We Were Made Possible by a Symbiotic Fusion of Two Prokaryotes about 1.8-2 bya Like Plants Which Also Acquired Phtosynthetic Endosymbionts. 2022-10-14 Jorma Jyrkkanen

ORIGIN OF MITOCHONDRIAMitochondria originated by permanent enslavement of purple non-sulphur bacteria. These endosymbionts became organelles through the origin of complex protein-import machinery and insertion into their inner membranes of protein carriers for extracting energy for the host. Mitochondria originated by permanent enslavement of purple non-sulphur bacteria. These endosymbionts became organelles through the origin of complex protein-import machinery and insertion into their inner membranes of protein carriers for extracting energy for the host. THE PROKARYOTE MICROBES THAT ENGULFED PURPLE NON-SULPHUR BACTERIA Archaea were the most likely candidate. In particular, The origin of eukaryotes remains unclear1,2,3,4. Current data suggest that eukaryotes may have emerged from an archaeal lineage known as ‘Asgard’ archaea5,6 (Isolation of an archaeon at the prokaryote–eukaryote interface. Hiroyuki Imachi, Masaru K. Nobu. 15 January 2020) EVIDENCE TO SUPPORT THIS THEORY OF THE EARLY ORIGIN OF HIGHER LIFE(Organismal Biology) Mitochondria (and chloroplasts) are approximately the same size as prokaryotic cells, but they are located inside much much larger eukaryotic cells instead of free-living. Mitochondria (and chloroplasts) each have their own DNA, their DNA is organized in a circular chromosome like typical prokaryotic genomes, and their genomes contain genes that are very similar to genes found in prokaryotic genomes. Mitochondria (and chloroplasts) reproduce by binary fission, the process that prokaryotes use to reproduce. In contrast, eukaryotic cells reproduce by mitosis. If the mitochondria (or chloroplasts) are removed from a eukaryotic cell, the cell has no way to produce new ones. In other words, the “instructions” to make new mitochondria/chloroplasts is not present in the eukaryotic nuclear genome; they are present in the mitochondria/chloroplast genomes. The membrane composition of mitochondria (and chloroplasts) is more similar in composition to prokaryotic membranes than to eukaryotic membranes.