
Did Our Ancestors Become Bipedal So They Could Throw? - dnetesn
http://nautil.us/blog/did-our-ancestors-become-bipedal-so-they-could-throw
======
joshbaptiste
I live in a world where 90% of my friends and family believe that they came
from the sins of a woman who decided to eat an apple. I recently read a book
called Sapiens, this book really drilled into my mind that we homo-sapiens are
a derivative of a single great ape that had two daughters, one that became the
ancestor of all chimpanzees and the other all humans.

If human origin interests you there is a great 10 minute video from the
Youtube Kurzgesagt channel that lead me to read Sapiens.

[https://www.youtube.com/watch?v=dGiQaabX3_o](https://www.youtube.com/watch?v=dGiQaabX3_o)

[https://www.amazon.com/Sapiens-Humankind-Yuval-Noah-
Harari/d...](https://www.amazon.com/Sapiens-Humankind-Yuval-Noah-
Harari/dp/0062316095/)

~~~
saalweachter
Minor derailing: it's not necessarily accurate or useful to think about
speciation as "one parent with two divergent children". It's usually more
about populations with fuzzy boundaries.

Speciation events tend to look more like, imagine you take a town of two
thousand people and send half of them to the moon for a million years. The
moon men and the earth men would evolve into two different species; if you
looked really hard, you could find a single common ancestor from whom everyone
in that town descended, but it's not like one of his children went to the moon
and one stayed on earth; some of his great-great-*-grandchildren went to the
moon and some stayed on earth. The common ancestor was hundreds or thousands
of years before the population split in two.

Moreover, breaks don't always happen cleanly. Imagine for the first ten or
hundred thousand years someone from earth would occasionally migrate to the
moon or a moon man would return to earth. The same thing would have happened
with proto-humans and proto-chimpanzees: long after the two species had begun
to diverge they would still be interfertile, and some mating (or "gene
transfer", if you prefer) would still happen long past the point you'd begin
calling them two different species. Eventually the two species would stop
being mutually fertile or even attractive and the rift would be complete, but
look at how many big cat and horse-like species can still occasionally pull it
off.

Evolution is messy, and the bush of life is complicated.

~~~
wyager
Yeah, but it's still interesting that there exists an "Eve" connecting any two
entirely different organisms.

~~~
Dylan16807
Not really. There's a hundred of them. A whole bunch of candidates that are at
the borderline and are ancestors of every member of the species.

~~~
wyager
Nope. Any two organisms have a unique MCRA of either gender.
[https://en.m.wikipedia.org/wiki/Mitochondrial_Eve](https://en.m.wikipedia.org/wiki/Mitochondrial_Eve)

~~~
Dylan16807
That is a very specific thing.

It only applies to mitochondria, not the genes in the nucleus or anything
constructed from those genes.

It's only unique because the "MR" in MRCA stands for "most recent".

You could have a species that's a million years old with an MRCA that's only
500 years old. You could also have a species with no MRCA. (As in, the only
way to find an MRCA is to trace back into ancestor species.) Picture two
islands where only males travel between them.

------
akeruu
I as told in Jr. High School that we ended bipedal in order to stand in the
bush so we could see further what was coming up and then, with our hands now
free, we could start building tools and use them. I don't know what this
explanation is worth but I find it makes a lot of sense.

------
GlennS
Maybe the reasoning is backwards? Given 4 limbs, how else would you layout an
upright walking creature?

The same across-the-chest muscle setup that makes us good at throwing also
allows us to throw an effective punch.

"push against the ground with your feet to exert significant force using your
hand" must have many, many uses.

------
cloudjacker
Isn't the answer most likely "no"

From both the editorial title law, as well as the flawed logic of causation to
draw a conclusion on evolution?

~~~
daveguy
I am sure you are being downvoted for mentioning Betteridge. I upvoted you
because using causation to describe evolution _is_ inherently flawed.
Discussing it in that framework only confuses the nature of evolution. Our
ancestors didn't become bipedal "because" of any one thing in particular. None
of our ancestors were sitting around saying "Hm. I wonder how we can influence
our future evolution." "Well, it would be nice if we could throw." There were
likely a _lot of benefits_ to bipedal motion in early humans and that's why
they out survived those on all fours.

------
bryanrasmussen
Perhaps the fault is with the English language itself that the article and
this post's title both imply that humans became bipedal in order to throw. I
use the word 'fault' because of course that is not how evolution works.

------
sunstone
While the origins and order from millions of years ago may remain unclear what
is clear is that by the time individuals had achieved the pathetic defensive
and offensive weapons of the modern human body something else had to be going
on.

A single modern human on the plans of Africa would almost instantly succumb to
the carnivorous interests of any number of hungry beasts. Modern humans in
their modern bodies alone have just nothing to inspire fear in anything bigger
than a koala bear.

One aspect is clear, humans living in groups are more viable, but that gets
you only so far. A whole group of humans facing the local lion with just their
bodies alone would just be chomped down one by one.

While throwing is not bad for hunting it's particularly devastating when
combined with stones and a group of humans for defence. Humans with a bit of
practise are stunningly accurate with throwing stones at speed. Imagine a
group of lions (or any other predator really) facing 20 or more humans
throwing stones with deadly intent. Humans in this circumstance are instantly
transformed from the neighbour weakling to a defensive force of undeniable
leathality and terror.

The real beauty of it is that the human doesn't have to be near the target to
impart the stinging blow. Other natural weapons red in tooth and claw require
the aggressor to make contact with the prey and possibly suffer injury.
Thrownn rocks avoid this danger entirely.

