Historians and philosophers of science agree that Darwin had an understanding of species which led to a workable theory of their origins. To Darwin species did not differ essentially from `varieties' within species, but were distinguishable in that they had developed gaps in formerly continuous morphological variation. Similar ideas can be defended today after updating them with modern population genetics. Why then, in the 1930s and 1940s, did Dobzhansky, Mayr and others argue that Darwin failed to understand species and speciation? Mayr and Dobzhansky argued that reproductively isolated species were more distinct and `real' than Darwin had proposed. Believing species to be inherently cohesive, Mayr inferred that speciation normally required geographic isolation, an argument that he believed, incorrectly, Darwin had failed to appreciate. Also, before the sociobiology revolution of the 1960s and 1970s, biologists often argued that traits beneficial to whole populations would spread. Reproductive isolation was thus seen as an adaptive trait to prevent disintegration of species. Finally, molecular genetic markers did not exist, and so a presumed biological function of species, reproductive isolation, seemed to delimit cryptic species better than character-based criteria like Darwin's. Today, abundant genetic markers are available and widely used to delimit species, for example using assignment tests: genetics has replaced a Darwinian reliance on morphology for detecting gaps between species. In the 150th anniversary of The Origin of Species, we appear to be returning to more Darwinian views on species, and to a fuller appreciation of what Darwin meant.
...More
Book
Brush, Stephen G.;
(2009)
Choosing Selection: The Revival of Natural Selection in Anglo-American Evolutionary Biology, 1930--1970
(/isis/citation/CBB001020903/)
Book
Reznick, David N.;
(2009)
The Origin Then and Now: An Interpretive Guide to the Origin of Species
(/isis/citation/CBB001020595/)
Chapter
Massimo Bernardi;
Adriana Bellati;
Michele Menegon;
(2015)
La specie tra evoluzione e conservazione
(/isis/citation/CBB690125746/)
Book
Brown, William;
Fabian, Andrew C.;
(2010)
Darwin
(/isis/citation/CBB001023129/)
Article
Nash, Richard;
(2015)
William Keith Brooks and the Naturalist's Defense of Darwinism in the Late-Nineteenth Century
(/isis/citation/CBB001510220/)
Essay Review
Smocovitis, Vassiliki Betty;
(2002)
The Darwin Adventure Continues
(/isis/citation/CBB000203383/)
Book
Engels, Eve-Marie;
(2009)
Charles Darwin und seine Wirkung
(/isis/citation/CBB001035152/)
Book
Ruse, Michael;
Travis, Joseph;
(2009)
Evolution: The First Four Billion Years
(/isis/citation/CBB001232307/)
Article
Rao, Veena;
Nanjundiah, Vidyanand;
(2011)
J. B. S. Haldane, Ernst Mayr and the Beanbag Genetics Dispute
(/isis/citation/CBB001034558/)
Article
Delisle, Richard G.;
(2011)
What Was Really Synthesized during the Evolutionary Synthesis? A Historiographic Proposal
(/isis/citation/CBB001023986/)
Article
Richards, Robert J.;
(2012)
Darwin's Principles of Divergence and Natural Selection: Why Fodor Was Almost Right
(/isis/citation/CBB001221609/)
Article
Haufe, Chris;
(2012)
Darwin's Laws
(/isis/citation/CBB001221610/)
Article
Delisle, Richard G.;
(2008)
Expanding the Framework of the Holism/Reductionism Debate in Neo-Darwinism: The Case of Theodosius Dobzhansky and Bernhard Rensch
(/isis/citation/CBB000931570/)
Article
Colley, Eduardo;
Fischer, Marta Luciane;
(2013)
Especiação e seus mecanismos: histórico conceitual e avanços recentes
(/isis/citation/CBB001420690/)
Article
Mikhail B. Konashev;
(2019)
Th. Dobzhansky and the Development of Evolutionary Biology in the USSR
(/isis/citation/CBB629293770/)
Chapter
Burian, Richard M.;
(2007)
“Nothing in Biology Makes Sense Except in the Light of Evolution” (Theodosius Dobzhansky)
(/isis/citation/CBB001022514/)
Article
Sarkar, Sahotra;
(2013)
Mayr's Recollections of Haldane: A Document with Brief Commentary
(/isis/citation/CBB001420749/)
Article
Weissman, Charlotte;
(2010)
The Origins of Species: The Debate between August Weismann and Moritz Wagner
(/isis/citation/CBB001022395/)
Article
Glick, Thomas F.;
(2008)
O Programa Brasileiro de genética evolucionária de populações, de Theodosius Dobzhansky
(/isis/citation/CBB001035151/)
Book
Díaz-Fierros Viqueira, Francisco;
(2009)
O Darwinismo e Galicia
(/isis/citation/CBB001035153/)
Be the first to comment!