Cro-Magnon

Cro-Magnons were the first humans (genus Homo) to have a prominent chin. The brain capacity was about 1,600 cc (100 cubic inches), somewhat larger than the average for modern humans. It is thought that Cro-Magnons were probably fairly tall compared with other early human species.

Description[]

Cro-Magnons were robustly built and powerful and are presumed to have been about 166 to 171 cm (about 5 feet 5 inches to 5 feet 7 inches) tall. The body was generally heavy and solid, apparently with strong musculature. The forehead was straight, with slight browridges, and the face short and wide. Cro-Magnons were the first humans (genus Homo) to have a prominent chin.

The brain capacity was about 1,600 cc (100 cubic inches), somewhat larger than the average for modern humans. It is thought that Cro-Magnons were probably fairly tall compared with other early human species.

It is still hard to say precisely where Cro-Magnons belong in recent human evolution, but they had a culture that produced a variety of sophisticated tools such as retouched blades, end scrapers, “nosed” scrapers, the chisel-like tool known as a burin, and fine bone tools (see Aurignacian culture). They also seem to have made tools for smoothing and scraping leather. Some Cro-Magnons have been associated with the Gravettian industry, or Upper Perigordian industry, which is characterized by an abrupt retouching technique that produces tools with flat backs.

Cro-Magnon dwellings are most often found in deep caves and in shallow caves formed by rock overhangs, although primitive huts, either lean-tos against rock walls or those built completely from stones, have been found. The rock shelters were used year-round; the Cro-Magnons seem to have been a settled people, moving only when necessary to find new hunting or because of environmental changes.

Culture[]

Similar to the Neanderthals, the Cro-Magnon people buried their dead. Some of the first examples of art by prehistoric peoples are Cro-Magnon. The Cro-Magnons carved and sculpted small engravings, reliefs, and statuettes not only of humans but also of animals. Their human figures generally depict large-breasted, wide-hipped, and often obviously pregnant women, from which it is assumed that these figures had significance in fertility rites. Numerous depictions of animals are found in Cro-Magnon cave paintingsthroughout France and Spain at sites such as Lascaux, Eyzies-de-Tayac, and Altamira, and some of them are surpassingly beautiful. It is thought that these paintings had some magic or ritual importance to the people. From the high quality of their art, it is clear that Cro-Magnons were not primitive amateurs but had previously experimented with artistic mediums and forms. Decorated tools and weapons show that they appreciated art for aesthetic purposes as well as for religious reasons.

Relationship with Neandarthals[]

After miners unearthed a skull and bones in a Neander Valley cave in Germany in 1856—three years before the publication of On the Origin of Species—the remains were initially described as either those of a “brutish” race or of someone disfigured by disease. As Darwinian evolution caught on, so did the realization that these fossils were evidence of an earlier human species. Scientists have been debating Neanderthal's place in human evolution ever since. An ongoing question concerns the possibility that Neanderthals and early humans mated, since they likely crossed paths during thousands of years of European cohabitation. In a new study, Mathias Currat and Laurent Excoffier present a simulation model based on what we know about the population density and distribution of Neanderthals and Cro-Magnons. Their results complement recent genetic and morphological evidence indicating that early human and Neanderthal interbreeding was unlikely.

The notion that modern Europeans directly descended from Neanderthals has mostly yielded to two competing models: One postulates that modern humans arose in Africa about 130,000 years ago and completely replaced coexisting archaic forms with no interbreeding, while the other proposes a gradual transition with interbreeding. Though mounting genetic evidence (based on mitochondrial DNA extracted from fossils) suggests Neanderthals and early humans did not breed, the evidence has been inconclusive. It's possible, for example, that any Neanderthal gene “leakage” could have been lost through genetic drift if the mating populations were small. And because so few fossils are available to analyze, previous studies could rule out only Neanderthal contributions over 25%.

Currat and Excoffier's model refines various parameters—such as geographic boundaries, local population variations, range expansion, and competition for resources—based on archeological and demographic data for both populations. Evidence suggests modern humans replaced Neanderthals over 12,500 years, for example, which constrains the speed at which modern humans could expand.

The authors started with a scenario based on a set of “plausible” parameter values—their basic scenario—and then varied the local interbreeding rate and, for example, the population size and location of Cro-Magnons, to produce eight alternate scenarios describing how Cro-Magnon colonization of Europe might have proceeded. They estimated the likely proportion of Neanderthal gene contributions to the modern gene pool using “coalescent simulations,” which generate the genealogies and diversity of genes in local populations based on simulations of their population densities and migration histories. The simulations show that if Neanderthals bred with Cro-Magnons without constraints over thousands of years, Neanderthal contributions to the modern gene pool “would be immense.” Surprisingly, the simulations also show that even a very small mixing should lead to high levels of Neanderthal DNA in modern humans.

History[]

In 1868, in a shallow cave at Cro-Magnon near the town of Les Eyzies-de-Tayac in the Dordogne region of southwestern France, a number of obviously ancient human skeletons were found. The cave was investigated by the French geologist Édouard Lartet, who uncovered five archaeological layers. The human bones found in the topmost layer proved to be between 10,000 and 35,000 years old. The prehistoric humans revealed by this find were called Cro-Magnon and have since been considered, along with Neanderthals (H. neanderthalensis), to be representative of prehistoric humans. Modern studies suggest that Cro-Magnons emerged even earlier, perhaps as early as 45,000 years ago.

Cro-Magnon

Contents

Description[]

Culture[]

Relationship with Neandarthals[]

History[]

References[]

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