Review of "A New Factor in Evolution" by James Mark Baldwin
J. McKeen Cattell
Professor Baldwin has here summarized, enlarged and unified several of his recent papers, especially those printed in Science (August 23, 1895, March 20, April 10, 1896). It appears that when Professor Lloyd Morgan was in America last winter he, Professor Baldwin and Professor Osborn found that they had independently reached somewhat similar conclusions regarding certain relations of ontogeny and phylogeny or to use Huxley's distinction and avoid technical words -- between development (of the individual) and evolution (of the animal series). As we all know, the biological questions most eagerly discussed at present are those concerned with the inheritance of acquired characters and the causes of the variations which have resulted in evolution. Professor Baldwin has approached the problem from a new standpoint, and has, I think, formulated ideas which have hitherto had somewhat shadowy contours.
An individual can adapt itself to new conditions. For example, a carnivorous animal, such as a dog, can live on cereals. It learns new habits, and certain adaptations take place in its digestive mechanism. Now if flesh were permanently withheld from the race of dogs those individuals would get on best whose congenital variations fitted them to live on cereals, and these variations being hereditary we might get ultimately a race of granivorous dogs. It would look as though the effect of use in the individual had been inherited, whereas this need
(572) not really be the case. We only have individual adaptations preceding in time race adaptations. It is thus possible- that many of the cases quoted by Neo-Lamarckians as examples of use-inheritance are invalid.
Professor Baldwin applies this principle, which he calls 'organic selection,' especially to adaptations in which consciousness is concerned. If conscious guidance can produce useful adaptations in the individual organism, these adaptations may become hereditary in the manner described above, and we have the course of evolution directed by consciousness, but without the need of assuming the hereditary transmission of acquired characters.
The clear statement of the fact that new traits may appear first as individual adaptations, and later through the occurrence of suitable congenital variations as hereditary modifications, is important. I am not quite sure how far it may be found in earlier writers. Darwin holds that the taste of the female, an individual trait, modifies organic evolution, and it is the essence of natural selection that under changed environment those individuals will survive who can best adapt themselves to it. If organic selection is itself a congenital variation, as Professor Baldwin indicates, we are still in the status quo of chance variations and natural selection. We have not found 'a new factor in evolution,' still less as Professor Osborn claims (cf. Science April 13, 1896) 'a mode of evolution requiring neither natural selection nor the inheritance of acquired characters.' We remain ignorant as to why the individual makes suitable adaptations, wily congenital variations occur in the line of evolution and why they are hereditary.
Professor Baldwin's paper is by no means confined to this one point, 'organic selection,' 'social heredity,' 'circular reactions,' etc., are commingled in a manner that will prove confusing to many readers. Indeed, I venture to say that I find the author's vigorous thinking too often obscure to an unfortunate degree. For example, I am not sure whether or not Professor Baldwin claims in this paper that the principle of 'organic selection' is set forth in his book on Mental Development, nor does my memory after a careful reading of the book enable me to decide the question. Or to take a more serious problem, I do not understand whether or not Professor Baldwin wishes to use consciousness -- pleasure, pain, intelligence, etc. -- as a vera causa in individual adaptations. The average reader will take it for granted that he does, and I admit that it seems to me that he runs with the hare and hunts with the hounds.