The Correlation between Relatives on the Supposition of Mendelian Inheritance

The Correlation between Relatives on the Supposition of Mendelian Inheritance is a science paper. Ronald Fisher wrote it in 1918. The paper was in a book named Transactions of the Royal Society of Edinburgh. In the paper, Fisher talked about how some traits in people and animals can be passed from parents to children through genes. This is called Mendelian inheritance. He also used a new math word in the paper: variance. Variance is a way to measure how different numbers are from each other.

Ronald Fisher in 1912

Genes can have a small effect by themselves, but can be important when all of their effects are considered together.

In 1900, scientists rediscovered Mendelian inheritance. But, there was a debate about how it worked. Some scientists, like Karl Pearson, believed in Charles Darwin's idea. Darwin said small changes in creatures are important for evolution. Others, like William Bateson, believed big changes were more important. Fisher believed small changes could be passed on through genes. He wrote about this in 1911 when he was a student. He showed that this is true in the paper he wrote in 1918.

Traits with many genes, like height, will be normally distributed. This is different from how people though genes worked at the time. They thought only a few genes mattered for a trait.

Fisher talked about variance. He said it is the "square" of another math term, the standard deviation. This helps understand how different numbers are spread out. Fisher also talked about how people have different traits, like height or eye color.