I’m really not sure about this at all:
Researchers were astonished to find that cabbage aphids sacrifice their lives to protect other members of the colony when a predator attacks.
I get the research, but not the surprise.
They suggested that because so many of the members of a colony were clones of each other the sacrifice of one had little impact on the genetic make-up of the group.
Isn’t that almost what we’ve come to expect from clonal colonies?
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Indeed, I am pretty certain Richard Dawkins discusses it in “The Extended Phenotype” which was out around 1982. The researchers may have been astonished, but as you point out, I can’t imagine the scientific community at large finds it particularly astonishing. Perhaps they can amaze us with the astonishing find that bees sting even though this results in their death.
There’s a difference between committing suicide and acting in a suicidal way with the expected outcome – A soldier who makes a “suicidal” attack on a pillbox is not committing suicide.
ChrisM, wasn’t it the Selfish Gene where he hypothesizes its genetically ‘sensible’ or worthwhile to sacrifice yourself for >2 siblings or >4 cousins or something like that? This is the same and as already stated, completely unsurprising.
Zorro. He may well have mentioned it in both. (I think the slefish gene is a 1976 book, making the aphid news still less news).
I don’t recall which one I read it in. I assumed it was the Extended Phenotype one because the whole concept was how the genes’ expression (phenotype) was not just the organism they reside in, but anything the genes directly or indirectly control, leading to the conclusion that a colony was a phenotype because one genotype controls it. I think the Brothers vs Cousins point you mention is very similar in that it relies on a genes’ eye view of things to make sense of it. But in the case of bothers and cousins, although there are genes in common, the genotypes involved are all different.
It’s Hamiltonian kin selection as the mechanism for altruism. Degree of relatedness between organisms does indeed affect behaviour. There is also the factor in a large number of insect species that some members of the species are not reproductives and therefore the only means by which they can influence the success of their genes in the future is to increase the fitness of the reproductives. ‘Suicidal’ behaviour is only to be expected under these circumstances.
In case anyone else was wondering, it’s
this Hamilton. His memorial service was very good, though it was most peculiar to see Dawkins giving a reading in a chapel.
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