ation 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 fanners, 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 HOWAFRICA BECAME BLACK • 389 hint why speakers of Niger-Congo languages, stemming from north of the equator, were able to displace Africa's equatorial Pygmies and subequato-rial 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 subequato-rial 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 colo- 390* GUNS, GERMS, AND STEEL nists 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, Sahar-ans 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 HOWAFRICA BECAME BLACK • 391 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
