Likelihood ratio tests and maximum likelihood estimates of dN/dS for six Drosophila species of the melanogaster group.

Abbreviation: LRT, Likelihood ratio test.1M1a: ω0 varies between 0 and 1 whereas ω1 = 1;2M2a adds to M1a, ω2>1, which is estimated from the data;3proportions of sites under ω0, ω1, and ω2.4Tests whether the dN/dS relative to the two partitions are significantly different from each other.