Adaptability: The Significance of Variability from Molecule to Ecosystem

In order to survive and reproduce biological systems must be adapted to the specific features of their environment. They must also be adaptable, or capable of functioning in an uncertain environment. The adaptability of biological matter is one of its most striking properties.
This adaptability may manifest itself at many different levels of organization, ranging from the molecular and cellular levels to the levels of the population and the community. One type of population, for example a microbial population, may rely on culturability and control of gene expression to cope with the uncertainty of the environment, while another, of metazoan plants, may rely on genetic and developmental plasticity, or it may restrict itself to an environment which is not so uncertain. Still another population, say of metazoan animals, may rely on social organization or on behavioral plasticity mediated by its neuromuscular system. Indeed, over the broad spectrum of biological nature, one can find the most diverse mechanisms of adaptability and also the most diverse strategies for using these mechanisms.
This great diversity may invite a certain amount of pessimism as to the possibility of understanding, or even describing, the patterns of adaptability which actually exist in nature. Fortunately, however, the problem is simpler than it appears at first. This is because all the different mechanisms and modes of adaptability have one thing in common: they are all adaptations to the uncertainty of the environment. This means that we can expect all forms of adaptability, regardless of their diversity, to have some common denominator.
In this book I want to describe this common denominator and then show how it can be used to analyze patterns of adaptability in nature. In particular I want to answer four questions:
1. What is adaptability?
2. What are the major mechanisms of adaptability?
3. What are the major strategies with which biological systems use
these mechanisms?
4. How do these strategies interlink in the development and evolution
of the ecosystem as a whole?