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Reviewed by Dong Wei, Institute of Vertebrate Paleontology and Paleoanthropology
(IVPP), Chinese Academy of Sciences, Beijing The Legend of Peking Woman and the Peking Man Site: Physical Evolution,
Cultural Aspects, and Clinal Replacement . About 75 years
have passed since the discovery of the first skull cap of Homo erectus
pekinensis in 1929 at a site called Dragon Bone Hill, about 50 km southwest
of downtown Beijing. The fossil (fig.1) has been popularly referred to as
Peking Man, but anatomical study has revealed, rather, that it should have
been called Peking Woman. The stories of the discovery of Peking Woman (or
conventionally Peking Man), the history of excavations at the Peking Man
site (fig.3), and the mysterious loss of the Peking Man fossils have been
told by contemporaries, especially Professor Lanpo Jia (1908-2001), to whom
Dragon Bone Hill is dedicated. While Jia’s books focused
mainly on providing the detailed chronological facts of the 1920s and 1930s
with literal narration and  photographic illustration, Dragon Bone
Hill concentrates largely on theories such as the recently developed
interpretations of the Peking Man site, comparison of the locality with the
other relevant sites, comments on different hypotheses of hominid evolution,
and, perhaps most significantly, proposition of a new evolutionary model. .
Fig.1: Homo erectus skull from Dragon Bone Hill (photo: IVPP).
The book is organized into nine chapters. The first two chapters of the book
retrospect the history of the discovery of Peking Man and the excavations
at the site, as well as the loss of the Peking Man fossils, which represent
around 50 individuals. The disappearance of the Peking Man fossils during
World War II remains a mystery, and fruitless attempts to recover them have
been made from time to time since their disappearance. This was a great loss
for world paleoanthropology, but fortunately the fossils had been cast,
photographed, studied, and documented before they were lost. The casts of
the fossils and publication of the initial researches were distributed worldwide,
making it possible for paleoanthropologists to continue their study of the
fossils. This is reminiscent of another excellent example of separate locational
conservation. Several David’s deer (Elaphurus davidianus), an
endemic species of China, were presented to some British explorers as gifts
by the Qing Dynasty’s imperial game officers toward the end of the dynasty.
The animals were shipped to England and raised there. During several Chinese
civil wars as well as World War II, many wild animals were energetically
hunted as food resources, and David’s deer went extinct in their homeland.
The David’s deer shipped to England escaped the disaster and survived.
Some of them were sent back to China by the British government in the 1980s,
restoring the otherwise extinct species in China. From this and the Peking
Man examples, the recommendation that invaluable fossils be at least cast
and photographed, with the records conserved in separate locations as multiple
backups, seems a necessity. Then, in case of destruction by disasters, such
as earthquakes, meteor bombing, fire, wars, terrorist attacks, etc., essential
data will be available for our continued study. Modern technologies, such
as CT scanning, provide tools for further detailing and recording the data
from fossils.
 The third
and fourth chapters discuss the physical evolution of Peking Man (fig.2).
The main competing hypotheses on the subject are enumerated, and some new
interpretations on Peking Man’s strangely thick skull structure are
proposed. The skull of Peking Man resembles the carapace of a turtle, low
and crouching, so massive and rimmed with such thick bone that his brain
size was limited to barely over a quart. His mandible, or lower jaw, is also
massive compared with that of modern humans, and in lateral view the skull
shows only a very small chin. Fig.2: Bust reconstruction of Peking Man (photo: IVPP). The authors attribute the evolving hominid
skull form to three major functional imperatives: housing a brain rapidly
increasing in size, serving as the bony anchor for the teeth and the muscles
which move them, and, in the case of Homo erectus, defense against
blunt trauma. The thickened mandible of Peking Man is also an adaptation
to protect against trauma to the jaw and lower face region. All three functions
are considered important by the authors in the attempt to understand the
unusual cranium of Homo erectus. In addition, they suggest that the
radiator brain hypothesis, in which blood circulation throughout the head
and skull is thought to act as a cooling mechanism, may explain why skull
thickness in Homo erectus decreased as this species evolved. According
to Boaz and Ciochon, as hominid brain size increased, selection may have
favored a thinner skull, which would have allowed more veins to pass through
it and thus more efficient regulation of the accompanying temperature rise.
