Authors: Professor Brian Cox
‘Dear friends, both known and unknown to me, fellow Russians, and people of all countries and continents, in a few minutes a mighty spaceship will carry me into the far-away expanses of space. What can I say to you in these last minutes before the start? At this instant, the whole of my life seems to be condensed into one wonderful moment. Everything I have experienced and done till now has been in preparation for this moment. You must realise that it is hard to express my feeling now that the test for which we have been training long and passionately is at hand. I don’t have to tell you what I felt when it was suggested that I should make this flight, the first in history. Was it joy? No, it was something more than that. Pride? No, it was not just pride. I felt great happiness. To be the first to enter the cosmos, to engage single-handed in an unprecedented duel with nature – could anyone dream of anything greater than that? But immediately after that I thought of the tremendous responsibility I bore: to be the first to do what generations of people had dreamed of; to be the first to pave the way into space for mankind. This responsibility is not toward one person, not toward a few dozen, not toward a group. It is a responsibility toward all mankind – toward its present and its future. Am I happy as I set off on this space flight? Of course I’m happy. After all, in all times and epochs the greatest happiness for man has been to take part in new discoveries. It is a matter of minutes now before the start. I say to you, “Until we meet again”, dear friends, just as people say to each other when setting out on a long journey. I would like very much to embrace you all, people known and unknown to me, close friends and strangers alike. See you soon!’
It’s too easy to attach trite labels to human actions – magnificent, horrific and everything in between – based on a simplified view of their causes. One can argue that the rockets carried aloft the egos of the superpowers alongside the astronauts, and this is surely right. But Gagarin spoke these words, and I challenge anyone to read them and not detect sincerity. All our actions mask a morass of motivations, worthy and less so, and the greatest human adventures are no less noble for that.
At 9.07am local time, Gagarin blasted off from Baikonur Cosmodrome in Kazakhstan, as every Russian cosmonaut has done since. Within 10 minutes, he was orbiting Earth at an altitude of 380 kilometres. His route took him across the Siberian wastes and the Pacific Ocean above the Hawaiian islands, past the tip of South America and into the South Atlantic, where he was greeted by a second sunrise before a 42-second de-orbit burn over the Angolan coast slowed
Vostok 1
into a parabolic orbit and an 8-g deceleration inside Earth’s thickening atmosphere. The journey once around his home world took 1 hour and 48 minutes. Gagarin ejected from the capsule 7 kilometres above ground and, as planned, cosmonaut and spacecraft completed the final descent apart. Gliding back to Earth by parachute, Gagarin landed 280 kilometres away from the intended landing site near the Russian city of Engels. Dressed in orange spacesuit and white helmet, a farmer and his daughter bore sole witness to his historic return. ‘When they saw me in my space suit and the parachute dragging alongside as I walked, they started to back away in fear,’ recollected Gagarin later. ‘I told them, don’t be afraid, I am a Soviet citizen like you, who has descended from space and I must find a telephone to call Moscow!’
Primates appeared relatively recently in the history of life on Earth. Studies of mitochondrial DNA suggest the Strepsirrhini suborder, containing the ancestors of Madagascar’s lemurs, diverged from our own Haplorhini suborder approximately 64 million years ago, which implies that a common ancestor was present before this time, but not a great deal earlier. The first complete primate fossil found to date is that of a tree-dwelling creature known as
Archicebus achilles
, dated at 55 million years old. Discovered in the fossil beds of central China in 2013, this tiny creature would have been no bigger than a human hand, making it not only the oldest but also one of the smallest known primates.
Our family, known as the Hominidae, or more commonly the great apes, share a common ancestor with Old World monkeys around 25 million years ago, and during the making of
Human Universe
we filmed a rare species of these distant cousins in the Ethiopian Highlands. The road out of Addis towards the 3000-metre Guassa Plateau is excellent to a point, and then not excellent. The scenery, on the other hand, improves with altitude. Golden grasses illuminated by shifting lambent light through dark clouds cling to near-vertical mountainsides framing pristine villages along the high valley floors. It is fresh, cold and insect-less on the peaks above the Rift; a place to drink tea and eat
shiro
, a spiced Ethiopian stew of chickpeas and lentils. After a night in the cold but magnificently desolate Guassa community lodge, we set off at dawn to intercept the gelada baboons on their way back to their caves and ledges from early-morning foraging expeditions on the higher slopes.
The gelada baboons are a species of Old World monkey found only in the Ethiopian Highlands. They are the only surviving species of the genus
Theropithecus
that once thrived across Africa and into Southern Europe and India. The males in particular are powerful, long-haired animals, weighing over 20 kilograms with a bright red flash of skin on their white chests. I was told not to look them in the eye, so I didn’t. Fifty thousand years ago, as our planet emerged from the last ice age, the gelada retreated into the highlands above the Rift where they still live, uniquely amongst extant primates, as graminivores, on a diet made up almost entirely of the tough high-altitude grasses and occasional herbs.
