August Weismann on Germ-Plasm Variation

Journal of the History of Biology 34 (3):517-555 (2001)
  Copy   BIBTEX

Abstract

August Weismann is famous for having argued against the inheritance of acquired characters. However, an analysis of his work indicates that Weismann always held that changes in external conditions, acting during development, were the necessary causes of variation in the hereditary material. For much of his career he held that acquired germ-plasm variation was inherited. An irony, which is in tension with much of the standard twentieth-century history of biology, thus exists – Weismann was not a Weismannian. I distinguish three claims regarding the germ-plasm: (1) its continuity, (2) its morphological sequestration, and (3) its variational sequestration. With respect to changes in Weismann’s views on the cause of variation, I divide his career into four stages. For each stage I analyze his beliefs on the relative importance of changes in external conditions and sexual reproduction as causes of variation in the hereditary material. Weismann believed, and Weismannism denies, that variation, heredity, and development were deeply intertwined processes. This article is part of a larger project comparing commitments regarding variation during the latter half of the nineteenth century.

Similar books and articles

Weismann Rules! OK? Epigenetics and the Lamarckian Temptation.David Haig - 2007 - Biology and Philosophy 22 (3):415-428.
Darwin on Variation and Heredity.Rasmus Grønfeldt Winther - 2000 - Journal of the History of Biology 33 (3):425-455.
The Development of Francis Galton's Ideas on the Mechanism of Heredity.Michael Bulmer - 1999 - Journal of the History of Biology 32 (2):263 - 292.
Difference Mechanisms: Explaining Variation with Mechanisms.James Tabery - 2009 - Biology and Philosophy 24 (5):645-664.
Héréditaire, Inné, Génétique, Etc.André Pichot - 1993 - Acta Biotheoretica 41 (1-2):127-138.
Germinal Selection.August Weismann - 1895 - The Monist 6 (2):250-293.
Individual Differences: Variation by Design.Anthony J. Greene & William B. Levy - 2000 - Behavioral and Brain Sciences 23 (5):676-677.
The Varied Lives of Organisms: Variation in the Historiography of the Biological Sciences.L. G. & D. M. - 2001 - Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 32 (1):1-29.
Accounting for Female Strategic Variation.J. Michael Bailey - 2000 - Behavioral and Brain Sciences 23 (4):589-589.
Sex, Death, and Evolution in Proto- and Metazoa, 1876–1913.A. J. Lustig - 2000 - Journal of the History of Biology 33 (2):221 - 246.

Analytics

Added to PP
2011-06-11

Downloads
1,676 (#3,216)

6 months
45 (#24,135)

Historical graph of downloads
How can I increase my downloads?

Author's Profile

Rasmus Grønfeldt Winther
University of California, Santa Cruz

References found in this work

Complexity and Organization.William C. Wimsatt - 1972 - PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association 1972:67-86.
Complexity and the Function of Mind in Nature.D. M. Walsh - 1997 - British Journal for the Philosophy of Science 48 (4):613-617.

View all 18 references / Add more references