Homo (KNM-WT 15000 from West
Turkana in Kenya) shows a weakly conical
thorax and, as reconstructed, only a
modestly wide pelvis (17). Still, it belonged
to an immature and thus incompletely
developed individual. At the
same time, the excellently preserved and
widely flaring adult pelvis (SH Pelvis 1)
from the Sima de los Huesos at Atapuerca
in Spain (18) is that of a Neanderthal
relative, and does no more than
confirm that this pelvic conformation is
primitive for the Neanderthal clade.
However, a recently reported adult pelvis
from Gona in Ethiopia (19), dated to
between 1.4 and 0.9 Ma and attributed
by its describers to the same species as
the Turkana specimen, joins more limited
materials described earlier (20, 21)
in showing great robusticity and the
broadly flaring conformation. Available
evidence thus now strongly suggests that
the wide, flat, heavy pelvic morphology
is indeed primitive for the genus Homo,
in which case, the basic body form of H.
sapiens, as well as that of its skull, is
highly derived.
The same can also be said for the
unique mode of cognition possessed by
all living H. sapiens. Alone among organisms,
as far as can be told, our species
exhibits symbolic mental processes.
That is to say, its members deconstruct
the world around them into a huge vocabulary
of mental symbols. These they
combine and recombine in imagination
to describe alternate worlds and situations,
based on a capacity for generating
a potentially infinite array of meanings