types of grave goods.
Evidence from one 50,000-year-old Neanderthal site in Spain has yielded intriguing suggestions about some aspects of gender and family relations. Here 12 individuals of various ages appear to have been killed and eaten by another group, during a period – judging by the tooth enamel of the victims – of food scarcity. DNA evidence shows that these 12 individuals were related, and that the adult males were more closely related than the females. Thus the men had most likely stayed with their birth family, while the women had come from other families, a pattern that would be replicated later among homo sapiens of many eras and places. Two of the children were offspring of the same woman, and were about three years apart in age; this birth interval, perhaps the result of long breastfeeding, is also something that would be replicated among many later foragers. Extrapolating from a single site to all of Neanderthal society is dangerous, but this provides a glimpse of Neanderthal social relationships, both hostile and caring.
What archaeologists term anatomically modern humans (AMHs or homo sapiens) spread from Africa into areas in Europe and Western Asia where Neanderthals lived, and the two groups lived side by side for millennia, hunting the same types of animals and gathering the same types of plants. Eventually Neanderthals became extinct, killed by humans or diseases they had brought in, or simply losing out in a competition for food as the climate worsened in a period of increasing glaciation that began around 40,000 years ago. Neanderthals and homo sapiens also had sex with one another, at least sometimes, for between 1.5 and 2.1 percent of the DNA in humans living today outside of sub-Saharan Africa comes from Neanderthals. Since 2010, genetic studies of Neanderthals have taken off. Scientists have found, for example, that the exchange of genes between Neanderthals and AMHs provided resistance to some viruses, but also increased the genetic risk to others, including COVID-19. They have also found sex-based differences. Neanderthal-derived DNA does not include the mitochondrial DNA passed from mother to child, which means that the children who passed on their genes came from Neanderthal males and AMH females. This does not mean that there was no sex involving Neanderthal females and AMH males, but simply that this did not produce offspring that survived. Similarly, no modern man to date has been found with a Neanderthal Y chromosome, which suggests that the male offspring of Neanderthal males and AMH females were not viable. Genetic research is also beginning to include various other recently discovered extinct members of the homo genus, such as the Denisovans, who also interbred with homo sapiens. All of this indicates that the human evolutionary path is more complex and multibranched than we used to recognize, more of a bush than a tree.
Homo Sapiens
Archaeologists distinguish anatomically modern humans (homo sapiens) from other members of the genus homo by a number of anatomical features, most notably a relatively slender build, a head with a large cranium (and forebrain) with a face tucked underneath it, small teeth and jaws, and a larynx situated lower in the throat. The earliest fossilized remains showing these features come from Ethiopia, and have been most recently dated as about 195,000 and 160,000 years old. What archaeologists term “behavioral modernity” developed after anatomical modernity, though whether this was gradual or the result of a sudden “cognitive revolution” about 50,000 years ago is hotly disputed. Behavioral modernity includes long-range planning, development of new technologies such as the bow and arrow, the wide use of symbols in burials and personal adornment, more complex speech, and broad networks of social and economic exchange.
Some scholars see the development of cognition and brain complexity as a social and cultural as well as a physical process. Some of this operated at the individual level: individuals who had better social skills were more likely to mate than those who did not – this has been observed in chimpanzees and, of course, in humans from more recent periods – and thus to pass on their genetic material, creating what biologists term “selective pressure” that favored the more socially adept. For humans, being socially adept includes being able to understand the motivations of others – that is, recognizing that they have internal lives that drive their actions. Such social skills were particularly important for females: because the period when human infants are dependent on others is so long, mothers with good social networks to assist them were more likely to have infants who survived. Cooperative child rearing required social skills and adaptability, and may itself have been an impetus to increasing complexity in the brain. Selective pressure may have also operated in the realm of language. As we know from contemporary research on the brain, learning language promotes the development of specific areas of the brain. Neurological research thus supports the argument of paleolinguists that gradually increasing complexity in language led to more complex thought processes, as well as the other way around.
Some of these social and cultural factors operated at the group level: as it developed, speech and other forms of communication allowed for stronger networks of cooperation among kin groups and the formation of larger social groupings. Family bands that were more socially adept had more contacts with other bands, and developed patterns of exchange over longer distances, which, as with trade in later periods, gave them access to a wider range of products and ways of using them and thus greater flexibility to meet any challenges to survival, including dramatic changes in climate. This was also the case with less utilitarian products, such as pigments and beads, which might have stimulated better forms of communication and higher levels of creativity as well as reflecting them. As Marcia-Anne Dobres and others have pointed out, new technologies and ways of using them were (and are) not simply invented to solve problems or address material needs, but also to foster social activities, convey world views, gain prestige, and express the makers’ ideas and sense of identity.
However and whenever behaviorally modern humans emerged, they did what homo ergaster did before them and what humans have done ever since: moved. First across Africa, and then into Eurasia, initially sporadically and then more regularly. They used rafts or boats to reach what is now Australia by at least 50,000 years ago and perhaps earlier, which required traveling across nearly 40 miles of ocean. During the last ice age, when much of the world’s water was in glaciers, a wide land bridge connected Northeast Asia and North America across what is now the Bering Strait. Humans moved to this area, Beringia, 20–25,000 years ago, and then stopped. New DNA analysis indicates that a human population lived in genetic isolation here for 5,000 years or so, and then some continued on to North America and others migrated back to Eastern Asia. Those in the Americas moved quickly, because by 15,000 years ago humans were already in southern South America, 10,000 miles from Beringia. Some scholars think that people came to the Americas much earlier, using rafts or boats along the coasts, but finding evidence for this is extremely difficult because ancient coastlines were submerged with the final melting of the glaciers between 15,000 and 10,000 years ago. Rising seas did not end migration, however, as humans responded by building boats, sailing to increasingly remote islands, including those in the Pacific, the last parts of the globe to be settled.
Eventually human cultures became widely diverse, but in the Paleolithic period people throughout the world lived in ways that were similar to one another, in small groups of related individuals – what anthropologists often refer to as “bands” – who moved through the landscape in search of food. Paleolithic peoples have often been called hunter-gatherers, but recent archaeological and anthropological research indicates that both historical and contemporary hunter-gatherers have depended much more on gathered foods than on hunted meat. Thus it would be more accurate to call them gatherer-hunters, and most scholars now call them foragers, a term that highlights the flexibility and adaptability in their search for food. Most of what foragers ate were plants, and although they did hunt large game, much of the animal protein in their diet came from foods scavenged or gathered, such as animals killed by other predators, insects, shellfish, small animals caught in traps, and fish and other sea creatures caught in weirs and nets. Paleolithic knotted and woven nets and baskets disintegrated long ago, but evidence of of them survives as impressions on fired clay fragments of storage containers from around 30,000 years ago, and knotting is probably much older than that.
Most foraging societies that exist today or did so until recently have some type of division of labor by sex, and also by age, with children and older people responsible for different tasks than adult men and women. Men are more often responsible for hunting, through which they gain prestige as well as meat, and women for gathering plant