Referee 2's Review:
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N.B. These are the comments made by the referee when reviewing an earlier version of this paper. Prior to publication the manuscript has been revised in light of these comments and to address other editorial requirements.
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The rationale for the work is well developed, the purpose is clear, the sample sizes adequate and the methods appropriate. The analysis of the data is appropriate. The conclusions reached are appropriate to the particular data set. However, my "beef" with this paper is that the data were collected at essentially the same time as for the MS by Voight et al. published in 2007 but point to a different conclusion. While it is too late now, I think it would have been better if the current data had been published with those in the 2007 paper. The overlap in the two studies methods etc. is substantial although the current data are new.
