Talk:Edward Blyth

This account relies way too heavily on the work of Loren Eiseley, which is not very well respected for its historical accuracy anymore. This really needs some updating using historiography from at least the 1980s, much less things more current. --Fastfission 21:03, 11 February 2006 (UTC)Reply

A solid refutation of Eiseley's view comes even earlier than the eighties: Joel S. Schwartz, "Charles Darwin's Debt to Malthus and Edward Blyth," Journal of the History of Biology vol. 7, no. 2, Autumn 1974, pp. 301-318, online at http://www.jstor.org/stable/4330617 Looks like Gould and Wilkins have already been cited as counterpoints to Eiseley at this point, but Schwartz is a good further reference. Lippard (talk) 18:17, 11 June 2011 (UTC)Reply

"Blyth was also a Christian, and probably would be branded today as a creationist" I removed this sentence as unhelpful, but it has been reinstated. I do not see why it is appropriate to label 19th century biologists with anachronistic terms taken from modern debates. The claim also comes close to the weaselly implication that a Christian is necessarily a creationist, which is both provocatively POV and untrue. Myopic Bookworm 09:16, 8 September 2006 (UTC)Reply

I have removed the comment about Darwin's copies of Blyth's articles being in the University of Cambridge Library, and the corresponding reference. This information was taken from a page on my web site, and more recent research indicates that the journals are not held at that location now. I am still trying to find out what has happened to them.
Andrew Bradbury. 09:22, 17 September 2006 (UTC)

"Blyth had discussed natural selection, but Eiseley didn't realize that most biologists did so in the generations before Darwin. Natural selection ranked as a standard item in biological discourse – but with a crucial difference from Darwin's version: the usual interpretation invoked natural selection as part of a larger argument for created permanency."

This section goes way, way too far. At heart there is a confusion between differential mortality (an everyday farmyard occurrence) and natural selection, which is a fully-fledged scientific hypothesis. In WP our job is to reflect standard knowledge, as indicated by suitable references: it's an encyclopaedia. Standard thinking is that only a few people anticipated Darwin on this topic, and none of them produced the full concept.

Blyth was certainly one of these; William Charles Wells, and Patrick Matthews would also qualify. There were more who wrote about some kind of evolution, and a few who anticipated particulate inheritance. The section in question needs to be more conservative; it's got too much personal opinion in it..

Macdonald-ross (talk) 07:24, 17 January 2008 (UTC)Reply

I now realise that a contributor has copied much of this content from a Stephen Gould article Natural selection as a creative force, without crediting it. The nub of it is that Gould here interprets natural selection in such a broad manner that almost any account of natural death is incorporated. I draw attention to a scientific definition of natural selection in Endler J.A. 1986. Natural selection in the wild. Princeton page 4. This definition calls for [abbreviated]

1. Variation among individuals

2. Differences in fitness

3. Inheritance

And if those requirements are met, then:

5. The trait frequency distribution will vary amongst age classes or life history stages

6. If the population is not at equilibrium then the trait distribution of all offspring will be predictably different from the distribution of all parents.

In Darwin's case, as we know, his account was arranged as follows (as for instance Huxley J.S. 1942. Evolution the modern synthesis. p14:

1. tendency of organisms to increase in number geometrically

2. but numbers remain roughly constant, therefore a struggle for existence occurs

3. All organisms vary appreciably, and some/much of the variation is heritable

4. Therefore the effects of differential survival will accumulate from generation to generation.

In both these cases the term 'natural selection' is hedged with requirements which are only partly met even by Wells, Blyth and Matthew. Hence Gould's "Natural selection ranked as a standard item in biological discourse" [said of pre-Darwinian biologists] is just not true if we use the term as Darwin did and as we do now.

On this basis, I intend to cool down some of the rhetoric in these pre-Darwinian pages with a more balanced account.

