That agency plays a role in the evolutionary process should not come as a surprise if accepted that it is one of the fundamental properties of life. It seems that even very primitive organisms exhibit agency. Choice can be recognised in the way organisms react to stimuli - and they react (in subtle ways) differently, sometimes even contrary to their urges or to what is expected. The influence of choice has been already recognised by a number of evolutionists (see, for example, Hameroff, 1998). This does not need to be seen as a form of Lamarckism. Choice does not need to trigger genetic mutations or other chemical alterations. By making certain choices, an organism changes and affects its environment and its own subsequent preferences, which can indirectly tip the balance in favour of some genes rather than others. Popper (who named this ‘Organic evolution'), writes:
Thus the activity, the preferences, the skill, and the idiosyncrasies of the individual animal may indirectly influence the selection pressures to which it is exposed, and with it, the outcome of natural selection. (1977, p.12)
This is compatible with Darwinism and is not acknowledged only because those who would like to see life in mechanical terms are not at ease with giving any credence to a factor that is so non-machine-like. As for Lamarckism, it has received a fresh breath of life recently. A new field of epigenetics (that studies what regulates genes, what turns them on and off) provides some support to the notion that choices we make can affect which genes will be activated in subsequent generations. A number of scientists are working on accumulating the evidence but the verdict is still open. Even if minimally proven right, the reliance on chance would be reduced further, but these ideas would have to overcome scientific inertia before being accepted. What is important, for the time being, is to recognise that choice does play a role in one way or another.
Nevertheless, although choice may explain some adaptations within species better than pure chance, it is not enough. To explain the more global aspects of the evolutionary process (e.g. an overall increase in complexity) another factor needs to be introduced.
- . An interpretation of evolution that was very popular before Darwin, asserting that the striving of organisms is the major cause of changes. So (to use a typical example), giraffes have long necks because they were stretching their necks to reach leaves that were high up, which was gradually transmitted to subsequent generations. This description is worth including because it seems so common-sensical that even nowadays many people erroneously interpret Neo-Darwinism in a similar way (Neo-Darwinism does not allow any acquired characteristics to be directly transmitted to subsequent generations).