The archetypal African village - a scatter of thatched huts among the dry grass and stunted flatthorns, women rhythmically pounding maize, a few tethered goats. It seems a timeless picture, at once intimately local and extremely ancient.

However nothing in Africa is ever that simple. Since the dawn of man the land has seen endless migrations. Peoples' origins are often startlingly unexpected, both in terms of the distances travelled and the timescales involved. It is easy in South Africa's Cape Province to spot those of European descent, less obvious that their local roots go back over three centuries. The Xhosa, who seem so much more authentically native, are more recent arrivals, while the true earliest inhabitants, the San hunter-gatherers, have all but vanished. Nowadays their descendants huddle in tiny beleaguered communities in Botswana and Namibia, evident refugees from European settlement further south. Yet some argue that they arrived there not from the Cape but from the Zambezi basin, some 2000 years ago. Others date their presence in the Kalahari at anything up to 100,000 years.

Such uncertainties exist everywhere. Now history (oral and written), archaeology, genetics and linguistics are combining to produce remarkable new insights, not least into the great migrations that have shaped modern Africa.

Of these, the most spectacular is that of the Bantu. Descendants of cattle-farmers of the once-fertile Sahara, they spilled out of their heartlands east of Nigeria in the first century bc to overrun almost the entire continent to the south. Essentially farmers (with advanced iron-making skills), they were forced ever onward by the inhospitable terrain. Moving through scattered groups of Pygmoids and Khoi-San hunter-gatherers, some took a western coastal route, a second wave passed through the Congo into the Zambezi area, while a third travelled eastwards into Kenya and the surrounding lands, then on down until they reached South Africa. There, further local migrations continued until, in the 19th century, descendants of all three original branches finally met in Zambia and Zimbabwe. Hence, in those countries, the wide range of ‘tribal' groupings beneath what outsiders might see as complete racial uniformity.

In the north and north-east the picture is no less fluid. Somewhere between 7000bc and 3500bc Caucasian agriculturalists from Arabia began to populate first Egypt and, rather later, Ethiopia and Eritrea. Ancient Christian and Jewish communities persist there to this day. In the seventh century Arab armies fought their way along the Mediterranean coast as far as the Atlantic. Their legacy is diffused across vast swathes of the north, in the Islamic faith and customs, the Arabic language, still-functioning trade routes and such splendours as Djenne and Timbuktu. They were followed in the 11th century by the Bedouins. Between these waves of settlement, a procession of Greek, Phoenician and Roman empires came and went. Stoically enduring all, the Berbers' way of life has changed little in five millennia.

Genetically, Africa is by far the most diversified continent. This is because, in human terms, it is the oldest. It is also a splendidly rich mixture of indigenes and arrivals, both recent and ancient - from the Near East, from Europe, India, Malaya, even Indonesia (the source of such typical ‘African' foods as the plantain and the banana). Everywhere, surprises abound. In central Zimbabwe, indistinguishable in appearance from their Bantu neighbours, live the Lemba, who have always claimed to be Jews. Last year, to everyone's amazement, they were vindicated. Their priestly clan names point to a Yemeni origin; the priests themselves carry the distinctive Cohen genetic marker. From the Cape to Cairo, such ‘anomalies' make up the rich pageant of African life.