ANTHRO CHP9

H. heidelbergensis

The species name H. heidelbergensis is now commonly used to refer to the Middle Pleistocene hominins that lived between H. erectus and the Neandertals. This group includes fossil hominins that lived in Europe, Asia, and Africa between (very roughly) 850,000 and 200,000 B.P. (see Mounier, Condemi, and Manzi 2011).

Paleolithic

The stone toolmaking techniques that evolved out of the Oldowan tradition, and that lasted until about 15,000 years ago, are described by the term Paleolithic

Pleistocene

Traditionally and correctly, the geological epoch known as the Pleistocene has been considered the epoch of early human (as opposed to merely hominin) life

Cold-Adapted Neandertals

By 75,000 B.P., after an interglacial interlude, western Europe's hominins (Neandertals, by then) again faced extreme cold as the Würm glacial began. To deal with this environment, they wore clothes, made more elaborate tools and hunted reindeer, mammoths, and woolly rhinos (see Conard 2011). The Neandertals were stocky, with large trunks relative to limb length—a phenotype that minimizes surface area and thus conserves heat. Another adaptation to extreme cold was the Neandertal face, which has been likened to an H. erectus face that has been pulled forward by the nose. Illustrating Thomson's rule, this extension increased the distance between outside air and the arteries that carry blood to the brain and was adaptive in a cold climate. The brain is sensitive to temperature changes and must be kept warm. The massive nasal cavities of Neandertal fossils suggest long, broad noses. This would expand the area for warming and moistening air.

glacials

Europe and North America experienced several ice ages, or glacials, major advances of continental ice sheets

Ice Ages of the Pleistocene

Europe and North America experienced several ice ages, or glacials, major advances of continental ice sheets. These periods were separated by interglacials, long warm periods. With each glacial advance, the world climate cooled and continental ice sheets—massive glaciers—covered the northern parts of Europe and North America. Climates that are temperate today were arctic during the glacials. The ice sheets advanced and receded several times during the last glacial period, the Würm (75,000-12,000 B.P.). Brief periods of relative warmth during the Würm (and other glacials) are called interstadials, in contrast to the longer interglacials. Hominin fossils found in association with animals known to occur in cold or warm climates, respectively, permit us to date them to glacial or interglacial (or interstadial) periods.

nOTES

For almost 40 years after finding 1470, the Leakey family and others scoured deposits near Lake Turkana for fossils similar to 1470. Between 2007 and 2009 they found them (see Gibbons 2012; Leakey et al. 2012). In 2012 Meave Leakey and her associates announced the discovery at Koobi Fora of a face and two jawbones, showing that 1470 was not unique. These new fossils, dating to 2.03-1.78 m.y.a., confirmed that H. rudolfensis lived in the same area and at the same time as at least two other species of Homo—habilis and erectus. Note that Paranthropus also existed at this time. The bushy tree of hominin evolution had produced at least four species living in Africa at the same time, but no doubt separated in space or by adaptation to different ecological niches. The face of the newly discovered H. rudolfensis skull—that of a juvenile—was well preserved and included upper teeth. It was a smaller version of the 1470 skull, both featuring an unusually flat face that contrasts with the more jutting upper jaw of H. habilis. The lower jawbones, one of which was remarkably complete, gave new information, because the 1470 fossil had no lower jaw. The new jaw and face showed that H. rudolfensis had an unusual U-shaped palate, with canines facing the front of the jaw rather than placed on the sides in a V-shaped palate, as in H. habilis. The new jaws also had smaller molars than expected, based on those of 1470. The new fossils were found within 10 kilometers of the 1470 discovery site, and within the same region where fossils of H. habilis and H. erectus have been discovered.

The Neandertals and Modern People

Generations of scientists have debated whether and to what extent the Neandertals may have been ancestral to anatomically modern humans especially those of the Middle East and Europe, where fossils of both groups have been found. The current prevailing view proposes that H. erectus split into separate groups: one ancestral to the Neandertals, the other ancestral to AMHs, who first reached Europe around 45,000 B.P. Current evidence leaves little doubt that modern humans evolved in Africa and eventually colonized Europe, displacing, or at least replacing, the Neandertals there. Page 160 Consider the contrasts between the Neandertals and AMHs. Like H. erectus before them, the Neandertals had heavy brow ridges and slanting foreheads. However, average Neandertal cranial capacity (more than 1,400 cm3) actually surpassed the modern average. Neandertal jaws were large, providing support for huge front teeth, and their faces were massive. The bones and skull were generally more rugged and had greater sexual dimorphism—particularly in the face and skull—than do those of AMHs. In some western European Neandertals, the contrasts with AMHs were particularly marked. The interpretation of one such fossil helped create the popular stereotype of the slouching cave dweller. This was the complete human skeleton discovered in 1908 at La Chapelle-aux-Saints in southwestern France. This was the first Neandertal to be discovered with the whole skull, including the face, preserved.

