Lamarck, the Founder of Evolution: His Life and Work

by A. S. Packard

Had his works been more accessible, or, where available, more carefully read, and his views more fairly represented; had he been favored in his lifetime by a single supporter, rather than been unjustly criticised by Cuvier, science would have made more rapid progress, for it is an axiomatic truth that the general acceptance of a working evolutionary theory has given a vast impetus to biology.

We will now give a brief historical summary of the history of opinion held by Lamarckians regarding the causes of the “origin of the fittest,” the rise of variations, and the appearance of a population of plant and animal forms sufficiently extensive and differentiated to allow for the play of the competitive forces, and of the more passive selective agencies which began to operate in pre-cambrian times, or as soon as the earth became fitted for the existence of living beings.

The first writer after Lamarck to work along the lines he laid down was Mr. Herbert Spencer. In 1866–71, in his epochal and remarkably suggestive Principles of Biology, the doctrine of use and disuse is implicated in his statements as to the effects of motion on structure in general;[204] and in his theory as to the origin of the notochord, and of the segmentation of the vertebral column and the segmental arrangement of the muscles by muscular strains,[205] he laid the foundations for future work along this line. He also drew attention in the same work to the complementary development of parts, and likewise instanced the decreased size of the jaws in the civilized races of mankind, as a change not accounted for by the natural selection of favorable variations.[206] In fact, this work is largely based on the Lamarckian principles, as affording the basis for the action of natural selection, and thirty years later we find him affirming: “The direct action of the medium was the primordial factor of organic evolution.”[207] In his well-known essay on “The Inadequacy of Natural Selection” (1893) the great philosopher, with his accustomed vigor and force, criticises the arguments of those who rely too exclusively on Darwinism alone, and especially Neodarwinism, as a sufficient factor to account for the origin of special structures as well as species.

The first German author to appreciate the value of the Lamarckian factors was that fertile and comprehensive philosopher and investigator Ernst Haeckel, who also harmonized Lamarckism and Darwinism in these words:

“We should, on account of the grand proofs just enumerated, have to adopt Lamarck’s Theory of Descent for the explanation of biological phenomena, even if we did not possess Darwin’s Theory of Selection. The one is so completely and directly proved by the other, and established by mechanical causes, that there remains nothing to be desired. The laws of Inheritance and Adaptation are universally acknowledged physiological facts, the former traceable to propagation, the latter to the nutrition of organisms. On the other hand, the struggle for existence is a biological fact, which with mathematical necessity follows from the general disproportion between the average number of organic individuals and the numerical excess of their germs.”[208]

A number of American naturalists at about the same date, as the result of studies in different directions, unbiassed by a too firm belief in the efficacy of natural selection, and relying on the inductive method alone, worked away at the evidence in favor of the primary factors of evolution along Lamarckian lines, though quite independently, for at first neither Hyatt nor Cope had read Lamarck’s writings.

In 1866 Professor A. Hyatt published the first of a series of classic memoirs on the genetic relations of the fossil cephalopods. His labors, so rich in results, have now been carried on for forty years, and are supplemented by careful, prolonged work on the sponges, on the tertiary shells of Steinheim, and on the land shells of the Hawaiian Islands.

His first paper was on the parallelism between the different stages of life in the individual and those of the ammonites, carrying out D’Orbigny’s discovery of embryonic, youthful, adult, and old-age stages in ammonites,[209] and showing that these forms are due to an acceleration of growth in the mature forms, and a retardation in the senile forms.

In a memoir on the “Biological Relations of the Jurassic Ammonites,”[210] he assigns the causes of the progressive changes in these forms, the origination of new genera, and the production of young, mature, and senile forms to “the favorable nature of the physical surroundings, primarily producing characteristic changes which become perpetuated and increased by inheritance within the group.”

The study of the modifications of the tertiary forms of Planorbis at Steinheim, begun by Hilgendorf, led among others (nine in all) to the following conclusions: