Deadly Harvest: The Intimate Relationship Between Our Heath and Our Food (3 page)

This map of the world shows the broad migration pattern of our human ancestors as they overflowed out of their ‘Human Homeland’ in east Africa. Note that we are just showing the overall pattern and timings, not the detailed wanderings and itineraries. The earliest waves of migrants, 60,000 years ago, hugged the coastlines of India and Indonesia to arrive in Australia. Later migrants arrived in Asia and in Europe. Finally humans crossed from Asia to North America and penetrated all the way down to the southern tip of South America. Meanwhile, other groups had already spread into the other parts of Africa itself. We show the location of one of these groups, the San Bushman, whom we talk about in some detail later in this chapter. We also show an area known as the Fertile Crescent, which we discuss in Chapter 2.

We can now piece together what happened. Over a period of a million years, successive waves of humanlike creatures overflowed out of Africa to populate most of the Old World. They had brains about half the size of ours, but walked upright and had many humanlike traits. They have been broadly called
Homo erectus
, of which the Neanderthals were just one branch. Then, about 250,000 years ago, a radical thing happened: a new breed of
Homo erectus
arose in East Africa, our own ancestor,
Homo sapiens
.

Homo sapiens
were brainier, more agile, more inventive, but more lightly built than
Homo erectus
. They were successful in their ability to survive and to multiply. However, to feed themselves, they needed around 100 square miles of living space per band of 50 people. So, in their turn, about 60,000 years ago, they overflowed out of Africa into Asia.

The Human Timeline

We have our humanlike beginnings with East African
Homo erectus
over 1,000,000 years ago. Out of that population,
Homo sapiens
arose and existed for 190,000 years before leaving Africa about 60,000 years ago. This period, from over 1,000,000 years ago to 60,000 years ago is critical—it is our
formative era
. It is the time when the African environment forged the bodies that we possess today and when the “Owner’s Manual” was written.

I will refer to this formative era frequently throughout the book, so I will give it a specific name. Geologists have a convenient, often-used epoch for this approximate time period—the Pleistocene, which runs from 1,600,000 years ago to 10,000 years ago. However, I want to conclude the formative era earlier, at about 60,000 years ago. Since our ancestors spent this time entirely in Africa, I will call this critical formative era the “
African Pleistocene
.”

Homo sapiens
spread further than
Homo erectus
. They migrated along the coastlines of India and Indonesia and got to Australia approximately 50,000 years ago. That continent was empty of humans at that time. Within 2,000 years, they occupied every corner of it, from the harsh Central Desert to the lush tropical rainforests. These are the ancestors of the Australian Aboriginals.

On the one hand, those areas that are rich in game and vegetation could support a relatively dense population of up to 50 people per 25 square miles. On the other hand, the early European settlers thought, wrongly, that the deserts and ‘outback’ were empty. But even they were populated, but at lower densities—down as far as 50 people per 300 square miles.

The total Aboriginal population of the Australian continent (about the same area as the continental United States) stabilized at around 800,000 people. The population density is said to have reached “saturation.” These densities are, of course, much lower than we are used to seeing in the industrialized West today. The U.S. supports 280 million people, an average density of 50 people on only 480 acres, or three-quarters of a square mile.

About 35,000 years ago,
Homo sapiens
was knocking at the doors of Europe. Here they found themselves in stiff competition with the Neanderthals. John Kappelman, an anthropologist who has written about the biology of ancient, humanlike creatures, reports that the Neanderthals were massive, at least 30% larger than the ordinary human today.
⁴
They had the heavily muscled body and stature of an Olympic wrestler and weighed up to 200 pounds (91 kg). On the other hand, their brains were somewhat smaller than modern man’s is today.

We will never know exactly what happened to the Neanderthals. However, every human male was a potent “Jack-the-Giant-Killer:” he was smarter, wilier, and more organized than the more powerful, yet dim-witted, giant of the forest. Over several thousand years, it is probable that he killed them all off. That is what happens when too-similar species compete for the same living space.

By 30,000 years ago, the Neanderthals had gone and the
Homo sapiens
newcomers had introduced their own, developing culture. This explains the quantum leap in art and technology of the time. These new people were the Cro-Magnons, the ancestors of Europeans. Meanwhile, in the Middle East, India, China, and Siberia, other
Homo sapiens
similar to the Cro-Magnons drove all the other branches of
Homo erectus
into extinction. By 20,000 years ago, humans had fanned out over the whole of the Old World.

About 15,000 years ago, toward the end of the last ice age, sea levels were still low and it was possible to canoe or walk from Siberia, across the Bering Strait to what is now Alaska. Finally, the first few humans broke out of the Old World and penetrated into the Americas. There they found a New World rich in plants and game, empty of humans, and free of competition, and they prospered well.

As they multiplied, their frontier advanced south. The swelling population spread, at an average rate of 8 miles per year, through territories that now include Canada, the United States, Mexico, and Central and South America, right down to Patagonia. By about 10,000 years ago, the Americas were peopled ‘to saturation’ for their ancestral lifestyle. We must remember that ‘saturation’ is still a very low density by modern standards: an average of 100 square miles of living space per band of 50 people. These first, pioneering peoples became the indigenous Indian tribes or “Amerindians.”

How Long is a Human Generation?

