Monday, June 29, 2009

The Centrality of Cooperation in Life: a first installment

A recent story in the New York Times science section about the importance of cooperation in ant colonies reminded us that we've been focused on things like disease and genetic causation in our blog for a while now. So we thought it was time to get back to other things, such as the importance of cooperation in all of biology, not just to ants.

Cooperation was in the subtitle of our book, and for a reason. Ever since Darwin's Origin of Species, whose 150th anniversary is rightly being celebrated this year, there has been what we think is an excessive belief that competition is central to the nature of life. In biology, this ethos is largely about the way that Darwinian evolution, with its stress on competition among individuals within a population, with its genetically determined winners, losers, inherent goods and bads, has fit the nature of our industrial culture's worldview. It is a convenient way to rationalize and hence justify self-interested gain by a few against the many.

Nobody can deny that there is competition in life, in the sense that some individuals do better at reproducing than others. Species have their day, and fade as other species flourish. It's an important mechanism for biological change and was a brilliant insight of Darwin, as well of others in his time (Wallace's attention was more on group competition against environmental limitations, than on individual competition). It helped demystify the origin and nature of life and its diversity.

However, it's not the whole truth about life. Instead, we think, a focus on competition draws disproportionate attention to the long-term historical aspects of life, even if the Darwinian explanation is accurate!, rather than what we can easily see every day before our very eyes. What we see everywhere, every day is mainly cooperation: among molecules within each of our cells, among cells within each individual, and among individuals. In a deep biological sense, if not in one that fits the value-loaded human word 'cooperation', even predator and prey must cooperate: both must be present for each to survive.

Classical evolutionary theory, and a lot of popular science writing based on it, assumes competition to be the fundamental force in life. But absolutely as essential to life is necessity for cooperation at all times and at all these levels--among genes in genetic pathways, among organelles in cells, among cells and tissues and organs, and in ecosystems among organisms within and between species.

And, our focus on cooperation leads us to a different view of natural selection and its importance in evolution. As we say in The Mermaid's Tale, natural selection does happen, but it depends on a lot of if's. For example, if a species over-reproduces, and if there is variation in the next generation, and if some of that variation leads its bearers to do better in a given environment, and if that's due to the inherited genome, and if the environment remains stable for long enough that this variant is favored consistently, and if the favored forms reproduce successfully, as do their offspring, and if they produce more offspring than organisms without the favored variant, then these favored organisms may become more common, due to natural selection. That is, they will be better adapted to their environment. But, all these if's must co-occur for natural selection to be an important force in change. If they are sporadic, or varying in nature and intensity, then their relative importance diminishes in relation to other aspects of life, including chance. Indeed, distinguishing chance from natural selection is no simple challenge.

No matter, to understand life in a deep sense one really has first to understand the nature of the countless cooperative interactions on which it is based. How those interactions change over long time periods of generations of cells, organisms, species, and ecosystems is important. But the interactions, and how they organize life, come first.

2 comments:

Regis said...

At any rate, I liked some of the vadlo biology cartoons!

Anne Buchanan said...

Thanks, Regis! Some of those _are_ good!