Juli Peretó and Antonio Lazcano

Juli Peretó, professor at the Department of Biochemistry and Molecular Biology of the University of Valencia, and Antonio Lazcano, from the National Autonomous University of Mexico, have analyzed the significance of Lynn Margulis' article in 'The Journal of Theorical Biology', a magazine in which in 1967 the American biologist also published the ideas that gave rise to her theory on the origin of eukaryotic cells. Currently, the work of Peretó and Lazcano is the most disseminated on the social networks of this magazine, an article that is part of the commemorative volume that will be published in December.

For a long time, endosymbiosis (association of individuals of different species for mutual benefit) had been considered a phenomenon with no role in the evolutionary process. Lynn Margulis, who was named an honorary doctor by the University of Valencia in 2001 and died on this day, November 22, 2011, demonstrated that the endosymbiotic phenomenon has an important role in the origin and evolution of eukaryotic cells (cells with a nucleus).

In the article, Peretó and Lazcano (the latter also an honorary doctor). causa by the University of Valencia) provide a careful contextualization of the work of this evolutionist in her pioneering article On the origin of mitosing cells, in which she summarized in an “extraordinarily coherent way the meaning of symbiosis to explain the origin of some cellular elements, the mitochondria and the chloroplast, despite the fact that her proposal on the motility apparatus could not be demonstrated,” explained Juli Peretó. Furthermore, the researchers highlight the important role played by Lynn Margulis's recapitulation of the contributions of her predecessors regarding the role of endosymbiosis.

Lazcano and Peretó explain that the evolutionary biologist was not the first to discuss this fact, but no one before had done so so extensively and deeply and at the same time provided verifiable hypotheses of reliable predictions that supported the endosymbiotic process.

How the article explains On the origin of mitosing cells: A historical appraisal of Lynn Margulis endosymbiotic theory, the long history of endosymbiosis defended by Lynn Margulis has raised criticism and questions about the originality of the biologist's contributions. According to experts, these criticisms were unfair and they emphasize that the critics were wrong, since they assure that Margulis's proposal was not simply a recapitulation of past ideas, but rather a coherent narrative of the role of endosymbiosis in the origin of eukaryotic cells.

In the article, Peretó and Lazcano show what reasons explain the rejection of a large part of the scientific community towards the researcher's ideas. Firstly, they highlight that the life sciences have been divided into delimited disciplines, a fact that according to experts hinders understanding between different specialists, especially between research from an evolutionary perspective.

Secondly, they consider that the penetrating influence of Pasteur and his followers had led to the growth of the idea that bacteria were pathogenic organisms, and this made it difficult to consider them as ancestors of existing life forms. Finally, the researchers emphasize that molecular biology – the predominant discipline in life sciences research at the time – had a great lack of an evolutionary perspective, due to the great influence of a reductionist perspective aimed at characterizing individuals only in terms of genes and molecules.

The experts assure that the revolution in molecular biology, together with new developments in microscopy, led to the rapid confirmation of the bacterial characteristics of the mitochondria and the chloroplast, a fact that verified the predictions made by Lynn Margulis. In addition, they highlight the growing interest in the geochemical history of the Earth, stimulated by interest in NASA's space exploration, which led to the recognition of bacteria as agents of geological changes, and not only as pathogens.

In the work, Juli Peretó, also deputy director of the Institute of Integrative Systems Biology, and Lazcano make an analysis of the books published by the biologist, in which she showed the evolutionary history of cells, from the origin of life to the appearance of eukaryotic cells, which are those that make up the most complex organisms. "The key to his writing - experts say - was his interdisciplinary perspective and the radically different use of certain biological terms. This change in the use of language was not a capricious act, but rather the recognition that an adequate description of biological phenomena requires a precise vocabulary that recognizes a less anthropocentric perspective on the evolutionary process."   

Lecture by Antonio Lazcano

Antonio Lazcano will give a lecture next Tuesday, December 12, on the research and life career of Lyn Margulis in the Darwin Room of the Burjassot-Paterna Campus: Symbiosis and evolution: Lynn Margulis and the origin of eukaryotic cells. This event is part of the program to celebrate 50 years of biology studies at the Universitat de València.

Career

Juli Peretó is a professor at the Universitat de València, deputy director of the Institute of Integrative Systems Biology (joint center Universitat de València-CSIC). He has been secretary and vice president of ISSOL (International Society for the Study of the Origin of Life) and has been a fellow of this society since 2014. He has been collaborating with Antonio Lazcano for more than twenty years and they are united by an interest in the history of ideas about the origin and evolution of life.

Antonio Lazcano is a member of the National College and professor of Origin of Life at UNAM (Mexico) and researches in Prebiotic Chemistry and the evolution of the most primitive biological processes. He has been president of ISSOL and has an honorary doctorate from the universities of Milan and Valencia. He is the director of the Lynn Margulis Center for Evolutionary Biology of the Galapagos Islands.

Article:

Antonio Lazcano and Juli Peretó. «On the origin of mitosing cells: A historical appraisal of Lynn Margulis endosymbiotic theory» Journal of Theoretical Biology, volume 434, December 2017, pages 80-87.

https://doi.org/10.1016/j.jtbi.2017.06.036

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