Roughly 3.5 million years ago,
Lucy australopithecus afarensis, one of the most important fossils
ever found roamed the African savanna. Today, using the latest scientific research
we're going to reconstruct her life and her death as much as we possibly can.
From the terrible danger she would have faced, to her greatest moments and perhaps even the
first glimpses of what makes us truly human. This is Life and Death Three Million Years Ago Lucy's life began in the same way as all life
does, with a bang. She was born into a world that was in many ways familiar to ours but in some
ways vastly different. Millions of years before our species had scarred the planet, this was a
wild world absolutely teeming with life. Some we would recognize as the ancestors of modern
animals others would be quite different. Like Theropithicus brumpti, a relative of the galada
but twice the size, weighing up to 50 kilograms. Likely it preferred to eat plants but you
wouldn't catch me getting in the way of one. Megantereon, sabretooth cats built like
a leopard on steroids with huge teeth and strong jaws to bring down the largest of prey.
Perhaps most dangerous of all, crocodiles. Many more species than we have
now, lurking hidden in the water. For a young australopithecus like Lucy, life
was far from guaranteed and the archaeological record is full of examples of our ancient
ancestors falling prey to these beasts. A paranthropus aka robust australopithecus
with two puncture marks in the skull. Probably caused by a leopard. Dragged across
the savannah by your skull, horrible way to go. The bones of thirsty australopiths, peppered
with the puncture marks of crocodile teeth. No doubt caught off guard
as they went for a drink. Ripped from the water's edge
by a crocodile lying in wait. Saddest of all perhaps the small Taung child. A
roughly three-year-old australopithecus africanus that lived around 2.8 million years ago. Judging
by the marks on the insides of their eye sockets, seemingly plucked from the
savannah by a predatory bird, probably an African crowned eagle,
and carried away to a grisly end. Lucy, however, survived these challenges. Possibly
by spending a lot of time still in the trees. Although we're confident Lucy was bipedal from
her short and wide hip, a fully extendable knee, and many other anatomical features, her upper body
and the upper bodies of other afarensis hominins are more complicated, seemingly retaining many
more ape-like features. In 2012 anthropologists found the intact shoulder blade of a young
australopithecus afarensis which they called Selam. This was a critical discovery because even
though Lucy is 40% complete her shoulder blades are missing. Denying us a crucial piece of the
anatomical puzzle. Selam's shoulder blades were much more similar to modern juvenile gorillas than
modern humans suggesting that some of their time was still being spent in trees. However, it is
also possible that these were archaic features that australopiths retained from our last common
ancestor with chimpanzees and that they served little practical purpose. Changing very slowly
due to a lack of strong evolutionary pressures. Apart from avoiding becoming lunch, her childhood
was probably similar to modern great apes. Playing with other kids, rolling around
in the grass, jumping on her siblings, watching the adults in her group, learning
the skills she would need to survive. Consistently, probably the greatest challenge
Lucy would have faced is finding food. Analysis of the teeth of 20
different australopithecus aferensis indicates that their diet involved a lot
of c4 plants. These are grasses, sedges, succulents the kinds of plants that
thrive in a dry open savannah environment. They could have been eating the grasses and seeds
themselves or possibly the roots and tubers which are much higher in calories. Because of their
inaccessibility, competition for these buried foods is rare and it could have provided a decent
meal for an australopith smart enough to dig for them. These foods are almost entirely avoided by
our closest relatives, chimpanzees and gorillas, and this change of diet marks a significant
moment in the direction of our evolution, away from the resources of the forest, towards
the more varied resources of open landscapes. Just because this food source has little
competition though does not mean that their life was easy. Teeth from australopiths that
lived 1 million years after Lucy showed that they experienced seasonal stress in their diets. Lucy
may well have faced similar hardships and likely spent a long time roaming the savannah in search
of food. Absolutely stunningly, footprints from Lucy's time have been preserved in the earth for
us to study today, called the laetoli footprints. What's fascinating about these footprints is that
recently more have been discovered from the same location that suggest there were different walking
styles, different gaits used by hominins at this time. How well australopiths could walk and run
has been a big debate in anthropology and these different footprints will certainly be analyzed
for clues to the evolution of our bipedalism. Not only are the Laetoli footprints an
incredible relic of ancient human life, they are the literal footsteps of some of our
most ancient ancestors, but they're also a reminder that three million years ago
humanity was very much in its infancy and there were probably many distinct groups, each subtly
different, each with its own specific quirks, survival strategies and biological adaptations.
When Lucy was wondering the earth though, trying her best not to starve, she almost
certainly was not just on the lookout for plants. She probably had a taste for something
meatier and had a secret weapon to get it. Many monkeys and apes use tools to acquire food.
So it's likely that there has never been a point in hominin evolution where we were not using
some form of primitive tools. What separates our lineage, hominins, from our other cousins though
is the ability to really modify tools and improve them. Particularly stone tools. It was believed
for a long time that the first modified stone tools were the Oldowan stone tools created by
our genus homo, specifically homo habilis, around 1 million years after Lucy had died. However,
recently stone tools were unearthed that date to 3.3 million years ago. Right in the ballpark
of Lucy's life. These have been dubbed the Lomekwi assemblage and are currently the oldest
deliberately modified stone tools ever found. Bones of animals, likely ungulates and bovids,
have also been unearthed bearing cut marks from an astonishing 3.4 million years ago. This
evidence suggests that Lucy's diet could have been supplemented by quite a bit of meat
and that she was creating tools to access it. This raises some really fascinating questions. First, how did they acquire this meat? Lucy was
only about one meter tall and was not likely to be a great sprinter so hunting large and fast animals
was probably not easy for her. Could troops of australopithecines have bullied faster predators
off their kills? It's certainly possible. Troops of other primates can be highly aggressive.
