Table 2.

Selective Pressure Analyses of Hypoxia-Exposed Animals in All-Mammals Data Set by Branch-Site Model

Genes	Branch-Site Model	−lnL	2Δ (lnL)	P Value	ω Values	Positively Selected Sites
HBA	Branch (terminal branch of Pantholops hodgsonii)
	Null	3,551.894			ω0 = 0.068, ω1 = 1, ω2 = 1
	Alternative	3,548.763	6.262	0.012	ω0 = 0.068, ω1 = 1, ω2 = 270.801	21-0.993, 80-0.994, 105-0.999, 132-0.994
HBB	Branch (last common ancestral branch of Delphinidae, Lipotes vexillifer, and Mesoplodon densirostris)
	Null	4,185.624			ω0 = 0.047, ω1 = 1, ω2 = 1
	Alternative	4,177.163	16.922	<0.001	ω0 = 0.047, ω1 = 1, ω2 = 494.933	63-1.000
	Branch (terminal branch of Kogia sima)
	Null	4,186.525			ω0 = 0.048, ω1 = 1, ω2 = 1
	Alternative	4,181.318	10.414	0.001	ω0 = 0.048, ω1 = 1, ω2 = 81.753	60-0.988, 88-0.933, 134-0.971
	Branch (terminal branch of Physeter macrocephalus)
	Null	4,182.625			ω0 = 0.044, ω1 = 1, ω2 = 1
	Alternative	4,178.154	8.942	0.003	ω0 = 0.045, ω1 = 1, ω2 = 822.915	3-0.938, 11-0.928, 12-0.995, 51-0.943, 60-0.960, 62-0.997, 73-0.936
	Branch (last common ancestral branch of Bos grunniens and Bos mutus)
	Null	4,189.876			ω0 = 0.046, ω1 = 1, ω2 = 1
	Alternative	4,186.130	7.492	0.006	ω0 = 0.048, ω1 = 1, ω2 = 999	136-0.956
NGB	Branch (terminal branch of Heterocephalus glaber)
	Null	2,529.909			ω0 = 0.059, ω1 = 1, ω2 = 1
	Alternative	2,526.051	7.716	0.005	ω0 = 0.059, ω1 = 1, ω2 = 999	3-0.973, 13-0.976, 15-0.998, 67-0.858, 97-0.952, 67-0.969, 97-0.949