Experiments in plant hybridisation / Mendel's original paper in English translation, with commentary and assessment by Sir Ronald A. Fisher, together with a reprint of W. Bateson's biographical notice of Mendel ; edited by J.H. Bennett.

  • Mendel, Gregor, 1822-1884.
Date:
[1965]
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Experiments in plant hybridisation / Mendel's original paper in English translation, with commentary and assessment by Sir Ronald A. Fisher, together with a reprint of W. Bateson's biographical notice of Mendel ; edited by J.H. Bennett. Source: Wellcome Collection.

    19/116 (page 5)
    INTRODUCTORY NOTES ON MENDEL'S PAPER 5 of the two or three factors used. Mendel's interest in these experiments was not, however, instigated by this question of statistical independence, for he seems scarcely to have con¬ sidered the possibility of linked inheritance. His interest, as his exposition shows, lay in the purely mathematical or com¬ binatorial properties of the set of genotypes made possible by two or three factors. The independence he was concerned to demonstrate was, so far as the distinction can be made, closer to a logical than to a statistical independence. His summary statement on this section is in fact {p. 27) Thereby is simultaneously given the practical proof that the constant characters which appear in the several varieties of a group of plants may be obtained in all the associations which are possible according to the lazvs of combination, by means of repeated artificial fertilisation. This stress on combinatorial mathematics, which has been almost constantly overlooked by commentators, very well deserves the attention of all who teach the subject; for it is common experience that young workers are at first quite unprepared even for the task of enumerating the genotypes to be expected when several factors are segregating, and this is an obvious first step towards exploring the possibilities of a cross. More recently, indeed, in the exploration of the com¬ plexities to be expected in tetrasomic and hexasomic inheri¬ tance, combinatorial mathematics, of by no means an elementary character, has provided the only possible means of clarification. Mendel's summary statement is also to be read as a hint to plant breeders. Practical plant improvement in this century might be described as an extensive commentary on this text. With the understanding that Mendel's interest in the simul¬ taneous segregation of characters was not concerned with the exclusion of linkage, several statements become intelligible. In addition, further experiments were made with a smaller number of experimental plants in which the remaining characters by twos and threes were united as hybrids; all yielded approximately the same results {p. 27). If there had been serious tests of statistical independence, they would have to have been as large as the two trials reported, the latter of which obviously strained Mendel's resources to