Category: Uncategorized

EUKARYOTIC HOMOLOGS ANTICIPATED. "We might expect to find closer and closer homologs of components of the several eukaryote-specific cellular machineries [now called eukaryotic signature proteins] as we explore inferred proteomes of such archaea [the group of phyla comprising Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota (TACK)]." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

NOT RARE. "In eukaryotes, endosymbiosis is common." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

ANOTHER RARE STAMP. "Even farther down the organismal path is the two-species bacterial consortium “Chlorochromatium aggregatum,” which has been championed as a model of bacterial multilineage multicellularity. In this symbiosis, green sulfur bacterial epibionts (Chlorobium chlorochromatii) surround a motile β-proteobacterium (Symbiobacter mobilis). The central bacterium relies extensively on the photosynthetic products of its epibionts and has undergone extensive genome reduction, a mark of evolved dependence." https://lnkd.in/d6GwkCt View in LinkedIn

RARE IS DOCUMENTED. "Nevertheless, syntrophic interactions between anaerobic methane-oxidizing archaea and sulfate-reducing bacteria have resulted in the evolution of aggregates with a measure of coordinated growth and reproduction between the partners." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

NOT UNIQUE BUT RARE. "Among studied exclusively prokaryotic multilineage consortia, varying levels of integration have been documented, although endosymbiosis is extremely rare." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

NOT UNIQUE ORIGIN. "Eukaryogenesis is not unique as an organismal merger of entities from taxonomically distinct lineages, although the tightness of integration between mitochondria and their host is probably the most derived currently known." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

BIOLOGICAL UNIQUENESS. "Eukaryotic cells undoubtedly exhibit many of the hallmark features of biological individuality, including spatiotemporal boundedness, indivisibility, and the integration, cooperation, and interdependence of parts." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

TRANSITIONS. "First, the parts of a new whole may retain some independence with respect to their ability to reproduce. Second, interdependence of parts is emphasized as a threshold that must be crossed for a new type of individual to have truly evolved. Both are what we see in the case of the eukaryotic cell." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

KIN VERSUS FOREIGN. "It is uncontroversial that eukaryogenesis involved the fusion of two taxonomically distinct units to form a new type of cell. Eukaryogenesis can thus be distinguished from evolutionary transitions based on the integration of closely related units (as in the evolution of multicellularity)." http://www.pnas.org/content/112/33/10278.full View in LinkedIn

NO SINGLE EVENT. "Margulis, a champion of endosymbiotic theory, argued for the community perspective on the eukaryotic condition. Symbiotic mergers similar to eukaryogenesis, she insisted, are ubiquitous in the history of life. As a result, our understanding of evolutionary processes requires the radical revision, perhaps abandonment, of many traditional neo-Darwinian ideas." http://www.pnas.org/content/112/33/10278.full View in LinkedIn