The debate appears to be skewed. 

It is true that geological studies show changes of the environment that contradicts the strong Gaia hypothesis of ecosystems working towards an optimum state. It is also true that there is evidence that ecosystems have collapsed from within. However, the frequency of such ecosystem collapses through geological history is many orders of magnitude lower than the extremely high frequency predicted by the Malthusian model of maximum reproduction. So evolution must be driven by something other than maximization of reproduction. The selfish gene model (the theoretical mechanism basis of the Medea hypothesis of life destroying itself) appears to be supported by simple computer simulations, but so does strong Gaia hypothesis. The strong Gaia hypothesis failed scale-up to more complex systems, and the missing frequency of Medean ecosystem collapses can be explained if the selfish gene model also fails scale-up to the greater complexity of real life because real life is too complex to be livable to such rigid, unselfcritical entities as the selfish gene model claims that living organisms are. In other words, the selfish gene model is based on the same methodological error as is the strong Gaia hypothesis. This is explained in greater detail on the pages "Moderating the Gaia/Medea debate" and "Self-organization" on Pure science Wiki, a wiki devoted to the scientific method unaffected by academic prestige obsession.
95.209.61.52  Martin J Sallberg