August Weismann

Born Jan. 17, 1834, in Frankfurt-am-Main; died Nov. 5, 1914, in Freiburg. German zoologist and theoretician of the evolutionary school. He studied in Göttingen (1852-56). In 1863 he became assistant professor, and from 1873 to 1912 he was a professor at the University of Freiburg.

Weismann’s early work was devoted to the histology of muscle tissue, the development of insects, and the biology of freshwater organisms. Beginning at the end of the 1860’s he shifted his main efforts to theoretical studies devoted to the defense, corroboration, and development of the teachings of C. Darwin. Taking a position of materialism, Weismann defended the mechanistic concept of life phenomena. He argued against vitalism and rejected Lamarckism, which recognized the inherently expedient response of living organisms to the impact of the environment and the inheritance of changes arising in this way. Weismann correctly stated that the problem of the inheritance of acquired characteristics could only be resolved through experimentation, and he proved experimentally the noninheritance of mechanical injuries. Weismann was the author of the speculative theories of inheritance and of individual development, which were inaccurate in details but which anticipated in principle the contemporary notions of the discrete nature of the carriers of hereditary information and their links with chromosomes. He was also the author of a concept of the role of inherited instincts in the individual’s development.

At the end of the 1940’s, Weismann’s teachings, which he called neo-Darwinism, were erroneously pronounced unscientific and reactionary by certain Soviet geneticists. In actuality, Weismann’s teachings were a further development of Darwin’s theory of evolution.