Cast = mould?

Context:

at the annual meeting of the Paleoanthro-
pology Society, Kristian Carlson of Indi-
ana University in Bloomington described
the endocast—the impression left inside the
skull by the brain—and suggested that the
forebrain might be reorganized in a modern
way. If so, Au. sediba’s brain and pelvis both
would have begun to evolve into more modern
shapes before the brain expanded, countering
the view that a big brain drove the evolution-
ary remodeling of the pelvis and brain.
Members of our genus were already liv-
ing when these hominins fell into the pit at
Malapa, so these particular individuals aren’t
our ancestors. But de Ruiter said they might
be late members of a species that previously
gave rise to Homo, or a close relative.
Other researchers, who examined casts
of the fossils at the meeting, agreed that on
fi rst glance they represent an unusual mix of
primitive and more modern traits. But most
thought it important to compare Au. sediba
directly with other ancient hominins in more
detail. “The pelvis does look more modern,”
says paleoanthropologist Christopher Ruff
of Johns Hopkins University in Baltimore,
Maryland. “But that doesn’t mean it looks
exactly like a modern human’s or that it gave
rise to early Homo.”
Even if Au. sediba is an evolutionary dead
end, says William Kimbel of Arizona State
University, Tempe, “it does still shed light
on the evolution of early Homo, because we
know nothing about the time period a half-
million to three-quarter million years before