Table 2.

Integration time estimates

Locus	Rate,* (subst./site/yr) × 109	Avg distance between 5′ and 3′ LTRs, subst./site	Calc. age, 106 yr	Age of LCA, 106 yr
HERV-K(C4)	2.28  ± 0.4	0.08	36.8	31
HERV-K(HML6.17)	3.71  ± 0.4	0.12	32.3	31
RTVL-Ia	2.28  ± 0.6	0.10	44.8	31
HERV-K18	5.00  ± 0.8	0.03	5.7	4.5
RTVL-Ha	4.39  ± 1.5	0.03	6.7	4.5

LCA, last common ancestor. 

^*Calibrated using OWM/ape distances and an estimated time of 31 million years (40–42).