A recent article titled ‘Protective buttressing of the human fist and the evolution of human hands’ rests on the assumption that human evolution has been characterised by competition for mates, however despite modern human’s propensity for violence and competition, it is an assumption that should not be taken for granted. 

A recent study by Michael H. Morgan and David R. Carrier titled ‘Protective
buttressing of the human fist and the evolution of human hands’ makes clear that the
human hand has unique proportions that allow it to be used effectively as a
fist. They suggest this is no accident – rather that the fist evolved to help
males compete for mating opportunities. However the premise of a competitive
past should not be accepted without questioning.

E.O. Wilson certainly thinks violence is in our blood
– or rather genes - saying in his latest 2012 book The Social Conquest of
Earth,
that “wars and genocide have been universal and eternal, respecting no particular
time or culture”. Indeed, even before Darwin’s idea of
natural selection was re-named by Herbert Spencer ‘survival of the fittest’,
the idea that our nature was a reflection of ‘nature red in tooth and claw’ was
widely held. 

Theories that rely on violence
as a potent force in hominid evolution suggest that it is a continuation from
an earlier primate state. Raymond Dart was the first to propose such a link, when
in the 1950s he put forward his killer
ape theory. In it he argued for the “predatory transition from ape to man”. Later
the anthropologist Robert Ardrey wrote that “man has
emerged from the anthropoid background for one reason only: because he was a
killer.”

Recently, the primatologist Richard W. Wrangham put forward the ‘chimpanzee
violence hypothesis’, which says that “selection has favoured a tendency
among adult males to assess the costs and benefits of violence, and to attack
rivals when the probable net benefits are sufficiently high.” Wrangham asserts
that this instinct is behind human’s history of warfare. 

So it is understandable that Morgan and Carrier accept a violent
evolutionary heritage as a foundation from which to hypothesise as to why the
human hand has developed the proportions it has. “Great apes” says Carrier, “are
a relatively aggressive group with lots of fighting and violence, and that
includes us”. However Carrier also made the interesting admission that not all
primates are violent, adding the important caveat, “with the notable exception of bonobos”.

There are scientists that do not assume that human evolutionary history is
a violent one. I.J.N. Thorpe for example, suggests that the archeological
record does not support the idea of a continuation of violence from an earlier,
violent primate state. Similarly, both the anthropologist Richard
Leakey, and the primatologist Robert W. Sussman, suggest that violence is a
relatively recent development in human history. 

In particular, the biologist
Jeremy Griffith says that bonobos – Carrier’s ‘exception’ – represent a living
model of human’s ancestors Australopithecus.
Griffith accounts for human’s current propensity for violence, saying it is not
a continuation of primate violence, but rather, that it is psychologically
derived – the result of a clash between an emerging consciousness and a
pre-established instinctive orientation. Prior to 2 million years ago, Griffith
says that our ancestors were still led by cooperative instincts, as bonobos currently
are today; and further he gives a credible
explanation for bonobos’ current cooperative state and humans’ cooperative past
– a process derived from nurturing that he calls ‘love indoctrination’.

The
case for bonobos representing a model of human evolution is a solid one. Not
only does the bonobo share (along with the common chimpanzee) more human DNA than any other primate (approximately 98%), but compared with common chimps, and indeed all other
primates, they appear to be most advanced in developing the particular traits
that define humans.

For
example, bonobos are more bipedal than any other primate; they are more neotonous
than common chimpanzees (humans have been described as “the neotonous clan of apes”); and while intelligence tests are hard to
calibrate, it appears that of all the non-human primates, bonobos have a unique
aptitude for language and conceptual thinking. Incidentally, unlike other theories such as Brian Hare's self-domestication hypothesis, Griffith’s theory does account for all these aspects.

The problem that this presents
for the ‘fist as weapon hypothesis’ is that bonobos have no use for a fist in
winning mating opportunities. As reported by Furuichi, and
later Hohmann
and Fruth, male bonobos do not physically
contest for mating opportunities. Instead,
as reported for example in a 2011 article by Martin Surbeck,
published in the Proceedings
of the Royal Society, bonobo males’ mating
success is largely influenced by the support of their mothers.

In
summary, should bonobos better represent human’s ancestors than other, more violent
species of primates, and indeed, violent competition does not characterize
human evolution, the main plank supporting Morgan and Carrier’s hypothesis is
removed. This would result in not only their theory missing the mark, but so
too, many other theories that rely on violent competition to account for human
evolution.