Refined control of cell stemness allowed animal evolution in the oxic realm
Animal diversification on Earth has long been presumed to be associated with the increasing extent of oxic niches. Here, we challenge that view. We start with the fact that hypoxia (<1-3% O2) maintains cellular immaturity (stemness), whereas adult stem cells continuously - and paradoxically - regenerate animal tissue in oxygenated settings. Novel insights from tumour biology illuminate how cell st
