As one travels south in Africa across the Saharan desert and reencounters rain in the Sahel zone just south of the desert, one notices that Sahel rains fall in the summer rather than in the winter. Even if Fertile Crescent crops adapted to winter rain could somehow have crossed the Sahara, they would have been difficult to grow in the summer-rain Sahel zone. Instead, we find two sets of African crops whose wild ancestors occur just south of the Sahara, and which are adapted to summer rains and less seasonal variation in day length. One set consists of plants whose ancestors are widely distributed from west to east across the Sahel zone and were probably domesticated there. They include, notably, sorghum and pearl millet, which became the staple cereals of much of sub-Saharan Africa. Sorghum proved so valuable that it is now grown in areas with hot, dry climates on all the continents, including in the United States.
The other set consists of plants whose wild ancestors occur in Ethiopia and were probably domesticated there in the highlands. Most are still grown mainly just in Ethiopia and remain unknown to Americans—including Ethiopia’s narcotic chat, its banana-like ensete, its oily noog, its finger millet used to brew its national beer, and its tiny-seeded cereal called teff, used to make its national bread. But every reader addicted to coffee can thank ancient Ethiopian farmers for domesticating the coffee plant. It remained confined to Ethiopia until it caught on in Arabia and then around the world, to sustain today the economies of countries as far-flung as Brazil and Papua New Guinea.
The next-to-last set of African crops arose from wild ancestors in the wet climate of West Africa. Some, including African rice, have remained virtually confined there; others, such as African yams, spread throughout other areas of sub-Saharan Africa; and two, the oil palm and kola nut, reached other continents. West Africans were chewing the caffeine-containing nuts of the latter as a narcotic, long before the Coca-Cola Company enticed first Americans and then the world to drink a beverage originally laced with its extracts.
The last batch of African crops is also adapted to wet climates but provides the biggest surprise of Figure 19.3. Bananas, Asian yams, and taro were already widespread in sub-Saharan Africa in the 1400s, and Asian rice was established on the coast of East Africa. But those crops originated in tropical Southeast Asia. Their presence in Africa would astonish us, if the presence of Indonesian people on Madagascar had not already alerted us to Africa’s prehistoric Asian connection. Did Austronesians sailing from Borneo land on the East African coast, bestow their crops on grateful African farmers, pick up African fishermen, and sail off into the sunrise to colonize Madagascar, leaving no other Austronesian traces in Africa?
The remaining surprise is that all of Africa’s indigenous crops—those of the Sahel, Ethiopia, and West Africa—originated north of the equator. Not a single African crop originated south of it. This already gives us a hint why speakers of Niger-Congo languages, stemming from north of the equator, were able to displace Africa’s equatorial Pygmies and subequatorial Khoisan people. The failure of the Khoisan and Pygmies to develop agriculture was due not to any inadequacy of theirs as farmers but merely to the accident that southern Africa’s wild plants were mostly unsuitable for domestication. Neither Bantu nor white farmers, heirs to thousands of years of farming experience, were subsequently able to develop southern African native plants into food crops.
Africa’s domesticated animal species can be summarized much more quickly than its plants, because there are so few of them. The sole animal that we know for sure was domesticated in Africa, because its wild ancestor is confined there, is a turkeylike bird called the guinea fowl. Wild ancestors of domestic cattle, donkeys, pigs, dogs, and house cats were native to North Africa but also to Southwest Asia, so we can’t yet be certain where they were first domesticated, although the earliest dates currently known for domestic donkeys and house cats favor Egypt. Recent evidence suggests that cattle may have been domesticated independently in North Africa, Southwest Asia, and India, and that all three of those stocks have contributed to modern African cattle breeds. Otherwise, all the remainder of Africa’s domestic mammals must have been domesticated elsewhere and introduced as domesticates to Africa, because their wild ancestors occur only in Eurasia. Africa’s sheep and goats were domesticated in Southwest Asia, its chickens in Southeast Asia, its horses in southern Russia, and its camels probably in Arabia.
The most unexpected feature of this list of African domestic animals is again a negative one. The list includes not a single one of the big wild mammal species for which Africa is famous and which it possesses in such abundance—its zebras and wildebeests, its rhinos and hippos, its giraffes and buffalo. As we’ll see, that reality was as fraught with consequences for African history as was the absence of native domestic plants in subequatorial Africa.
