[ExI] The Grand Arc of Humanity

[Stuart LaForge]

Quoting Rafal Smigrodzki:

> Did you ever wonder what was the specific, unique development in the
> history of the world that set humans on our path, separate from animals and
> out to reach the stars?

I agree that the Grand Arc of humanity does seem to an improbably long  
queue of positive feedback loops. These loops became links in a causal  
chain that led to humanity's current ascendancy. Exactly which link  
set us apart from other animals is not easy to discern.

> I don't mean all the prerequisites for humans to exist. There is a
> combination of string landscape properties that defines the specific
> physics that allowed inflation, hydrogen and gravity, which allowed for the
> formation of stars that are necessary for humans, but stars are also needed
> for chloroplasts and rhodobacteria, so this is not specific enough. Nuclei
> and mitochondria were needed to create larger creatures, such as humans but
> nuclei and mitochondria also created snails and trees, so again not
> specific enough. Trees populated by snails and the like created an unusual
> ecological niche, that of a tree-dwelling fast moving omnivorous creature
> with stereoscopic vision and arms adapted to the grasping of sticks, and we
> needed our vision and arms to become what we are but then lemurs, gibbons
> and hundreds of other primate species have been around for 55 million
> years, so these adaptations are not sufficient for an intelligent species
> to appear, or else ruins of cities older than the Himalayas would be
> littering the planet. The ability to use tools such as sticks and to have
> rudimentary language also isn't sufficiently specific, since apes have been
> doing these things for millions of years and were getting nowhere fast.
>
> But there came a day when an Australopithecine made a stick that was longer
> and sharper than what the chimpanzee uses to dig for tubers and to pick
> termite mounds. That stick could hurt if used by a creature with
> stereoscopic vision and strong, grasping hands. That stick could be thrust
> at a predator, or prey.

If that's the case, then these Senegalese chimps have caught onto the  
"longer sharper stick" idea. They fashion spears to hunt bush-babies  
that hide in tree hollows. Curiously these spears are more often used  
by females who cannot run down their prey the way the males do due to  
being encumbered by clinging offspring. Of course, if your hypothesis  
is correct, this raises the question of why there are no chimp cities?

https://phys.org/news/2015-04-chimps-senegal-fashion-spears.html#:~:text=To%20date%2C%20the%20chimps%20are,not%20count%20that%20as%20hunting.

> An Australopithecine on the ground + leopard means
> a snack for the leopard but an Australopithecine + sharp stick + leopard
> means a very sore leopard, possibly even a big dinner for the ape. The
> sharp stick completely changed the equation. It propelled the
> Australopithecine from the rank of lowly scavenger and often easy prey to
> the level of a moderately bad-ass all-around brawler, not hardcore enough
> to take on lions but just too tough to kill under most circumstances. It
> changed the ape from an occasional hunter to a frequent hunter, giving
> access to the meat and the marrow and the energy to feed a bigger brain
> without forcing an increase in size.

But as the Senegalese chimps demonstrate, a sharp stick, while  
necessary, is not sufficient. Australopithecus was bipedal, which  
meant it could wield the sharp stick with both hands and therefore  
significant force and even the momentum of a running start. The sharp  
stick is just a sharp stick without the improbably long queue of  
happenstance that that allowed the utility of the sharp stick to be  
maximized. The following video demonstrates my point that  
knuckle-walkers cannot effectively weaponize sticks against predators:

https://www.youtube.com/watch?v=bKpZUsRJWBg

> And most importantly, this is the
> first time in the history of the Earth that the survival and thriving of a
> social, large, terrestrial animal with stereoscopic vision and manipulatory
> appendages became dependent on the creation of a tool - a tool not merely
> aiding survival, like a stone wielded by a monkey to crush nuts, but
> actually indispensable for survival due to the incredible boost in
> abilities it afforded the user. The sharp stick was just such an amazing
> quantum leap that once the ape learned to use it, the ape couldn't live
> without it and it became a hominid.

I think what set the Australopithecine apart was not just tool-use but  
metatool-use. There really isn't a good word for the concept yet but I  
suppose metatechnology or metacrafting might work. Basically it just  
means the fashioning of tools that can then be used to create other  
tools that can then be used to create yet other tools and so forth.  
For example, while several species (both primates and birds) have been  
observed using rocks as hammers to smash open food items. But using  
rocks as hammers to knapp pieces of flint into blades that can then be  
used to sharpen sticks that can then be used to hunt prey . . . that  
seems like an exclusively hominid trick thus far. After all, what good  
using a sharp stick to bring down big prey if you are having to  
butcher it with your teeth and fingernails? They have found fossilized  
animal bones dated to 3.3 million years ago, the time of  
Australopithecus, that show cracks, groves, and abrasions consistent  
with the use of stone tools.

> So here is my opinion about when the Grand Arc of Humanity started - with a
> big, sharp stick. Everything before was generic, prerequisites like size,
> stereoscopic vision, manipulatory arms, sociality, all necessary but
> insufficient to create something as unique as us. The sharp stick was the
> keystone to the portal to the technological civilization that opened before
> the Australopithecine - all of what followed flowed then logically from
> that point. The need to make and use a tool prevented us from becoming
> generic predators that survive by the tooth and claw. The sharp stick is an
> external adaptation - not of the body but dependent on the learning mind
> for its usefulness. The ability to use the sharp stick channeled our
> evolution towards the use of more and more tools, with ever less need for
> genetic adaptation and more cultural transmission. Apes can use fire and
> love cooked foods but they wouldn't benefit from fire much even if they
> could maintain it.

How much of that is related to environmental selective effects? If one  
relocated enough chimps to a colder temperate climate, say Europe,  
then after several generations of selection, might not the survivors  
be more predatory and adept at fire use?

> Hominids with sharp sticks can feed the fire with meat
> and can fend off predators while on the ground, which is why we lost the
> adaptations to swing from tree branches and improved our ground mobility.
> The sharp stick can also be thrown - it became the spear, and that moved
> the hominid to the rank of serious badass, the kind you want to stay away
> from. Access to fire gave us cooked food which reduced the amount of time
> needed to chew from 6 hours a day to 30 minutes and it freed 25% of our
> metabolic energy from digestion to thinking, so our brains grew because we
> had the time and the energy to actually use them. Bigger brains meant more
> ability to invent cultural adaptations, which meant stronger pressure for
> bigger brains and also dramatically faster adaptability to changed
> circumstances, which meant spreading throughout the world of different
> climates and different food sources. Finally, the sharp stick meant we
> could kill each other from ambush, safely, leading to the
> self-domestication of us, H. sapiens, and extinction of the other Homo's.

While I don't think it was a sharp stick alone that carried the day  
for humanity, I think you are not far off. I instead think it was the  
development of metatechnology embodied as stone tools that could be  
used to reliably cut and sharpen wooden sticks, butcher dead animals,  
and in the case of flint, also start fires that was the hominid killer  
app. It was likely not an accident that the stone handaxe became a  
dominant feature of hominid life for over 1.5 million years.

> A bunch of positive feedback loops started with this first technology and
> in geologically no time at all propelled us to the moon and beyond.
>
> The Grand Arc of Humanity is now close to its end. H.sapiens will soon
> disappear, hopefully by uploading, maybe in other ways. But it all started
> with a sharp stick held by a hungry ape.
>
> Rafal

Thanks for a thought provoking post, Rafal. If you beefed it up with  
some references and alternative lines of evidence and reasoning, then  
you might have the makings of popular science book on your hands. You  
write well enough that you should at least consider the possibility.

Stuart LaForge