KP 271: Lubenow (1992)
states that this lower humerus is indistinguishable from a human bone,
Parker and Morris (1982) state that it is a human bone. Lubenow quotes a
number of scientists who state that KP 271 is very humanlike. He does not
quote from Feldesman (1982), who found that KP 271, "far from being more
'human-like' than Australopithecus, clearly associates with the
hyperrobust Australopithecines from Lake Turkana".
KP 271 has usually been assigned to the australopithecines
(and recently to A. anamensis) because no other hominids
are known from 4 million years ago.
Although Lubenow considers this conclusion
"shocking", there are plausible reasons for it. The
lower humerus of chimps is very similar to that of humans, and it
is reasonable to suppose that australopithecines would be even
more similar, especially since the upper end of the humerus in
australopithecines is known to fall within the human
range. Patterson and Howells (1967) state that both KP
271 and an australopithecine upper humerus were, based on their
measurements, virtually identical to some modern humans, yet
Lubenow is able to conclude that KP 271 is "strikingly
close" [his italics] to modern humans, while the upper
humerus is only "quite similar, based on visual
assessment".
Lubenow's claim that the lower humerus is "relatively
easy to discriminate between humans and other primates" is
incorrect. Patterson and Howells say that "it is difficult
to identify family from only the distal end of the hominoid
humerus". Most of the measurements they used had
considerable overlap between humans and chimps. Because of this,
they were forced to use multivariate analysis, but even this
advanced statistical technique was not able to completely
distinguish human and chimp populations. Because the lower
humerus is such a poor diagnostic indicator, it was premature to claim
that KP 271 can not be an australopithecine fossil.
The claim that KP 271 was human has been one of the stronger
creationist arguments because, although it had not been proven,
neither was it demonstrably wrong (unlike almost every other
creationist argument about human evolution). However a recent
paper now strongly indicates that KP 271 is an australopithecine
and not a human fossil.
Lague and Jungers (1996) conducted an extensive study of the
lower humeri of apes, humans, and hominid fossils. They used
multivariate analysis, a technique which is highly praised by
creationists when it delivers results favorable to them. Lague
and Jungers' results show convincingly that KP 271 lies well
outside the range of human specimens. Instead, it clusters with a
group of other hominid fossils so strongly that the probability
that it belongs to the human sample, rather than fossil hominid
group, is less than one thousandth (0.001). They conclude:
"The specimen is therefore reasonably attributable to
A. anamensis (Leakey et al. 1995), although the
results of this study indicate that the Kanapoi specimen is
not much more "human-like" than any of the other
australopithecine fossils, despite prior conclusions to the
contrary" (Lague and Jungers 1996)