in Genes underlying altruism published in october of last year, three biologists/researchers think through what “genes for altruism” ought to look like and how we will recognize them (“we” meaning teh scientists!):
(i) Genes underlying altruism should satisfy Hamilton’s rule of rb > c, where r is relatedness of actor to recipient, b is benefits to the recipient and c is costs to the actor. Altruism exists, and to the extent that this type of behaviour has evolved, we expect genetic variation to underlie it. In this sense, there must be genes ‘for’ altruism (genes showing allelic variation that is statistically associated with variation in altruistic behaviour) that are potentially detectable….
(ii) Genes underlying altruism should be environmentally sensitive. If genes for altruism are to evolve, then at least some carriers must reproduce. This inference implies that genes underlying altruism should be conditionally expressed as a function of their social environment….
(iii) Genes underlying altruism should increase in number and complexity with social-behavioural sophistication….
(iv) Genes underlying altruism should coevolve with, or depend on, the previous evolution of genes for kin recognition….
(v) Genes for altruism may reside in regions of low recombination, exhibit co-expression and show modular genetic architecture….
(vi) Genes underlying altruism should be at least partially additive. The evolution of altruism requires heritable variation, and we therefore expect genes for this and other evolved social traits to have significant additive effects that are responsive to kin-mediated selection….
(vii) Genes underlying altruism should exhibit strong pleiotropy. Pleiotropy (multiple phenotypic effects of alleles) should be fundamental to the evolution of altruism, given that it involves combinations of costs and benefits that may be simultaneously physiological, morphological, reproductive and behavioural….
the authors offer some candidate “genes for altruism” (this is a truncated version of their table. i’ve only included the ones for humans here — they also suggested some for eusocial insects):
i think teh scientists should also look for some genes related to violence — particularly tempermental, hotheaded sorts of violence — the kind that raises the testosterone levels of scots-irish, but not yankee, folks when they’re insulted. those types of fly off the handle behaviors, i think, are often altruistic in nature, since the hotheaded individual can be more willing to sacrifice himself in a fight or in battle for his kin.
also, i guess that “genes for altruism” ought to be found in differing frequencies — even variations — in different human populations, especially long-term inbred versus long-term outbred ones.
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