Physically, Homo sapiens is not that special in the animal world. But the species has discovered ways of finding food and beating the odds of survival in every habitat from jungle to Arctic wasteland.
It has also come to obsess Alice Roberts, who started off in medicine, becoming a surgeon and an anatomist. She was captivated by the evolutionary story of the ape that walked and talked, and is now professor of public engagement in science at the University of Birmingham, UK. Her expertise spans anthropology, archaeology and palaeopathology.
She also has a huge track record of TV shows, from Digging for Britain and The Lost Scrolls of Pompeii to Witches of Essex, and a growing pile of books. Roberts was editor-in-chief of the latest, , which tells the story of human evolution with illustrations and contributions from an international team, including Michael Marshall, who quizzed her about her latest work.
Advertisement
听
Michael Marshall: What鈥檚 the big idea in this latest part of your journey into the human past?
Alice Roberts: When I was working at the University of Bristol, something happened that was really important to how I think about humans. When I was a young surgeon, teaching anatomy to students, we built a dissection room in the vet school. I was roped in to teach there and remember looking at a lamb鈥檚 heart.
It was the first time I properly understood the way the heart changes from the fetus to the heart in a baby and an adult. I was thrown into a bigger department where I was forced to see humans as another mammal. And that is what we are. It really changed the way I look at us all.
How should we think about our bodies as products of evolution, about our history being written in our skeletons and our organs?
There鈥檚 biochemistry going on in our cells that goes back to these earliest single-celled creatures living in the ancient oceans. If we look at our arms and legs, they go back about 360 million years, when the first amphibians crawl onto land, and fins have become limbs. We can see that change, map the bones of our arm, and see where they鈥檝e come from in evolutionary terms. You can do that with every bit of the body.
I laid out the skeleton of Homo floresiensis and it sent shivers down my spine... it was so human and yet not
听
Can you give me some examples?
I鈥檝e always said I could put the humerus of a female chimp in a medical students鈥� exam and they wouldn鈥檛 notice the difference 鈥� the bone is about the same size and shape; all the features are there. The more you look, the more similarities you start to see. Hands are really interesting: so similar and, at the same time, subtly different. The human thumb is longer and really chunky compared with the chimp thumb.
听
I鈥檓 always struck when palaeoanthropologists compare ape and human hands and confidently say, 鈥渙bviously that one is Homo habilis鈥�. It鈥檚 not obvious to me鈥�
Exactly. Because if we鈥檙e saying chimp hands are quite similar to human hands, if you鈥檙e looking at other hominins, [then] they fit into the gap between the two. It鈥檚 difficult when the fossil record is fragmentary as well. I鈥檓 quite nervous about some classification. It makes me feel uncomfortable 鈥� as somebody from a medical background who likes a lot of data.
听
Humans do seem to have one exceptional thing 鈥� our brain. How much difference does this make?
I think it鈥檚 the biggest thing. If I characterise humans in as few words as possible, it is: walks on two legs, small teeth, big brains. Big brains are connected with walking on two legs, but I鈥檓 not sure how.
There are lots of theories linking that [bigger brains] to bipedalism: the two are happening at the same time, or bipedalism is happening and then brains are growing. People have said, it frees your hands so you can use tools and that drives brain expansion. Or you鈥檙e able to move in different ways and maybe cover greater distances, so you鈥檝e got larger social networks. Maybe that鈥檚 driving brain expansion.
We have similar-sized bodies to other apes, yet the human brain isn鈥檛 just bigger, it鈥檚 got more folds 鈥� packing in an awful lot of cortex into an already massive brain. We tend to say, humans are over here and the rest of the natural world is over there. It totally influences the way we deal with it.
听
The number of human species that coexisted before us and alongside us really stands out now. How has that changed our understanding?
The first other humans we knew about were Neanderthals. We understand now there鈥檚 an overlap, that they weren鈥檛 a human ancestor that developed into modern humans. We鈥檝e got about 20 different hominin species now, and more every year.
In 2008, I was making The Incredible Human Journey, my first landmark series for the BBC. In Jakarta, Indonesia, I went to the museum and introduced myself as a biological anthropologist, and they said, great, in that cupboard is Homo floresiensis [LB1], you can lay out this fossil. I was blown away. There I was with LB1 and the table with bubble wrap on it.
