Nei and Lin used this letter used to represent the nucleotide diversity in a population.
Nei and Lin used this letter used to represent the nucleotide diversity in a population. This letter names a theorem that describes how an equation with n variables, in k dimensions can be rewritten in terms of n-minus-k parameters. A quantity denoted by this letter is equal to the pressure needed to prevent water movement across a semipermeable membrane. Huckel's rule states that a cyclic system with "4n plus 2" electrons in these orbitals is aromatic. Double bonds in alkenes consist of a sigma bond and a bond denoted by his letter. For 10 points, name this letter which is used to symbolize a constant equal to the ratio of a circle's circumference to diameter. 
Nei and Lin used this letter used to represent the nucleotide diversity in a population.
pi