This quick tour through Africa’s food staples suffices to show that some of them traveled a long way from their points of origin, both inside and outside Africa. In Africa as elsewhere in the world, some peoples were much “luckier” than others, in the suites of domesticable wild plant and animal species that they inherited from their environment. By analogy with the engulfing of Aboriginal Australian hunter-gatherers by British colonists fed on wheat and cattle, we have to suspect that some of the “lucky” Africans parlayed their advantage into engulfing their African neighbors. Now, at last, let’s turn to the archaeological record to find out who engulfed whom when.
WHAT CAN ARCHAEOLOGY can tell us about actual dates and places for the rise of farming and herding in Africa? Any reader steeped in the history of Western civilization would be forgiven for assuming that African food production began in ancient Egypt’s Nile Valley, land of the pharaohs and pyramids. After all, Egypt by 3000 B.C. was undoubtedly the site of Africa’s most complex society, and one of the world’s earliest centers of writing. In fact, though, possibly the earliest archaeological evidence for food production in Africa comes instead from the Sahara.
Today, of course, much of the Sahara is so dry that it cannot support even grass. But between about 9000 and 4000 B.C. the Sahara was more humid, held numerous lakes, and teemed with game. In that period, Saharans began to tend cattle and make pottery, then to keep sheep and goats, and they may also have been starting to domesticate sorghum and millet. Saharan pastoralism precedes the earliest known date (5200 B.C.) for the arrival of food production in Egypt, in the form of a full package of Southwest Asian winter crops and livestock. Food production also arose in West Africa and Ethiopia, and by around 2500 B.C. cattle herders had already crossed the modern border from Ethiopia into northern Kenya.
While those conclusions rest on archaeological evidence, there is also an independent method for dating the arrival of domestic plants and animals: by comparing the words for them in modern languages. Comparisons of terms for plants in southern Nigerian languages of the Niger-Congo family show that the words fall into three groups. First are cases in which the word for a particular crop is very similar in all those southern Nigerian languages. Those crops prove to be ones like West African yams, oil palm, and kola nut—plants that were already believed on botanical and other evidence to be native to West Africa and first domesticated there. Since those are the oldest West African crops, all modern southern Nigerian languages inherited the same original set of words for them.
Next come crops whose names are consistent only among the languages falling within a small subgroup of those southern Nigerian languages. Those crops turn out to be ones believed to be of Indonesian origin, such as bananas and Asian yams. Evidently, those crops reached southern Nigeria only after languages began to break up into subgroups, so each subgroup coined or received different names for the new plants, which the modern languages of only that particular subgroup inherited. Last come crop names that aren’t consistent within language groups at all, but instead follow trade routes. These prove to be New World crops like corn and peanuts, which we know were introduced into Africa after the beginnings of transatlantic ship traffic (A.D. 1492) and diffused
since then along trade routes, often bearing their Portuguese or other foreign names.
Thus, even if we possessed no botanical or archaeological evidence whatsoever, we would still be able to deduce from the linguistic evidence alone that native West African crops were domesticated first, that Indonesian crops arrived next, and that finally the European introductions came in. The UCLA historian Christopher Ehret has applied this linguistic approach to determining the sequence in which domestic plants and animals became utilized by the people of each African language family. By a method termed glottochronology, based on calculations of how rapidly words tend to change over historical time, comparative linguistics can even yield estimated dates for domestications or crop arrivals.
Putting together direct archaeological evidence of crops with the more indirect linguistic evidence, we deduce that the people who were domesticating sorghum and millet in the Sahara thousands of years ago spoke languages ancestral to modern Nilo-Saharan languages. Similarly, the people who first domesticated wet-country crops of West Africa spoke languages ancestral to the modern Niger-Congo languages. Finally, speakers of ancestral Afroasiatic languages may have been involved in domesticating the crops native to Ethiopia, and they certainly introduced Fertile Crescent crops to North Africa.
