Page 470 - Cultures and Organizations

The Evolution of Cultures 435

Most of these ancestral bands probably also engaged in skirmishes
along territorial boundaries initiated by groups of males. Physical strength,
resilience to disease, and capacity for coordinated collaborative action were
factors that jointly determined the success in these actions. Larger bands
would have assimilated smaller ones, sometimes by killing adult males and
infants and adopting females. Successful groups would have split up when
an aspiring leader left the mother group, followed by part of the group
members. 6
So, fi ssion and fusion of groups has been a mechanism for combining
genetic and cultural evolution for millions of years. The normal course of
evolution among apes has been that separation of subpopulations gradu-
ally led to the formation of new races and, after millions of years, new
species—a process called speciation. In contrast, the splitting and merging
and the exchange of females among our ancestors would have tended to
promote genetic similarity but cultural variation between groups, instead
of genetic divergence and speciation as is usual in the animal kingdom.
Fossil evidence is sketchy and still growing, which means that naming is
still controversial and subject to revision. So far, the evidence suggests that
a few million years ago, several isolated populations of hominins existed
in what is now Africa. They created diversity in genetic materials and
developed into very different forms—for example, the recently announced
“Ardi” (Ardipithecus ramidus), who lived 4.4 million years ago in what is
now Ethiopia, or the well known “Lucy” (Australopithecus afarensis), who
lived in the same area a million years later. Many lineages have died out
since then. No traces of anything but the crudest tool use were found.
From around 1.8 million years ago, brain size started to grow rapidly.
This development was probably associated with refinements in communi-

cation skills and in what evolutionary psychologists call “theory of mind.”
Theory of mind is the level of understanding of the beliefs, desires, and

intentions of others. Today’s humans can understand utterances fi ve levels
of mind deep—for example, “I believe that you think that he hoped that
she would rejoice at his distress.” Theory of mind is crucial for maintaining
moral circles in a socially complex world, and it has gradually developed
during our history.
There are still many guesses concerning this period, such as about
how soon and how often hominins left Africa. The forebears of Homo erec-
tus may have left Africa 1.8 million years ago, giving rise over several hun-
dred thousand years to Homo heidelbergensis, which later evolved into Homo