听
鈥淭he hobbit鈥� 鈥� the original Homo floresiensis!
The original H. floresiensis! I laid out the skeleton and it sent shivers down my spine because it was so human and yet not, especially the skull. It has a tiny skull and a tiny brain. And yet, we know it is anatomically human. We know they were making stone tools. That was a big revelation. In the archaeological record, we鈥檝e got brains getting bigger and stone tools appearing 鈥� we just assumed the two went together. Then you find tiny-brained individuals making stone tools on Flores.
I love it when new discoveries throw big spanners in the works. It did change my concept of what it was to be human. It鈥檚 a paradox that I hold in my head continually. I will rail against human exceptionalism while saying humans are exceptional. If we look at our culture and our tech, we are utterly exceptional. If you鈥檙e looking at individual bits of us, you can see where it has come from; it hasn鈥檛 just exploded into being. We are fundamentally, at the end of the day, animals.
听
Still primates. But eventually the Neanderthals, the Denisovans, they all disappeared. Why is our species left?
It鈥檚 a very hard question. You鈥檙e pushing tens of thousands of years, if not hundreds of thousands, of evolution into one question and one answer. One hypothesis, which is hard to test but it has the best evidence 鈥� and I鈥檓 cautious because I don鈥檛 think it鈥檚 one thing 鈥� is about the social networks modern humans had. The evidence is extraordinary. It seems raw material is travelling further in human networks. If you try to work out why, you鈥檙e talking about groups of people who are connected and exchange objects, raw materials and artefacts.
So you think, OK, you鈥檝e got small bands of people, but they know others. Maybe if you fall on hard times and you aren鈥檛 managing to get enough food for your tribe, there are other people you can call on.
听
听
Like the rest of the natural world, we are evolving. Will we change over the next few hundred years?
Not much. When we see evolution happening rapidly, it鈥檚 usually because something awful has happened 鈥� a population has been reduced to just a few. Then you get profound effects based on that selection of genetic diversity.
If we remain a big global species, I think most change will be the change we鈥檝e been able to detect in the immune system, that kind of thing. We鈥檙e not going to grow extra arms and legs, certainly not in the next 100 years.
It's a paradox I hold in my head. I will rail against human exceptionalism while saying we are exceptional
One really interesting and very scary thing on the horizon is the ability for us to change DNA. I don鈥檛 know how that will play out. That鈥檚 a big ethical question.
听
Is your work feeding into the fiction you are writing?
I鈥檝e written two children鈥檚 books set in the ice age. I was imagining what it was like when modern humans first met Neanderthals. I wanted to bring it alive as a story.
Then my first novel for adults is out in September, The Goddess Queen, the story of Cleopatra and Mark Antony. When we talk about Cleopatra, we talk about her love affairs, but politically she鈥檚 incredible. What intrigued me was the potential for things to have played out differently: there鈥檚 a lot of chance and contingency in human history, just as in evolutionary history. Different books, but with the same themes and ideas.
听
Overall, where is our relationship with nature? What should that be?
There are billions of us. Our culture is exceptional. But by taking this evolutionary approach, you鈥檝e got less of a hard line between the rest of the natural world and us, you can see where this culture has actually come from, even if it makes us feel completely separate.
Today, it鈥檚 important to remember we鈥檙e not separate. I don鈥檛 believe in any supernatural phenomena. I don鈥檛 believe in any divinity. Another way of framing that is, I think nature is enough, and for me as a humanist, I draw quite a strong moral lesson from the knowledge that I am part of the natural world, that all those other species out there are close cousins, that what evolution has conferred on us is this incredible intelligence and understanding.
We understand the impacts we鈥檙e having. When we have a deleterious impact 鈥� even if it鈥檚 not happening immediately 鈥� we understand that by virtue of the lifestyles we鈥檙e living, we are impacting negatively on biodiversity. Morally, we need to limit that impact. Because however insulated we feel from the natural world, we鈥檙e part of it. If that disappears, we鈥檙e not going to be here very long.
听
This is an edited version of a New 杏吧原创 video interview that will be available at from 10 June. Michael Marshall is a writer based in Devon, UK