Thus, the evidence derived from plant names in modern African languages permits us to glimpse the existence of three languages being spoken in Africa thousands of years ago: ancestral Nilo-Saharan, ancestral Niger-Congo, and ancestral Afroasiatic. In addition, we can glimpse the existence of ancestral Khoisan from other linguistic evidence, though not that of crop names (because ancestral Khoisan people domesticated no crops). Now surely, since Africa harbors 1,500 languages today, it is big enough to have harbored more than four ancestral languages thousands of years ago. But all those other languages must have disappeared—either because the people speaking them survived but lost their original language, like the Pygmies, or because the people themselves disappeared.
The survival of modern Africa’s four native language families (that is, the four other than the recently arrived Austronesian language of Madagascar) isn’t due to the intrinsic superiority of those languages as vehicles for communication. Instead, it must be attributed to a historical accident: ancestral speakers of Nilo-Saharan, Niger-Congo, and Afroasiatic happened to be living at the right place and time to acquire domestic plants and animals, which let them multiply and either replace other peoples or impose their language. The few modern Khoisan speakers survived mainly because of their isolation in areas of southern Africa unsuitable for Bantu farming.
BEFORE WE TRACE Khoisan survival beyond the Bantu tide, let’s see what archaeology tells us about Africa’s other great prehistoric population movement—the Austronesian colonization of Madagascar. Archaeologists exploring Madagascar have now proved that Austronesians had arrived at least by A.D. 800, possibly as early as A.D. 300. There the Austronesians encountered (and proceeded to exterminate) a strange world of living animals as distinctive as if they had come from another planet, because those animals had evolved on Madagascar during its long isolation. They included giant elephant birds, primitive primates called lemurs as big as gorillas, and pygmy hippos. Archaeological excavations of the earliest human settlements on Madagascar yield remains of iron tools, livestock, and crops, so the colonists were not just a small canoeload of fishermen blown off course; they formed a full-fledged expedition. How did that prehistoric 4,000-mile expedition come about?
One hint is in an ancient book of sailors’ directions, the Periplus of the Erythrean Sea, written by an anonymous merchant living in Egypt around A.D. 100. The merchant describes an already thriving sea trade connecting India and Egypt with the coast of East Africa. With the spread of Islam after A.D. 800, Indian Ocean trade becomes well documented archaeologically by copious quantities of Mideastern (and occasionally even Chinese!) products such as pottery, glass, and porcelain in East African coastal settlements. The traders waited for favorable winds to let them cross the Indian Ocean directly between East Africa and India. When the Portuguese navigator Vasco da Gama became the first European to sail around the southern cape of Africa and reached the Kenya coast in 1498, he encountered Swahili trading settlements and picked up a pilot who guided him on that direct route to India.
But there was an equally vigorous sea trade from India eastward, between India and Indonesia. Perhaps the Austronesian colonists of Madagascar reached India from Indonesia by that eastern trade route and then fell in with the westward trade route to East Africa, where they joined with Africans and discovered Madagascar. That union of Austronesians and East Africans lives on today in Madagascar’s basically Austronesian language, which contains loan words from coastal Kenyan Bantu languages. But there are no corresponding Austronesian loan words in Kenyan languages, and other traces of Austronesians are very thin on the ground in East Africa: mainly just Africa’s possible legacy of Indonesian musical instruments (xylophones and zithers) and, of course, the Austronesian crops that became so important in African agriculture. Hence one wonders whether Austronesians, instead of taking the easier route to Madagascar via India and East Africa, somehow (incredibly) sailed straight across the Indian Ocean, discovered Madagascar, and only later got plugged into East African trade routes. Thus, some mystery remains about Africa’s most surprising fact of human geography.
WHAT CAN ARCHAEOLOGY tell us about the other great population movement in recent African prehistory—the Bantu expansion? We saw from the twin evidence of modern peoples and their languages that sub-Saharan Africa was not always a black continent, as we think of it today. Instead, this evidence suggested that Pygmies had once been widespread in the rain forest of Central Africa, while Khoisan peoples had been widespread in drier parts of subequatorial Africa. Can archaeology test those assumptions?
