
No One Knows Why Humans Can Walk - sergeant3
https://lithub.com/no-one-really-knows-why-humans-can-walk/
======
hyperpallium
What was the _evolutionary pressure_ that made us intelligent - could it be
_ranged attack_?

First, what I'm calling the Geo-Fermi Paradox - why are we the only
intelligent animal on Earth?

Sure, it has advantages - but other animals would gain those advantages too.
So why didn't they become intelligent (or, at least, more intelligent) too?

Sure, there was climate-change in Africa that rewarded adaptivity - but why
didn't all animals in the region become intelligent (or, at least, more
intelligent)?

This article has a good argument for bipelalism (due to forests becoming
plains). And an interesting argument for stone throwing (and not available to
bipeds like ostriches and emus).

Throwing rewards _spatial reasoning_ , providing an evolutionary pressure It's
not clear to me that this would lead to intelligence - but maybe it did. (OTOH
bonobos, chimpanzees, gorillas, orang-utans, and capuchins throw too
[https://wikipedia.org/wiki/Projectile_use_by_non-
human_organ...](https://wikipedia.org/wiki/Projectile_use_by_non-
human_organisms)).

~~~
im3w1l
If we consider other hominids, we don't know exactly, but it seems we
outcompeted them. If we consider more distant animals, because we converted
the entire planet to provide for us much faster than they could evolve to
catch up with us.

~~~
hyperpallium
I think that's the "we just happened to be first" argument. Which could be
true, but not very satisfying, because no detail.

~~~
clacke2
We didn't have to be first. Other primates might have picked up the rock
before we did, but eventually lost the race. Maybe the fire-cooking, rock-
throwing domesticating niche is just that competitive.

So it might be more like "we are the ones that remain", but yeah, either
variant is a spin on the old weak anthropic principle, which is never quite
satisfying.

~~~
hyperpallium
And we do seem to have wiped out/outcompeted Neanderthals etc.

> fire-cooking, rock-throwing domesticating niche

Just knowing if that _was_ the evolutionary pressure along the path would be
enough for me (even if it could have been another ape or a corvid or whatever
- or maybe they are on that path now?)

BTW Matt Ridley has the theory that division of labour (trade enabling
specialization) was the gradient.

------
xtagon
This is fascinating. Software can now simulate natural motion, including
realistic bipedal walking animations that react to simulated forces while
continuing to stay upright. I remember seeing this in Endorphin years ago and
I believe these techniques are now used in games. What's interesting to me is
that, we still don't exactly know how _that_ works either! Genetic algorithms,
deep neural networks, etc. are black boxes in the end.

------
floriol
Doesn't it have to do something with the "average" primate body plan? I really
like highlighting the running aspect, since we truly seem to be record holders
in endurance running, which was largely enabled by sweating. And since the
primate body plan has upper limbs with significantly more freedom of motion
compared to "running on 4" animals like deer, primates have to actively use
many muscles to be able to put its weight on them (I am only familiar with the
human skeleton in detail, but I assume primates have a similarly free scapula,
while horses' are much more restricted, their first legs connect nearly
vertically into it, making standing basically energetically free)

So, isn't bipedalism simply the energetically better way of locomotion for the
primate body plan (look at other primates, they semi-walk on their lower
limbs, only balancing with their hands - but they are not great at running and
live mostly on trees so climbing is more important there)?

------
hyperpallium
> [hunter-gatherers] ended up with bodies designed to do two somewhat
> contradictory things: to be active much of the time, but never to be more
> active than absolutely necessary.

I've found the most beneficial exercise for me is hours-long walks/rides, well
within my comfort zone - much lower than the heart-rate reccommended. Partly
because it's enjoyable.

------
coenhyde
I like the water ape theory. ie we had a period of time in our history where
we spent a lot of time in low lying water that encouraged us to stand upright.
There's a few things which point in this direction. iirc we're the only
primate which can control its breath; good for swimming under water. Our
fingers wrinkle when we spend time in water; good for picking things up in
water. And we lost our hair; hair may have gotten caught on underwater objects
drowning the hairiest amongst of us.

~~~
sliken
Seems like a stretch. We suck at swimming (compared to bears for speed or
distance). The breath thing seems unlikely, polar bears for instance seem
quite adept at swimming underwater. Hair doesn't seem an issue either, hair
(assuming it's not knotted) doesn't easily catch on things, and hairy bears
seem quite adept under water. Sure whales used to be hairy (and has some
residual hair today), but that's more the lack of need than any lethal
hair+water problem that kills them off before they reproduce.

I've seen numerous speculation on the finger wrinkles, possibly an
adaption.... or possibly just happenstance. Sure today's fingers prune
significantly, not sure they would do the same if heavily callused by a decade
or two of hunter gathering for all your food. In any case it's not unique to
humans, macaques have similar and I suspect it's noticed because they bathe.
Couldn't find any information on other primates.

[edit for minor spelling/grammar tweaks]

~~~
montychain
Water ape theory doesn't suggest humans have to be great swimmers to survive
at waterside areas. There's a lot of stuff to eat where the water is shallow
as well as probably a ton of fruit on the trees near the coast. Bi-pedaling
would help in spending a lot of time standing in the shallow waters looking
down at river bottom. Humans nimble fingers help with finding and dealing with
various shellfish that were probably crawling around in the bottom sludge.

