[i] ^aAll data sets available in the Supplemental material.

[ii] ^bBased on most recent data.

[iii] ^cOur estimate based on most recent data (for fragment size calculation, see Supplemental material). Fragment length distributions were log-normal (Supplemental Fig. S1).

[iv] ^dftp://ftp.ebi.ac.uk/pub/databases/RHdb/.

[v] ^eNo longer publicly available, but downloaded from http://shgc-www.stanford.edu/ at initiation of project.

[vi] ^fhttp://www.broad.mit.edu/ftp/distribution/human_STS_releases/july97/rhmap/.

[vii] ^ghttp://dogs.genouest.org/RH10K-som-details.html#Resources.