In the case of the Pygmies, the answer is “not yet,” merely because archaeologists have yet to discover ancient human skeletons from the Central African forests. For the Khoisan, the answer is “yes.” In Zambia, to the north of the modern Khoisan range, archaeologists have found skulls of people possibly resembling the modern Khoisan, as well as stone tools resembling those that Khoisan peoples were still making in southern Africa at the time Europeans arrived.
As for how the Bantu came to replace those northern Khoisan, archaeological and linguistic evidence suggest that the expansion of ancestral Bantu farmers from West Africa’s inland savanna south into its wetter coastal forest may have begun as early as 3000 B.C. (Figure 19.4). Words still widespread in all Bantu languages show that, already then, the Bantu had cattle and wet-climate crops such as yams, but that they lacked metal and were still engaged in much fishing, hunting, and gathering. They even lost their cattle to disease borne by tsetse flies in the forest. As they spread into the Congo Basin’s equatorial forest zone, cleared gardens, and increased in numbers, they began to engulf the Pygmy hunter-gatherers and compress them into the forest itself.
By soon after 1000 B.C. the Bantu had emerged from the eastern side of the forest into the more open country of East Africa’s Rift Valley and Great Lakes. Here they encountered a melting pot of Afroasiatic and Nilo-Saharan farmers and herders growing millet and sorghum and raising livestock in drier areas, along with Khoisan hunter-gatherers. Thanks to their wet-climate crops inherited from their West African homeland, the Bantu were able to farm in wet areas of East Africa unsuitable for all those previous occupants. By the last centuries B.C. the advancing Bantu had reached the East African coast.
In East Africa the Bantu began to acquire millet and sorghum (along with the Nilo-Saharan names for those crops), and to reacquire cattle, from their Nilo-Saharan and Afroasiatic neighbors. They also acquired iron, which had just begun to be smelted in Africa’s Sahel zone. The origins of ironworking in sub-Saharan Africa soon after 1000 B.C. are still unclear. That early date is suspiciously close to dates for the arrival of Near Eastern ironworking techniques in Carthage, on the North African coast. He
nce historians often assume that knowledge of metallurgy reached sub-Saharan Africa from the north. On the other hand, copper smelting had been going on in the West African Sahara and Sahel since at least 2000 B.C. That could have been the precursor to an independent African discovery of iron metallurgy. Strengthening that hypothesis, the iron-smelting techniques of smiths in sub-Saharan Africa were so different from those of the Mediterranean as to suggest independent development: African smiths discovered how to produce high temperatures in their village furnaces and manufacture steel over 2,000 years before the Bessemer furnaces of 19th-century Europe and America.
With the addition of iron tools to their wet-climate crops, the Bantu had finally put together a military-industrial package that was unstoppable in the subequatorial Africa of the time. In East Africa they still had to compete against numerous Nilo-Saharan and Afroasiatic Iron Age farmers. But to the south lay 2,000 miles of country thinly occupied by Khoisan hunter-gatherers, lacking iron and crops. Within a few centuries, in one of the swiftest colonizing advances of recent prehistory, Bantu farmers had swept all the way to Natal, on the east coast of what is now South Africa.
It’s easy to oversimplify what was undoubtedly a rapid and dramatic expansion, and to picture all Khoisan in the way being trampled by onrushing Bantu hordes. In reality, things were more complicated. Khoisan peoples of southern Africa had already acquired sheep and cattle a few centuries ahead of the Bantu advance. The first Bantu pioneers probably were few in number, selected wet-forest areas suitable for their yam agriculture, and leapfrogged over drier areas, which they left to Khoisan herders and hunter-gatherers. Trading and marriage relationships were undoubtedly established between those Khoisan and the Bantu farmers, each occupying different adjacent habitats, just as Pygmy hunter-gatherers and Bantu farmers still do today in equatorial Africa. Only gradually, as the Bantu multiplied and incorporated cattle and dry-climate cereals into their economy, did they fill in the leapfrogged areas. But the eventual result was still the same: Bantu farmers occupying most of the former Khoisan realm; the legacy of those former Khoisan inhabitants reduced to clicks in scattered non-Khoisan languages, as well as buried skulls and stone tools waiting for archaeologists to discover; and the Khoisan-like appearance of some southern African Bantu peoples.
Guns, Germs, and Steel Page 45