Biomedical Engineering Reference
In-Depth Information
for instance, throwing for hunting or some other primary use were con-
tinually reconfining the shape.
8
2. Paleontology, and the crisis deriving from the recognition of fossil
hominid phyletic diversity—another innovation of the 1960s and 1970s,
following spectacular south and east African hominid fossil finds
(Mary Leakey's
Zinjanthropus
, Louis Leakey's
Homo habilis
, Donald
Johanson's
Australopithecus
“Lucy,” and so on) showing that more
than one species of hominid must have coexisted at many points in the
course of hominid evolution. Many paleoanthropologists today place
the total number of hominid species at about twenty, in three or four
separate genera (
Australopithecus
,
Paranthropus
,
Homo
, and perhaps
Ardipithecus
and others). Hominid diversity seems to have peaked about
two million years ago, when three, four, five, or possibly even more sep-
arate hominid species coexisted on the planet (and all in East Africa). The
present situation, in fact, where there is only one surviving species,
Homo
sapiens
, seems to be an unusual state of affairs in the five-million-year
span of “human” evolution. There may have been other periods with only
one hominid (prior to about five million years ago, for example, when
the combined number of hominid
and
chimp species may have been no
greater than one), but the last thirty thousand or so years—since the
extinction of the Neanderthals—is certainly unusual in having only one
living representative of the hominid family. Fossil hominid diversity was
not accepted without a struggle, however: there was a certain degree of
ideological resistance stemming from the liberal antiracialist climate of
the post-Auschwitz era, when it was dogmatically assumed that only one
hominid species could exist at any given time (the “single species hypoth-
esis”). This is interestingly tied to the reevaluation of
race
in the early
post-World War II era, when a broad cultural consensus emerged that
the humans living today are more or less equal in terms of cultural worth
and standing in the “family of man”—culminating in UNESCO'
State-
ment on Race
, which branded race an “unscientific” category and “man's
most dangerous myth” (Ashley Montagu's epithet).
3. Molecular anthropology, and the crisis (turning point) stemming from
the recognition that all living humans have descended from a small group
of Africans who lived roughly 135,000 years ago. “Modern humans”
are therefore relatively recent in a
biological
sense, though nothing is
