
Autocorrelation in normalized conservation rates at fourfold sites shared between S. cerevisiae and S. paradoxus. (Left) Rates are not correlated along the S. cerevisiae genome, even for genes as close as several thousand base pairs. The average distance between genes in our data set is ∼3000 bp. (Right) In contrast, mouse-human conservation rates are significantly correlated along the human genome at separations up to several megabases.











