From: Hofmann, Jim (jhofmann@exchange.fullerton.edu)
Date: Wed Aug 07 2002 - 16:06:15 EDT
Of Possible Interest:
ScienceWeek - August 9, 2002 Vol. 6 Number 32
13. ON THE EMERGENCE OF MODERN HUMAN BEHAVIOR
Science 2002 295:1278
C.S. Henshilwood et al (Iziko Museum of Cape Town, ZA) discuss
the emergence of human behavior, the authors making the
following points:
1) Archaeological evidence associated with modern cognitive
abilities provides important insights into when and where modern
human behavior emerged (1). Two models for the origins of modern
human behavior are current: (a) a late and rapid appearance at
approximately 40 to 50 thousand years ago (ka) associated with
the European Upper Paleolithic and the Later Stone Age (LSA) of
sub-Saharan Africa (2,3) or (b) an earlier and more gradual
evolution rooted in the African Middle Stone Age (MSA;
approximately 250 to 40 ka)(4,5). Evidence for modern behavior
before 40 ka is relatively rare and often ambiguous (2).
However, in sub-Saharan Africa, archaeological evidence for
changes in technology, economy, and social organization and the
emergence of symbolism in the Middle Stone Age may support the
second model (4, 5). Examples of these changes include
standardized formal lithic tools (5), shaped bone implements
(5), innovative subsistence strategies such as fishing and
shellfishing, and the systematic use of red ochre.
2) Utilized ochre is found in almost all Stone Age occupations
in southern Africa that are younger than 100 ka. The ochre may
have served only utilitarian functions (e.g., skin protection or
hide tanning)(3) or may have been used symbolically as
pigment(4). Evidence for the latter is a persistent use of ochre
with saturated red hues to produce finely honed crayon or pencil
forms. However, no ochre pieces or other artifacts older than
approximately 40 ka provide evidence for abstract or depictional
images, which would indicate modern human behavior(2).
3) The authors report they have recovered two pieces of engraved
ochre from the Middle Stone Age layers at Blombos Cave, South
Africa. Situated on the southern Cape shore of the Indian Ocean,
the cave is 35 meters above sea level. A 5- to 60-cm layer of
aeolian sand containing no archaeological artifacts separates
the Later Stone Age from the Middle Stone Age occupation layers.
A mean date of 77,000 years was obtained for the layers
containing the engraved ochres by thermoluminescence dating of
burnt lithics, and the stratigraphic integrity was confirmed by
an optically stimulated luminescence age of 70,000 years on an
overlying dune. These engravings support the emergence of modern
human behavior in Africa at least 35,000 years before the start
of the Upper Paleolithic.
References (abridged):
1. The term "modern human behavior" as used here has no
chronological implication and means the thoughts and actions
underwritten by minds equivalent to those of Homo sapiens today.
Key among these is the use of symbols.
2. P. A. Mellars, K. Gibson, Eds., Modelling the Early Human
Mind (McDonald Institute Monographs, Cambridge, 1996).
3. R. G. Klein, The Human Career (Univ. of Chicago Press,
Chicago, IL, 1999).
4. H. J. Deacon, J. Deacon, Human Beginnings in South Africa:
Uncovering the Secrets of the Stone Age (David Philip, Cape
Town, South Africa, 1999).
5. S. McBrearty and A. Brooks, J. Hum. Evol. 38, 453 (2000)
Science 2002 295:1278
Jim Hofmann
Philosophy Department and Liberal Studies Program
California State University Fullerton
http://nsmserver2.fullerton.edu/departments/chemistry/evolution_creation/web
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