Friday, 24 August 2012

Generalised symbiosis

Universal Darwinism requires a generalised theory of symbiosis.

Currently this area is largely covered by the concept of a biological interaction.

The theory of biological interaction uses the terminology of symbiosis - although the conventional definition of symbiosis specifies close interactions and excludes competition.

The terminology is illustrated in the following table (showing combinations of fitness deltas):

-CompetitionAmensalismPredation / Parasitism
+Predation / ParasitismCommensalismMutualism

What's the best way of expanding the theory of symbiosis to cover all biological interactions?

The most obvious option is just to ditch the traditional concept of symbiosis, and redefine it to refer to any form of biological interaction. The terms "competition" and "predation" already cover practically any level of interaction between the parties.

Another option involves adding the following terms:

  • Protosymbiosis;
    • Protomutualism;
    • Protocompetition;
    • Protoamensalism;
    • Protocommensalism;
    • Protopredation;
    • Protoparasitism.

These terms refer to biological interactions in which neither of the parties have been interacting with each other for long enough to be adapted to the other's presence.

The second option has the virtue of not demanding redical redefinition of the terms "mutialism" and "symbiosis". It does redefine the more-common terms "competition" and "predation", though.

The idea is based on the concept of protocooperation. Under the proposal, this term would become a largely-redundant near synonym of "protomutualism".

I think we have to choose between these two options - or very similar ones. The existing situation is an irregualar and unsustainable mess - a terminological hangover.

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