Table 2. BEAST divergence date estimation for two hypothetical mtDNA rates of evolution.

	Fixed Clock dates @ 4.0%	Calibration dates (used to estimate rate)	Yule birth-death Estimated dates @ 14.2%
h	925,000 ybp (95% CI  = 1,099,800−753,800 ybp)	1,800,000 ybp +/− 0.1 (95%  = 1.964−1.636 million ybp)	1,710,400 ybp +/− 1,378 (95% CI  = 1.913−1.512 million ybp)
hCR	237,000 ybp (95% CI  = 294,900−183,200 ybp)	500,000 ybp +/− 0.180 (95%  = 796,000−204,000 ybp)	16,230 ybp +/− 1,335 (95% CI  = 22,042−8,840 ybp)
hCRN	237,000 ybp (95% CI  = 294,900−183,200 ybp)	18,000 ybp +/− 0.003 (95%  = 22,900−13,000 ybp)	16,230 ybp +/− 1,335 (95% CI  = 22,042−8, ybp)
hN	237,000 ybp (95% CI  = 294,900−183,200 ybp)	6,000 ybp +/− 0.00125 (95%  = 8,000−3,900 ybp)	8,640 ybp +/− 260 (95% CI  = 10,789−6,477 ybp)

Groups are denoted as: h  =  the hentzi species clade; hCR  =  all specimens within the CRB and everything to the north; hCRN  =  all specimens north of the Colorado River; hN  =  every specimen north of the CRB (but not including the CRB).