Jun 03 2010

Altruism in Squirrels

Creationists always seem to be about 100-150 years behind the times in their understanding of evolutionary theory. They keep raising arguments that were dealt with by Darwin himself, and think that giving it a new name is enough (like irreducible complexity). One assertion I frequently hear is that evolution cannot explain altruism. For example, from Apologetics Press:

Altruism is in direct conflict with evolutionary theory. Yet, evolutionists always have been able to put a spin on it. As Buchanan acknowledged: “For several decades, researchers have had a possible explanation: apparently selfless acts are nothing of the kind, but are instead a clever way of promoting individual self-interest” (2005).

They go on to misinterpret research about the role of altruism in a social animal – they actually think that because humans are social and will engage in behavior that is directed toward the benefit of the group rather than the individual, this is somehow incompatible with evolution. They are stuck in the early 20th century vision of evolution as always a brutal fight for survival – nature “red in tooth and claw.”

But cooperation is as much a boon to survival as competition. And in highly social animals there is no confusion as to why there appears to be a balance of instincts towards selfish and selfless acts. This is partly explained by kin-selection – sacrificing oneself so that one’s genes may survive in close relatives. Since our ancestors often lived in small tribes or groups, most of the people they knew were relatives. But social behavior goes beyond kin-selection – there are clear advantages to the individual from getting along, cooperating, and being perceived as not being selfish.

But what about in non-social animals? Squirrels, for example, are notorious loners. There are little or no selective pressures toward behaviors needed to reinforce the social glue, because there is not much of a squirrel society. A recent study sheds some light on this question. University of Alberta researcher Jamieson Gorrell discovered a female red squirrel had adopted an abandoned infant from a nearby tree. The mother was likely taken by a predator. The squirrel already had some young of its own, and only adopted one of the abandoned babies. But Gorrell thought this was curious behavior for a loner like a squirrel.

So Gorrell reviewed the research and found that there were four other cases described in the literature of such adoptions. In every case, the adopted baby squirrel was closely related to the adopting female. This observation has several implications.

First, it indicates that these mother squirrels must be able to recognize their kin, even though they do not (apparently) keep close contact with their sisters and cousins. Researchers hypothesize that the constant chattering of baby squirrels is a means of identity, and can be an indication of kinship.

Further, evolution calculation is apparent in this behavior. Mother squirrels will adopt an abandoned relative so as to pass on more related genes. But they will only pick one squirrel from an abandoned litter, so as not to spread themselves too thin or take away too many resources from their own litter.

It is also interesting how consistent this behavior is among squirrels (at least as has been observed so far – quirky exceptions are expected, but likely not common). It seems reasonable to conclude that this behavior is genetically determined instinct – which establishes that altruistic behavior is a heritable trait and subject to natural selection.

I understand why it might be disconcerting to think that our own behavior, especially our deepest emotions, were crafted by blind selective forces maximizing genetic transfer into future generations. For me, the scientific truth is what it is, and I am comfortable embracing what it is to be human, regardless of our origins. My feelings are no less profound and personally meaningful because they were crafted by evolution, rather than some other process.

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