The Accidental Species: Misunderstandings of Human Evolution Read Online Free Page A

but a pathological version of a modern human were varied, but had one aspect in common: they failed to emphasize (or even mention) that LB-1 wasn’t an isolated case that could be singled out as pathological. Remains of the same kind of creature had been recovered from strata at Liang Bua representing an enormous span of time, back to a time before modern humans were known to have existed in the region. This fact alone should have been enough to question any idea that
Homo floresiensis
was a pathological offshoot of modern humans.
    The fundamental problem with the microcephaly idea lies less with the idea of microcephaly, or pathology, than that its proponents subscribe to an untenable view of human evolution—one that can only admit to a single pathway of evolution in which human beings stand at the head of a single line of ancestors, each one progressively improved compared with the one before. In that worldview, Flo can
only
be a human being—in which case one then has to explain how she came to look so odd. Proponents of this view tend to be both passionate and argumentative, and become more so as evidence mounts to discredit it. This suggests that the argument is less about one curious fossil than an attempt to shore up a view of the world that is fundamentally mistaken.
    The same problem besets the assertion that as a consequence of its small brain,
Homo floresiensis
would not have been able to make tools. It is now known that a wide variety of animals can make tools, many of a sophistication to rival anything made by early hominins. Some of these creatures have very small brains indeed—brain size per se need have little or no connection with technical ability. The idea that brain size matters comes from the view that human evolution is progressive, linear, and inevitably improving.
    The problem remained, however, that irrespective of its origins,
Homo floresiensis
really did have a disproportionately tiny head. Scaling a modern human down to Hobbit size would have created a creature with a tiny head, but only if it were pathological. The heads of
Homo erectus
were, in contrast, smaller than those of
Homo sapiens
, so perhaps
Homo floresiensis
would be better seen as a dwarfed (but nonpathological)
Homo erectus
.
Homo erectus
was a remarkably variable species with perhaps a tendency to smallness, 20 something that might play in its favor as a possible ancestor of
Homo floresiensis
. Specimens found in the Republic of Georgia dated to around 1.7 million years ago seem to represent a sample of
Homo erectus
of a primitive, early kind. 21 These creatures were small, some comparable in size with
Homo floresiensis
, but their brains were at least twice the size of LB-1. Shrinking
Homo erectus
down to the size of
Homo floresiensis
would still produce a creature with too large a brain. Flo had to have evolved from something smaller still.
    Two possible solutions presented themselves. One was a study on island dwarfism in now-extinct hippopotamuses that lived on Madagascar, showing that in some cases, the brains of animals subject to island dwarfism would be reduced more than one would expect, even when one scaled a full-sized animal down to midget size. 22 This makes sense in terms of energetics. A possible cause of island dwarfism is that castaways evolve a smaller size in response to the pressure of reduced resources. The brain is, proverbially, the most expensive organ to run in terms of its mass, and so might be expected to evolve a disproportionately small size. Yet such a reduction has its limits. A brain can’t reduce to the extent that function would be impaired. However you look at it, a race of cretins or microcephalics isn’t going to survive for very long. But even when the further downsizing of brains of island species was accounted for, the brains of
Homo floresiensis
looked too small, even for
Homo erectus
.
    The second solution was that
Homo floresiensis
was a dwarfed version of an even earlier, more