The Eclipse of Darwinism - Motivation For Alternatives

Motivation For Alternatives

There were a variety of different factors that motivated people to propose other evolutionary mechanisms as alternatives to natural selection. Natural selection, with its emphasis on death and competition, did not appeal to some naturalists because they felt it was immoral, and left little room for teleology or the concept of progress in the development of life. Some of these scientists and philosophers, like St. George Jackson Mivart and Charles Lyell, who came to accept evolution but disliked natural selection, raised religious objections. Others, such as Herbert Spencer, the botanist George Henslow (son of Darwin's mentor John Stevens Henslow also a botanist), and Samuel Butler, felt that evolution was an inherently progressive process that natural selection alone was insufficient to explain. Still others, including the American paleontologists Edward Drinker Cope and Alpheus Hyatt, had an idealist perspective and felt that nature, including the development of life, followed orderly patterns that natural selection could not explain.

Some felt that natural selection would be too slow, given the estimates of the age of the earth and sun (10–100 million years) being made at the time by physicists such as Lord Kelvin, and some felt that natural selection could not work because at the time the models for inheritance involved blending of inherited characteristics, an objection raised by the engineer Fleeming Jenkin in a review of Origin written shortly after its publication. Another factor at the end of the 19th century was the rise of new faction of biologists, typified by geneticists like Hugo DeVries and Thomas Hunt Morgan, who wanted to recast biology as an experimental laboratory science. They distrusted the work of naturalists like Darwin and Alfred Russel Wallace, dependent on field observations of variation, adaptation, and biogeography, as being overly anecdotal. Instead they focused on topics like physiology, and genetics that could be easily investigated with controlled experiments in the lab, and discounted things like natural selection and even the degree to which organisms were adapted to their environment, which could not easily be tested experimentally.