The terms symbiogenesis, endosymbiosis and endosymbiogenesis

The term symbiogenesis refers to the genesis of a new species or kind of life through the merger of two or more existing species. This term has been coined by scientists Merezhkovsky and Margulis.

Endosymbiosis refers to the symbiogenetic process and the resulting state, in which one partner (species) lives inside another [1,2]; for example, a chloroplast in an eukaryote. Such a the symbiotic relationship, including the hypothesized process leading to it, “blurs” the concept of species (biologist disagree on the definition of the term ‘species’ [3], anyway), making species distinction time-dependent. In the chloroplast case, a species turned into an organelle.

Endosymbiogenesis refers to the origin of a new lineage—a sequence of species that forms a line of descent.

The terms symbiogenesis, endosymbiosis and endosymbiogenesis belong to the vocabulary of evolutionary biology. They define hypothetical processes thought to explain the origin of species in addition to the inertwined processes of random mutation and natural selection. Recent advances in molecular biology and systematics provide experimental support for symbio-diversity thinking and reasoning.

Keywords: cytology, theoretical biology, molecular biology, theory of evolution, symbiosis

References and further reading
[1] Virtual Fossil Museum: Endosymbiosis - the Origin of Domain Eukarya [www.fossilmuseum.net/Evolution/Endosymbiosis.htm].
[2] Rob R. Dunn: Every Living Thing. First Edition. HarperCollins Publishers, New York, 2009; see Chapter 7 and 10.
[3] Marc Ereshefsky: Species. Stanford Encyclopedia of Philosophy 2010 [plato.stanford.edu/entries/species/].