DONALD R. FORSDYKE
DONALD R. FORSDYKE
"preprint version" differs from the "definitive published version"
in the Notes
and Records of the Royal Society (2010) 64, 139-154, doi:10.1098/rsnr.2009.0045
The latter was posted as "Online FirstCite Alert" on 29th October 2009 and, to celebrate the 350th annniversary of the RS, with other papers was made freely available (open access).
"History is rich in examples of disregarded ideas ..., some of them of an importance that came to be recognized long after their publication. One such instance is discussed in Donald Forsdyke's article on the theory of ‘physiological selection’ that George Romanes advanced in 1886 and William Bateson subsequently championed as a way of explaining the failure of breeders to produce sterile hybrids from intra-species (as opposed to inter-species) crosses. The Romanes–Bateson hypothesis found little support for more than a hundred years, but now, as Forsdyke observes, it is receiving favourable attention in the light of modern work on yeast hybrids."
Robin Fox, Editor
Based on an address – “Bateson’s contributions to evolutionary theory” – delivered at the
John Innes Centenary Symposium (9th September 2009), and at
the Galton Institute Conference on “William Bateson: his
Exceptions and the Origin of Species Revisited” (The Royal Society, 1st
October 2009). Online versions of the addresses are at the websites of
BATESON APPROVED “AN ADDITIONAL SUGGESTION”
CRYPTIC VARIABILITY OF THE REPRODUCTIVE SYSTEM
COLLECTIVE VARIATION OF A POPULATION SUBSET
SPORADIC AND REGULAR STERILITIES
CHROMOSOMES AND THE RESIDUE OR IRRESOLUBLE BASE
TWO FACTORS MUST COMPLEMENT TO PRODUCE STERILITY
COMPLEMENTATION LIKE SWORD AND SCABBARD
MODERN CHROMOSOMAL VIEWS
End Note (November 2009)
End Note (July 2010)
In his theory of “physiological selection,” Romanes postulated germ-line “collective variations” that accumulate in certain members of a species, who are thus “physiological complements” producing fertile offspring when mutually crossed, but sterile offspring when crossed with others. Unlike Darwin’s natural selection that secured reproductive isolation of the fit by elimination of the unfit, physiological selection postulated variations in the reproductive system that were not targets of natural selection; these sympatrically isolated the fit from the fit, leaving two species where there was initially one.
Bateson approved physiological selection. He noted that Mendel’s “unit characters” were “sensible manifestations” of what we now refer to as “genes,” but postulated a “residue,” distinct from genes, that might affect gene flow between organisms and so originate species. The reproductive isolation of the parents of a sterile hybrid was due to two complementing non-genic factors (the “residue”) separately introduced into the hybrid by each parent. Modern studies, especially of yeast hybrids, support the Romanes-Bateson viewpoint.