Sick Hobbits, Quarrelsome Scientists - The Fossil Chronicles - page 147

neath surfaces, relatively wide back ends, nonprotruding occipital lobes,
and stubby temporal lobes, which typify brain shape in microcephal-
ics, also existed in one particular group of small-brained early African
hominins that originated at some unknown date before 2.5 million years
ago . 48 These primitive hominins, the so-called robust australopithecines
(Paranthropus), are not thought to have been our direct ancestors.
However, brain shape had become more advanced in another group
of small-brained hominins that overlapped in time with robust austra-
lopithecines— namely the gracile australopithecines (Australopithecus
africanus) who were discovered by Raymond Dart and who are believed
to have had a more direct evolutionary relationship with humans . 49 Fur-
thermore, while brain size remained relatively static over the evolution
of Paranthropus, it increased dramatically in descendants of Australopithe-
cus. 50 What is particularly intriguing is that microcephalic endocasts are
characterized by pathological shapes in the parts of the brain that Dart
identified as being advanced toward a human condition in Taung and
also that my team independently observed advanced shapes in the same
parts of Hobbit's endocast. I will explore these connections further in
the next chapter. For now, suffice it to say that molecular geneticists are
onto a technique for glimpsing the human past that may turn out to be
very powerful when combined with evidence from the fossil record.
One of the things that struck my colleagues at Mallinckrodt and me
as we proceeded to work on Hobbit's endocast was that the direction of
our research was being channeled toward microcephaly because of the
negative reaction to the discovery of Homo floresiensis by a mere handful
of colleagues. Had you looked into a crystal ball before LB1 was dis-
covered and told us that we would be redirecting our research to focus
on microcephaly, we would have been very surprised, if not downright
incredulous. But shift scientific gears we did. As had happened his-
torically with the other discoveries discussed earlier, scientific evidence
eventually accumulated and prevailed over the unsubstantiated asser-
tions that LB1 was a microcephalic. 51 Consequently, a number of doubters
and fence sitters have now backed away from this belief. But that doesn't