Re: FWD: free will and fitness

Wed, 1 Jun 1994 17:46:00 PDT

Wilson writes:

"Wasn't there some work done in last couple of years that linked fitness
with suicide...something along the lines of a suicide victim actually
increasing the fitness of his blood relations by decreasing pressure on
limited resources?"

To give the comment a bit more context, one could ask: since suicide reduces
your fitness to 0 if you commit suicide before you reproduce, how is it
possible to have such a behavior arise via selection? The answer, to which
you refer, involves inclusive fitness: If my loss of fitness is "made up" by
increased fitness achieved by my relatives by my action, then the net fitness
(from the viewpoint of the supposed allele for suicide) could be positive and
so there would be selection (so the argument goes) for such an allele.

BTW, a similar argument has been made for homosexuality, again a behavior
which appears to reduce individual fitness, hence should be selected against.
Posit that the homosexual makes up for lost individual fitness by acting in a
manner that increases his/her relatives' individual fitness. If the net
result is an overall increase in the fitness of the allele, then the allele
for homosexuality would increase.

Note that in both arguments (assuming you accept them as adequate arguments),
the allele in question would not increase to a frequency of 1 since as the
number of recipients of the fitness increasing behavior decreases, then the
net inclusive fitness will no longer be positive: i.e, no inclusive fitness
accrues from a population in which all commit suicide, for example.

D. Read