Toward a Complete Record

In light of the recent discussion of the disregard syndrome,¹ I would like to add something to your Jan. 7 cover story on SNPs.² The fact that most nucleotide substitutions are synonymous, and the idea that the ratio of nonsynonymous to synonymous substitutions can indicate adaptive change, was described at length by Motoo Kimura in the1970s.^3,4 The neutral theory of molecular evolution fundamentally affected subsequent evolutionary thought, even though it met some resistance at first. Technology has only recently allowed us to catalog SNPs on a genomic scale (hence the catchy new acronym), but Kimura described generally what we would see, and why.