The science of life : fully illustrated in tone and line and including many diagrams

BOOK 4

word Evolution came later. And the question whether the process included man was either not raised, or plainly or tacitly answered in the negative.

The first attempt to explain Transformism was to ascribe it to the effort of the living being to adapt itself to the often difficult conditions under which it had to live. The French naturalist Lamarck (1744-1829) pointed out that the individual was responsive to its circumstances, that it used and developed this organ and made little use of and therefore did not greatly develop that, that within limits need and exercise called forth structure ; and he supposed that these individual adaptations were in a measure inherited. ‘The three-toed horse—if we may use an example unknown to Lamarckwhich under changing conditions was always scampering on firm prairies and scarcely ever going on soft ground, made no use of its once useful side-toes, and so they were not stimulated to develop, while the business toe got all the work and all the benefit. The foals, according to the Lamarckian idea, inherited the enhanced main toe and the reduced side ones. This line of argument was made exceedingly plausible by the known fact that we all develop best the organs we use most : the rower his biceps, the singer his chest. The weakness of the Lamarckian case, or at least the unproven assumption of it, was that the individual development was in any degree inherited.

In ordinary biological discussion the individual development is called an “ acquired characteristic”?; the size of the rower’s biceps, for instance. Lamarck assumed the inheritance of acquired characteristics and found in that a partial explanation of Transformism. ‘To this day the belief in the inheritance of acquired characters is called Lamarckism. With the inclusion of an involuntary response to the environment (such as the response of growing corals to currents or the darkening of some birds’ feathers when they are reared in a warm and humid atmosphere) and the inheritance of this response, it is called Neo-LamarckismLamarckism modernized.

Lamarck’s realization of at least a limited evolution of species, Transformism, was based on an infinitely smaller knowledge of fact than we have to-day. He relied chiefly on fossil shells, rudimentary structures, and the manifest anatomical resemblances of animals for his belief that Evolution occurred. It was only later (1828) that Geoffroy St. Hilaire called attention to the embryological evidence for Evolution.

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THE SCIENCE OF LIFE

CHAPTER 1

Several distinguished living biologists are Neo-Lamarckians. And the view has appealed to many people because of the moral attractiveness of the idea of effort achieving enduring consequences. Master what you can of mathematics and your child will compute with greater ease ; be merciful and your children will find it less difficult to practise mercy. One likes to think in that fashion. And with various additions and improvements Lamarckism is to be found vigorously paralleled in much modern thought outside the world of biological specialists. “There has been added to the individual effort the idea of an upward driving force of a general sort. Bergson finds an élan vital, George Bernard Shaw a life-force, both mystical drives towards adaptation, coming from or acting through the organism. Both owe something, no doubt, to Schopenhauer’s idea of a driving Will in things. Whether such an hypothesis is necessary or even harmonious with the facts of the case we shall leave the reader to judge at the end of this Book 4. We give it here as a second theory, which must be treated with respect, the theory of an upward drive in life.

Now, while Lamarck was elaborating his transformist ideas, an English clergyman, Dr. Malthus (1766-1834), was developing certain views that did not at first sight seem to have any bearing upon natural history and Transformism at all. His preoccupations seem to have been purely social. He was struck by the rapid increase of the human population about him—and he lived in a prolific age. It was increasing, he thought, much faster than was the food-supply. Consequently there was already a harsh struggle for subsistence going on. Mankind was breeding its way towards starvation ; the weakest would go to the wall. Famine and the check of pestilence were the natural counters to this drift towards over-population and an unendurable poverty, and he urged his follow-creatures to avoid such miseries by restraining their increase through late marriage and through continence. The artificial interference with conception known as birth-control or Neo-Malthusianism, we may note, had no place in his philosophy. That was as far as he got; he betrayed no consciousness of the bearing of his observations upon the ideas of Transformism, of which indeed he may have been quite unaware.

It happened, however, that his writings were read by two scientific travellers and naturalists who were both coming to believe in the fact of Evolution but by no means