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Wilhelm Ludvig Johannsen
(3 Feb 1857 - 11 Nov 1927)
Danish botanist and geneticist who investigated in plant heredity. He coined the term "gene" (1909) for each portion of a chromosome that controls a phenotype.
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Science Quotes by Wilhelm Ludvig Johannsen (4 quotes)
No hypothesis concerning the nature of this 'something' shall be advanced thereby or based thereon. Therefore it appears as most simple to use the last syllable 'gen' taken from Darwin's well-known word pangene since it alone is of interest to use, in order thereby to replace the poor, more ambiguous word, 'Anlage'. Thus, we will say for 'das pangene' and 'die pangene' simply 'Das Gen' and 'Die Gene,' The word Gen is fully free from every hypothesis; it expresses only the safely proved fact that in any case many properties of organisms are conditioned by separable and hence independent 'Zustiinde,' 'Grundlagen,' 'Anlagen'—in short what we will call 'just genes'—which occur specifically in the gametes.
— Wilhelm Ludvig Johannsen
Elemente der Exakten Erblichkeitslehre (1909), 124. Trans. G. E. Allen and quoted in G. E. Allen, Thomas Hunt Morgan: The Man and His Science (1978), 209-10 (Footnote 79).
The genotypic constitution of a gamete or a zygote may be parallelized with a complicated chemico-physical structure. This reacts exclusively in consequence of its realized state, but not in consequence of the history of its creation. So it may be with the genotypical constitution of gametes and zygotes: its history is without influence upon its reactions, which are determined exclusively by its actual nature. The genotype-conception is thus an 'ahistoric' view of the reactions of living beings—of course only as far as true heredity is concerned. This view is an analog to the chemical view, as already pointed out; chemical compounds have no compromising ante-act, H2O is always H2O, and reacts always in the same manner, whatsoever may be the 'history' of its formation or the earlier states of its elements. I suggest that it is useful to emphasize this 'radical' ahistoric genotype-conception of heredity in its strict antagonism to the transmission—or phenotype-view.
— Wilhelm Ludvig Johannsen
'The Genotype Conception of Heredity', The American Naturalist (1911), 45, 129.
The science of genetics is in a transition period, becoming an exact science just as the chemistry in the times of Lavoisier, who made the balance an indispensable implement in chemical research.
— Wilhelm Ludvig Johannsen
The Genotype Conception of Heredity', The American Naturalist (1911), 45, 131.
This constitution we designate by the word genotype. The word is entirely independent of any hypothesis; it is fact, not hypothesis that different zygotes arising by fertilisation can thereby have different qualities, that, even under quite similar conditions of life, phenotypically diverse individuals can develop.
— Wilhelm Ludvig Johannsen
Elemente der Exakten Erblichkeitslehre (1909), 165-70. Trans. in Ernst Mayr, The Growth of Biological Thought: Diversity, Evolution and Inheritance (1982), 782.
See also:
- 3 Feb - short biography, births, deaths and events on date of Johannsen's birth.
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- 
