Neo-Lamarckian experimentalism in America: Origins and consequences

The 1890's and the first decades of the twentieth century saw a vigorous de bate about the mechanisms of evolutionary change. On one side, August Weism ann defended the selectionist hypothesis; on the other, Herbert Spencer def ended neo-lamarckian theory. Supporters of Spencer, notably the American pa leontologist and evolutionary theorist Henry Fairfield Osborn, recognized t hat the questions raised by Weismann and Spencer could only be settled expe rimentally. They called for the application of experimental methods, and th e establishment of a new institution for the purpose of confirming Me inher itance of acquired characters. To a great extent, the experimental program championed by Osborn and others was implemented and, although it failed to reveal soft inheritance and was soon eclipsed by Mendelian and chromosomal genetics, it did make significant and lasting contributions to evolutionary biology. Thus the importance of methodological and institutional innovatio n and theoretical pluralism to the progress of science is illustrated and u nderscored.