Fig. 3

Bayesian Skyline Plots. Effective size over time plots estimated in BEAST using a Bayesian Skyline prior using a mutation rate of 1% (1e-6) per million years. Mean values are shown and confidence values were excluded for clarity. The x-axis indicates time in ‘thousand years ago’ (kya). a. Range-wide estimates for North America (grey, n = 79), Central and South America (lime green, n = 13), Eurasia (pink, n = 49) and Africa and Oceania (blue, n = 7). North America dataset ran for 50,000,000 generations, Eurasia 20,000,000 generations, Central/South America and Africa/Australasia ran for 5,000,000 generations. b. Estimates of recovered Clades, Clade A (pink, n = 116) and B (dark green, n = 33) compared to total (grey, n = 149). The total dataset and Clade A ran for 80,000,000 generations, Clade B ran for 10,000,000 generations. c. Estimates by FWECs sampled: Rio Grande (red, n = 16), Coastal (blue, n = 13), Colorado (purple, n = 11), Atlantic (orange, n = 9), Mississippi (green, n = 26), the Great Basin and St. Lawrence FWECs were excluded because of low sample size. All FWEC datasets were run for 5,000,000 generations, with the exception of Atlantic (3000,000). Bayesian skyline plots were constructed in TRACER, the data was exported and visualized using Excel