John Maynard Smith
(1920-2004)
John Maynard Smith was a British theoretical and mathematical evolutionary biologist and geneticist. His first degree, at Trinity College, Cambridge, was in aeronautical engineering. He studied fruit-fly genetics at University College London under
J.B.S.Haldane for a second degree in genetics.
Years earlier he had read about Darwinian evolution in the works of Haldane at Eton. Influenced by Haldane's communist party affiliation, Maynard-Smith too joined the party but gave it up during World War II
During the late 1980s he worked with the evolutionary biologist
Eörs Szathmáry. Together they wrote an influential 1995 book
The Major Transitions in Evolution, a seminal work which continues to contribute to ongoing issues in evolutionary biology.
The Major Transitions in Evolution
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Transitions described in the book
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Transition from:
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Transition to:
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Notes
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Replicating molecules
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"Populations" of molecules in compartments
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Can't observe
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Independent replicators
(probably RNA)
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Chromosomes
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RNA world hypothesis
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RNA as both genes and enzymes
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DNA as genes; proteins as enzymes
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Prokaryotes
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Eukaryotes
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Can observe
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Asexual clones
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Sexual populations
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Evolution of sex
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Protists
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Multicellular organisms —
animals, plants, fungi
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Evolution of multicellularity
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Solitary individuals
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Colonies with non-reproductive castes
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Evolution of eusociality
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Primate societies
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Human societies with language, enabling memes
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Sociocultural evolution
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Maynard Smith and Szathmáry identified several properties common to the transitions:
- Smaller entities have often come about together to form larger entities, e.g. chromosomes, eukaryotes, sex multicellular colonies.
- Smaller entities often become differentiated as part of a larger entity, e.g. DNA-protein, organelles, anisogamy, tissues, castes
- The smaller entities are often unable to replicate in the absence of the larger entity, e.g. DNA, chromosomes, organelles, tissues, castes
- The smaller entities can sometimes disrupt the development of the larger entity, e.g. meiotic drive (selfish non-Mendelian genes), parthenogenesis, cancers, coup d’états.
- New ways of transmitting information have arisen, e.g. DNA-protein, cell heredity, epigenesis, universal grammar.
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Teacher |
Scholar
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