More than 2 million years ago, a mutation reduced the power of chewing muscles in human ancestors. This could indicate that they were preparing their food more, but perhaps also making more controlled use of their mouth. Expanded nerve outlets appeared in the thoracic vertebrae Homo erectuswhich indicates the millisecond control of breathing necessary for speech.
And later, 400,000 years ago Homo heidelbergensis the remains found in Atapuerca, in northern Spain, had perfectly preserved ear canals tuned to the frequencies used in human speech. Since these Atapuerca hominins were likely ancestors of Neanderthals, there is a good chance that at least a simple form of language was widespread in this period, if not earlier.
Paintings first appeared, or were preserved, about 50,000 years ago, but beads and ornaments can be traced back to much earlier. The oldest so far are shell beads from the Es-Skhul Cave on Mount Carmel in Israel, dating back around 130,000 years. They mark personal identity, and hence the idea that one person can appreciate these signals in another. Shell beads were found again at Blombos in South Africa around 70,000 years ago, along with a piece of engraved ocher.
The burials are of similar antiquity: both Neanderthal and early modern burials date back to around 130,000 years ago, although older finds such as numerous human remains in a cave at Atapuerca, or cut marks on a skull Bodo in Ethiopia, may indicate that a special interest in the human body already existed. The burials suggest that early humans had a strong sense of the needs of others.
Some burials, both early modern and Neanderthal, had red ocher smeared on the bodies. It is likely that this had a symbolic meaning. “Symbolism” has played a crucial role in all modern human behavior, underpinning language, religion, and art. However, studying their origins presents pitfalls, because other animals seem capable of using symbols, as when one chimpanzee offers another a cut leaf.
The line between such “signs” and symbols is easily blurred. But the projection of symbols into the outside world in the form of material objects is a measurable step, as long as they survive. The pearls and burials are among the earliest evidence of behavior that may, in fact, have much deeper origins.
The great explosion (100,000 years ago)
More than 100,000 years ago, the first modern humans began to expand out of Africa, resulting in the largest diaspora in human history. Variation in modern human DNA preserves geographic cues that tell us something about past population movements. Even better, fossil DNA can be isolated from bone samples dating back up to about 50,000 years in cold climates, and sometimes even older.
The findings confirm that Neanderthals were a truly separate species, with their ancestors separating from ours between 500,000 and 700,000 years ago, and living until about 40,000 years ago.