Table 4.
IMa joint estimates of demographic parameters: Ne (effective population size = θ/4μ; where θ is genetic diversity and μ is mutation rate), Nem (effective migration rate = θm/4; where m is the migration rate per generation), and population splitting times (t/μ) under two models based on concatenated cytb and CR sequences. The 90% highest posterior density (HPD) intervals corresponding to parameter estimates are indicated in parentheses. Unless otherwise indicated, estimates are based on the assumed site-specific mutation rate, 9.36% per Myr for the combined cytb/CR haplotype.
| Demographic model: | Isolation with migration (90% HPD) | Isolation only (90% HPD) |
|---|---|---|
| Ne Britain/Ireland | 150,000 (62,000–233,000) | 215,000 (139,000–325,000) |
| Ne Central Europe | 481,000 (243,000–1,035,000) | 416,000 (225,000–844,000) |
| Ne Ancestral | 112,000 (40,000–374,000) | 262,000 (157,000–422,000) |
| Nem into Britain/Ireland | 3270 (110–20,140) | – |
| Nem into Central Europe | –a | – |
| Splitting time | 19,000 years (5900–51,500) | 10,000 years (5700–14,500) |
| Alternative splitting time 1b | 6765 years (2100–18,335) | 3560 years (2030–5160) |
| Alternative splitting time 2c | 5260 years (1630–14,260) | 2770 years (1580–4015) |
The posterior density function smoothed peak approached zero for gene flow into Central Europe.
These estimates assume a mutation rate of 26.29% per Myr. This value is based on the Bayesian median posterior estimate assuming homogeneous rates among sites, and does not take into account the 95% CI of the estimate.
These estimates assume a mutation rate of 33.81% per Myr. This value is based on the Bayesian median posterior estimate using a gamma-distributed rate heterogeneity across sites, and does not take into account the 95% CI of the estimate.