On this week’s ResearchBlogCast we discussed Adaptation, Plasticity, and Extinction in a Changing Environment: Towards a Predictive Theory (see my post reviewing it). The basic idea was to discuss a simple mathematical model which treated biological populations as something more than simply static constants buffeted by changes in physical parameters. In particular there’s often an implicit model that species exist at a particular and precise equipoise with an environment, and that when those environmental parameters are shifted that the species is in jeopardy unless it can track its optimal environment through migration.
In some ways this would be mighty convenient for us if it were so. If species were static we wouldn’t have to worry about weeds becoming resistant to pesticide, or diseases wrecking havoc to our crops, and so forth. But biology is dynamic, both on the life history and evolutionary scale. I think it would benefit us to take this into account when we humans consider the value we place on conservation, and the decisions we make to maintain biodiversity. Kevin Zelnio pointed out that there have been worries about the disappearance of charismatic fauna for about a generation now, and though species such as the tiger and elephant are still endangered (and because of their relatively long generation times this is problematic), many species which we were told as children would become extinct by the time we were adults remain a presence today in the wild. Some of this is surely due to conservation after the awareness of the threats, but another issue may be that some of these species are more resilient than we think, or give them credit for. Dave Munger reminded us that in 2007 100,000 Lowland Gorillas “discovered”, tripling the numbers of the species immediately. One way of looking at it is that these gorillas were mighty lucky that they’d been unnoticed…but another issue may be that gorillas coevoled to some extent with hominids and may have some sense where to go to avoid human habitation.
This is not to recommend complacency. And I haven’t even broached the serious normative issues as to the value of biodiversity outside of its human utilitarian consequences. These are points over which reasonable people can discuss and differ. Rather, when we speak of the environmental and non-human life we often speak as if humanity and physical nature are the two active forces operative on a passive and static biological nature. This is obviously not true. Our species’ mastery of the physical sciences in the past 200 years has given us a sense of power over the biological world, but we shouldn’t get complacent, and we shouldn’t dismiss the resilience and cleverness of nature, though that resilience and cleverness does not always redound to our benefit.