WCP627

Enclosure (WCP627.8439)

[1]1

(1)

Dear Sir2,

It is not easy to make the ordinary reader understand such a question as to variation as you put to me. It can perhaps be best explained by a reference to very familiar cases with which every body is acquainted.

Everyone who will think over the subject of variation among the men & women he sees around him will be surprised at the wonderful differences not only in the larger characteristics such as height, weight, and complexion but also on every single part that can be easily observed such as the length or shape of the head ear nose mouth & eyes, the length of the arms, legs & fingers & especially the proportions of all or any of these parts to the others; he will find all [of] them to vary in a most unexpected degree & very often each one seems to be quite independent of all the others.

[2] (2)

The result is that if you could examine a large number of any one race or variety of man and if the question were as to the modification by selection of any one of these numerous characters, the whole population of that race consisting of perhaps a hundred many millions of individuals could be divided into two portions each consisting of those in which the particular character was above or below the average; and although those which do not differ noticeably from the average are the most numerous, yet those which are very considerably above or below may certainly be reckoned as I state at one quarter of the whole so that nature has to select for her purpose from this enormous number of favourable or unfavourable individuals. As it is certain that out of the whole population amongst all living creatures of the individual which are born every year of by far the larger portion die without leaving offspring—i.e. in infancy is in early youth—it necessarily follows that those which are in some way [3] (3) inferior or imperfect will on the average be those from which the most generation is not produced. Those that survive & do leave offspring will therefore be on the whole better adapted to their environment, and as almost every conceivable character does vary in this way there is an overwhelming amount of material to carry on a continuous improvement as regards any desc beneficial change. As re It is therefore absolutely inconceivable, that taking the facts of variation to be as they have been proved to be, that there should be the slighter obstacle in the way of continuous improvement — none of that hazzard of life which ignorant objection assume that the course of evolution could ever have depended on a few pairs only a few the chance meeting of a

The very large number of observations of variation what has been made demonstrate that in respect of variation there is no essential difference between man & all other animals,. which It is only certain that the an enormous majority of animals multiply [4] (4) much more rapidly than does man.

Nature has everywhere & in all parts of the world an enormous overwhelming number of favourable variations to select from and it is this immune surplus age of material, and not the chance variation if a few individuals which gives to her operation such a much greater certainty man universality & power of minute adjustment than those of men.

When we consider that in the care of a single species, the wild rock pigeon, human selection has produced such wonderful varieties.

It is therefore absolutely certain that the each successive ancestral form which had to the evolution of man did exist in such vast numbers & did often such an amount of variation th as to render give it in each case the superiority which natural selection required is necessary to the successful operation of natural selection & the same thus may be and in the case of all their domestic animals It is the vast scale or which nature work that is always forgotten by objection.

Incomplete draft of a letter in WGW’s hand from ARW to James Leon Williams. The posted letter was dated 27 June 1913, and was printed in George Wood Clapp's book The Life and Work of James Leon Williams in 1925 (see WCP5262). Williams had had an interview with Wallace that summer, but had not gotten around to asking his opinion on a subject of interest to him, whether "in his opinion, the appearance of humanity could ever have depended on the survival and variation of a single pair of ancestors." So he wrote to Wallace soon after, and received the letter in reply.
Williams, James Leon (1852-1932). American prosthodontist and pioneer dental histologist.

Published letter (WCP627.8438)

[1]1 [p. 238]

It is not easy to make the ordinary reader understand such a question as to variation as you put to me. It can perhaps be best explained by a reference to very familiar cases with which everybody is acquainted.

Everyone who will think over the subject of variation among the men and women he sees around him will be surprised at the wonderful differences, not only in the larger characteristics such as height, weight or complexion, but also in every single part that can be easily observed such as the length or shape of the head, ears, nose or eyes, the length of the legs, arms or fingers, and especially the proportion of all or any of these parts to the others. He will find all these to vary in a most unexpected degree and very often each one seems to be quite independent of all the others. The result is that if you could examine a large number of any one race or variety of man, and if the question were as to the modification by selection of any one of these numerous characters, the whole population of that race, consisting perhaps of many millions of individuals, could be divided into two portions consisting of those in which the particular character was above or below the average; and although those which did not differ noticeably from the average would be most numerous, yet those which were very considerably above or below the average might certainly be reckoned (as I stated) at one quarter of the whole, so that nature has to select for her purposes from this enormous number of favorable or unfavorable individuals.

As it is certain that, of all living creatures which are born every year, by far the larger portion die without leaving offspring—i.e., in infancy or in early youth—it necessarily follows that those which are in some way inferior or imperfect will, on the average, be those from which the next generation is not produced. Those that survive and do leave offspring will therefore be, on the whole, better adapted to their environment, and as almost every conceivable character does vary in this way, there is an overwhelming amount [2] [p. 239] of material to carry on a continuous improvement as regards any beneficial change.

It is therefore absolutely inconceivable, taking the facts of variation to be as they have been proved to be, that the course of evolution could ever have depended on a few pairs of individuals only.

The large numbers of measurements and of observations which have been made demonstrate that in respect of variation there is no essential difference between man and all other animals. It is also certain that an enormous majority of animals multiply much more rapidly than does man.

Nature has everywhere in all parts of the world an overwhelming number of favorable variations to select from and it is this immense surplusage of material, and not the chance variation of a few individuals, which gives to her operations such a much greater certainty, universality and power of minute adjustment than those of men.

It is therefore absolutely certain that each successive ancestral form which led to the evolution of man did exist in such vast numbers and did offer such an amount of variation as to give it in each case the superiority which was necessary to the successful operation of natural selection.

It is the vast scale on which nature works that is always forgotten by objectors, and it is this that demonstrates the complete fallacy of both the Mutationists and the Mendelians. They alike deal only with comparatively very rare variations, the former with what are called sports, the latter with abnormalities, which usually occur among domesticated animals or cultivated plants and therefore cannot possibly have been the agency by which the vast scheme of evolution has been carried on for millions of ages through the whole of the seas and lands of our globe. That agency is the universal and conspicuous variability of every part and organ of all living things.

Alfred R. Wallace.

An enclosure to a letter dated 27 June 1913, from ARW to Williams, which was printed in George Wood Clapp's book The Life and Work of James Leon Williams in 1925. Williams had had an interview with ARW in summer 1913, but had not gotten around to asking his opinion on a subject of interest to him; whether "in his opinion, the appearance of humanity could ever have depended on the survival and variation of a single pair of ancestors." He wrote to ARW’s son William soon after (see WCP6407), asking him to pass the question on to ARW. The above is ARW’s reply.

Published letter (WCP627.8441)

[1]

Old Orchard,

Broadstone,

Dorset.

June 27th. 1913

Dr L. Williams

Dr. Sir

I hope the enclosed statement will sufficiently answer your question. The main points want stating & restating again & again to impress the ordinary ignorant objector.

Yours very truly | Alfred R. Wallace [signature]

Please cite as “WCP627,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/wallace/letters/WCP627