Behaviour, Development and Evolution - an Introductory Blog (2/3)

The Importance of Adaptation

From an early stage in its life each individual has to deal with many challenges.  When young its ecology may be very different from that of the adult, in which case it may have special adaptations to deal with those conditions. Like a caterpillar before metamorphosing into a butterfly, a human child has adaptations to deal with each stage of its life cycle. The prevalence of play in the young is an example.

Despite the changes in the individual’s repertoire of behaviour as it grows up, early experience can have long lasting effects on its preferences and habits when it finally matures. These aspects of its behaviour are often stable, but in stressful conditions they may change when the stress is accompanied by new forms of experience. The change can be adaptive since it can enable the individual to cope with a world that may be very different from the one in which it grew up.

Parent and offspring are often thought to be in conflict. On this view, the communication between them takes the form of mutual manipulation. The offspring seeks to gain maximum advantage from its parent and the parent seeks to defend its long-term reproductive interests. Against this view, communication is often such that both the sender and receiver of a signal or cue may benefit by both parties treating it as useful to themselves. In the case of parent-offspring relations, parents do well to take into account the condition of their offspring and the offspring must likewise pay attention to the condition of their parent. In other words, their interactions are adaptive for both parties.

Like humans, many animals choose their mates carefully. This is especially true in birds and many mammals. Inbreeding has costs but so too does excessive outbreeding. The way in which an optimal balance is achieved is in part through experience with close kin in early life leading to a preference for a mate who is a bit different but not too different from familiar kin. An important issue is whether the avoidance of incest found in most human societies serves the same function as the avoidance of inbreeding. A common function is questionable and the taboos or more likely to be an expression of conformism directed at individuals doing what most people would not do.

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