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.


Elemente der Exakten Erblichkeitslehre (1909), 165–70. Trans. in Ernst Mayr, The Growth of Biological Thought: Diversity, Evolution and Inheritance (1982)

Wilhelm Johannsen Quotes

This constitution we designate by the word genotype. The word is entirely independent of any hypothesis; it is fact, not hypothesis that different...

This constitution we designate by the word genotype. The word is entirely independent of any hypothesis; it is fact, not hypothesis that different...

This constitution we designate by the word genotype. The word is entirely independent of any hypothesis; it is fact, not hypothesis that different...

This constitution we designate by the word genotype. The word is entirely independent of any hypothesis; it is fact, not hypothesis that different...