Table 1. Counts of SNPs categorized according to allele ancestry, relative fitness, and reference structure.

The reference structure column refers to whether the amino acid in the reference tertiary structure matches the amino acid encoded by the non-synonymous polymorphism in the derived allele, ancestral allele, or neither allele. Calculations use 1 + s for relative fitness of derived allele and 1 for relative fitness of ancestral allele. Numbers in parentheses are the sum of the count for the ancestral allele having higher fitness and the count for the derived allele having higher fitness.

Reference structure	Higher fitness allele	Ancestral major allele	Derived major allele	Total
ancestral	ancestral derived	77 (108) 31	2 (3) 1	79 (111) 32
derived	ancestral derived	2 (6) 4	3 (5) 2	5 (11) 6
neither	ancestral derived	12 (17) 5	1 (1) 0	13 (18) 5
		131	9	140