Genetic Altruism Essay Research Paper Altruism is

Genetic Altruism Essay, Research Paper

Altruism is thought of as being behaviour exhibited by one individual to benefit another, with no direct gain but at some cost for that first individual. Apparent altruism is the idea that although behaviour may seem to be fully altruistic (i.e. non-selfish) behaviour there is actually a gain for that individual. Genetically this gain tends to refer to the fitness of the individual i.e. their reproductive success.

It was Darwin who first suggested the problematic paradox introduced by some altruistic behaviour. Darwin’s initial theory of evolution (1859) is based on the idea that all individuals live to reproduce, therefore some behaviour, for example a mother shielding her child from a fatal instance (e.g. a predator etc…) was not beneficial to that individual i.e. it would hinder and not benefit their ability to reproduce later on. It was Hamilton (1963) who suggested that the reproductive success of an individual did not necessarily relate to the individual’s ability to reproduce but related to the individual’s ability to pass on their genes. This then means that the ability of an individual to pass on their genes is done through, not only supporting of their own offspring but also by ‘facilitating the reproductive potential of their relatives’ (Cardwell 1996). This is referred to as the Kin Selection Theory i.e. the idea that apparent altruistic behaviour is, in fact, nepotistic, i.e. beneficial to those with whom genes are shared, therefore providing us with a genetic reason for apparently altruistic behaviour.

One example to argue in favour of the Hamilton’s Kin Selection Theory is the instance, in which, bees will commit suicide if the life of their queen is threatened or in danger. We could argue that this is truly altruistic behaviour; that the bees choose to sacrifice their own lives to save their queen as a results of their ’social’ programming but simply by agreeing with Darwin’s evolutionary ideal that all organisms live to reproduce we must take into consideration that many ‘worker’ bees, like ants are unable to reproduce. Therefore the duty of worker bees and ants is not to ensure their own individual reproduction but to ensure the reproduction of their genes through the GROUP in which they live. Therefore the suicidal act of a hive of bees to save their queen is not programmed to be altruistic but is programmed to ensure that those, whom have the responsibility of continuing the replication of their genes i.e. the queen, continue to live.

Hamilton also argued that the degree to which apparent altruism is shown is proportional to degree of genetic relatedness between individuals, therefore the more genes that are shared the more one would facilitate the needs of another individual. Hamilton refers to this as ‘inclusive fitness’ (1963) the idea that to those whom you are closely related you are more likely to exhibit altruistic behaviour than those to whom you are distantly related. This then suggests that altruistic behaviour shown towards those whom share 50% your genetic make-up (the same amount as your off-spring) might be phenotypically altruistic but is still genetically selfish (Barash 1982) i.e. the relative to whom you are exhibiting altruistic behaviour may not possess similar phenotypes (for example they might have brown hair, while you have blond) but still possess genes which are similar enough to yours to warrant that any altruistic behaviour shown would be in your own interests and would go towards fulfilling your genetic aim.

One example of this is the instance studied by Sherman (1981) in which it was found that Belding’s ground squirrels would not show aggressive behaviour to close relatives (e.g. sisters, mothers, daughters), sharing resources such as food and burrow sites and would even defend each other against other aggressors. It is argued by Hamilton that this is due to the inclusive fitness principle i.e. the idea that all organisms examine the cost and benefit. In this case the cost of sharing resources, burrow sites and the energy expended in defending one another are out-weighed by the benefits in ensuring the survival of close relatives, therefore ensuring your genetic material will be shared by descending generations. The same cost when the benefit is less (when it is not a close relative, for example, a third cousin) creates a situation in which the large cost is not justified by the minimal benefit to the organism. This is why animals are less likely to show altruistic behaviour to those more distantly related.

The second genetic explanation for apparent altruistic behaviour is Reciprocal Altruism. This is an instance in which, unlike the Kin Selection Theory where the genetic benefit is directly seen by the organism, the genetic benefit is not so automatic. In Reciprocal Altruism (also described as Delayed Reciprocal Altruism) altruistic behaviour is shown with the assumption that it would be reciprocated in the future, therefore enhancing the organism’s fitness (i.e. ability to reproduce) at some point in the future by returning the favour. This means that although altruistic behaviour is being shown to organisms whom are unrelated, therefore eliminating the Kin Selection Theory this behaviour is still genetically beneficial. Instances such as this, for example, where young baboons without mates will work together to steal a dominant male’s mate (Pac