For the 19th-century New York politician, see Augustus Weismann.
August Weismann
ForMemRS HonFRSE
Born
(1834-01-17)17 January 1834
Frankfurt am Main, Germany
Died
5 November 1914(1914-11-05) (aged 80)
Freiburg, Germany
Alma mater
University of Göttingen
Known for
Germ plasm theory
Awards
Darwin–Wallace Medal (Silver, 1908)
August Friedrich Leopold Weismann FRS (For), HonFRSE, LLD (17 January 1834 – 5 November 1914) was a German evolutionary biologist. Fellow German Ernst Mayr ranked him as the second most notable evolutionary theorist of the 19th century, after Charles Darwin. Weismann became the Director of the Zoological Institute and the first Professor of Zoology at Freiburg.
His main contribution involved germ plasm theory, at one time also known as Weismannism,[1] according to which inheritance (in a multicellular animal) only takes place by means of the germ cells—the gametes such as egg cells and sperm cells. Other cells of the body—somatic cells—do not function as agents of heredity. The effect is one-way: germ cells produce somatic cells and are not affected by anything the somatic cells learn or therefore any ability an individual acquires during its life. Genetic information cannot pass from soma to germ plasm and on to the next generation. Biologists refer to this concept as the Weismann barrier.[2] This idea, if true, rules out the inheritance of acquired characteristics as proposed by Jean-Baptiste Lamarck.[3] However, a careful reading of Weismann's work over the span of his entire career shows that he had more nuanced views, insisting, like Darwin, that a variable environment was necessary to cause variation in the hereditary material.[4]
The idea of the Weismann barrier is central to the modern synthesis of the early 20th century, though scholars do not express it today in the same terms. In Weismann's opinion the largely random process of mutation, which must occur in the gametes (or stem cells that make them) is the only source of change for natural selection to work on. Weismann became one of the first biologists to deny Lamarckism entirely.[5] Weismann's ideas preceded the rediscovery of Gregor Mendel's work, and though Weismann was cagey about accepting Mendelism, younger workers soon made the connection.
Weismann is much admired today. Ernst Mayr judged him to be the most important evolutionary thinker between Darwin and the evolutionary synthesis around 1930–1940, and "one of the great biologists of all time".[6]
^Romanes, George John. An examination of Weismannism. The Open court publishing company in Chicago 1893 [1]
^Germ-Plasm, a theory of heredity (1893)- Full online text. Esp.org. Retrieved on 2012-02-25.
^Huxley, Julian 1942. Evolution, the modern synthesis. p. 17
^Winther, Rasmus (2001). "August Weismann on Germ-Plasm Variation". Journal of the History of Biology. 34 (3): 517–555. doi:10.1023/A:1012950826540. PMID 11859887. S2CID 23808208.
^Essays upon heredity (1889) Oxford Clarendon Press – Full online text. Esp.org. Retrieved on 2012-02-25.
^
Mayr, Ernst 1982. The growth of biological thought. Harvard. p. 698
August Friedrich Leopold Weismann FRS (For), HonFRSE, LLD (17 January 1834 – 5 November 1914) was a German evolutionary biologist. Fellow German Ernst...
The Weismann barrier, proposed by AugustWeismann, is the strict distinction between the "immortal" germ cell lineages producing gametes and "disposable"...
biological concept developed in the 19th century by the German biologist AugustWeismann. It states that heritable information is transmitted only by germ cells...
orientation, and sociobiology. In 1892, the German evolutionary biologist AugustWeismann proposed in his germ plasm theory that heritable information is transmitted...
either by other mechanisms such as genetic contamination or as fraud. AugustWeismann's experiment, considered definitive in its time, is now considered to...
I meant to say. Dogma was just a catch phrase." The Weismann barrier, proposed by AugustWeismann in 1892, distinguishes between the "immortal" germ cell...
(78): 502–503. Bibcode:1871Natur...3..502D. doi:10.1038/003502a0. Weismann, August (1892). Das Keimplasma: eine Theorie der Vererbung [The Germ Plasm:...
Weismann, Weissman, Weisman, Waismann, and Vaisman. AugustWeismann (1834–1914), German biologist, evolutionary theorist and proposer of the Weismann...
hereditary material produces. The distinction resembles that proposed by AugustWeismann (1834–1914), who distinguished between germ plasm (heredity) and somatic...
clear distinction between germline and somatic cells. For example, AugustWeismann proposed and pointed out, a germline cell is immortal in the sense...
field of biology at the start of the 20th century through the work of AugustWeismann, Thomas Hunt Morgan, and others, building on the rediscovered work...
acquired characteristics. The experimental work of the German biologist AugustWeismann resulted in the germ plasm theory of inheritance. This led him to declare...
teenager he read the genetic and evolutionary works of Hugo de Vries and AugustWeismann and the philosophical works of Ludwig Feuerbach. He noted Goethe as...
"biometrical" school of heredity by Darwin's cousin, Francis Galton. In 1883 AugustWeismann conducted experiments involving breeding mice whose tails had been...
1904, summa cum laude. Her thesis work was on insect musculature with AugustWeismann as thesis advisor. She then worked as a zoological assistant at the...
medical degree in 1867 and then studied zoology at Freiburg under AugustWeismann followed by studies in Paris. He received a D.Phil. in Würzburg studying...
of acquired traits was shown to have little basis in the 1880s when AugustWeismann cut the tails off many generations of mice and found that their offspring...
& T. Cremer (1982). "Cytogerontology since 1881: a reappraisal of AugustWeismann and a review of modern progress" (PDF). Human Genetics. 60 (2): 101–121...
inheritance, however, was described only in 1890 by German biologist AugustWeismann, who noted that two cell divisions were necessary to transform one...
subsequently referred to the specific concepts of natural selection, the Weismann barrier, or the central dogma of molecular biology. Though the term usually...
theory of heredity that originated with Gregor Mendel (1822–1884), AugustWeismann (1834–1914) proved that inheritance only takes place through gametes...
certain interpretations of Mendelian inheritance and the theories of AugustWeismann. The word eugenics is derived from the Greek word eu ("good" or "well")...
before moving to University of Freiburg, where he was supervised by AugustWeismann. Again he left after one semester, this time to join University of...
November 3 – Georg Trakl, Austrian poet (suicide) (b. 1887) November 5 – AugustWeismann, German evolutionary biologist (b. 1834) November 9 – Princess Therese...
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