Seminar by Emma Hammarlund

Why and how animals diversified dramatically in the Cambrian remains an enigma. Since long, we have presumed the event relates to an increase in oxic niches, and the ongoing hunt for geological evidence hereof is at record high intensity. Meanwhile, other scientific disciplines have noted that multicellularity remains viable through a smaller pool of immature cells (i.e. with high stemness) that – quite absolutely – requires low oxygen conditions. Therefore, a yet unnoticed paradox emerge: How can animals like us renew tissue through hypoxia-driven cell stemness despite a life in the oxic realm? I will present clues from the field of tumor biology that can be applied to the geobiological enigma of animal diversification on Earth, where also observations of primordial multicellularity and oxic conditions fit.