The fifth, sixth, and seventh chapters explore the cultural aspects of Peking
Man, i.e. artifactual evidence for tool manufacture and use, proof for the
use of fire in sedimentary deposits, speaking ability as determined by skull
anatomy, as well as lifestyle. Peking Man used small quartz flakes to slice
and scrape muscle from bone and hefty chopping tools made of sandstone for
bigger jobs, such as cutting through the rib cage of a large carcass. Based
on multiple lines of evidence, the authors interpret the Homo erectus
population at the Peking Man site to have been scavengers, sometimes
practicing cannibalism, rather than hunters as in many previous interpretations.
The hominids developed a dependent scavenging relationship with dangerous
large carnivores. Both the physical evolution and cultural aspects of Peking
Man were associated with the Ice Age environment. His body size increased,
and the length of his legs grew. Techniques of tool making improved as a
consequence of Homo erectus’ migrations across the Old World,
climatic changes accompanying the onset of the Ice Ages, and competition
with carnivores for food resources and habitats. Fire was first and foremost
a means by which Homo erectus could effectively compete with these
other species and hold its own in the Pleistocene, especially during colder
periods.
The last two
chapters comment on the Out of Africa and Multi-regional Evolution hypotheses
and propose a new evolutionary model, Clinal Replacement, to interpret the
origin and evolution of Homo erectus. The authors support this theory
with anatomical, archaeological, geological, paleontological, and paleoecological
evidence. Just as in Stephen Hawkings’ efforts to unify the disparate
theories of General Relativity and Quantum Physics, the Clinal Replacement
hypothesis is a laudable attempt to compromise the Out of Africa with the
Multi-regional Evolution hypotheses. A “cline” is defined by the
authors as a geographic cluster of biological characteristics in a human
population group, usually with a gradient of change in those characteristics
into surrounding groups. According to the Clinal Replacement theory, Homo
erectus ergaster evolved into Homo erectus erectus in both Asia
and Africa at the same time. Geographically linked or bordering populations
of Homo erectus had some genetic overlaps at their edges forming a
kind of genetic chain. However, data from the rapidly evolving biomolecules
of modern human populations do not record this relatively ancient event,
since the rapid mode of molecular evolutionary change in Homo sapiens
has served to overprint prior genetic change.  The authors posit that this
overprinting has conspired with a more complete fossil record for later phases
of human evolution to give the impression of total replacement of species
as hypothesized by Out of Africa theorists. In addition, total replacement
does not satisfy the expectations of population genetics, nor can it resolve
the disparity between the global population of hominids, which had to be
large, and effective population size, which the Out of Africa model requires
to be small. The Clinal Replacement theory resolves this problem by envisioning
many small populations moving and replacing other populations, while explaining
the continuity in traits long cited by multi-regionalists.
Fig.3: The main fossil-producing layers at Dragon Bone Hill’s Locality
1, viewed from Pigeon Hall Cave (photo: R.L. Ciochon). .
Narrative and informative, with intermittent commentary, the style of this
book may be more enjoyable for Western readers than Lanpo Jia’s book,
The Story of Peking Man: From Archaeology to Mystery (Oxford
University Press, 1990). In Dragon Bone Hill, Boaz and Ciochon
introduce the profound theories of paleoanthropology in a simple way that
makes the book reader-friendly for both experts and the general public.
References: Lanpo Jia 1990. The Story of Peking Man: From Archaeology to Mystery (Oxford
University Press).
This review appears on pages 95-96 in Vol.4, No.1 of Athena
Review.
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