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Endogenosymbiosis is an evolutionary process, proposed by the evolutionary and environmental biologist Roberto Cazzolla Gatti, in which "gene carriers" (viruses, retroviruses and bacteriophages) and symbiotic prokaryotic cells (bacteria or archaea) could share parts or all of their genomes in an endogenous symbiotic relationship with their hosts.
Secondary endosymbiosis has occurred several times and has given rise to extremely diverse groups of algae and other eukaryotes. Some organisms can take opportunistic advantage of a similar process, where they engulf an alga and use the products of its photosynthesis, but once the prey item dies (or is lost) the host returns to a free living state.
Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.2 billion years ago an archaeon absorbed a bacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living eukaryotic cells.
The endosymbiosis theory of organogenesis became widely accepted in the early 1980s, after the genetic material of mitochondria and chloroplasts had been found to be significantly different from that of the symbiont's nuclear DNA. [24] In 1995, English evolutionary biologist Richard Dawkins had this to say about Lynn Margulis and her work:
The theory of endosymbiosis, as known as symbiogenesis, provides an explanation for the evolution of eukaryotic organisms. According to the theory of endosymbiosis for the origin of eukaryotic cells, scientists believe that eukaryotes originated from the relationship between two or more prokaryotic cells approximately 2.7 billion years ago.
Reductive evolution is the process by which microorganisms remove genes from their genome.It can occur when bacteria found in a free-living state enter a restrictive state (either as endosymbionts or parasites) or are completely absorbed by another organism becoming intracellular (symbiogenesis).
Many animals can glow in the dark. In a new study, scientists report that deep-sea corals that lived 540 million years ago may have been the first animals to glow, far earlier than previously thought.
The viral eukaryogenesis hypothesis posits that eukaryotes are composed of three ancestral elements: a viral component that became the modern nucleus; a prokaryotic cell (an archaeon according to the eocyte hypothesis) which donated the cytoplasm and cell membrane of modern cells; and another prokaryotic cell (here bacterium) that, by endocytosis, became the modern mitochondrion or chloroplast.