Next semester will bring a new course. one I’m calling Ecology, but presently, only one half of the class appears to be ecology, while the second will cover molecular biology and topics of Biotech and Recombinant DNA Tech.
We will be using E.O. Wilson’s 1971 text, Primer of Population Biology as a primary source of material in the first unit, so far I’m not sure what to use for the second unit.
Chapter 6 of Richard Dawkins’ opus, The Selfish Gene, is titled ‘Genesmanship.’ This chapter discussed the array of strategies that genes appear to take in order to guarantee their immortality.
-Immediately, I must say that Dawkins has already assured us that any altruistic speech about the intent of genes is given merely to provide suitable language for the discussion rather than to actually attribute any actual wants or needs of the genes in question. Further, the term ‘strategy’ is used in precisely the same way; if genes had brains, their actions could be described as strategy, but in the absence of this consciousness, their action merely resembles a strategy.
In this chapter Dawkins faces one of the most difficult conundrums for evolutionary biology: altruistic behavior. If genes truly do act in a selfish manner, how can acts of altruism be explained. This is not a new problem. Other biologists (including J.B.S. Haldane and W.D. Hamilton) had previously addressed this problem providing responses that approach an answer, but aren’t sufficiently quantifiable to satisfy Dawkins – and they shouldn’t be to you either.
The solution Hamilton et al approached was to recognize something called kin selection. This is putting a title of the idea that it is worthwhile to accept some risk to your own hide in order to keep your kin alive. The reason for this is plain, if genes are in the business of perpetuating themselves, then any body that contains them is as good as any other. By adding the notion of genetic distance, there is a quantifiable way to account for the extent to which another person in your kin group also carries your genes.
How does this become quantifiable? Simply, by using a value for relatedness to compare against the risk of ‘sticking your neck out’ for your kin. For example, you are related to yourself 100%. You carry 50% of your mother’s genes (and vice versa) and 50% of your father’s genes (and vice versa). An identical twin sibling would bear 100% of your genes as well, while a non-twin would bear only 25% of your genes. Given this, you are most likely to rescue your twin, then your parent (or offspring, who bear the same relatedness) and then your other sibling.
Hamilton described the following equation to model altruistic behavior:
where B is the benefit gained by the individual who is helped, times a relatedness factor r – as discussed above, and C is the cost to the individual who is acting altruistically.
Atop this, one might assume that a younger person is worth more than an older person to you because they are more likely to add copies of your genes to the gene pool in the future. So, If your father and your son have both fallen into the sea during a violent storm, you would put your son’s rescue ahead of your father’s.
Although this may explain a lot about how kin groups will work together to defend a family/tribe from outsiders, it involves a lot of calculating (how many cousins would I have to save to be worth one sibling?) that is unlikely to be happening in the real world. One person who noticed this and started doubting whether kinship calculations were realistic explanations for altruism was EO Wilson.
And this is odd. Odd, because it was Wilson who was a keen supporter of Hamilton’s work early on. But, like any good scientist, Wilson was ready to throw any or all of his ideas in the trash if a better explanation presented itself. (Am I being fair? Not really – scientists are humans and all humans cling to their ideas and identify with them, but scientists at least acknowledge that this is wrong and will come around to sensible thinking.)
Wilson was interested in the question of altruism for good reason. His passion is the insect world – and not just any part of the insect world, but the world of ants. Who isn’t interested in ants? You might think you don’t care, but spend a moment watching them work and you’re spellbound. How do these tiny creatures carry out such amazing actions? They build, they problem-solve, they farm – livestock and horticulture and they’re social.
It’s the social behavior that holds Wilson’s interest. It bears repeating what social means in this context. We, in our human lives think of social in a lot of ways: saying hello to people you work with, tipping your barber and pizza delivery guy, dating and – recently – even computers (the definition of antisocial for decades) claim to be social. Twitter, tumblr, facebook, myspace(?), etc. But none of this fits the definition of social that ants engage in. Ants, like a number of their hymenoptera kin, are social to the extreme. Sure, they organize and divide labor amongst their numbers. Some are specialized so much that a glance will tell you who is the soldier and who is the worker.
These animals divide duties so rigorously, that even reproduction is done only by specialized individuals. If you think about evolution a lot, and subscribe to Dawkin’s selfish gene idea, then this arrangement needs explanation. Why do all these sister ants work so hard if they don’t get to pass on their genes?
But they do. Just like all the cells of your body that work together for the good of the organism. The cells of your arm – or your heart – or your brain – don’t get to reproduce. Only your sex cells do. But your arm and heart and brain all benefit from that because they are genetically identical. When your sex cells make a baby, all the genes of the organism get passed on, not just those of the sex cell – again, because they are all identical. Dawkins describes your body as one big survival machine built to pass on genes. I would be willing to bet that Wilson would describe ants using much the same language. The only difference being that ants have made a leap from specialization at the cellular level, to specialization at the organismal level.
So ants are social (and so too are bees and many wasps, etc). Does this have anything to do with altruism? Dawkins says yes. At the level of the social organism, we have pure altruism. Every being is tied to the survival of the group as intimately as every cell in your body is tied to the survival of your body as a whole. It’s tempting to say that identical twins should feel the same way. The survival of each individual is worth less than the survival of at least one of them, so twins should show the same degree of altruistic behavior between one another as our ants do.
But there is a difference. Social insects have mastered altruism to such an extent that they build it into their makeup from the start. Soldier and worker ants simply do not mate in most species (approximately 100 species of 12,000+ known do have workers that mate, but that appears to be the exception)1,2. Because the workers are not reproductive and are not even built for reproduction and identical twins do – so it’s not a fair comparison. Altruism is not truly altruistic if acting selfishly does not benefit you more than being pro-social.
And this is essentially where Wilson comes in, he extends this idea to species that are not genetically tied arguing that altruism doesn’t count when it’s selfish. And here he meets Dawkins, because Dawkins does believe that altruistic behavior is selfish, and that all altruistic behavior can be calculated (or at least approximated) based on relatedness. It is from this highly related group that benefits from pro-social behavior that society emerges. Wilson says this calculation is too unwieldy to represent what is done in real life and that behavior that appears altruistic can always be explained by straight up selfishness. In fact, he thinks that it is society that gets the ball rolling by promoting pro-social behavior among previously selfish individuals.
So, what do you think?
Peeters, C. “The occurance of sexual reproduction among ant workers” Biological Journal of the Linnean Society (1991), 44: 141-152.