Evolutionary biologists at McGill University have discovered molecular signals that can maintain social harmony in ants by putting constraints on their fertility. Dr. Ehab Abouheif, of McGill’s Department of Biology, and post-doctoral researcher, Dr. Abderrahman Khila, have discovered how evolution has tinkered with the genes of colonizing insects like ants to keep them from fighting amongst themselves over who gets to reproduce.
“We’ve discovered a really elegant developmental mechanism, which we call ‘reproductive constraint,’ that challenges the classic paradigm that behaviour, such as policing, is the only way to enforce harmony and squash selfish behaviour in ant societies,” said Abouheif, McGill’s Canada Research Chair in Evolutionary Developmental Biology.
It’s unfortunate that group selectionism is gaining some traction once again. It almost never makes any sense and simply acts as a way of taking the easy explanation over the difficult answer.
This study found that evolution has changed the genetic make-up of ants to the point where social harmony is achieved through “reproductive constraint”. In other words, some worker ants have less or no fertility level relative to others because of particular gene regulations. Big deal. This doesn’t point to any group selectionism.
What makes far more sense is that ants which promote social harmony are more successful on average. Instead of looking toward the goal-oriented ideas of group selectionism, it’s more reasonably to view this as individual genes promoting their own fitness. That is, most ants in a colony, if not all, are going to share a high degree of genes. It isn’t that the vehicle for these genes – the organism, in this case, the ant – is important. The survival of the gene itself is important. With more harmony comes, perhaps, more reproduction and more success. And what’s being reproduced are a high number of shared genes.
Think of it this way. My brother and I share 50% of our genes. If I help him to reproduce, I have roughly 25% of my genes surviving to the next generation. Of course, if I simply reproduce on my own, that’s 50% of my genes that will be passed on. But if I’m fighting with my brother over the same woman, we decrease our reproduction odds. It may just benefit me on the level of the gene to help him reproduce at my own expense. Having assistance will help his odds (even if this assistance is passive, as in not fighting him). This will give 25% of my genes a better chance of surviving than the 50% of genes I ‘own’ have when there is conflict.
Rather than showing the notion of group selectionism to be valid (though it remains plausible), this research offers some interesting evidence which favors natural selection occurring at the level of the gene
Filed under: Evolution, News | Tagged: Canada Research Chair in Evolutionary Developmental Biology, darwin, Dr. Abderrahman Khila, Evolution, group selection, McGill University, natural selection, reproductive constraint, Richard Dawkins, sciencedaily.com, selfish gene, the selfish gene | 8 Comments »