Sprecher
Beschreibung
Christa Schleper
The question about the emergence of complex life forms on Earth remains one of the big mysteries in evolution and is directly linked to the origin of life, because shortly after the formation of LUCA (the last universal common ancestor) there was a deep split into two major branches, the Bacteria and Archaea. For about 2 billion years, both these groups evolved and diversified and were the only inhabitants on our planet until the first complex, eukaryotic cells evolved. Newest models converge on a symbiosis or a merger, between a bacterium and an archaeon that led to the formation of the first complex cell with organelles.
The hypothesis is fueled by the recent discovery of Asgard Archaea.
Genomic studies of these archaea and then recent cultivation of living strains shed light on the closest known prokaryotic relatives of eukaryotes. They reveal unexpected cellular complexities, including cell morphology but also cellular dynamics.
The findings support that an Asgard archaeon was likely the host for the (alpha-) proteobacterial endosymbiont in this crucial event of early evolution that gave rise to all complex life forms.