The Homo sapiens evolved in the tropical hot African land mass. The homo sapiens would have evolved out of the archaea secreted porphyrions and RNA viroids independently. The sub-Saharan African soil is depleted of selenium. Selenium deficiency leads to RNA viroidal mutations. Thus extremes of temperature and selenium deficiency lead to RNA viroidal diversity. This RNA viroidal diversity would have led to rapid evolution of homo sapiens from the eukaryotic cell. This eukaryotic cell would have evolved into homo sapien species over some time. The RNA viroids are the basis of the HERV genes which contributes to the dynamicity of the homo sapien genome. The Homo neanderthalis evolving in the Eurasian steppes on the other hand are retroviral resistant while the homo sapiens is retroviral sensitive. The homo neanderthalis archaeaon secretes digoxin which can destroy the retrovirus. Selenium deficiency leads to cardiomyopathy & pancreatitis. Hashimoto's thyroiditis due to selenium deficiency is associated with cerebral small vessel disease, normal pressure hydrocephalus, Hashimoto's encephalopathy, non-vasculitic autoimmune meningitis, and autoimmune dementia.
