All these features make us good runners. Compared with other animals – four-legged ones – we are not very fast sprinters at short distances, but we are actually excellent endurance runners. And we are unique among primates in developing this capability of endurance running. Over long distances, trained humans can even outrun horses and dogs.
Some explanations of human anatomy and locomotion have suggested that the apparent adaptations to running are actually just byproducts of a body designed for walking on two legs. Certainly, long legs improve efficiency in walking as well as running. But the springiness of the leg and foot, and those big bum muscles, aren’t really used in walking – but they are great for running. American anthropologists Dennis Bramble and Daniel Lieberman gathered the physical evidence and published an article in the journal Nature in 2004, arguing that, while walking was undoubtedly a fundamentally important way of getting about, for us and our ancestors the role of running had been overlooked. They suggested that the human body has evolved to cover long distances: walking and running.
But why run at all when walking uses up less energy? Well, in the days before weapons like bows and arrows, endurance running might have enabled our ancestors to get close enough to an animal to throw weapons at it from close range, or even to run it to exhaustion. It’s difficult to imagine how hunting large mammals could have been achieved in those early days without some running. I mean, imagine trying to walk an antelope to exhaustion. Equally, endurance running could have helped in scavenging: getting to a carcass before carnivores.5 Although running uses more energy than walking, it’s still worth it if it increases the chances of getting an animal to eat. For instance, a three-hour endurance run costs around 900kcal (about 30 per cent higher than walking the same distance). If the hunter manages to kill a 200kg duiker, he’d get around 15,000kcal in return. If he brought down something bigger, say a 200kg wildebeest, the return could be a stonking 240,000kcal, for the same effort.6
So you could imagine a scenario where, over tens of thousands of years, early humans who had bodies that were better at endurance running – through random but lucky mutations in their genes – had an advantage, passed their genes on … and so our bodies today bear witness to that early way of life. However we make a living today, we have legs and bottoms befitting a persistence hunter.
Although theories of form and function in human evolution should not stand or fall depending on ethnographic evidence (why should any humans today be behaving in exactly the same way as our earliest ancestors?), it’s interesting to look at how modern hunter-gatherers hunt. The Bushmen who still hunt today, like !Kun and //ao, use a combination of endurance walking and running over great distances. While they use bows and poisoned arrows, so don’t need to get as close to the animal as would have been necessary before this development, they still have to cover a lot of ground, quite swiftly, in pursuit of their quarry. And even though they have bows and – poisoned – arrows, the technique itself is still persistence hunting.6
It’s hard to know how much meat hunter-gatherers like the Bushmen actually eat. Theo thought that it was quite rare for the hunters to bring down an oryx or kudu, but, when they did, the whole village would feast. Nothing belonged to any one person: sharing was the unwritten law among the Bushmen. Smaller animals were caught on a more regular basis, with snares – and hooks. Hanging from the trees in the village were long sticks ending with vicious-looking hooks: springhare probes. Hunters would push them down the burrows to catch these large rodents.
Being able to hunt in the middle of the day gave the Bushmen a unique advantage, a particular niche, away from other predators and scavengers. (Presumably this would also have been a key advantage for our early ancestors as well. It’s impossible to know if early Homo had the ability to follow the tracks of animals, but it seems reasonable to assume that they did. Surely they must have also worked out what it meant when vultures gathered on the horizon.)6 While the lions, leopards and hyenas hunted at night, the Bushmen of the Kalahari could track and hunt in the noonday sun. But when dusk fell, it was time to get back to the safety of the village. Bushman villages are always situated a safe distance away from waterholes.
But I wasn’t going home to the village that night. Whereas the Bushmen thought it wise to leave the waterholes to the predators, I was going to try sleeping out in the bush. I had planned to stay out there – just 20m from the waterhole – with a bedroll (two sleeping bags in a canvas bag), basic provisions and a video camera, to make a diary. I wasn’t entirely alone: Theo (with gun) and cameraman Rob were both going to sleep another 20m away from me. But that was far enough away for me to feel alone. As dusk gathered around us, and barking geckos set up their staccato chorus in the fading light, we collected thorn branches and arranged them around our respective bedrolls to keep the hyenas at bay. I’m not kidding. As darkness fell, I was startled to hear a hyena howling at the waterhole, just metres away. It was an eerie sound. We shone our torches out into the darkness but saw nothing. Theo and Rob barricaded me into my small camp then retired to their own thorny kraal.