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Neandertal technology, a Middle Paleolithic tradition called Mousterian, included a variety of tools designed for different jobs. The Neandertals elaborated on a revolutionary technique of flake-tool manufacture (the Levallois technique) invented in southern Africa around 200,000 years ago, which spread widely throughout the Old World. Uniform flakes were chipped off a specially prepared core of rock. Additional work on the flakes produced the special-purpose tools shown in Figure 9.5. Scrapers were used to prepare animal hides for clothing. Larger points were attached to spears. Other special tools were designed for sawing, gouging, and piercing (Conard 2011).

THE NEANDERTALS

Neandertals were first discovered in western Europe. The first one was found in 1856 in a German valley called Neander Valley—tal is the German word for "valley." Scientists had trouble interpreting the discovery. It was clearly human, yet different enough from modern Europeans to be considered strange and abnormal. This was, after all, 35 years before Dubois found the first H. erectus fossils in Java and almost 70 years before the first australopith was found in South Africa. Darwin's On the Origin of Species, published in 1859, had not yet appeared to offer a theory of evolution through natural selection. There was no framework for understanding human evolution. Over time, the fossil record filled in, along with evolutionary theory. There have been numerous subsequent discoveries of Neandertals in Europe and the Middle East, and extending eastward to central Asia and even Siberia. (Figure 9.4 shows the geographic distribution of Neandertal fossils.)

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The Neandertals moved about within a particular territory—their home range. Their contacts with outsiders were limited (and, as we just saw, potentially hostile). There is no evidence that Neandertals engaged in long-distance trade. By contrast, we know that AMHs living far inland in Europe used shells imported from the Mediterranean and Atlantic coasts. Unlike Neandertals, AMHs were tied into regional social networks; they had relatives, trade partners, in-laws, and allies in other groups. The expanded, regional network and the alliances and social support it offered were key differences between AMHs and Neandertals. Wynn and Coolidge (2011) interpret the archaeological and fossil evidence as indicating that Neandertals were suspicious of both outsiders and change. Their limited imagination is shown in their unchanging tool designs. Their tools, found across Eurasia, varied little in form or function over thousands of years, and miles. Neandertals no doubt were eventually exposed to the far more effective spears and spear throwers made by their AMH contemporaries, but they borrowed none of those techniques.

AMHs

anatomically modern humans

Mousterian

Neandertal technology, a Middle Paleolithic tradition called Mousterian, included a variety of tools designed for different jobs

interglacials

long warm periods

note

A massive hominin jaw was discovered in 1907 in a gravel pit at Mauer, near Heidelberg, Germany. Dubbed "Heidelberg man," or Homo heidelbergensis, the jaw appears to be around 500,000 years old. The deposits that yielded this jaw also contained fossil remains of several animals, including bear, bison, deer, elephant, horse, and rhinoceros. The species name H. heidelbergensis is now commonly used to refer to the Middle Pleistocene hominins that lived between H. erectus and the Neandertals. This group includes fossil hominins that lived in Europe, Asia, and Africa between (very roughly) 850,000 and 200,000 B.P. (see Mounier, Condemi, and Manzi 2011). A hominin jaw that is more than one million years old, found in Spain, is the oldest known hominin fossil in Europe and may be ancestral to H. heidelbergensis. Some of the earliest likely Page 156members of H. heidelbergensis come from northern Spain's Atapuerca Mountains, where the site of Gran Dolina has yielded the remains of 780,000-year-old hominins. The Spanish researchers who excavated them call this group Homo antecessor, but others include them in H. heidelbergensis. The nearby Spanish cave of Sima de los Huesos has yielded thousands of fossils representing at least 33 hominins, dated considerably later, at about 300,000 years B.P. Another early possible H. heidelbergensis fossil is a cranial fragment found at Ceprano, near Rome, Italy, dated to 850,000 B.P. (see Mounier et al. 2011). Other European fossils now assigned to H. heidelbergensis have been found in England (at Swanscombe), Germany (at Steinheim and Mauer), and Greece (at Petralona).

H. habilis and H. erectus

A team headed by L. S. B. and Mary Leakey discovered the first representative of H. habilis (OH7—Olduvai Hominid 7) at Olduvai Gorge in Tanzania in 1960. Olduvai's oldest layer, Bed I, dates to 1.8 m.y.a. This layer has yielded both small-brained Paranthropus boisei fossils (average 490 cm3) and H. habilis skulls, with cranial capacities between 600 and 700 cm3. (Table 9.1 gives cranial capacities for the various forms of Homo discussed in this chapter.) The Leakeys named their new find Homo habilis (which means "able man" in Latin), because they assumed that H. habilis had toolmaking ability and was responsible for the Oldowan tools also found in Bed I. We now know, however, that toolmaking preceded H. habilis and may be as old as 3.3 m.y.a.

