Mendelism / by R.C. Punnett.

  • Reginald Crundall Punnett
Date:
1912
Catalogue details

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

Credit: Mendelism / by R.C. Punnett. Source: Wellcome Collection.

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    II HISTORICAL related by ' the community of descent which the accepted theory of evolution demands, though as to the exact course of descent for any particular group of animals there is often considerable diversity of opinion. It is obvious that all this work has little or nothing to do with the manner in which species are formed. Indeed, the effect of Darwin's Origin of Species was to divert attention from the way in which species originate. At the time that it was put forward his explanation appeared so satisfy¬ ing that biologists accepted the notions of variation and heredity there set forth and ceased to take any further interest in the work of the hybridisers. Had Mendel's paper appeared a dozen years earlier it is difficult to believe that it could have failed to attract the attention it deserved. Coming as it did a few years after the publication of Darwin's great work, it found men's minds set at rest on the problems that he raised and their thoughts and energies directed to other matters. Nevertheless, one interesting and noteworthy attempt to give greater precision to the term heredity was made about this time. Francis Galton, a CQUsin of Darwin, working upon data relating to the breeding of Basset hounds, found that he could express on a definite statistical scheme the proportion in which the different colours appeared in successive generations. Every individual was conceived of as possessing a definite heritage which might be ex¬ pressed as unity. Of this, ^ was on the average derived from the two parents {i.e. ^ from each parent), ^ from the four grandparents, ^ from the eight great- grandparents, and so on. The Law of Ancestral
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