The Correlation Between Relatives on the Supposition of Mendelian Inheritance

The Correlation Between Relatives on the Supposition of Mendelian Inheritance is a scientific paper by R.A. Fisher which was published in the Philosophical Transactions of the Royal Society of Edinburgh in 1918, (volume 52, pages 399–433). In it, Fisher puts forward a genetic model that shows that continuous variation amongst characters could be the result of Mendelian inheritance. The paper also contains the first use of the term variance.

Background
Mendelian genetics was rediscovered in 1900. However, there were differences of opinion as to what was the variation that natural selection acted upon. The biometric school, led by Karl Pearson followed Darwin's idea that small differences were important for evolution. The Mendelian school, led by William Bateson, however thought that Mendel's work gave an evolutionary mechanism with large differences.

Joan Box, Fisher's biographer and daughter tells us in her book that Fisher, then a student, had resolved this problem in 1911.

Fisher originally submitted his paper to the Royal Society to be published in the Transactions of the Royal Society of London. The two referees, the biologist R. C. Punnett and the statistician Karl Pearson expressed reservations and that there were areas which they were unable to judge for lack of expertise. Though they did not reject the paper, Fisher was having a feud with Pearson since 1917, and instead the paper was sent to the Royal Society of Edinburgh, who published it in their Transactions.

Fisher's model
Fisher defines his new term of variance, as the square of the standard deviation, because of the manner in which variances of independent random variables may be added. He notes the continuous variation in human characters.