evolutionary theorist
charles darwin
['carl gustav mosander', 'henri cartan', 'william rowan hamilton', 'isaac newton', 'carl auer von welsbach', 'lyudmila chernykh', 'thomas newcomen', 'karl drais', 'albert einstein', 'cyril jackson', 'marija gimbutas', 'annibale de gasparis', 'nikolai chernykh', 'herschel', 'lewis swift', 'sequoyah', 'egide walschaerts', 'takashi murakami', 'otto hahn', 'linear', 'marguerite laugier', 'joseph priestley', 'eugene shoemaker', 'tsutomu seki', 'frederick scott archer', 'ernst mayr', 'lionel penrose', 'kirchhoff', 'james dunlop', 'cavendish', 'lee de forest', 'paolo maffei', 'heinrich ruhmkorff', 'werner heisenberg', 'henri lebesgue', 'gotthold ephraim lessing', 'moog', 'auguste charlois', 'tom gehrels', 'purple mountain observatory', 'edward said', 'james watt', 'carl wirtanen', 'gridshell', 'gustav rose', 'carlos torres', 'alessandro malaspina', 'leibniz', 'nauchnyj', 'dmitri mendeleev', 'rudolf diesel', 'stallman', 'indiana asteroid program', 'hermann goldschmidt', 'sir alexander fleming', 'vapnik', 'emmett chapman', 'franz anton mesmer', 'urata', 'clyde tombaugh', 'sir nigel gresley', 'edwin mcmillan', 'christopher cockerell', 'harold urey', 'johan gadolin', 'george berkeley', 'ephraim shay', 'thorstein veblen', 'mike brown', 'cornelis johannes van houten', 'ernest hemingway', 'christopher alexander', 'roger penrose', 'robert bunsen', 'ingrid', 'loneos', 'alonzo church', 'ernest johnson', 'microsoft', 'bickley', 'tycho', 'sir winston churchill', 'michael brown', 'seymour papert', 'max wolf', 'ernest rutherford', 'oak ridge observatory', 'claude chappe', 'james bradley', 'gerry anderson', 'maurice martenot', 'vint cerf', 'donald knuth', 'lord rayleigh', 'bernhard schmidt', 'kazuro watanabe', 'robert luther', 'noam chomsky', 'edwin hubble']
August Weismann
Friedrich Leopold August Weismann (17 January 1834 – 5 November 1914) was a German evolutionary biologist. Ernst Mayr ranked him 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 was the germ plasm theory, at one time also known as Weismannism, according to which (in a multicellular organism) inheritance 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 the an individual acquires during its life. Genetic information cannot pass from soma to germ plasm and on to the next generation. This is referred to as the Weismann barrier. This idea, if true, rules out the inheritance of acquired characteristics as proposed by Jean-Baptiste Lamarck. The idea of the Weismann barrier is central to the modern evolutionary synthesis, though it is not expressed 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 was one of the first biologists to deny soft inheritance entirely. 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 1930–40, and was "one of the great biologists of all time".