"Theory of Ancestral Contributions in Heredity," handwritten manuscript by Karl Pearson, published in Proceedings of the Royal Society (vol. 81:547) (10)

1980. [handwritten] 10 to isolated lines of inheritance, with restricted matings. (ii) asserting that a gametic knowledge of parents is equivalent to a knowledge of ancestry. In neither case does the argument touch the ancestral position, which is summed up in the assertion that if we measure inheritance by the [resemblance?] of somatic characters between offspring and ancestry, then in a population mating at random: The more ancestors of any grade with a grim somatic character, the more offspring with that character. For ancestry of different grades the influence is diminished in geometrical progression at each stage. These principles were deduced empirically from observations & records, without any theory as to the mechanism of heredity. If Mendelism be true for [obscured] any characters in cross-fertilized plants, then these [obscured] hold also for heredity in that plant-population, for they are essential features of the Mendelian theory, (and as a matter of fact of a good many [end]