The discovery of Lucy, a 3.2million-year-old skeleton, in 1974 is one of the most important in the quest to find out the origins of mankind. One of the team leaders when Lucy was found in Ethiopia was Yves Coppens.
He is now 85 and has spent all his life studying prehistory and sharing his passion with the public, via the television, radio and books.
He continues to give conferences, and his popularity means tickets are sold out within hours.
When did your interest in fossils start?
I don’t know where this great interest came from, but it started when I was six or seven years old. It was perhaps because children have a great imagination.
When you study palaeontology you find actual objects, but behind that you need a great deal of imagination to understand them. I started with archaeology.
I was born in Brittany, where there are several menhirs, so I started with a period which began thousands of years ago, rather than millions.
After my doctorate I began to be interested in an earlier period. I wanted to start on human palaeontology but the professors at that time wanted us to start on animals first, to train for the bigger challenge of man.
So I had the choice between small rodents or the elephant family and I chose the bigger mammals.
I had an extraordinary experience in Siberia. I was in a sector looking for mammoth remains and we could only go down a metre at most because the ground below was frozen.
One day I arrived at the dig and there at the bottom I could see what I thought was a hairpiece or piece of material, and I was furious because I thought someone had been interfering with my work and had left something behind.
I climbed down and found I was standing on the back of a frozen mammoth. I was used to working with bones, and here I was on a body, with flesh, skin and hair.
How did you find Lucy?
It started years before we found her in 1974. I began research in Africa in 1960. I worked first in Chad and then in Ethiopia in 1967, but some 1,000 kilometres from where we found Lucy. So I understood the type of fossils that you found in this area, and their significance.
Around 1969, my geologist colleague brought me an elephant tooth fossil from the region where we later found Lucy. This tooth was between two and three million years old. So it was worth continuing to search in that area.
My colleague found more remains and so in 1972 we set up an expedition led by American, Donald Johanson, geologist Maurice Taieb and me. By 1973, we had found a knee, made up of a piece of tibia and a piece of femur from a pre-human species and the same species as Lucy.
It was the following year when we found more human bones, which seemed to belong to the same skeleton, and which we called Lucy after the Beatles song, Lucy in the Sky with Diamonds.
We had 40% of a skeleton.
This is what it made it so important, because you could learn so much about the individual it came from; size, proportions, articulations, and so the movement and behaviour.
Afterwards we made more discoveries, until we had to leave when conditions in the country became dangerous in 1977.
It takes years, then, to find a skeleton like Lucy?
Human remains are extremely difficult to find. When I was in the south of Ethiopia, out of five tonnes of fossils from vertebrates, we found only one that came from a human, and a few teeth.
For a palaeontologist, all the finds are important because you can learn from them what the surrounding environment was like at a certain time. You can learn whether it was savannah or forest or desert, by studying the types of animals and vegetation there at a certain time.
Did understanding the whole story of an area lead you to your theory that our species of humans developed as a result of climate change?
Absolutely. As I had studied plants, animals and geology I could understand the environment that Lucy lived in.
Three million years ago it was humid in the south of Ethiopia to start with and then became dryer.
Lucy walked, but she also climbed, because there were still trees. However, as the climate gradually changed, so did pre-humans.
Humans began to stop needing their ability to climb and developed their capacity to walk. It is an example par excellence of Darwin’s theory of natural selection.
It happened little by little. We imagine, looking back, that the adaptations happened straight away, but there were a whole series of attempts and failures, attempts and failures, attempts and failures, before one succeeded.
Is Lucy the mother of us all?
There is a whole world of pre-humans in which, somewhere, there is our ancestor. Certain of my colleagues think that the pre-human Lucy is our ancestor.
I don’t think so, and that is because Lucy has very big teeth and she still climbed.
The first human is, perhaps, 2.8million years old and so I think she is too close in age, at 3.2million years old, to have allowed the change from a species that still climbed, like Lucy, and had such big teeth to become man.
I think it was too short a period for a species to have lost the use of its upper arms to climb. But the last time I saw Donald Johanson, he told me he still thinks Lucy is our ancestor.
Lucy was incredibly important, though, because when she was found she was the oldest pre-human skeleton to have been discovered, the most complete and she was the first to reveal there were pre-humans who both walked and climbed.
You appear often on the television and the radio, you have written several books, you continue to give conferences all over Europe and you obviously wish to share your passion with the public, and not just with the scientific world. Why is that?
At first, when I was a student and passionate about prehistory, I did not even consider talking to the public.
My ambition was to be a scientist and make discoveries and become a scholar like my father who was a role model for me.
I was also very shy. However, I was often asked to talk about my field, first to students and then to a wider public and I was seduced by this audience.
I realised that I like people, all people, young and old, and that it was agreeable to pass on what I knew and what I had discovered and so I became a popular, perhaps too popular, science figure.
I wanted to continue to be a researcher and that was not simple, because as soon as the public is interested, there is a great deal of demand, all the time.
So I have always kept a third of my time dedicated to pure research, a third as a director of research and a third for the public.
Last week I was at Tarragona, in Spain, to take part in a jury for the presentation of two PhD theses. At the same time, I was asked to present a conference and the week before I presented a conference in Clermont Ferrand.
So, there is a huge demand to understand more about our origins?
Yes, there is a huge demand. It is important for the whole of humanity. Now that we can analyse DNA, I meet lots of people who have found out what their roots are. It is a basic human need.
I found the first pre-human fossil in Ethiopia, in 1967. It is less well known, but was the jaw bone of a pre-human species and was 2.6million years old.
At that time Ethiopia was an Empire. Whenever the Emperor made a speech, he always referred to the fact that his country was the cradle of civilisation, as a great matter of pride.
Later Colonel Gaddafi wanted to organise research in Libya, so that an ancestor of the human race could also be found in his country.
Are we ever going to find the truth about our origins?
Perhaps we will get closer if, one day, we can study fossil genetics. Unfortunately, DNA is fragile, so it is difficult. We tried with Lucy, but we did not find any. The oldest genetic material we have found is one million years old.
Will the present climate change alter us as humans?
It will change the way we behave, but not our physical structure. Over three million years, thanks to our brain, we have learned to understand who we are, and we have learned to anticipate.
Before, if I needed a “stone” I would pick one up when I needed one and throw it. Today I have made a stock of “stones” ready for use in the future.
This ability to anticipate means we are less vulnerable to climate change than we were before.
Current climate change won’t change our physical aspect as it did millions of years ago, but it will change our way of life and it will affect us as populations have to move from rising sea levels and we have to change agricultural methods.
Are we continuing to change?
There is no reason why we should not continue to evolve.
I will give you a personal example. I had a son late in life, who is now 23.
We both had a brain scan to see which different parts were activated when we used a touch-sensitive screen.
In my son’s brain there were fireworks, and in mine it was dusk. It suggests our brains are developing, fast, to work with computers.
Are you still as fascinated by fossils as you were as a child?
I am 85, and I continue to work. I have been lucky to have a vocation. My son tells me that. He is interested in many things, but says he would like to have a passion in something specific.
My father was a scientist and my mother was a concert pianist, and they allowed me to develop my passion.
As well as palaeontology and natural sciences I studied medicine, not to be a doctor, but to learn how the human body functions.
If I have to choose between a fossil of a plant, an animal, or a human, I am most attracted by human remains. They have a special power.