Evolution involves change over time.
and I have here five skulls of five different fossil
individuals out of about six thousand of fossil
individuals that are known that help document the
course of human evolution.
Well you can see from just these five representing
about 2.5 million years ago to about 1 million years ago
to near the present, that there were changes in the
size of the braincase, and also in the size and shape
of the face, and you can see that the brain got larger over
time and that the face generally got smaller over
time until you get to our species where we have the
largest brain and the smallest face that's tucked
in underneath the braincase.
So that's very different from what we have
2.5 million years ago with a small braincase and
a large, sloping face.
So what we see then is change over time in the physical form,
in this case brain size and
the size of the face.
But human evolution evolved not only change in
the physical form of early humans up to ourselves,
but also change in behavior.
So I have some of the stone tools that
helped show us some of the changes that occurred
in the behavior seen in the archaeological remains,
and so what we the earliest stone technologies
known back to a little bit more than
2.5 million years ago.
The earliest technologies consisted of basically a rock,
like a cobblestone like this,
which was battered,
and you also have the core,
and hammerstone was brought back down on this cobble,
and flake scars were made,
and what flew off from the
cobble itself were the sharp stone flakes,
which were really useful for cutting meat
off of animal bones, and also maybe whittling a stick,
and that stick could be used to dig in the ground for
roots and tubers, or maybe even deeper into the ground
for water during times when things were dry.
About 1.5 million years ago, we see that the early humans
were able to make really large flakes,
and take those flakes and to strike them all the way around,
creating a sharp edge all the way around.
And this was a really handy tool to carry about with you
for a lot of different purposes.
This is the oldest known handaxe,
and handaxes were around for yet another million years.
Things changed pretty slowly.
Well what we see then, beginning about a half
million years ago is that the stone handaxes became
smaller and they became more and more refined to the
point where they became almost really pieces of art,
really beautiful craftsmanship,
and then technology kept getting smaller as you see
these fine blades and then even the innovation of
arrowheads, and arrowheads were great of course for
killing fast and dangerous prey.
And so the history of technology has been pretty
much the same ever since, going from big and clunky to
really small and refined.
We then see over the next 100,000 years
up to the present, innovation really picks up,
and we have origin of, say, bone harpoons,
which were used for fishing, and also objects where we
see symbolic markings for the first time on the bones:
on antlers, on many different kinds of objects,
indicating that early humans were beginning to live in a
symbolic world, where they used language to communicate
with one another.
We even have artifacts like this.
This is one of the oldest known artist's palettes.
Humans of our species put pigment over this flat
surface and they used that pigment and sometimes put it
in their mouth to make paint,
or mixed it with water,
and they put art on to cave walls,
these fantastic painted caves that we know from
Europe, from Africa, from Asia and Australia,
and eventually all around the world,
and that represents the origin of art.
And so what we have then here is not only change in
physical form: brain size and the size of the face,
but also change in behavior, and that's evolution. 87 00:04:14,567 --> 00:00:00,000