Protists in Evolution, and Symbiogenesis
The Woodstock of Evolution -- The World Summit on Evolution (ScientificAmerican.com): "Australian botanist Geoff McFadden, from the University of Melbourne, lectured on 'Protists and Cellular Phenomena in Evolution.'
Darwin ignored protists, but Ernst Haeckel included them in his comprehensive tree of life. Constantin Mereschkowsky was the first to appreciate the significance of protists in early eukaryotic evolution. A.F.W. Schimper noted that chloroplasts in plant cells very much resembled cyanobacteria. The the ultimate theoretical model was provided by Lynn Margulis: the key step was the endosymbiosis of cyanobacteria within a phagotrophic eukaryotic host, a process she calls symbiogenesis. The symbiotic theory of mitochondrial origin is supported by the different nature of internal and external membranes in mitochondria. In primary endosymbiosis, 1,000 genes were acquired by the nucleus from an incorporated cyanobacteria. A second round of gene transfer involved the engulfment of another plastid-containing eukaryote in secondary endosymbiosis. See also, Endosymbiosis and The Origin of Eukaryotes Illustration Endosymbiosis in Evolution
Darwin ignored protists, but Ernst Haeckel included them in his comprehensive tree of life. Constantin Mereschkowsky was the first to appreciate the significance of protists in early eukaryotic evolution. A.F.W. Schimper noted that chloroplasts in plant cells very much resembled cyanobacteria. The the ultimate theoretical model was provided by Lynn Margulis: the key step was the endosymbiosis of cyanobacteria within a phagotrophic eukaryotic host, a process she calls symbiogenesis. The symbiotic theory of mitochondrial origin is supported by the different nature of internal and external membranes in mitochondria. In primary endosymbiosis, 1,000 genes were acquired by the nucleus from an incorporated cyanobacteria. A second round of gene transfer involved the engulfment of another plastid-containing eukaryote in secondary endosymbiosis. See also, Endosymbiosis and The Origin of Eukaryotes Illustration Endosymbiosis in Evolution