A week later, I pulled up at a set of Hereford traffic lights with Slade's Greatest Hits on the car stereo, which duly reached the song whose chronic familiarity had long since bred indifference.
By the time they were discovered, Colonel William Prescott and his men had completed a redoubt atop Breed's Hill (which was an indefensible decision in the eyes of many historians, since Breed's Hill was lower and less impregnable than Bunker Hill).
The time of herd book closure does not directly indicate the time since breed divergence, since distinguishable breeds must have existed before herd book closure.
The breeds evaluated here represent populations that have diverged over many generations, approximately 200 years since breed formation occurred.
To estimate the time since breed divergence for the pig breeds in this study we used SNP with pairwise distance between 10 kb and 300 kb, and estimated correlation of phase for each 2.5 kb interval.
It should be remembered, however, that while modern cattle breeds have been created relatively recently (< 400 generations, [ 12]), in some cases there has been strong selection since breed divergence [ 13].
We observed a correlation of phase of 0.57 and 0.30 at 1 Mb and 5 Mb, respectively, between these two breeds, indicating that a T of 40 may overestimate the actual time since breed divergence.
Since breed and tumor location are so closely correlated, it is not possible from this study to determine whether the association between CNAs and breed was driven by breed itself or by the anatomical location of the tumor in that breed.
If two populations diverged from a common ancestral population, their correlation of phase can be expressed as r 0 (1-c) 2T, where r 0 2 is a measure of LD in the common ancestral population, c is the recombination distance between markers and T is time since breed divergence in generations [ 30].
