The Dawn of Human Culture (15 page)
In practice, ESR faces many hurdles, of which the most serious is the possibility that teeth at any given site have experienced a 04 True Humans.r.qxd 1/29/02 5:04 PM Page 125
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flat, receding
forehead
shelf-like
browridge
flat, receding
forehead
sharp
angulation
skull broad across the
at rear
base
of skull
late Indonesian
Homo erectus
(Ngandong XI)
0
5 cm
flat, receding
0
2 in
forehead
shelf-like
browridge
flat, receding
forehead
sharp
angulation
at rear
of skull
skull broad across the base
classic Indonesian
Homo erectus
(Sangiran 17)
FIGURE 4.10
Skulls of late and classic
Homo erectus
from Indonesia (top redrawn by Kathryn Cruz-Uribe mainly after originals by Janis Cirulis in W. W. Howells 1967,
Mankind in the Making
.
New York: Doubleday, pp. 160; bottom redrawn by Kathryn Cruz-Uribe from photographs).
complex history of uranium exchange with the burial environment.
Exchange almost always involves uranium uptake from ground water, but it may also involve loss, and the precise pattern of uptake and loss 04 True Humans.r.qxd 1/29/02 5:04 PM Page 126
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will manifestly affect the annual radiation dose to which a tooth has been subjected. The possibility that this dose changed significantly through time often leaves ESR results open to question, and the dates from Ngandong and Sambungmacan are no exception. If they are valid, they provide strong circumstantial support for the survival of southeast Asian
erectus
until it was swamped or replaced by modern human invaders after 60,000 years ago. But even if the Ngandong and Sambungmacan skulls are actually closer to 300,000 years old, they still show that southeast Asian populations were on a different evolutionary track than their European and African contemporaries.
* * *
Homo erectus
fossils from China, and they tell basically the same story. The discovery of
erectus
in China stems from the age-old Chinese custom of pulverizing fossils for medicinal use. In 1899, a European doctor found a probable human tooth among fossils in a Beijing (then Peking) drugstore, and the search for its origin led paleontologists to a rich complex of fossil-bearing limestone caves and fissures on the slope of Longghu-shan (“Dragon Bone Hill”), about 40 kilometers (24 miles) southwest of Beijing, near the village of Zhoukoudian. In 1921, the Swedish geologist J. G. Andersson began excavating in a collapsed cave at Zhoukoudian that was particularly intriguing not only for its fossils, but also for quartz fragments that prehistoric people must have introduced. The site was called Locality 1 to distinguish it from other fossil-bearing caves nearby.
Andersson’s excavations produced two human teeth which came to the attention of Davidson Black, a Canadian anatomist who 04 True Humans.r.qxd 1/29/02 5:04 PM Page 127
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was teaching at the Peking Union Medical School. Black secured a grant from the Rockefeller Foundation, and in 1927, excavation began again at Locality 1. Black died in 1933, and in 1935, he was succeeded by Franz Weidenreich, an eminent German anatomist who had been teaching at the University of Chicago. Excavations continued until 1937, and they eventually produced five more or less complete human braincases, nine large braincase fragments, six facial fragments, fourteen partial lower jaws, 147 isolated teeth, and eleven limb bones. The specimens represented more than forty individuals of both sexes and various ages.
Black assigned the Locality 1 fossils to a new species,
Sinanthropus pekinensis
(“Peking Chinese Man”). Later, in 1939, Weidenreich and G. H. R. von Koenigswald compared the
Sinanthropus
fossils to those of Javan
Pithecanthropus,
and they concluded that the skulls were very similar in their shelf-like browridges, receding foreheads, low-domed braincases, thick, inwardly sloping skull walls, and other features (Figure 4.8). For the sake of convenience, Weidenreich continued to call them
Sinanthropus pekinensis
and
Pithecanthropus erectus,
but he noted that they could be regarded as variants of a single primitive human species,
Homo erectus
. This anticipated a professional consensus that crystallized in the 1960s and that continues to the present day.
The Locality 1 fossils were lost at the beginning of World War II, but Weidenreich had described them in detailed monographs and he had prepared an excellent set of plaster replicas, now housed at the American Museum of Natural History. Excavations at Locality 1 produced a few additional fragmentary
erectus
fossils between 1949 and 1966, but following the original Locality 1 excavations, the most diagnostic
erectus
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east-central China (Figure 4.7). The specimens include a lower jaw from Chenjiawo and a skull from Gongwangling, both in Lantian County; a partial skull and a fragmentary mandible from Lontandong Cave in Hexian County; a fragmentary skullcap from a fissure deposit on Qizianshan Hill in Yiyuan County, two badly crushed, partial skulls from a river deposits at Quyuankekou in Yunxian County, and two skulls unearthed in a cave near Tangshan in Nanjing County. Chinese anthropologists often use county names rather than site names when they refer to the fossils.