EVOLUTION OF HOMINIDS
These hominid evolutionary trees trace our genetic history as humans to the Old World monkeys that roamed Earth 25 million years ago. Discoveries of various remains, including those of the famous
Australopithecus afarensis
skeleton, commonly called Lucy, have helped us piece together an idea of our ancestry. It is believed that around 7 or 8 million years ago we split from the chimpanzees and the process of evolution into bipedal
Homo sapiens
began as these monkeys started to spend more time on the ground than in the trees.
EVOLUTIONARY TREE OF MONKEYS AND PRIMATES
They approach with nonchalant agility in small groups, which reflect the most complex social structure of any non-human primate. Most of the groups I saw contained one or two males and perhaps eight or ten females and their young. These are referred to as reproductive units, and clearly defined hierarchies exist within them. Females usually remain in the same unit for life, but males move between them every four or five years. There are also male-only units of ten or fifteen individuals. These social units are arranged into higher groupings known as bands, herds and communities. The community we encountered numbered several hundred individuals who wandered past in their little tribes, females and young pausing to eat, groom and play whilst the larger males eyed us closely.
Despite the 25-million-year separation in evolutionary time, the gelada are very easy to anthropomorphise, especially from a vantage point amongst them, probably because their behaviour seems reminiscent of our own and their babies are cute. Like us, they spend most of their time on the ground and operate in social groups. Some researchers familiar with the geladas claim they exhibit the most sophisticated communication behaviour of any non-human primate, employing gestures and a range of different vocalisations strung together into sequences communicating reassurance, appeasement, solicitation, aggression and defence. For all their sophistication, however, the gelada are a long way from possessing anything more complex than the simplest of human characteristics and abilities. This is, of course, an utterly obvious observation – they are monkeys! But what isn’t obvious is why. The gelada separated from our common ancestor at the same time, but that self-evident statement leads to a deeper question: what is it that happened to our ancestors during those 25 million years that led us to the stars and left them on the hillsides of the Guassa Plateau eating grass?
I am an aviation geek. I love aircraft. As I set off to film the African scenes for ‘ApeMan SpaceMan’, I noticed that the Ethiopian Airlines Boeing 787 I boarded at London Heathrow, bound for Addis Ababa, registration ET-AOS, was named ‘Lucy’. On the morning of 24 November 1974, Donald Johanson and a team of archaeologists were searching for bone fragments at a site near the Awash River in Ethiopia. The area was known to be a site rich in rare hominid fossils, but on that particular morning, Johanson and his graduate student Tom Gray found little to inspire them. As is often the way in science, however, a dash of serendipity, coupled with an experienced scientist who understands how to increase the chances of receiving its benefits, made a seminal contribution to the understanding of human evolution. Johanson shouldn’t even have been there – he had planned to spend time back at the camp updating his field notes – but as they prepared to leave, Johanson decided to wander over to a previously excavated gully and have one last look. Even though they’d surveyed the area before, this time Johanson’s eye was drawn to something lying partially hidden on the slope. Closer inspection revealed it to be an arm bone and a host of other skeletal fragments – a piece of skull, a thigh bone, vertebra, ribs and jaw all emerged from the ground and, crucially, they were all part of a single female skeleton. The find triggered a three-week excavation, during which every last scrap of fossil AL 288-1 was recovered. They named it Lucy, after track 3, side one, of
Sgt. Pepper’s Lonely Hearts Club Band
, because this was 1974 and they played it a lot on their tape recorder. ‘Home taping kills music’, they used to say back then, but it also names airliners.
Lucy lived 3.2 million years ago in the open savannah of Ethiopia’s Afar Depression. Standing just over 1 metre tall and weighing less than 30 kilograms, she would have looked more ape-like than a human. Her brain was small, about one-third of the size of a modern human’s and not much larger than a chimpanzee’s. The anatomy of her knee, the curve of her spine and the length of her leg bones suggest that Lucy regularly walked upright on two legs, although there are a handful of scientists who would disagree. What is generally agreed upon, however, is that Lucy was a member of the extinct hominin species
Australopithecus afarensis
, and she was either one of our direct ancestors, or very closely related to them. Her bipedalism was probably an evolutionary adaptation caused by climate change in the Rift. As the number of trees reduced and the landscape became more savannah-like, the arboreal existence of our more distant ancestors became less favoured, and the increasing distances between trees selected for
Australopithecus
’s upright gait made travel across the ground more efficient.
In ‘Who Speaks for Earth?’, the thirteenth chapter of Carl Sagan’s
Cosmos
, there are two pictures set side by side. One is of footprints covered by volcanic ash 3.7 million years ago near Laetoli, in Tanzania, probably made by an
Australopithecus afarensis
like Lucy. Some 400,000 kilometres away and 3.7 million years later, another hominin footprint was left in the dust of the Sea of Tranquility. Together, they speak eloquently of our unlikely, magnificent ascent from the Rift Valley to the stars. The remainder of this chapter deals with the 3 million years between Lucy and the Moon. The timescale is ridiculously small: less than a tenth of one per cent of the period of time during which life has existed on Earth. Lucy was little more than an upright chimpanzee; an animal, a genetic survival machine. We bring art, science, literature and meaning to the Earth; we are a world away, and yet separated by the blink of an eye. ‘Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring,’ wrote Sagan. I’d like to add that we owe it to Lucy as well.