By: Donald Forsdyke

Donald Forsdyke — Sat, 26 Jan 2008 20:50:51 +0000

Dear Dr. Laden,Everyone, including you, is crossing the wires. Yes “hopeful monsters” is Richard Goldschmidt’s, but there are two main idea sets on “macromutation,” that due to de Vries and that due to Goldschmidt. The de Vries macromutation is primarily phenotypic – one sees immediately that something “macro” has happened at the organism level. Goldschmidt’s (at least that set out in his 1940 book that Olivia Judson cites) is primarily genotypic. It is a change in the genome that may build up progressively over many generations until the organism suddenly flips and startling new phenotypes can then gain a foothold.Goldschmidt called this a change in “reaction pattern.” Your fellow anthropologist Gregory Bateson (1904-1980) later saw this in terms of a change in genome context. So there can be the conventional point mutations (micromutations) that can change individual genes, and other mutations that build up until they cumulatively change the “reaction pattern” of a chromosome or set of chromosomes. To distinguish the latter from individual micromutations Goldschmidt called them macromutations. Until manifest in a change in phenotype, these macromutations are invisible.So the problem is that people are mixing up Goldschmidt and de Vries. Goldschmidt’s ideas have roots in ideas William Bateson (Gregory’s dad) was enunciating in the early decades of the 20th century. Again, people tend wrongly to conflate William Bateson and de Vries, and hence create even more problems. More on this may be found in our new biography of William Bateson, due to be released by Springer (New York) in April (see: http://post.queensu.ca/~forsdyke/book04.htm)Sincerely,Donald Forsdyke, Queen’s University, Canada

By: Colugo

Colugo — Thu, 24 Jan 2008 16:47:05 +0000

Aaron Filler is a booster of saltationism, which I am somewhat sympathetic to. (I think he’s wrong about Morotopithecus and the ’20 million years of bipedalism’ model, however.)

Comments on: Hopeful Monsters and Hopeful Models

By: Donald Forsdyke

By: Colugo