The extremes of climate change produce endosymbiotic archaeal growth. This results in neanderthalisation of the human species. This occurred during the ice age &is possibly a continuing phenomenon during the periods of global warming. The homo neanderthalis are matrilineal &the residual matrilineal societies of the Dravidians, Semites, Basques, Celts &Berbers are neanderthalic. The global warming produces endosymbiotic archaeal growth &neanderthalisation. The homo neanderthalis population is susceptible to civilizational diseases. The homo sapien population suffers from endemic depression &lack of creativity with a propensity to develop recurrent infections. The homo sapien population is relatively protected from civilizational diseases. The Neanderthals consequent to archaeal symbiosis can generate new viruses serving as viral reservoirs. The archaeal endosymbiosis in Neanderthals produces stem cell transformation protecting the stem cell reservoirs of viruses from immune attack. These newly generated viruses in homo neanderthalis to which they are immune can attack &exterminate the homo sapiens population. There is an eternal conflict between Neanderthals &Cro-magnon homo sapiens.