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cus, which has held sway in the literature for over a century. Further,
the identity of the small feature on the left side of LB1's virtual endocast
that we initially recognized as a lunate sulcus in a posterior humanlike
position (arrow 2) may simply have been a small crescent-shaped sulcus
on the brain's surface that lacked the other attributes of lunate sulci at
deeper levels, as is the case for the small percentage of human brains
that superficially appear to have lunate sulci . 9
In any event, no signs of a lunate sulcus in a forward apelike posi-
tion appeared on LB1's virtual endocast, contrary to the expectations
for a similarly sized ape brain. Although the humanlike projection of
LB1's occipital lobes was an advanced trait, this region was not as full or
protuberant as that of the much larger-brained Homo erectus (figure 17). A
likely functional interpretation is that LB1's expanded posterior associa-
tion cortex was related to an increased ability to synthesize information
from multiple senses. Indeed, this interpretation was offered over a cen-
tury ago by Elliot Smith when he speculated about the enlargement of
the posterior association cortex during hominin evolution. He further
suggested that this region enlarged in conjunction with the evolution of
both bipedalism and bigger brains. I think Elliot Smith might have been
as surprised as I was to see protruding occipital lobes and the lack of an
apelike lunate sulcus in a brain as small as Hobbit's.
In addition to being diminutive, Hobbit's endocast was extremely
wide because of expansion at the back of its temporal lobes (arrow 3
in figure 18). This is interesting, because the temporal lobes of human
brains are relatively expanded compared with the other lobes, although
they do not appear to be nearly as relatively wide as LB1's. 10 (Until
recently, the overall size of the human frontal lobe was also thought to
be relatively enlarged, but thanks to research by Katerina Semendeferi
and others, this is no longer believed true.) 11 Although interpreting the
expansion at the back end of LB1's temporal lobes from a functional
point of view is difficult, this region is generally known to be associated
with the recognition of objects and faces in people and other primates. 12
As discussed in chapter 5, also fascinating is the speculation of the cog-
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