Whether or not you've been following CBC Television's epic series The Great Human Odyssey, the concluding episode to anthropologist/producer Niobe Thompson's deep dive into the origins of our species offers insights enough for any hominid to chew on.
The series draws on recent archeological and genetic findings to lay out the scientific equivalent of a creation story for humankind. It chronicles our ancestors' rise and near extinction in Africa and successful expansion into an ice-age world already occupied by close cousins such as Neanderthals. The final instalment investigates humanity's most audacious prehistoric trick: crossing the oceans to settle every major island and continent on Earth except Antarctica.
Niobe Thompson spoke with The Globe's science reporter about making the series.
What fresh perspective on the story of our species were you hoping to bring to viewers?
We've known for some time that humans that look like us first started walking the African landscape roughly 200,000 years ago. But what's trickier, and I think a lot more interesting, is to ask: When did we first begin to think like modern humans? There's been a real focus shift in paleoanthropology to look at this question and we were very lucky to get into two excavations on the coast of South Africa where we're seeing evidence of that human spark. Starting about 75,000 years ago we see the arrival of some pretty sophisticated projectile tools along with indications that we're beginning to use symbols to communicate – a strong proxy for language.
What do you think ignited the spark?
One of the discoveries that was new to me is that if you look at the climate record of Africa, the picture we're getting now is of really punishing volatility. That just accelerates through the last million years to the time when our species arrives. You can see there was a very strong selection pressure for adaptability. Our closest call came about 150,000 years ago when population genetics suggest there were fewer than 1,000 breeding adults left. That suggests we're descended from a small number of survivors who were lucky but also clever enough to learn how to cope with a changing climate.
How does culture fit in?
Culture is key, because culture is the accumulated knowledge a group of humans would have had for dealing with the challenges of their world. But the ability to change cultural practice to deal with environmental change is just as important, and flexibility is possible when a larger group contains within it knowledge about the past.
The series points to cave art as a key indicator of human emergence. Is art just a side effect of us being brainy apes or was it more central to our survival?
We know from social anthropology that a crisis can spur intensive art-making. I believe this tells us that art is always intertwined with the sacred in traditional cultures and that depictions of the spirit world and the visual or aural transformation of our world must have helped us deal with anxious times.
You had some amazing adventures with traditional cultures while making the series. How did these experiences affect how you think about our ancient ancestors?
Whenever I am living with traditional cultures I have the experience of being overwhelmed with the skills my hosts have for living in their environment. A person cannot become a hunter or a free-diving gatherer or a reindeer nomad as an adult. This is an immense package of skills that one must begin mastering as a child. These experiences help me understand how our ancestors adapted to different worlds as they spread out across the planet.
Are we underestimating what our prehistoric ancestors were capable of?
We live with an unquestioned assumption that because our modern culture is built on invention and complexity, these qualities are new. That isn't true. There was an immense span of time before written history when our ancestors were inventing technology to solve the challenges of their world. A good example is the Polynesian ocean-voyaging culture, which in my view was the most advanced ocean-navigating culture in human history, considering what the Polynesians had to work with.
Now that we've taken over the planet, how optimistic are you that we'll manage to face the challenges of the next 100,000 years?
We are the only species in the history of life on Earth with the ability to imagine our future. That capacity gives us the power to change our behaviour based on what we believe may come to pass. That's why I'm hopeful, but it's hard to ignore the fact that our history is one of severe diebacks followed by miraculous recoveries. Perhaps we'll survive another 100,000 years, but with a few dents in our population genetics.
The final episode of The Great Human Odyssey airs on CBC-TV, Thursday at 8 p.m. on The Nature of Things. To learn about the science behind the series and to watch additional scenes, see cbc.ca/greathumanodyssey.
This interview has been condensed and edited.
Ivan Semeniuk