expansion, which gradually spread West Afri- lier back-migrations into the continent and of children buried inside a rock shelter in It was not a streamlined process of australopiths in Africa that we haven’t really appreciated can farming practices across the continent eventually carried to the southernmost tip of Cameroon.15 Comparing the 3,000- and steadily evolving into modern , but a very much yet,” Prendergast says. between roughly 5,000 and 1,000 years ago. Africa as other migrating populations 8,000-year-old DNA with ancient genomes Only time will tell whether researchers’ By comparing DNA from ancient hunter- moved southward, the researchers found. collected elsewhere and with genomes of messy and haphazard journey that includes current arsenal of technologies is enough to gatherer remains in southern Africa with Such studies have also provided insight modern people allowed the researchers to interwoven ancestries of many groups. untangle the complete story of human evo- modern-day Khoe-San people, evolutionary into deep divergences that occurred in reconstruct some of the earliest branches lution. Perhaps novel technologies—such as biologist Carina Schlebusch of Uppsala Uni- human populations long before migrations of our species’ evolutionary tree. In addi- paleoproteomics, a nascent field that aims to versity in Sweden and her colleagues found of farmers and herders. Mary Prendergast, tion to the deep split between Khoe-San reconstruct ancestry from fossilized proteins, that some Khoe-San groups carry DNA that an anthropologist at Saint Louis Univer- groups and other African populations— one another more than 200,000 years ago. “ghost” lineage whose fate is uncertain. which are more durable than DNA—will help ancient farmers brought with them.14 They sity in Madrid, and her colleagues recently from which non-Africans also descend— One lineage is ancestral to central African “There’s all this deep, deep population struc- researchers “push further back in time,” notes also carry mixed Eurasian ancestry that had sequenced the first ancient DNA from West their model suggested that two other major hunter-gatherers known as Aka and Mbuti, ture with various differentiated branches of biological anthropologist Rebecca Acker-

been introduced to North Africa with ear- Africa, material extracted from the remains lineages split just as deeply, diverging from GIORGIOMORARA © ISTOCK.COM, and the second is a previously unknown the human tree throughout the Pleistocene mann of the University of Cape Town.

Comparing ancient DNA from and with modern human genomes has revealed that modern humans interbred OUR HISTORY IN AFRICA with these other hominin groups. Hominin fossils that reveal clues to the emergence of sapiens are rare in Africa, but in combination with studies of modern human genomes, researchers are piecing together an ever more complex timeline of human history.

DENISOVANS Denisovans, only known from from ancient DNA and a handful of bones and teeth, were closely related to Neanderthals.

HOMO HEIDELBERGENSIS Named after its initial discovery near Heidelberg, Genomic analyses suggest that the Germany, fossils similar to majority of people living outside Africa HOMO NEANDERTHALENSIS were later found to also occur in Africa. It routinely Compared with modern humans, hunted large and may have built dwellings today trace most of their ancestry back HOMO SAPIENS Neanderthals had shorter, stockier made of wood or rock. to a single migration event of a small Eventually, the hallmarks of our skeletons and larger noses, but their own species—exceptionally large group of modern humans who left Africa brains were just as large, if not larger. brains, flat faces, and small jaws— between 60,000 and 70,000 years ago. appear in the fossil record. Genetic Homo erectus may have been the first studies suggest that H. sapiens hominin to wield fire and stone axes. started to split into several major *Note that the scale of this graphic changes across its width. While Homo sapiens has The species spread across Asia, where it lineages of modern humans more existed for the past few hundred thousand years, it’s noteworthy that Homo erectus, continued to evolve. In Africa, it gave rise than 200,000 years ago. living from around 2 mya to perhaps 100 kya, is still the longest-lived hominin species. to Homo heidelbergensis.

EARLY HOMO SPECIES Hominins of the genus Homo shared distinctly small back teeth, which experts think allowed them to consume diverse diets. One species of early Homo evolved Only known from skeletons found in South Africa, into Homo erectus. this species had a remarkably tiny brain but SPP. modern-human–like features such as the shape of This diverse group exhibited both its teeth and possibly the habit of burying its dead. , , ape- and human-like characteristics. SPP. Some species are thought to Members of these relatively small-brained have used stone tools and to have genera probably emerged not long after evolved into the genus Homo. the human-chimpanzee divergence, and AND HOMO LUZONENSIS are the first known species of apes that Researchers have recently discovered two small hominin habitually walked upright. species on Pacific islands, Homo floresiensis on Flores in Indonesia and Homo luzonensis in the . Some analyses of modern human genomes hint that Homo sapiens may have interbred with other hominins in Africa.

7 mya 6 5 4 3 2 1 mya 500 kya 100 kya 50 kya Present