Hunting requires many different strategies of which stone throwing may be one.
Defence in the dark of night from a closing dread predator would be best
effected with a hail of well placed stones every few seconds. Very few
predators would be willing to risk it for very long.

Luckily for humans, herds of elephants only eat vegetation.

------
bloatisgood
Generally living organisms become bipedal when they have another use for their
legs other than walking. See birds. In our case it was the usage of tools.

~~~
derefr
Is there an evolutionary story for why T. Rex ended up bipedal with mostly-
vestigial forelimbs? It works fine for their ecological niche, but I can't
picture the evolutionary intermediates between them and a quadrupedal
ancestor.

~~~
bitwize
The current thinking is that T. rex used its stubby arms to grasp prey when it
went in for the kill. A similar line of thinking applies to the flapping wings
of birds: earlier theropods flapped their forelimbs in order to help hoist
themselves on top of their prey to make the killing bite.

Their common ancestors may have evolved bipedalism because forelimbs proved
cumbersome when taking down large prey.

~~~
bobsil1
Mountain lions use front paws broader than rear to grasp large prey as they
bite the neck. As large as elk and deer.

~~~
bitwize
We're dealing with larger than mountain lion scale beasties here. Fun fact
about hippos: they can't jump. Like at all, unless they're submerged and can
use the buoyancy of the water. The same is true of just about any modern
tetrapod within that size range. If you're a tetrapod the size of a mountain
lion or even a bengal tiger, you can still have speed, agility, and the
ability to spring, pounce, and grapple with the forepaws. At T. rex scales,
the square-cube law has something to say about that.

------
SlipperySlope
Given that humans are otherwise well adapted as pursuit hunters, able to
select a single prey animal and run it to heat exhaustion - it makes sense
that bipedalism is another adaption for endurance running.

[https://en.m.wikipedia.org/wiki/Endurance_running_hypothesis](https://en.m.wikipedia.org/wiki/Endurance_running_hypothesis)

------
Super_Jambo
I really like the idea put forward here:

[http://www.meltingasphalt.com/music-in-human-
evolution/](http://www.meltingasphalt.com/music-in-human-evolution/)

And the research into the evolution of shoulders doesn't really contradict
this.

------
omginternets
Throwing, specifically? I would have thought the advantage being selected was
the ability to use two limbs for fine motor tasks: building, throwing,
grasping, pulling, knapping, etc...

~~~
derefr
Ah, but other apes can already do many of those things (and some of them
_better_ , given that they basically have four "hands" instead of two hands
and two feet.)

The question is what forced humans into this particular, odd body-shape that
no other ape has. Long-distance running (for "endurance" hunting, where you
just tire out the thing you're chasing) has been the hypothesis I've heard the
longest, but running and throwing works too.

~~~
omginternets
Fair point, but I was considering the fact that being bipedal allows you to
_constantly_ be doing one of those things. Simply being able to carry things
around over long distances seems like a bigger advantage than throwing.

Of course this is all speculative, and I suspect that the point of the
Nautilus article was to entertain the thought, so in that respect it's a great
article.

>Long-distance running (for "endurance" hunting, where you just tire out the
thing you're chasing)

I've recently read claims (though I forget where -- primary sources, if memory
serves) that directly contradict this point (which I'd also heard). From
memory:

\- foot structure is ill-adapted to continuous running (stress fractures, I
believe)

\- knees are also problematic

\- some physiology / metabolitic arguments

I must also admit that this hypothesis seems fishy if only because I can't
think of many tasty animals that man can actually keep up with...

~~~
derefr
> I can't think of many tasty animals that man can actually keep up with

"Long-distance" doesn't have to imply "in a straight line", keep in mind. If
we can herd prey in arbitrary directions, we can have other members of our
tribe stationed where we're herding them, turning the marathon into either a
pincer trap or a relay race.

~~~
omginternets
I don't mean to imply that the theory has no merit -- what you've just cited
is, I think, the more convincing part of the argument.

I'll try to dig up the refs tonight, because it makes for interesting reading.

~~~
derefr
Cool, would love to read through that. I feel like I got a solid understanding
of this sort of topic based on the position that was popular a decade or so
ago, and then haven't really kept up with the debate since then.

------
semessier
seems quite plausible, also in the light of (disclaimer: this is not coming
from an anthropologist) a notion that the performance of 300 000 year old
spares were to rival that of today's high-performance carbon spears
(translated in meaning). The latter appears to be quite irritating and would
fit the argument of the bipedal suggestion from the linked Nautilus article.

The 300k years coming from the newspaper article below:

Filser, Hubert, 300 000 Jahre alte Speere können mit modernem Olympia-Gerät
mithalten (newspaper article) [http://www.sueddeutsche.de/wissen/archaeologie-
jahre-alte-sp...](http://www.sueddeutsche.de/wissen/archaeologie-jahre-alte-
speere-koennen-mit-modernem-olympia-geraet-mithalten-1.3100120)

which in turn seems to refer to:

Conard et al., Excavations at Schöningen and paradigm shifts in human
evolution and Schoch et al., New insights on the wooden weapons from the
Paleolithic site of Schoeningen

------
kabdib
William H Calvin makes a similar argument in _The Throwing Madonna_ (and less
succinctly, but more entertainingly, in _The River That Flows Uphill_). He's
got a lot to say about the evolution of hand-eye coordination and throwing as
well.

