Selfish traits not favoured by evolution,
study shows
By Melissa Hogenboom
Science reporter, BBC News
2 August 2013 Last updated at 10:29 GMT
Humans and animals could not evolve in a co-operative environment by being selfish, scientists say
Evolution does not favour
selfish people, according to new research.
This challenges a previous
theory which suggested it was preferable to put yourself first.
Instead, it pays to be
co-operative, shown in a model of "the prisoner's dilemma", a
scenario of game theory - the study of strategic decision-making.
Published in
Nature Communications, the team says their work shows that
exhibiting only selfish traits would have made us become extinct.
Game theory involves
devising "games" to simulate situations of conflict or co-operation.
It allows researchers to unravel complex decision-making strategies and to
establish why certain types of behaviour among individuals emerge.
“
Start Quote
It's almost like what we had
in the cold war, an arms race - but these arms races occur all the time in
evolutionary biology”
Dr Christoph Adami
Michigan State University
Freedom or prison
A team from Michigan State
University, US, used a model of the prisoner's dilemma game, where two suspects
who are interrogated in separate prison cells must decide whether or not to
inform on each other.
In the model, each person is
offered a deal for freedom if they inform on the other, putting their opponent
in jail for six months. However, this scenario will only be played out if the
opponent chooses not to inform.
If both
"prisoners" choose to inform (defection) they will both get three
months in prison, but if they both stay silent (co-operation) they will both
only get a jail term of one month.
The eminent mathematician
John Nash showed that the optimum strategy was not to co-operate in the
prisoner's dilemma game.
Co-operating is key for evolution
Co-operating
is key for evolution
"For
many years, people have asked that if he [Nash] is right, then why do we see
co-operation in the animal kingdom, in the microbial world and in humans,"
said lead author Christoph Adami of Michigan State University.
Mean
extinction
The
answer, he explained, was that communication was not previously taken into
account.
"The
two prisoners that are interrogated are not allowed to talk to each other. If
they did they would make a pact and be free within a month. But if they were
not talking to each other, the temptation would be to rat the other out.
"Being
mean can give you an advantage on a short timescale but certainly not in the
long run - you would go extinct."
These
latest findings contradict a
2012 studywhere it was found that selfish people could get ahead
of more co-operative partners, which would create a world full of selfish
beings.
This
was dubbed a "mean and selfish" strategy and depended on a
participant knowing their opponent's previous decision and adapting their
strategy accordingly.
Crucially,
in an evolutionary environment, knowing your opponent's decision would not be
advantageous for long because your opponent would evolve the same recognition
mechanism to also know you, Dr Adami explained.
This
is exactly what his team found, that any advantage from defecting was
short-lived. They used a powerful computer model to run hundreds of thousands
of games, simulating a simple exchange of actions that took previous
communication into account.
A previous study found that selfish strategies were favourable
"What
we modelled in the computer were very general things, namely decisions between
two different behaviours. We call them co-operation and defection. But in the
animal world there are all kinds of behaviours that are binary, for example to
flee or to fight," Dr Adami told BBC News.
"It's
almost like what we had in the cold war, an arms race - but these arms races
occur all the time in evolutionary biology."
Social
insects
Prof
Andrew Coleman of Leicester University, UK, said this new work "put a
break on over-zealous interpretations" of the previous strategy, which
proposed that manipulative, selfish strategies would evolve.
"Darwin
himself was puzzled about the co-operation you observe in nature. He was
particularly struck by social insects," he explained.
"You
might think that natural selection should favour individuals that are exploitative
and selfish, but in fact we now know after decades of research that this is an
oversimplified view of things, particularly if you take into account the
selfish gene feature of evolution.
"It's
not individuals that have to survive, its genes, and genes just use individual
organisms - animals or humans - as vehicles to propagate themselves."
"Selfish
genes" therefore benefit from having co-operative organisms.
The
selfish gene?
In
1974, Richard Dawkins published
a gene-centred view of Charles Darwin's theory of natural selection.
He
argued that it was not groups or organisms that adapt and evolve, but
individual genes and each living organism's body was a survival machine for its
genes.
Prof
Andrew Coleman from Leicester University explains that this new work suggests
that co-operation helps a group evolve, but does not argue against the selfish
gene theory of evolution.
Rather,
he adds, it helps selfish genes survive as they reap the awards of inhabiting
co-operative groups.
http://www.bbc.co.uk/news/science-environment-23529849
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