||One behavioural characteristic that is still very much with us
today is our fondness for meat with our vegetables. Indeed,
London-based anthropologist Leslie Aiello and her colleague
Peter Wheeler (the originator of the cool heads theory)
suggested that we needed to eat meat in order to facilitate our
brain growth. Brains need lots of calories to fuel them, and
require high-grade nutrients in order to grow. Yet, as Aiello
and Wheeler acknowledged, meat-eating is more a means than a
motive for brain enlargement. They also argue that the parallel
reduction in size of human intestines, as shown by an alteration
of the shape of the ribcage in Homo ergaster, is evidence for a
change to eating more meat than vegetables. In other words, the
oldest true humans had lost the vegetarian pot-belly so
characteristic of australopithecines. But this change in the
ribcage happened before the dramatic brain growth. Early humans
such as Homo habilis, Homo rudolphensis, and Homo ergaster may
have been more scavengers than hun