Did you know that humans are violent? The
level of lethal violence is defined as
the percentage of deaths due to
conspecific violence under the number of
total deaths by any means.
Researchers have debated about whether
lethal violence is due to psychological,
societal, or evolutionary factors. This
curiosity over which factor was more
prominent has led scientists to research
lethal violence with an evolutionary and
phylogenetic perspective. Jose Maria
Gomez and his peeps analyzed data to see
if the human race's levels of lethal
aggression is caused by its position on
the phylogenetic tree. First
the researchers analyzed levels of
lethal violence in over 1,000 mammalian
species to determine if there was a
phylogenetic link between aggression and
position on the evolutionary tree. But
what is phylogeny? While it may sound
like an ostentatious word for mucus
phylogeny describes a tree diagram
which demonstrates the evolutionary path
that modern species have taken from
their ancestors. They can be based on DNA
similarities and morphology. Phylogenetic
trees are what the researchers used to
organize and analyze if lethal
violence is passed through evolution.
Not only did they examine contemporary
mammals but they also examined fossil
records looking for imperfections in
bone fragments and other evidence to
suggest a violent death. By examining
fossil records the scientists were able
to gain a better understanding of
violence in both prehistoric and
historic time. Once it was determined
that there was a relationship between
position on the phylogenetic tree and
levels of lethal violence in a species,
Gomez and his associates analyzed fossil
records and written records to examine
lethal violence and human populations
and their ancestors, such as Homo
neanderthalensis- you know those guys
with the big sticks and the latest style
of cheetah hide.
The researchers ended up with two main
results- the first idea they discovered
was that the more territorial and more
social species, like meerkats, had higher
levels of lethal violence than solitary
and anti-social species. They accounted
for this when doing the statistics tests.
Ew, statistics. The second result that
researchers found was the relationship
of human lethal violence over time. They
estimated that the level of lethal
violence from the phylogenetic trees was
2% with a margin of error of
.02% and compared it
to three eras of human history. Human
lethal violence estimate fits under the
approximated percentage of lethal
violence during prehistoric times. During
historic times, surprisingly, the human
level of lethal violence actually grew
higher than expected, but by modern times
we got our act together and lowered the
level of human lethal violence. This can be
accounted for by the evolution of
societal sophistication. One possible
explanation for the existence of lethal
violence in such populations is behavior,
which we discussed in module 4. That
lethal violence was and is a proximate
cause with the ultimate causes being
survival from other threatening
individuals within the population,
fighting as a competition for mates, and
competition for limited food. In
conclusion, Gomez and those other rad
scientists found a phylogenetic
relationship between lethal violence
levels in primates and humans. Since
humans are so closely related to
primates, it indicates that humans
evolved a portion of their lethal
violent tendencies from primates. After
all of the blood, sweat, and tears of the
researchers, they determined that the
human race's position on the phylogenetic
tree has some relation to our level of
lethal violence.
song- "Come On Get Higher" by Matt Nathanson
PS no meerkats were harmed in the making
of this video
