Sunday, July 16, 2006

Teaching in Wild Meerkats

Meerkats are small, insect-eating mammals in the mongoose family. Lately, Science magazine has splashed a picture of a (really cute) baby meerkat on its website, to highlight a paper about teaching in wild meerkats. BBC News also has a helpful article on the discovery.

It's interesting that they say "the scientists suggest meerkats are only the second non-human animal species found to teach its young actively."

One might think the other species are the usual suspects: chimps or some primate but no, it turns out that "the only other clear demonstration of teaching behaviour in species other than Homo sapiens is, they say, the finding reported earlier this year that ants can help their fellows locate food."

Given that these two instances of teaching are located in groups found so far apart phylogenetically, chances are there are lots of other examples of teaching in the animal kingdom. As the authors of the study say: "The lack of evidence for teaching in species other than humans may reflect problems in producing unequivocal support for the occurrence of teaching, rather than the absence of teaching."

To the meerkat, the cost of teaching is that adults spend less time on foraging for food which they can otherwise feed themselves with. On the other hand, the benefit is that young meerkats will learn faster to avoid dangerous animals which they might mistake for edible ones: accelerating the learning curve might improve survivability of the young and the group in general. So is the evolution of teaching in animals an example of natural selection acting upon a group?

In the ecological context, teaching is a pretty powerful tool: "So teaching might be expected only to evolve where pups would find it hard to absorb information just by watching." Biological defence mechanisms evolved by prey take a while to emerge, but if predators can learn to side-step them, and then pass on this information directly (so that young do not have to learn the whole repertoire of side-stepping tricks entirely on their own) through instruction, then the prey are pretty much done for if they rely entirely upon natural selection. Effectively we are considering the difference between biological and cultural evolution, where 'culture' is taken in the broad sense of socially (as opposed to biologically, e.g. instinct and fixed behavior patterns) transmitted and accumulated knowledge.

This also has some bearing on the ideas of sociobiology, which works on the assumption that many (most?) animal behaviors have a genetic component, thus allowing them to be acted upon by the economy of natural selection. But if many behaviors have a learned component, as this study suggests might be plausible, then it'll be impossible to use a simple genetic model to understand the heritability of behavior.

Perhaps it will be instructive to look at behavior in other social animals, or in the relatives of the meerkat (that include the toddy cat that sits on the palm leaf of the Raffles Museum logo). Singapore is well placed for such study, being sited in the middle of the SE Asian biodiversity hotspot. Who knows who might author the next headlining article in Science?

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