In the years of the post-Darwinian debate, many American naturalists invoked the name of Lamarck to signal their belief in a purposive and anti-Darwinian view of evolution. Yet Weismann’s theory of germ-plasm continuity undermined the shared tenet of the neo-Lamarckian theories as well as the idea of the interchangeability between biological and social heredity. Edward Drinker Cope, the leader of the so-called “American School,” defended his neo-Lamarckian philosophy against every attempt to redefine the relationship between behavior, development, and heredity beyond (...) the epigenetic model of inheritance. This paper explores Cope’s late-career defense of neo-Lamarckism. Particular attention is dedicated to the debate he had with James Mark Baldwin before the publication of Baldwin’s own “A New Factor in Evolution”. I argue that Cope’s criticism was partly due to the fact that Baldwin’s theory of social heredity threatened Cope’s biologistic stance, as well as his attempt to preserve design in nature. This theoretical attitude had a remarkable impact on Baldwin’s arguments for the theory of organic selection. (shrink)

Darwin’s claim about natural selection is reconstructed as an empirical claim about a causal connection leading from the match of the physiology of an individual and its environment to leaving surviving progeny. Variations in this match, Darwin claims, cause differences in the survival of the progeny. Modern concepts of fitness focus the survival side of this chain. Therefore, the assumption that evolutionary theory wants to explain reproductive success in terms of a modern concept of fitness has given rise to the (...) so-called tautology problem. It is shown that the tautology problem reappears in the treatment of fitness proxies in today’s experimental evolutionary biology when these proxies are considered to indicate fitness only. Taking Darwin’s empirical claim seriously suggests, by contrast, that fitness proxies are first of all measures of the match between organism and environment, which I call the organism’s ‘fittedness’. At the same time, they are indeed related to reproductive success. Thus looking in both directions, at fitness and at fittedness, they are janiform. Acknowledging this situation not only allows for rejection of the tautology objection, but also for integration of Darwin’s argument into current evolutionary biology. It is suggested that this helps reframe and alleviate the dispute between the Modern Synthesis and the Extended Evolutionary Synthesis. (shrink)