For about an hour I sat on my bedroll, listening intently to the sounds of the night around me. The long grass was dry and rustly, and I could quite clearly hear the sound of LARGE animals walking through it. I caught myself holding my breath. I had no idea what (though I knew hyenas were out there) or how many creatures were walking around my sleeping place to the waterhole. I heard hyenas again: blood-chilling howls. Theo had described these animals as the most fearless creatures of the bush. Lions, leopards and elephants would often run away if startled or shouted at by a human being. Hyenas stood their ground.
Then, in the stillness, I heard a strange sound: quite quiet, but rhythmic, coming from the direction of the waterhole. It took me a while before I worked out what it sounded like. It was the sound of lapping. Like a huge cat with a massive saucer of milk. Was that the sound of a leopard drinking? I was too scared to turn on my torch.
Eventually, in a quiet interlude, I plucked up the courage to move around, turn on a small headlamp and get into bed. My bedroll was tucked under the leaning branch of a tree. Theo said I was less likely to get stepped on by an elephant that way. I could hear rustlings close by, and in the light of my headlamp I saw a tiny mouse and straw-coloured stick insects in the grass around me. I shone a larger torch around but couldn’t see anything moving outside my circle of thorns.
Lying down and turning the headlamp off, I saw a bat flying low over me. He came back again and again, flying just inches from my face, so close I could hear his wings flapping. He was a benign presence. I knew what he was, and I knew what he was up to: hoovering up flying insects from the air. It was the other, rustling, mysterious sounds that gave me goosebumps and brought tears pricking into my eyes. Tucked up in my sleeping bag, I felt incredibly vulnerable. My legs were enclosed, swaddled so that I couldn’t leap up and run away. And I was low, on the ground. I felt very exposed, and I just had to hope that Theo knew his stuff and the thorn branches really were enough to protect me from the wildness all around.
I looked up through the branches of the tree above at the southern stars. Eventually I started to fall asleep, and I welcomed it. I was fatigued by international travel and tired in my bones after going tracking with the hunters. It was good, deep sleep, breathing clean air in the wilderness.
I woke suddenly. It reminded me of being woken, as a child, by cats fighting on the roof. A terrifying sound ripped through the chill night air. A howling, screeching, growling sound. More than one animal.
I lay on my back, absolutely still. I was frightened to the core and my instinct was to lie as still as possible – and listen. My breathing had become halting and heavy, and I made a conscious effort to make my breaths as quiet as possible, while I tried to work out what was going on out there in the darkness. Was it lions? Leopards? Hyenas? The noise went on for what was probably only half a minute, but it echoed in my ears in the silence afterwards. I lay very still, looking
at the stars and questioning the wisdom of this venture. It was a long time before I got back to sleep.
When I next awoke, the sky was a light grey above me. Dawn was approaching fast. I felt so much more courageous now that my eyes worked to reveal my environment. I extricated myself – still moving slowly and as quietly as possible – from the bedroll and stood up to look around. There were rustling noises, but nothing big lurking nearby. The birds had started singing. The darkness and terror and chill of the night were gone. The sky was turning from grey to pink, and I could feel the air around me getting warmer by the minute.
I walked over to Theo and Rob’s camp, and we drank some warmish coffee before heading to the waterhole to check out the evidence of the previous night’s activity. On one trail, there were prints of at least one hyena – a very large female. And there were the wider, shorter paw prints of leopards: a female leopard and her cub. At the waterhole itself there were many muddy, deep prints of hyenas. Theo told me that’s what the awful noise had been: a few hyenas, he thought at least four, squabbling at the waterhole. Close to the water were prints of a – very brave – roan antelope. As we walked back up a trail towards my camp, Theo pointed out more tracks: African wildcat, and the massive paw prints of a big, male leopard – just metres away from where I’d been sleeping.
