WCP1773

[1]

Parkstone, Dorset.

March 3rd. 1895

My dear Prof. Lloyd Morgan¹

Thanks for your very interesting letter. You will be surprised to hear that I agree with almost all of it, & the few outstanding differences are such that if we had an hours talk I feel sure we should come to a complete agreement. One or two of these ^points I will however try to clear up now.

First as to definite & indefinite variations. I have, I think, always admitted some amount of definite variation — as in Geddes' theory of flower- development² (Darwinism, p. 433[?]³) and of course in number-variation, as of vertebrae, antennae joints &c.. And everywhere there may be a certain definiteness in variation, inasmuch as certain parts in a species or race will vary much oftener & to a greater amount than other parts. But, what I have always arg[u]ed, & now am more convinced of than ever, is, that no definite variations ever can, by themselves, form a new species if such variations are in no degree adaptive; and my whole objection to Galton's⁴ views is, that he maintains that his variations can and do form species "without any help whatever from natural selection". — This he reiterates and enforces, as his special point, and it is against this [2] view only that my whole argument against him is founded directed.

I now maintain, not only that most specific characters are adaptive, but that all are either themselves adaptive or correlated with those that are so ^{(or have recently been so)}. This is really, as it seems to me, an identical proposition to those who accept natural selection. To simplify matters let us take (a), (b), and (c). as successively modified species, — that is, that a portion of (a) has become adapted to a slightly different environment, becoming (b), & that a portion of (b) has been again modified becoming (c). & we might have a larger or a divergent series. Now in each case the real specific character of (b) or (c) is that characters or group of characters (or others necessarily correlated with them) by means of which the form has become adapted to the different environment. Such characters are therefore necessarily adaptive, & they will differentiate the species from all its allies, living or extinct. The species-describer may claim other characters which the species has in common with extinct or unknown species, & which are not therefore ^true "specific characters". You may say, why [3] may there not be, along with these adaptive characters, others not adaptive which get characterise the species. I admit the possibility but, with what is known of the nature and amount of variation, the probability appears to me infinitesimal. For, take the closely allied species a, b, c, d, e, f, g, &c. One of these, say (d) we will suppose to possess a character quite peculiar to it, and found normally in every individual of the species, which ^character is yet not in any way adaptive & never has been so. Can you picture to yourself how this state of things came about? I cannot. Still less can I see any glimmer of a reason why it should come about. For it means that, during ^{the progress of} a certain slight amount of adaptive modification from (c) to (d) — a character(x) which appeared rarely or sporadically ^{or did not exist} in (c) became absolutely fixed and uniform in (d) — & in every individual that survived at all events — and then, when another equally slight modification occurred in any direction, this unadaptive character (x) ceased altogether to appear, in neither case being hurtful, or useful, or being correlated [4] with the characters that were so. Now this seems to me to be opposed to all we know of variation of every kind. Take any of Bateson's⁵ or Galton's cases — Can you imagine some one species of Felis acquiring 6 or 7 toes, in every individual of the species, ^{and in that species only} solely through the "organic stability" of that particular variation? Is there any indication whatever, among domestic animals or plants, of some trivial & functionless variation appearing, first here & there, then increasing, till at last every individual born possesses it? Yet this is what must happen if Galton's theory has any truth in it.

I hope these few remarks will clear up any point of view on this matter, which is the essential feature of Galton's theory, which he puts forth as a tremendous blow to "natural selection".

I meant to ask you if you had read my Glacial Lake article in "Fortnightly" of Dec. 1893. Two or three American geologists adduced that same argument as to lake-contours, about the same time, & it seems to me to be quite conclusive.

Yours very truly | Alfred R. Wallace [signature]