, Homo.

But there's still some debate about who started eating meat first.

The earliest widely-accepted evidence of meat-eating comes from cut-marked bones found at the site

of Gona, Ethiopia from about 2.5 million years ago.

The hominins there - probably members of some early Homo species - were capable of breaking

But we don't know how much meat they ate, or if they were hunting their own prey or

So, sites like Gona show us that hominins could get meat, but it's hard to tell how

Another site, called Kanjera South in Kenya is the first to show early members of our

genus -- most likely Homo habilis or Homo erectus - eating meat on a regular basis

The site dates back 2 million years, and it includes bones that   have been cut into or

broken open with stone tools spanning hundreds of thousands of years.

So our ancestors were clearly eating meat and marrow pretty often by then.

But getting that meat came with serious risks.

Aside from the inherent threat of getting injured during a hunt, there are other dangers

Even today, studies of many modern hunter-gatherer groups show that hunts often fail - even when

they're using things like projectile weapons.

And even if those ancient hominins weren't hunting the prey, scavenging it from other

They'd have to get to the carcass quickly enough to steal some meat before it went bad,

or, if they were feeling less patient, they'd have to try to drive the predator off of its

And neither option was particularly safe.

Less risky than trying to scare a lion off a wildebeest carcass, right?

Well in 2010, a site from that same Koobi Fora formation in Kenya showed that, about

1.95 million years ago, the hominins there were fans of seafood.

Among the animal remains found at the site were fossils of catfish and turtles - nice,

But there were also fossils of crocodiles found there.

So getting attacked by a croc while foraging for fish or turtles would've been a very

So, in terms of the calories and nutrients

Which is why our ancestors kept eating plants, too.

And while they seem less dangerous to find and eat, plants have their own fun, unexpected

ways of trying to kill us, or at least make us really sick.

Many plants, including things like unripe tomatoes, contain toxins that act as chemical

But you'd only feel the negative effects if you ate a LOT of it at once.

To avoid this, some animals feed on a lot of different plants in a day.

And one of the hallmarks of our genus, as we've evolved, is eating a more varied diet.

For example, one study of carbon isotopes in the fossils of several early Homo species

showed that they sometimes foraged from bigger plants like leafy bushes and trees, but also

ate ground plants like grasses and sedges.

Being willing to eat different plants made us more versatile and helped us avoid getting

poisoned by eating too much of the same thing.

And by continuing to eat our veggies, we gave ourselves some backup options, in case we

So, many of the plant-based foods we might snack on today -- like cashews or kidney beans

-- came with serious risks in the past if they were consumed raw.

But we managed to survive as a species - somehow.

And there's one more thing that millions of people all over the world eat today, which

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The Risky Paleo Diets of Our Ancestors

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