RE: J Mol Evol (2003) 57:343–354—An equation in the discussion was incorrectly printed as E[S]=θ × (1 + 1 √2+1√3 +...+1√10). This should have been E(S)=θ × (1 + 1/2 + 1/3+... +1/9). The correct equation was used in our calculations.