Abstract

This thesis intends to address one type of approach to evolutionary theory that seeks to criticise the neo-Darwinist account of evolution and individuation, that of symbiosis. This thesis will begin by examining current evolutionary theory through Darwin to neo-Darwinism, with a view to discerning which types of mechanisms neo- Darwinism rules out, and which it allows. This will be achieved by using a methodology which treats groups of related scientific theories or practices as research programmes. This methodological approach will allow comparison between competing research programmes, and it will be possible to determine whether or not a competing research programme is really a challenge to neo-Darwinism, or simply a sub- programme which shares some of the same metaphysical commitments and mechanisms as neo-Darwinism. The second half of the thesis will assess the ‘symbiosis’ challenge to neo-Darwinism on these terms. This section will conclude that symbiosis as it is usually formulated by its proponents is not a separate research programme that rejects neo-Darwinism in any significant way, but rather it is a sub-programme of neo- Darwinism. But I will also argue that there are aspects of this programme, if they were to be made more prominent, would in fact constitute an alternative research programme which could not only be treated as a separate research programme, but a research programme that is incompatible with neo-Darwinism. Bacteria in particular are organisms which function through symbiosis and their functioning problematises neo-Darwinism’s account of individuation on a fundamental level. It will be concluded that neo-Darwinism is either a theory of very limited scope, or one which can be made into a general theory, but this can only be achieved through fundamental changes to neo-Darwinism itself.