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Homo erectus:

bare and
sweatING

How early humans began hunting large animals
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3Mya

(millions of years ago)

You are a weak
and small animal,

often finding yourself as lunch for hungry carnivores,

but you wish to become a predator of the savannah.

The problem is... how?

How to Become a Predator of the Savannah*

*Applicable only to hominins of the Plio/Pleistocene. If you are another animal (e.g., dolphin), this tutorial will not work.

Lose hair coverage

Create basic stone tools

Adapt your body structure
‍to be able to run

Develop the ability
to sweat profusely

Homo
Australopitecus
4
3
2
1
Millions of years ago

1,8Mya

Selective pressures transformed you into a tall primate without fur, yet still without claws or sharp canines.

However,
A. afarensis
H. erectus

with that huge new brain, see if you can figure out that flaked stones can be used to sharpen wooden sticks.

Now you can learn Persistance hunting

Australopithecus
afarensis
Homo erectus

WOW!

That's great!

Start by finding prey.
Do this at the hottest time of the day.

Don't attack. Instead, scare the animal with shouts and stones.

Now that it has fled,

pursue it.

The fleeing prey, covered in fur, will need to stop in the shade to cool down.
But you, even running under the scorching sun, keep your temperature stable.
The reason?
Bare and sweating, heat is continuously radiated away from the body.
You're
Bare AND
sweatING.
When your body heats up, it produces sweat and wets your skin.
The hot skin heats the water from the sweat until it evaporates.
The heat generated inside the body is transferred to the water outside the body (sweat). Upon evaporation, the water
transfers
the heat
to the air.
Under the current circumstances, this innovation represents a huge advantage.
As you approach, the antelope standing in the shade to cool off will be forced to flee with its temperature still high.
Even if the animal distances itself again, keep running. This may happen a few times.
Eventually, it will enter hyperthermia.
When that happens,
the hunt will be over.

The transition of our lineage's species to predators was gradual, probably including species before erectus and involved multiple factors, not all described in this story.

Persistence hunting is still used today by some traditional hunter-gatherer cultures.

Humans have become one of the best long-distance runners (endurance running) in the animal kingdom.

Our lineage continued to be preyed upon after becoming hunters. There is ample evidence of Homo species killed by predators such as bears, hyenas, and large felines.

Up to 70:1 is the EROI (energy return on investment) that a persistence hunt can generate. For every calorie spent, 70 are acquired, considering a large prey (Kudu of 314kg). For a small one (Kudu of 199kg), the minimum EROI is 26:1.

References

Carrier, D.R., Kapoor, A.K., Kimura, T., Nickels, M.K., Scott, E.C., So, J.K., Trinkaus, E., 1984. The Energetic Paradox of Human Running and Hominid Evolution [and Comments and Reply]. Current Anthropology 25, 483–495. https://doi.org/10.1086/203165

Bramble, D.M., Lieberman, D.E., 2004. Endurance running and the evolution of Homo. Nature 432, 345–352. https://doi.org/10.1038/nature03052

Liebenberg, L., 2008. The relevance of persistence hunting to human evolution. Journal of Human Evolution 55, 1156–1159. https://doi.org/10.1016/j.jhevol.2008.07.004

Glaub, M., Hall, C.A., 2017. Evolutionary Implications of Persistence Hunting: An Examination of Energy Return on Investment for !Kung Hunting. Hum Ecol 45, 393–401. https://doi.org/10.1007/s10745-017-9908-3

Hora, M., Pontzer, H., Wall-Scheffler, C.M., Sládek, V., 2020. Dehydration and persistence hunting in Homo erectus. Journal of Human Evolution 138, 102682. https://doi.org/10.1016/j.jhevol.2019.102682

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