biology

Humans might not be walking the face of the Earth were it not for the ancient fusing of two prokaryotes — tiny life forms that do not have a cellular nucleus. UCLA molecular biologist James A. Lake reports important new insights about prokaryotes and the evolution of life in the Aug. 20 advance online edition of the journal Nature.

Lake has discovered the first exclusively prokaryote endosymbiosis. All other known endosymbioses have involved a eukaryote — a cell that contains a nucleus. Eukaryotes are found in all multicellular forms of life, including humans, animals and plants.

“We thought eukaryotes always needed to be present to do it, but we were wrong.”

In the Nature paper, Lake reports that two groups of prokaryotes — actinobacteria and clostridia — came together and produced “double-membrane” prokaryotes.

“Higher life would not have happened without this event,” Lake said.

“This work is a major advance in our understanding of how a group of organisms came to be that learned to harness the sun and then effected the greatest environmental change the Earth has ever seen, in this case with beneficial results,” said Carl Pilcher, director of the NASA Astrobiology Institute.

Link: physorg.com

More:
Microbes Within Microbes Within Microbes: blogs.sciencemag.org/origins/