Macdonald-ross (talk) 19:12, 19 January 2008 (UTC)Reply

"The theologian William Paley had earlier presented this argument, doing so to refute (in later pages) a claim that modern species preserve the good designs winnowed from a much broader range of initial creations after natural selection had eliminated the less viable forms: "The hypothesis teaches, that every possible variety of being hath, at one time or other, found its way into existence (by what cause of in what manner is not said), and that those which were badly formed, perished".^{[citation needed]}"

The quotation can be found here – Paley is setting up someone else's argument, and it's not really natural selection. Perhaps "natural attrition" or "natural deaths" would be more appropriate. . . dave souza, talk 08:16, 19 May 2009 (UTC)Reply

I've removed the following as original research. The quotations from Blyth clearly refer to variation within a species as defined by John Ray, not speciation. . dave souza, talk 08:16, 19 May 2009 (UTC)Reply

Thus it has been argued that like the other proto-evolutionary biologists, Blyth grasped part of the story, but he rejected the critical part, the production of new species. But this is not, in fact, the case. In his 1835 paper, Blyth wrote:

"It is a general law of nature for all creatures to propagate the like of themselves: and this extends even to the most trivial minutiae, to the slightest individual peculiarities; and thus, among ourselves, we see a family likeness transmitted from generation to generation.

"When two animals are matched together, each remarkable for a certain given peculiarity, no matter how trivial, there is also a decided tendency in nature for that peculiarity to increase; and if the produce of these animals be set apart, and only those in which the same peculiarity is most apparent, be selected to breed from, the next generation will possess it in a still more remarkable degree; and so on, till at length the variety I designate a breed, is formed, which may be very unlike the original type.
(Italics added for emphasis). ^[1]

Or:

"The true physiological system is evidently one of irregular and indefinite radiation, and of reiterate divergence and ramification from a varying number of successively subordinate typical plans; often modified in the extremes, till the general aspect has become entirely changed, but still retaining, to the very ultimate limits, certain fixed and constant distinctive characters, by which the true affinities of species may be always known; the modifications of each successive type being always in direct relation to particular localities, or to peculiar modes of procuring sustenance; in short, to the particular circumstances under which a species was appointed to exist in the locality which it indigenously inhabits, where alone its presence forms part of the grand system of the universe, and tends to preserve the balance of organic being, and, removed whence (as is somewhere well remarked by Mudie), a plant or animal is little else than a "disjointed fragment."
(Italics added for emphasis) ^[2]

Or again:

"A variety of important considerations here crowd upon the mind; foremost of which is the inquiry, that, as man, by removing species from their appropriate haunts, superinduces changes on their physical constitution and adaptations, to what extent may not the same take place in wild nature, so that, in a few generations, distinctive characters may be acquired, such as are recognised as indicative of specific diversity? It is a positive fact, for example, that the nestling plumage of larks, hatched in a red gravelly locality, is of a paler and more rufous tint than in those bred upon a dark soil.17 May not, then, a large proportion of what are considered species have descended from a common parentage?"
(Italics added for emphasis). ^[3]

This is not to say that Blyth had the whole mechanism of evolution sewn up. He didn't. But on the other hand, as Hoyle and Wickramasinghe noted in 1981:

"[Edward] Blyth and [Charles] Lyell were nearer the truth than Darwin." ^[4]

Fred Hoyle and Chandra Wickramasinghe are hardly reliable expert sources on natural selection. . . dave souza, talk 08:16, 19 May 2009 (UTC)Reply

Yes, I agree. Notions of struggle for existence, over-fecundity (Malthus), variation within a species (Ray, Linnaeus), evolution (Lamarck), hard heredity (Lawrence) and even natural selection in a limited form (Wells), had all appeared before Blyth, and are indeed good starting-points, but as isolated ideas. The complete synthesis (minus hard heredity) was achieved by C.D., and not by Blyth. Incidentally, I've located the source of the Paley quote, and added the final clause of his sentence, wickedly omitted by some other contributor! Macdonald-ross (talk) 08:49, 19 May 2009 (UTC)Reply