TABLE 3.

Proportions of HERV-K(HML2) loci that are full-length proviruses, and inferred recombinational deletion rates, among the three different age categories^a

Age (millions of yr)	No. of HERV loci examined	No. of host individuals examined	Mean proportion of full-length proviruses	Rate of recombinational deletion (no. of recombinational deletion events/locus/generation)	Confidence interval for rate of recombinational deletion	Mean proportion of full-length proviruses in simulation
6 to 30	25	1d	0.88	4.3 × 10−7	1.0 × 10−7-1.1 × 10−6	0.74
0.8 to 6	66b	10-19e	0.14	1.5 × 10−5	9.5 × 10−6-2.3 × 10−5	0.05
Less than 0.8	8c	10-19e	0.30	8.0 × 10−5	1.8 × 10−5-5.6 × 10−4	0.33

^aDetails of individual loci are given in Tables 1 and 2.

^bNine loci from reference 16 plus 57 examined in the present study.

^cTwo loci from reference 16 plus six examined in the present study.

^dData from the published human genome sequence.

^eSamples from 10 or 18 individuals were screened in the study reported in reference 16, and we screened or rescreened a total of 19 samples in the present study.