So aggressive that if lucy's life was anything like a chimpanzees then another major challenge
was probably avoiding other australopiths. Lucy could have also been scavenging meat off
carcasses of abandoned prey. Large predators like lions often leave a lot of meat on the bones and
that doesn't even include the bone marrow inside. Perhaps australopiths like Lucy were developing
stone tools to strip the bones of small slivers of meat or use them to smash through
the long bones to get to the marrow. Instead of competing with top predators, Lucy was probably
fending off other scavengers like vultures. The second important question is, what was going
on in Lucy's brain? If our interpretation of the evidence is correct and hominins like
lucy were making modified stone tools, then it suggests something dramatic had
shifted in the brains of australopiths compared to other apes. Lucy's brain would have
been a similar size to a modern chimpanzees, just marginally bigger on average. Yet chimpanzees
in studies have so far been unable or unwilling to produce modified stone tools and even seem
unable to use a sharp flake to open a box containing food. So even though the change
between the two skulls is small, something dramatic was going on underneath. The brains
of australopiths were perhaps being rewired. Another incredible artifact that allows us to get
a glimpse inside lucy's brain is the intriguing Makapansgat cobble. This cobble was
found in a cave in South Africa in layers dated to 2.95 million years ago that
also contained the remains of australopiths. Curiously this rock is several kilometers
away from where it would be naturally, perhaps as far as 32 kilometers. It's probably
too big to be carried in by the by a bird, in the stomach of a bird, and the cave showed no evidence
of flooding that could have brought it in. No one can really deny this rock really triggers
that sense within us that likes to find faces, pariedolia. This ability is definitely not unique
to us. Chimpanzees process faces in a similar way to humans. Many animals have evolved this sense
out of simple self-preservation. Spotting faces ultimately reduces the chances of being bitten
by them. It is possible that this rock stood out to an australopith. That something about the
rock said "hey take me home let's go back to the cave". Again suggesting that something was really
changing in the brains of australopiths. This is especially interesting because so far endocasts
of australopith brains and chimpanzee brains have shown little difference in organization.
So the change must have been incredibly subtle, but very significant. Perhaps all of our artistic
expression and creativity ultimately has its roots in a simple moment of curiosity by
an australopith like Lucy. Lucy was not simply an upright walking ape, she was taking
the first tentative steps towards becoming human. One of the major events in Lucy's
life might have been giving birth. This was probably quite difficult for Lucy. The
combination of upright walking, which narrowed our hips, and slowly increasing brain size was
probably starting to put a strain on pregnant women. Baby australopiths would have probably
had to rotate slightly to pass through the birth canal. This meant that giving birth was certainly
harder than it had been earlier in our evolution and therefore might have become
a more collaborative process. Instead of Lucy giving birth on her own like a
chimpanzee does commonly, she could have been surrounded by other women, perhaps her own mother,
assisting her in bringing new life into the world. Who knows what effect this increased collaboration
had on our evolution? Usually when we imagine increased cooperation in our prehistoric ancestors
we picture them hunting together but that's just one way we cooperate and the increasing
difficulty of giving birth could have been an extremely significant factor in our evolution,
in the evolution of our complex social systems. How much of a role Lucy's baby daddy played in
raising children is subject to huge debate. The issue revolves around the size differences
between males and females, called sexual dimorphism. In primates, species that have a
high degree of sexual dimorphism tend to live in societies where there is one massive guy trying
to have all the sex with all the women and play a little role in the raising of children. Silverback
gorillas and mandrills are two perfect examples. Absolute beasts! Compared to other apes, humans
don't have a high degree of sexual dimorphism and males tend to be very involved in the raising
of children. Some studies of australopithecus afarensis have come to the conclusion that there
was a high degree of dimorphism. Others have argued that the degree of dimorphism is similar
to humans and that therefore males were more involved in family life. In support of this idea,
australopithecines seem to have developed slower and had longer childhoods than our modern ape
cousins, probably because they might have had to learn how to produce stone tools and live
slightly more complex lives. So more investment was probably required from somebody and that could
have been dad, who knows? It's just hard to say for sure because we don't have a perfectly
preserved male and female australopith so all these estimates are based on reconstructions.
The specimens we do have are not only incomplete but also separated by hundreds of thousands of
years, plenty of time for a species to change. Whatever happened in the twists and turns
of lucy's life at some point, of course she died, she's dead, spoiler alert.
Judging from the fractures on her bones, some have suggested that she
died from falling. Though others contend that these fractures could
have been caused by large animals. Either way, her death was probably sincerely
mourned by her family. Humans, of course, we grieve for our dead even chimpanzees
grief for their dead, especially infants, even staying by their side for days. As the evidence suggests that australopits might
have formed even closer bonds, we can only imagine the pain that they would have felt watching over
her body. Little would they know we would still be watching over Lucy more than 3 million years
later. Captivated by the stories she can tell, not just of herself but of the
origins of everyone alive today.
