I mentioned earlier that ecology is the science that looks at the sustainability of natural resources. So far in this blog, I have mostly ignored ecology in favor of economics and evolution. I mean to address that gap over the next couple of blog entries. Specifically, I want to give you a shorthand version of what I think are the fundamental theories in ecology. Let’s start with what ecology does not tell us. The following are not supported by scientific research :
1.Everything is connected
2. Nature is in balance
3. Ecology is a summary of natural history and physical geography
Everything is connected
This concept drives me crazy. It is true that ecology takes a systems approach to looking at nature. As a result, no factor – no matter how obscure – can be rejected beforehand as having an effect on the species or spaces of interest ( see law# 5 in Dodds (2009). The same is true in economics when dealing with a global economy. Still, any science that holds all possibilities as equally important can predict nothing. Some things are much more closely connected than others. It is from these robust relationships that predictions are built. Second-hand and even third-hand relationships can and should be considered but by placing too much emphasis on the obscure, the ecologist very rapidly leaves the arena of science for the land of mythology and story-telling.
Nature is in balance
I am attracted to this concept. The stability-diversity discussion pointed out that certain types of stability can be predicted. The issue here is whether nature tends to be stable. We know from evolution that “stable” is a relative idea. Both the stage and the players of the drama we call life have changed repeatedly. Ecologists all agree that our data is messy. We cannot decide, however, whether that is because of our lack of understanding of the factors that cause change or because ecosystems are chaotic by nature. When a clear definition of chaos is applied (basically that small differences in your starting point make huge differences in your end point; Sherratt and Wilkinson (2009) p. 146), ecosystems tend to hug the boundary between stable and chaotic. If this concept of the balance of nature is true, nature is not keen on letting us know.
Tales in time and space
History and geography provide an important context for economics. Natural history and physical geography do the same for ecology. However, these observations in time and space do not point us in a direction for ecological theory. In their elite forms, natural history and physical geography lead to complex classifications and databases for making sense of all that has been observed. But the sheer weight of evidence does not lead us to good predictions. Ecology is overrun by all-encompassing generalizations that exclude nothing and explain everything. A better (and riskier) approach is to make hypotheses that can be proven wrong and see how general and robust they can be.
Dodds (2009) lists 35 laws, 5 candidate laws and 9 useful generalizations in ecology. None of these have predictive value. At best, they define what plants and animals need to survive and list the possible fates of groups of living things. In my next post, I will try to sketch out the theories that do exclude possibilities and form a starting point for a predictive science of ecology.