(A review from Journal of the History of Biology 2004)
In the years following the publication of Origin of Species, George Romanes developed his theory of physiological selection in which he posited that “physiological peculiarities” lead to hybrid sterility between individuals and thus isolation which would allow natural selection to “promote diversity of character, and thus to evolve species in ramifying branches instead of linear series” (Romanes, 1886, qtd. p. 46). He felt that these physiological peculiarities may involve the reproductive system and in a series of works that received a mixed reception from his contemporaries made his case for this mode of speciation. Over one hundred years later, Donald Forsdyke feels that he has managed, in some degree, to finish Romanes’ work.
Forsdyke is a molecular biologist who sees biology to be a branch of information science (p. 14). In this book, he argues that “the chemical basis of the origin of species by ‘physiological selection’ is something biochemists have known about for many decades”. This basis is “the species-dependent component of the base composition of DNA” (p. 2). In an extended – and often technical – examination of his “Physiological Selection Theory,” Forsdyke suggests that the ratio of the DNA bases guanine and cytosine (G+C) to the total bases is a specific characteristic which can correlate with phylogenetic distance. Given that “compatibility in (C+G) percentages is required for recombination between DNA molecules” (p. 133), one is left with the theory that differences in C+G between individuals can lead to hybrid sterility and thus speciation. Following this natural selection can work. Thus we see Romanes’ theory updated.
All of this stems from a series of papers written by Forsdyke in the 1990’s. He then set out in the late 1990’s to find a Victorian precursor to this work, and eventually rediscovered Romanes. Somewhat bizarrely, he muses that “[o]ur conclusions seemed so simple – so childishly simple perhaps … that the question arose as to why Darwin and those perspicacious Victorians associated with him had got so confused?” – this following a 100+ page discussion of the discoveries of modern molecular biology! If Forsdyke’s theory turns out to be right (and it is currently not widely accepted by evolutionary biologists), perhaps the Victorians did not reach his “childishly simple” conclusion because they did not have the technology to both conceptualize and prove it?
Whatever the merits of the scientific theory, Forsdyke’s historical analysis is severely flawed, consisting as it does of examining the writings of Romanes, John Thomas Gulick, and William Bateson for foreshadowings of his own biological research. In fairness to the author, he admits that this methodology yields an “unabashed ‘Whig history'” (p. 3). More importantly, there is virtually no analytical engagement with the historical literature regarding developments after 1859. While his wish to “let the Victorians tell the story” (p. 27) is on one level admirable, assembling quotations alone does not make an historical work. There is no presentation of the scientific theories within their socio-cultural mileau, and apart from a scattered reference or two to the literature, a reader is left with the opinion that there is no active research being done on the early post-Origin years. Indeed, relying on a twenty-eight year-old quote by John Lesch, Forsdyke supports the view that “[t]he development of evolutionary theory in the two decades from Darwin’s death to the turn of the century remains very largely terra incognita for the historian” (p. 220). Such a view is not surprising when one considers that the vast majority of the historical studies cited by Forsdyke date from prior to the mid-1980’s.
In short, this book is more of a view of current molecular biology (and in particular, Forsdyke’s view of his position within it) than an historical study. It is somewhat disingenuous of McGill-Queen’s University Press to label this work as “History of Science.” Under such a rubric, it is unlikely to appeal to the audience of this journal.
Donald R. Forsdyke, The Origin of Species Revisited: A Victorian Who Anticipated Modern Developments in Darwin’s Theory, (Kingston & Montreal: McGill-Queen’s University Press, 2001), x + 275 pp., $49.95. [link]