Portrait of the Human as a Young Hominin
The swifts arrive with thunder at their backs. Winter birds, they appear, loudly, and in great numbers, pursuing the emerging insect swarms just as the wet season begins after more than four months without rain. The arrival of the migratory birds marks the return of fertility and life, the continuation of a seasonal pattern that will last for millions of years to come.
The birds barrel through the mountain air of the East African highlands that will one day be part of Kenya and Ethiopia. The rise of these highlands, along with that of the Tibetan plateau thousands of miles away, has diverted the winds that once watered northwestern Africa, changing the patterns of rainfall across the region, and beginning the slow decline of the Sahara and Sahel into desert.
In Kanapoi, an area in what is now northwestern Kenya, Lake Lonyumun is spread wide and shallow, well over 300 kilometers from north to south and some 100 kilometers wide. It fills a vast crack in the continent, the East African Rift. It is fed by rivers that carve through a base of laminated claystones, dense assemblages of mollusk shells, and thick, solidified sandbars, precursors to rivers that will still exist in the modern day—the Omo, the Turkwel, and the wide and gentle Kerio.
The rain brings creatures, the wild ancestor of the domestic cat.