The bulk of our hair is on the top of the head - the only place that would be
burnt by the sun if you stay all day standing in shallow waters.

The shape of our nose (nostrils directed down) are made convenient to stand
vertically without getting water into airways.

What is the picture of a paradise? A beach with a white sand, sun shining,
clear blue water, lots of palm trees near the coast. This is because its our
natural habitat. Not deep forests, not savannah. It's tropical beach!

If I was to be left alone and naked on an inhabited piece of land I would
definitely choose a tropical beach out of all untouched locations on the
planet, because it is the most likely place where I would be able to survive.

------
sasaf5
It would be more difficult to use tools if we had to use all members for
locomotion. The ones who started walking straight got an advantage for being
able to fight with spears and bows.

~~~
bilbo0s
But the spears and bows did not come along until well after the walking
upright. We know that from the fossil and archeological record.

Of course, it's still possible that those who could walk upright could throw
stones better I suppose? So the fundamental idea of tool use has merit. But
the tools would have been far more primitive than spears and bows. And still,
the walking would likely have happened before the stone throwing, so there's
still a little uncertainty even with the idea that it helped us with primitive
tool use.

I think it's probably more that you could see predators better and get a head
start for the tree. But I have no data to back that up, it's just my gut
hunch.

~~~
bpodgursky
That's not totally true. We really have no record of anything except carved
stone tools and pottery, because wood degrades. We have no real idea when
humans started using wooden tools like spears.

------
hyperpallium
persistence hunt
[https://youtube.com/watch?v=826HMLoiE_o](https://youtube.com/watch?v=826HMLoiE_o)

~~~
NeedMoreTea
Never been especially convinced by the endurance hunting theory, as dogs are
far better at it than we are, with much greater endurance. So why no bipedal
Fido?

~~~
AstralStorm
Because the dog or cat would need vast incremental changes to body plan, while
a tree ape does not need too much.

------
danans
> Most large animals can’t run for more than about nine miles before they
> drop.

Feels like they are implying something here ... Can't figure out if I'm
offended

~~~
pandapower2
i genuinely have no idea what you are suggesting. can you elaborate?

~~~
danans
it's a joke. I'm an animal who would drop if I ran 9 miles.

~~~
Simon_says
Are you large?

~~~
danans
Larger than I'd like! Let's say I'm of medium height but sometimes wear size L
shirts.

------
throwaway66920
> The young and gracile protohuman famously known as Lucy... was hardly the
> sort of presence to intimidate a lion or cheetah.

And look at us now

------
ncmncm
I do. I'm just not telling.

But quite a lot of birds walk, and a lot more of their dinosarian relatives
did. Ostriches and emus favor it, when they are not running. Faster than we
can.

Orangutans do it too, though not very often.

~~~
samplatt
Birds (especially large birds) inherited a long line of large, fast-moving,
bipedal predator ancestors. We don't really have that; primates evolved
~55Mya, and before that we were mostly rodent-ish animals which depended on
being small and hidden to survive rather than running fast or long distances.

There's a lot to be said for parallel/convergent evolution, but it's certainly
not hard & fast rule.

------
ARandomerDude
Wonder no more.

Genesis 1:26-27 ESV

Then God said, "Let us make man in our image, after our likeness. And let them
have dominion over the fish of the sea and over the birds of the heavens and
over the livestock and over all the earth and over every creeping thing that
creeps on the earth." [27] So God created man in his own image, in the image
of God he created him; male and female he created them.

~~~
lone_haxx0r
Now no one knows why god can walk.

~~~
clairity
or why an omnipresent being would need to.

~~~
ijidak
I don't think the God of the Bible is omnipresent, no?

Reference: [https://www.jw.org/en/bible-teachings/questions/god-
omnipres...](https://www.jw.org/en/bible-teachings/questions/god-omnipresent/)

~~~
NateEag
The mainline Christian denominations disagree with the Jehovah's Witnesses on
that point (and many others - [preachy] overview:
[https://biblereasons.com/christianity-vs-jehovah-
witness/](https://biblereasons.com/christianity-vs-jehovah-witness/)).

------
i_feel_great
Too hard to chew gum crawling on all fours

------
bigred100
It’s cause they learn when they are a small baby, so that they can get around.