We’re used to thinking of ourselves as dominant animals. Top of the pecking order. Right at the top of the food chain. Sleeping out in the Namibian bush was a truly frightening, awe-inspiring and humbling experience.
Before I left Nhoma, I talked to Arno about the lodge, the village and what he thought about the future of the Bushmen. Arno and his wife Estelle had set up the camp eight years before, with nine huts, toilets and washing facilities. And the three hundred or so tourists who stayed there each year were also catered for, eating dinners prepared by some of the Bushmen in the large open-sided thatched building. Arno had installed a pump at what had been a semi-permanent waterhole, so that there was water available there for humans and animals throughout the year. This meant that the Bushmen did not have to move around the landscape, following water and animals, and that Nhoma became a permanent village. This wasn’t out of the ordinary; there are very few truly nomadic Bushmen left now. Some had criticised the set-up at Nhoma village for failing to preserve a traditional way of life, and for encouraging the Bushmen to settle down; not only that, tourism provided the Bushmen with an income, enabling them to buy Western clothes and maize-based foods to supplement their bush food. But for Arno it was important that the people had some autonomy, and a choice in their own future. Tourism was allowing, even encouraging, the traditional way of life to continue for a while, but Arno did not think it was sustainable.
‘How much longer do you think the Bushmen will hunt?’ I asked.
‘Oh – maybe fifteen years,’ he replied. ‘There are only eleven hunters left in the whole village. The children go to school and they want other things.’
The Bushmen – and their way of life – had survived for hundreds of years after the incursion of agriculturalists into the area. In most places where foragers come into close contact with food producers, the hunters lose their independence and end up right at the bottom of the social pile.
In the late nineties, archaeologists from Cape Town University excavated at Cho/ana in northern Namibia, with Bushmen as part of the team. They found four levels of archaeology: the first (uppermost) level related to the recent historical period, with occupation by Bushmen, black Africans and Europeans. The archaeologists found items like bottle glass, plastic beads and bullets, as well as local materials like nuts and ostrich eggshell. But they also found stone tools in this top layer which suggested the Bushmen had been making lithics until very recently (even though Lorna Marshall and others had found that the Bushmen had no folk memory of using stone tools). The second level of archaeology contained local materials as well as pottery from Mbukushu people who had moved into the area some three hundred years ago. In the third level, Divuyu pottery indicated that the Bushmen had contact with the farming people of the Tsodilo Hills in modern-day Botswana, going back around 1500 years. Level four, dating to between three and four thousand years ago, contained natural materials and stone tools, but no pottery, so the archaeologists presumed that this layer pre-dated contact with agriculturalists. Based on this evidence, and interviews with Bushmen elders, the archaeologists concluded that the Ju/’hoansi had been independent hunter-gatherers for millennia, and that they had continued with their way of life, while more exotic materials had been incorporated into their culture with increased contact with the outside world.3 But it seemed that this traditional society may now, finally, be in danger of becoming swamped.
In the 1950s ethnographer Lorna Marshall had spent several years with the Bushmen, and in her 1976 book, The !Kung of Nyae Nyae,2 she had written:
I personally wish the !Kung could have remained as they were, remote, self-sustaining, independent, and dignified; but that is wishful thinking. Our modern society does not allow people to remain remote. Furthermore, many of the !Kung themselves want change; they want to have land and cattle like the Bantu.
The Bushmen were not ignorant. They may not have had televisions but they knew there was a wider world out there. I tended to agree with Arno. It was sad in many ways that this way of life was disappearing, but these were people, not museum exhibits – they had to be able to make their own choices. I felt very privileged to have visited Nhoma and learnt about their traditions, and I left wondering if I’d ever go back and, if I did, whether the Bushmen would still be there.
African Genes: Cape Town, South Africa
My first destination in Africa had provided me with insights into life in a contemporary hunter-gatherer culture, and the fragile nature of this way of life in the modern world. I had learnt about the deep roots of Bushmen ancestry and click languages, adaptations to endurance running in humans, and enjoyed an impromptu crash course in African beadwork. Flying from Nhoma to Windhoek to Cape Town, I was in search of more genetic revelations about African ancestry.
