Table 2.

Logistic regression models with sex as the dependent variable

	Bison			Brown bears
Explanatory variable	All	Postcrania	Noncave	All	Alps	Non-Alps	Mammoths*
Intercept-only	1.31E-10	8.80E-05	8.51E-12	0.00973	0.110	0.000122	4.21E-05
Cave/noncave	0.00176	0.00646		0.367		0.0399
Material1	0.618	0.634	0.716	0.264	0.758	0.0695	0.132
Material2	0.227		0.245	0.594	0.671	0.590
14C age	0.768	0.534	0.614	0.0122	0.133	0.174	0.992
Latitude	0.954	0.657	0.682	0.619	0.494	0.0244
Longitude	0.490	0.527	0.965	0.0171	0.708	0.417
Altitude	0.676	0.802	0.847	0.0157	0.158	0.911
Alps/non-Alps				0.000363
Endogenous	0.707	0.790	0.941	0.137	0.521	0.439
GC ratio	0.312	0.625	0.468	0.723	0.386	0.168
DNA fragment length	0.237	0.343	0.705	0.352	0.717	0.514
5′ deamination (C$\to$T)	0.558	0.681	0.644	0.162	0.446	0.148

The row corresponding to an intercept-only model shows P values for the intercept term, which tests the null hypothesis that there is a 1:1 male to female ratio. All other cells contain P values from LRTs, comparing a logistic regression model of the form “sex ∼ X,” where X is a single explanatory variable, to the intercept-only model above it. Ps <0:05 are shown in boldface italics. Material1 consists of factors such as tooth, leg, astragalus, foot, petrous, other skull, vertebrae, flat bone, and horn. Material2 collapses factors from Material1 into crania and noncrania. Full model fitting results can be found in SI Appendix, Tables S1 and S2.

^*Mammoth data are from ref. 4.