Table 2.

Ks estimations of ancient polyploidy and taxon divergence

Materials	Mt-Mt paralogsa	Gm-Mt paralogsa	Gm-Gm paralogsa	Gm-Mt orthologsb	References
ESTs	0.65–0.70	-	0.45–0.50	0.40–0.50	Blanc and Wolfe, 2004
ESTs	0.71	-	0.54	-	Schlueter et al., 2004
39 Gene families	-	-	0.57± 0.05	0.57± 0.02	Pfeil et al., 2005
Lipoxygenases	0.75	0.62c	0.46	0.45d	This study

^aThe median Ks value between paralogs represents polyploidy events.

^bThe median Ks value between orthologs denotes taxon divergence between soybean and Medicago.

^{c, d} The median Ks values between Gm-Mt paralogs and Gm-Mt orthologs are compared to rule out skewing estimates caused by differential substitution rates. Thus, the ancient polyploidy predates the taxon divergence.