Today: Cavemen Rule, Part III:
Australopithecus.
But first, a disclaimer: today we’re going to be
covering a huge period, on the scale of millions of years, in just a few
minutes. That’s not because this period
is any less interesting or worthy of study than others, but because I want to
focus more on the emergence of “people” as we think of them—that is, in the
words of paleoanthropologist John Shea, behavioral variability. But to really enjoy the wonder of
“personhood’s” emergence, we need a little background information, which will
be covered in this video, and the next.
Let’s start by jumping into our Wu-Tang Elevator and going back to the
Africa of around three MYA…
So as we begin to explore our surroundings, we become
familiar with a few different creatures that belong to what we know as the
genus Australopithecus, or “Southern
Ape” in Latin. We would have seen these
guys as decidedly more chimpanzee-like than human-like, with one important
difference: Australopithecus walked
upright (1).
There were a few different species of Australopithecus, and they seem to have
been around generally between four and two MYA.
The different species show variation according to a theme that is very, very important in the study of human
origins: robustness vs. gracility. That
is, a heavier-set build as opposed to a lighter, less brawny physical
morphology. Consider, for instance, the
robust gorilla, as opposed to the gracile bonobo. Gorillas live in dense jungle, where you
don’t really need to run from anything, and rely on tough, hard-to-chew stems
and shoots (2). The forests inhabited by
the bonobo, on the other hand, are less dense, and they rely on softer,
easier-to-chew fruits (3).
Australopithecus
lived on the savanna, rather than in the forest (4), which made it necessary
for them to stand up to look out over the tall grass. Australopithecus
was therefore evolutionarily pressured by a treeless environment for greater
gracility. Since they were less brawny,
they became more reliant on tools. This
set of traits gradually led to the emergence of the genus homo about 2.8 MYA.
So what was Australopithecus
like? Most of us are familiar with
the iconic Lucy, discovered in 1974:
When
I was a little kid, I saw this picture, and mistook the jawbone for her
smiling.
When she was alive, she probably looked kind of like a
chimpanzee that stood upright:
Although Lucy is a lot more famous, we also have a
beautiful skull of an infant Australopithecus
from Ethiopia that its discoverers have named Selam, or “Peace”:
Beautiful.
Here’s what she looked like when she was alive. I actually think she was on a National Geographic cover a while back,
so maybe you’ve seen her before:
Aw, she’s so cute! I wanna give her a
hug!
When paleoanthropologists examine this wonderfully
preserved skull, along with others that we’ve found, it becomes clear that
their skulls were a lot more like those of chimpanzees than humans. For instance, their brains appear to have
been comparable in size to those of modern chimps (5). Their behavior was probably not much more
“human-like” than chimpanzees either, although it was recently discovered that
they were able to use stone tools (6):
On the other hand, there is one, very compelling,
piece of evidence that there was, even then, just a spark of something
incredible going on in the brains of these creatures. It is possible that among Australopithecus abstract thought, the
idea that one thing could represent
another thing, was already in its infancy.
At a site associated with Australopithecus
fossils in Makapansgat Cave, South Africa, an unassuming jasperite pebble was
found, which was naturally shaped in such a way that it crudely resembles a
humanlike face. Now of course, there’s
lots of natural stuff that looks like other stuff, just think of clouds in the
sky! But the eerie thing about the
Makapansgat Pebble is that it is of a geologically different composition from
the surrounding environment (7). The
nearest source of jasperite is miles away.
The chances of it somehow getting to Makapansgat by itself are astronomically,
negligibly small. It had to--and even as
I say this, I get chills up my spine—It
had to have been carried there.
The pebble is small enough to carry without any
trouble—half a pound—and could have been held easily in one hand. It would not have made a very good tool,
given its shape, and certainly not one useful enough to carry miles away from
its source. What appears to have
happened is that somewhere around 3 million years ago, an Australopithecus found
this thing, looked at it, and a synapse fired somewhere in his little monkey
mind, flashing like lightning on the horizon.
He found this pebble, thought, hey,
this looks like me—an abstract thought—and considered this interesting
enough to take back to camp to show his friends. I wish I could’ve been there to see him find
this thing. I’d give a million dollars
just to find out exactly what went through his mind, and what significance it
had.
Would you like to see it? Of course you would. Here it is: the oldest face in the world:
I love this.
When we look at this pebble, we experience exactly the same jolt of
recognition, and see exactly the same face and features, that someone saw three million years ago. Isn’t that cool? So we see, even at this early stage, the
faintest flickers and glimmers of what would, someday, make us “people”.
Next time, we’re going to talk about the transition
from Australopithecus to Homo, and what we know about the very
earliest members of our genus.
Sources
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