H. habilis and H. erectus

Another important habilis find is OH62, the partial skeleton of a female H. habilis from Olduvai Bed I. This was the first find of an H. habilis skull with a significant amount of skeletal material. OH62, dating to 1.8 m.y.a., consists of parts of the skull, the right arm, and both legs. The fossil, found by Tim White in 1986, was surprising because of its small size and apelike limb bones. Not only was OH62 just as tiny as Lucy (3 feet, or 0.9 meter), but also its arms were longer than expected. The limb proportions suggested greater tree-climbing ability, compared with later hominins. H. habilis may still have sought occasional refuge in the trees. The small size and primitive proportions of H. habilis were unexpected, given what was known about early H. erectus in East Africa. In deposits near Lake Turkana, Kenya, Richard Leakey had uncovered two H. erectus skulls Page 148dating to 1.6 m.y.a. By that date, H. erectus (males, at least) had already attained a cranial capacity of 900 cm3, along with a modern body shape and height. An amazingly complete young male H. erectus fossil (WT15,000) found at West Turkana in 1984 by Kimoya Kimeu, a collaborator of the Leakeys, has confirmed this. WT15,000, also known as the Nariokotome boy, was a 12-year-old male who had already reached 5 feet 5 inches (1.67 meters). He might have grown to 6 feet had he lived.

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Archaeologists have found and studied several sites of H. erectus activity, including cooperative hunting. Hearths at various sites confirm that fire was part of the adaptive kit controlled by H. erectus. Evidence for human control over fire has been found in Israel, dating back to almost 800,000 years ago. The newest evidence of fire, dated at 1 m.y.a., comes from Wonderwerk Cave (South Africa), where microscopic plant ashes and burned bits of bone have been found in soil that previously yielded dozens of stone tools (Berna et al. 2012). However, no remains of a hearth or campfire area, where fires would have been lit repeatedly, have Page 153been found in Wonderwerk Cave. The first hearths date back only 400,000 years (Rice 2012). Fire provided protection against predators. It permitted H. erectus to occupy cave sites, including Zhoukoudian, near Beijing, China, which has yielded the remains of more than 40 specimens of H. erectus. Fire widened the range of climates open to human colonization. Its warmth enabled people to survive winter cold in temperate regions. Cooking breaks down vegetable fibers and tenderizes meat. Cooking also kills parasites and makes meat more digestible, thus reducing strain on the chewing apparatus.

OUT OF AFRICA I: H. ERECTUS

Hominins migrated out of Africa in multiple waves. First to expand was H. erectus, whose spread occurred between 2 and 1 m.y.a. Much later, populations of anatomically modern humans (AMHs) certainly left Africa, maybe more than once, as early perhaps as 110,000 B.P., but mainly around and after 70,000 B.P. That last wave included the ancestors of all humans on Earth today. H. erectus initiated the expansion of hominins beyond Africa—to Asia and Europe. Small groups broke off from larger ones and moved a few miles away. They foraged new tracts of edible vegetation and carved out new hunting territories. Through population growth and dispersal, H. erectus gradually spread and changed. Fueling this expansion was commitment to an essentially human lifestyle based on hunting and gathering. This basic pattern survived until recently in certain parts of the world, although it now is fading rapidly. We focus in this chapter on the biological and cultural changes that led from early Homo, through intermediate forms, to anatomically modern humans.

