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.