A human generation can only be approximated and we have to work with averages. In the past, female
Homo sapiens
were child-bearing from the age of about 15 to about 35 years. Thus,
on average,
people were born to mothers who were 25 years old (halfway between 15 and 35). The rough-and-ready length of a generation is therefore taken as 25 years.

We look a little different on the outside, of course. Over the last 2,400 generations, superficial racial differences have evolved, but underneath we are all still the same. We all have a common recent origin. In other words, everyone on this planet still inhabits a body designed for life in our ancestral homeland, the tropical, east African savanna. The DNA evidence is a ringing endorsement of the Leakeys’ fossil evidence. The cradle of mankind is in the African Rift Valley stretching from Olduvai in northern Tanzania, all the way through Kenya to Lake Turkana in southern Ethiopia.

What was Our Homeland Like?

What was this overflowing pot, our homeland or Garden of Eden, like? This environment and lifestyle shaped our natures, our bodies, and our biology. Let us look at a snapshot of this place.

If we conjure up a picture of the African savanna landscape, it is the classic image of open, rolling grassland with the occasional tree, bush, and shrub. In the wetter areas, there are thickets and groves of beautiful flowering shrubs and trees. In parts, termite mounds stand up to 25 feet (8 meters) high. The floor of the African Rift Valley is not very high above sea level, but there are nearby plateaus; some mountains rise to over 10,000 feet (3,000 meters). There are several large, and many small, lakes, many waterholes, and some streams and rivers. Many of the watercourses are dry for most of the year, but flood during the rains.

The weather fluctuates between mild and hot for most parts of the year, about 55ºF to 90ºF (13ºC to 32ºC).
There are rainy and dry seasons. Annual rainfall is moderate: between 35 inches (900 mm) and 60 inches (1,500 mm), and the rain comes in unpredictable storms and showers.

Our ancestors were not alone in the savanna. They shared the land with a wide variety of creatures: giraffe, lion, elephant, warthog, rhinoceros, hyena, antelope, gazelle, zebra, baboons, chimpanzees, vultures, eagles, flamingos, and many more. In addition, there were snakes, porcupines, crocodiles, lizards, tortoises, snails, grasshoppers, and a myriad of small mammals, reptiles, and insects. The lakes, streams, and waterholes teemed with many species of freshwater fish, shellfish, frogs, toads, ducks, geese, and other aquatic creatures.

Our ancient ancestors lived for countless generations in these circumstances. This environment fashioned our bodies, our naturally adapted lifestyle, and our mentality. With this sketch of it in mind, we can discover how nature designed us to live in this environment. In particular, we will focus on the kind of eating pattern that is right for us.

THE SAN BUSHMEN

How did our human ancestors make use of this environment? We can learn a great deal by examining how primal tribes live today. However, there are allowances to be made: such tribes have been pushed into more marginal lands, and sometimes modern materials filter in from the outside world. Nevertheless, working from studies carried out over the past 150 years, we can piece together a good, solid picture of our ancestors. As our main illustration, we will look at the San Bushmen who live in southern Africa.

The San Bushmen (more correctly called by their own name, the !Kung) at one time occupied a large part of southern Africa. Negroid Bantu herders (Zulus and Xhosa) migrating from West Africa have pushed them into a smaller, remote area—the Kalahari—over the past 600 years. The Kalahari is a sandy wilderness, well covered with trees, scrub, vines, creepers, and grasses. The sand drains the rainfall fast, so there is little surface water, just scattered waterholes. Animal life is varied, and many species such as antelope, lion, giraffe, zebra, and elephant thrive there. It is very like our ancestral homeland, but without the streams and lakes.

The San are short, slender, and fine-featured with a reddish-yellow skin. Laurens van der Post describes the color as “Provençal apricot.”
⁵
The San have tightly coiled, peppercorn colored, and woolly hair. Their noses are broad, and they have pointy ears with no lobes. They have high cheekbones and somewhat Mongoloid eyes.

The Italian geneticist Ornella Semino and others have shown that the San are southern Africa’s most ancient inhabitants.
⁶
In 60,000 years, they have migrated only 1,500 miles from humanity’s homeland in the African Rift Valley. Anthropologists have studied the San extensively since the 1950s and found the San living the same way that our ancestors have since the dawn of time.

The San live in groups of 40 to 60 people (about 6 to 10 families). A typical group (or band) has about 15–20 men, 15–20 women, and a further 15–20 dependent children. The group “owns” their territory of some 125 square miles (320 km
²
) within which they roam. They camp for a few days in a place and then move on. In the space of six months, one band was recorded by the ethnic archaeologist John Yellen, as having moved 37 times, an average of once every five days.
⁷
When they have exhausted the food supply of the area, they travel to the next site, which can be up to 20 miles away.

The San wear no clothes. They do not have any possessions beyond what is easily portable and can be carried long distances. Babes-in-arms are carried by their mothers, but everyone else has to walk. They carefully choose the next campsite for the availability of plant and animal food. Sometimes the whole group will move to the place where the men have killed a large animal and then stay until the meat is all gone. Game animals that come to waterholes are a rich source of food. To avoid frightening them away, and in spite of the inconvenience, they camp at least a quarter mile away from a waterhole.

How the San Feed Themselves

What use do the San make of their feeding environment? The Japanese anthropologist Jiro Tanaka and others have lived among the San and monitored their lifestyle for years at a time.
⁸
The only “work” to be done by the band is the daily quest for food. The roles adopted by each member of the band are natural and instinctive.