Note

If the country of Georgia provides the earliest evidence for H. erectus outside of Africa, the country of Indonesia provided the very first fossil evidence for H. erectus as a species. In 1891, the Indonesian island of Java yielded the first (although not the most ancient) H. erectus fossil find, popularly known as "Java man." Eugene Dubois, a Dutch army surgeon, had gone there specifically to discover a transitional form between apes and humans. Of course, we now know that the transition to hominin had taken place much earlier than the H. erectus period and occurred in Africa. However, Dubois's good luck did lead him to the most ancient human fossils then known—parts of an H. erectus skull and a thigh bone. Later excavations in Java uncovered additional remains. The various Indonesian H. erectus fossils date back at least 700,000, and perhaps as much as 1.6 million, years. The four-stage photo spread at the left shows a reconstruction of H. erectus based on the Javanese find Sangiran 17, the most complete H. erectus skull from Indonesia. Fragments of a skull and a lower jaw found in northern China at Lantian may be as old as the oldest Indonesian fossils. Other H. erectus remains, of uncertain date, have been found in Algeria and Morocco in North Africa. H. erectus remains also have been found in Upper Bed II at Olduvai, Tanzania, in association with Acheulean tools. On p. 152, you will find a photo of one such find, OH9, which dates back perhaps 1.4 million years, along with a photo of a Javanese find, Sangiran 2, which may be a bit older. African H. erectus fossils also have been found in Ethiopia, Eritrea, and South Africa (in addition to Kenya and Tanzania). The time span of H. erectus in East Africa was long. Later H. erectus fossils have been found in Bed IV at Olduvai, dating to 500,000 B.P., about the same age as an important group of fossils found near Beijing, China. The largest group of H. erectus fossils ever found comes from the Zhoukoudian cave, near Beijing, China. The Zhoukoudian ("Peking"—now Beijing—"man") site, excavated from the late 1920s to the late 1930s, was a major find for the human fossil record. Zhoukoudian yielded remains of tools, hearths, animal bones, and more than 40 hominins, including five skulls. One of these Beijing fossils, Skull XII, is shown on p. 152. The Zhoukoudian group lived between 780,000 and 400,000 years ago, when the Chinese climate was colder and moister than it is today. These dates are based on animal remains found with the human fossils. The people at Zhoukoudian hunted venison; seed and plant remains show they gathered as well as hunted. What about Europe? No definite H. erectus remains have been found in western or northern Europe, whose earliest fossil hominins are now generally assigned to a Middle Pleistocene group known as Homo heidelbergensis (see the next section).

Hunting, Tools, and Teeth

The ecological niche that separated H. erectus from earlier hominins involved greater reliance on hunting, along with improved cultural means of adaptation. Significant changes in technology occurred during the 200,000-year period between Bed I (1.8 m.y.a.) and Lower Bed II (1.6 m.y.a) at Olduvai. Out of the crude Oldowan tools in Bed I evolved more varied tools. The earliest (1.76 m.y.a.) tools of the Acheulean type (see the following section) associated with H. erectus come from the site of Kokiselei near Lake Turkana in Kenya (Wilford 2011c). These tools show signs of symmetry, uniformity, and functional differentiation. H. erectus was making and using tools for different jobs, such as smashing bones or digging for tubers. The new technology allowed H. erectus to acquire meat more reliably and to dig and process tubers, roots, nuts, and seeds more efficiently. New tools that could batter, crush, and pulp coarse vegetation also reduced chewing demands.

Acheulean

The main Lower Paleolithic toolmaking tradition used by H. erectus was the Acheulean

Paleolithic Tools

The stone toolmaking techniques that evolved out of the Oldowan tradition, and that lasted until about 15,000 years ago, are described by the term Paleolithic (from Greek roots meaning "old" and "stone"). The Paleolithic, or Old Stone Age, has three divisions: Lower (early), Middle, and Upper (late). Stone tools were made from rocks, such as flint, that fracture sharply and in predictable ways when hammered. Quartz, quartzite, chert, and obsidian also are suitable. Each of the three main divisions of the Paleolithic had its typical toolmaking traditions—coherent patterns of tool manufacture. The main Lower Paleolithic toolmaking tradition used by H. erectus was the Acheulean, named after the French village of St. Acheul, where it was first identified. Recent finds in Kenya date the oldest Acheulean hand axes to 1.76 m.y.a.

Sister Species

Two recent hominin fossil finds from Ileret, Kenya (east of Lake Turkana), are very significant, mainly for two reasons: They show that (1) H. habilis and H. erectus overlapped in time rather than being ancestor and descendant, as had been thought, and (2) sexual dimorphism in H. erectus was much greater than expected (see Spoor et al. 2007; Wilford 2007a). One of these finds (KNM-ER 42703) is the upper jawbone of a 1.44 million-year-old H. habilis. The other (KNM-ER 42700) is the almost complete but faceless skull of a 1.55 million-year-old H. erectus. These finds negated the conventional view (held since the Leakeys described the first habilis in 1960) that habilis and then erectus evolved, one after the other. Instead, they apparently split from a common ancestor prior to 2 m.y.a. Then they lived side by side in eastern Africa for perhaps half a million years. According to Meave Leakey, one of the authors of the report (Spoor et al. 2007), the fact that they remained separate species for so long "suggests that they had their own ecological niche, thus avoiding direct competition" (quoted in Wilford 2007a, p. A6). They coexisted in the same general area (an ancient lake basin), much as gorillas and chimpanzees do today. Given these finds, the fossil record for early Homo in East Africa must be revised as follows: Page 149H. rudolfensis (2.03-1.78 m.y.a.), H. habilis (1.9-1.44 m.y.a), and H. erectus (1.9-0.4? m.y.a). The oldest definite H. habilis (OH24) dates to 1.9 m.y.a., as does the oldest erectus.