REVILLE COLUMN: Biology explains, or tries to, all human characteristics as products of evolution. Such explanations are much easier achieved for some characteristics than for others.
It was particularly difficult to explain how evolution could have produced altruism, but a tentative explanation is now available. Extended discussion can be found in This is Biology by Ernst Mayr (Harvard University Press, 1997) or at www.theunityofknowledge.org
Altruism is the practice of unselfish concern for the welfare of others. It is observed, not only in humans, e.g. helping a charity that offers no benefit to us or our loved ones, but also in other animals, for example chimpanzees.
Four different forms of human altruism are observed - altruism towards kin, towards romantic partners, towards friends, and towards other individuals. Each can be explained in evolutionary terms.
"Selfish gene" theory is the modern version of the theory of evolution by natural selection. This new version views evolution from the perspective of the genes (the coded genetic information in each organism) rather than of the whole organism.
The more a gene increases the reproductive success of an organism, the more likely it will spread through the population over the generations. The real beneficiary of evolutionary success is the gene, because it can exist over the generations, whereas an organism can only last for one generation.
It can be said that a gene, in acting to enhance the reproductive success of an organism, is acting ultimately in its own interest and not that of the organism in which it resides, hence the title Selfish Gene theory. This is metaphorical language. A gene is a chemical (DNA) and is incapable of motivation.
To take matters a step further, it can be appreciated that a gene can also spread through a population, even if it reduces an animal's chances of survival and reproduction, if, in doing so, it increases the chances of survival of a close relative. This is the basis for the evolution of altruism towards kin and romantic partners.
Consider an animal who possesses a gene that predisposes it to show altruism towards offspring, parent or sibling. Because there is a high chance that the recipient of such altruism also possesses this gene, such acts will cause that gene to spread.
This could explain the evolution of family love. The more closely related two people are, the greater the chance they will also possess this gene and, hence, the greater the love.
Romantic partners are usually not related, but both have an interest in the well-being of their offspring. Any gene that causes altruism towards any other who also has an interest in their offspring, who will also likely possess this gene, will spread throughout the population.
The evolution of altruism between friends is explained on the basis that a lasting relationship between two people with similar interests, or complementary skills, benefits both even without acts of altruism being carried out. But because the relationship is mutually beneficial, each has an interest in the welfare of the other and this underpinned the evolution of the human tendency to form bonds of friendship. Again, none of this reasoning is consciously felt.
The fourth form of altruism is between people who are neither kin, romantic partners nor friends. Reciprocal altruism evolved because it is often possible to perform an altruistic act that benefits the recipient more than it costs the altruist. If this altruism is reciprocated, both benefit.
An example of an altruistic act that benefits the receiver more than it costs the giver is food- sharing. Consider an animal who kills another animal that is too large to be eaten entirely before it putrefies. If the excess is given to others to eat, this presents no cost to the giver, but greatly benefits the receiver.
The problem is to visualise how reciprocal altruism could get established in a group in the beginning. Why would the initial recipient of altruism bother reciprocating, particularly when there will usually be a delay before they will have an opportunity to reciprocate? Why not cheat?
The answer is that while cheating may work in the short-term, no altruist will be tricked twice. In the long term it is better to reciprocate and benefit from many further acts of altruism directed towards you. The benefits of this strategy greatly outweigh the benefits from cheating once.
If altruism, love, and so on are biologically programmed, what are the implications for our notions of morality?
I believe the concept of free will remains valid. We are each self-conscious and reasoning and we can rise above our biological foundations. Although the foundation of a house is an essential support for the structure built on it, the form of that structure can be varied to a great extent depending on the imagination of the architect.
Also, of course, the fact that our commonly accepted rules of morality have a biological as well as a rational/moral basis doesn't weaken the power of the rational/moral. It just means that these rules make sense no matter how you look at them.
William Reville is associate professor of biochemistry and director of microscopy at UCC