Excitingly, these proteins are functionally enriched for membrane bending, vesicular biogenesis, and trafficking activities, suggesting that eukaryotes evolved from an archaeal host that contained some key components that governed the emergence of eukaryotic cellular complexity
after endosymbiosis.
Thus, eventually, it's the avoidance of competition and the process that I call endo - geno - symbiosis (i.e., the capacity of endogen «gene carriers» to share parts of their genome in a symbiotic relationship with their hosts,
after the idea of «
endosymbiosis» proposed by Sagan, 1967) that drives the expansion of the diversity of living beings.