The Chinese
erectus
fossils have been dated to between 800,000
and 400,000 years ago, mainly by paleomagnetism, by associated mammal species, and by the climatic shifts recorded in the surrounding deposits. “Climate dating” depends on the assumption that local shifts can be accurately correlated with the dated sequence of global shifts recorded on the deep sea floor. The sum of the evidence suggests that the oldest Chinese
erectus
fossil is probably the Gongwangling (Lantian) skull, dated to about 800,000 to 750,000 years ago. The youngest fossils come from Zhoukoudian Locality 1 and Hexian, where at least some specimens accumulated after 500,000 years ago. The dating provides nothing to suggest that
erectus
arrived in eastern Asia long before 1 million years ago, and it indicates that it persisted after other kinds of people had emerged on the west. The Chinese
erectus
fossils differ from the Indonesian ones in some details, and the differences appear to grow with time. This may mean that the Chinese and Indonesian specimens represent two divergent Far Eastern evolutionary lineages, but the basic point remains the same—
erectus
or its variants followed a separate evolutionary trajectory from like-aged populations in Africa and Europe.
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* * *
erectus
story that Java lacks, for unlike Java, China has provided numerous stone artifacts that local
erectus
populations produced. At most sites, the artifacts are attributed to
erectus
based on similar geologic antiquity, but artifacts are directly associated with
erectus
fossils at the Lantian sites and especially at Zhoukoudian Locality 1. The oldest known artifacts come from sites in the Nihewan Basin, about 150 kilometers (90 miles) west of Beijing.
Paleomagnetic analysis of enclosing sediments places their age between 1.3 and 1.1 million years ago.
Some of the Chinese artifacts are as finely trimmed or shaped as like-aged Acheulean artifacts from Africa and Europe, but the Chinese assemblages consistently lack hand axes. Harvard archeologist Hallam L. Movius first stressed the contrast in the 1940s, and he pointed out that hand axes had not been found anywhere in Asia east of northern India. The distinction does not depend on excavation, since in Europe and especially Africa, hand axes are often found on the surface, either because they have been eroded from their burial places or because they were never buried to begin with.
Movius proposed that a rough line through northern India separated the expansive Acheulean Tradition of Africa, Europe, and western Asia on the west from the non-Acheulean tradition in eastern and southeastern Asia (Figure 4.7). His boundary has stood the test of time, and it sends the same message as the fossils—from the moment that people first arrived in eastern Asia, they followed a different evolutionary track than their African and European contemporaries. If the Mojokerto and Sangiran dates that we discussed earlier mean that 04 True Humans.r.qxd 1/29/02 5:04 PM Page 130
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people had colonized eastern Asia by 1.8 to 1.6 million years ago, then hand axes might be absent because the colonists left Africa before hand axes were invented. However, Indiana University archeologists Nicholas Toth and Kathy Schick have suggested an alternative. If the colonists left after hand axes appeared, they may have passed through a kind of “technological bottleneck,” perhaps a large region that lacked suitable raw material for hand axe manufacture, and by the time they emerged, they could have lost the hand axe habit. It was clearly not essential to their continued success, and thereafter isolation by distance could have prevented its reintroduction. Such isolation probably explains why a strong artifactual contrast persisted between east and west, even after 250,000 years ago, when people in the west had given up hand axe manufacture.
* * *
erectus
people were skilled deer stalkers. Against this, though, we note that the Locality 1 deposits also provided numerous fossilized hyena feces or coprolites and that many of the animal bones were damaged by hyena teeth. The conspicuous evidence for hyena activity means not only that hyenas could have introduced many of the animal 04 True Humans.r.qxd 1/29/02 5:04 PM Page 131
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bones, but it also suggests that hyenas successfully competed with
erectus
for living space. Based just on the Locality 1 evidence, we might conclude that as a predator or scavenger on other large mammals,
erectus
was less effective than hyenas.
Animal bones from broadly contemporaneous sites in Africa and Europe suggest that
Homo heidelbergensis
and its immediate successors were equally ineffective hunters. This is true even though
heidelbergensis
and
erectus
produced very different stone artifacts, and the ecological similarity serves to remind us that differences in stone artifacts between regions may say little about key aspects of underlying behavior. More important to this book, the apparent ecological similarity between
heidelbergensis
and
erectus
implies that they remained behaviorally alike even after they had diverged in anatomy.
We will show now that Europe and Africa illustrate the same fundamental point—archeological (behavioral) residues remained strikingly similar on both continents, even as Europeans evolved into Neanderthals and Africans evolved towards modern humans. The pattern was broken only about 50,000 years ago, when the Africans developed the modern capacity for culture and then rapidly exported both their anatomy and their behavior to the rest of the world.
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5
HUMANITY BRANCHES OUT
By 1 million years ago humans had spread to the northern and southern coasts of Africa and they had also colonized southern Asia as far east as China and Java. But what about Europe? The Dmanisi site puts people on the southern flank of the Caucasus Mountains, at the “Gates of Europe,” by 1 million years ago (Figure 5.1). Yet, despite searches that began in the 1830s and that industrial activity has long aided, Europe has yet to produce a single site that is indisputably older than 800,000 years, and it has provided only one or two that are clearly older than 500,000 years. Enthusiasts have repeatedly proposed other sites that antedate 500,000 years or even 1
million years, but Leiden University archeologist Wil Roebroeks and his colleagues have shown that most such sites are dubiously dated or that their artifacts could be geofacts, that is, rocks that were naturally fractured by geologic processes.