The most viewed preprints on Haldane’s Sieve this month were:

• The existence and abundance of ghost ancestors in biparental populations. Gravel and Steel prove results on the existence of individuals that are genealogical ancestors to all individuals alive today but genetic ancestors of none.
• Author post: Genome Sequencing Highlights the Dynamic Early History of Dogs. Ilan Gronau discusses some finer points of the population genetics methods used in Freedman et al.
• Demography and the age of rare variants. Mathieson and McVean explore the use of low frequency alleles in demographic inference.
• Author post: Worldwide Patterns of Ancestry, Divergence, and Admixture in Domesticated Cattle. Jared Decker responds to a review of his paper (with colleagues) on cattle domestication by Joe Pickrell.
• A C++ template library for efficient forward-time population genetic simulation of large populations. Thornton describes code for efficient population genetic simulations.