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)