On a sunny spring day in Camps Bay, I met up with Professor Raj Ramesar, of the Cape Town University, to find out about the results of an ambitious study of the diversity of mitochondrial DNA among Capetonians.
In 2007, 326 Capetonians had volunteered to have their mtDNA sampled by the African Genome Education Institute, using salivary swabs to collect precious cells containing their genetic fingerprints. Cape Town is a cosmopolitan city. As well as a wide-ranging mix of Africans, people from other continents have also made Cape Town their home over the centuries. It’s a classic melting pot of cultures – and genes.
The results of the Cape Town study bore out that diversity. Everyone taking part in the study was asked what ethnic group they considered themselves to belong to. Of those people who considered themselves either white or coloured, 8 per cent had a maternal ancestry traceable to West Africa. This fits with waves of Bantu-speaking people moving down from the Niger region into southern Africa, bringing agriculture with them, starting around 3000 years ago.1 Among just the ‘white’ people, 3 per cent had black African mtDNA markers, and 10 per cent of black Africans had maternal lineages traceable not to Africa, but to Europe. Twenty per cent of black Africans had markers that went back to some of the earliest Africans: very early branches of the human family tree.
Ten of the original volunteers had assembled on the day I met Raj, and their maternal ancestry could be traced back to lineages originating throughout Africa, Europe and Asia. Firstly, Raj explained that the genetic markers used to construct the lineages actually represented tiny differences in DNA between people. ‘As different as we may look on the outside, we are practically identical at a genetic level,’ said Raj. ‘But the minor differences are what we use to plot population migrations from one part of the world to another.’
Then he revealed the results of the mtDNA tests to the volunteers. Some who felt themselves to be African through and throug
h found they had maternal lineages on Asian and European branches of the tree. Of course, mitochondrial DNA reveals only a small bit of our ancestry: just the ‘motherline’. But nevertheless, there is still something quite profound about being able to trace part of your heritage back that far.
Although mtDNA traces only one line down through the centuries and millennia, among the many ancestors we all gather as we follow our family trees back through time, the study threw up some surprises for the participants involved. The results show quite graphically what a subjective and shifting concept ethnicity is. While similarities and differences between human populations are fascinating, the idea of ‘race’ doesn’t make sense in biology – it’s a concept pulled together from a ragbag selection of physical characteristics, culture and religion and attachment to place of birth. Ultimately though, however much we may feel that we come from a particular place, our genes show that our ancestry is far more diverse – and more interesting.
Rather boringly and predictably, I thought, my mtDNA was of European vintage. I was on the ‘I’ branch. But once I’d got over the lack of exotic genes in my motherline, I have to admit feeling a sense of wonderment at the revelation. Someone had managed to take some minute cells from my mouth, delve into my mitochondrial genome and pull out this fact about my ancestry. I know my family tree only back to my great-grandparents, going back perhaps two hundred years, but here was this piece of information, passed down to me from one of my very ancient female ancestors. It means my maternal ancestry goes back to the second wave of modern humans migrating into Europe around 26,000 years ago.2
On the one hand, we can all trace elements of our ancestry back to a great range of places and times. But the mitochondrial DNA family tree also shows very clearly that, if we go back far enough, all the lineages converge – in Africa. In 1987, three geneticists at the University of California, Rebecca Cann, Mark Stoneking and Allan Wilson, published a seminal paper in Nature, reporting on an analysis of mtDNA from 147 people, and showing how their maternal lineages could be traced back to one woman, in Africa, some 200,000 years ago.3 Since then, mtDNA from thousands and thousands of people has been analysed, and the tree has grown bushier, but the origin has stayed firmly anchored. If you traced your ancestry back far enough, along the ‘motherline’ (your mother’s mother, then her mother… and keep going), then eventually you’d get to a point where you reach a common female ancestor of everyone alive on the planet today. It’s not surprising that the geneticists have named her mitochondrial, or African, Eve.
The Incredible Human Journey Page 5