Heredity, Natural Selection, and Evolution

Early Studies in Heredity

What is the law of independent assortment?

This Mendelian principle deals with the prediction of the outcome of dihybrid (two-trait) crosses—in other words, two individuals hybrid for two or more traits that are not on the same chromosome (called a dihybrid cross; see below). The law states that during gamete formation, the alleles of a gene for one trait, such as plant height, segregate independently from those for another trait, such as seed color. From this, Mendel concluded that traits are transmitted to offspring independently of one another. In other words, the separation of alleles for one trait does not influence or control the distribution of alleles from the second trait. This law holds true as long as the two traits in question are located on separate chromosomes or are so distant from each other on the same chromosome that they sort independently.