First the link to this week’s complete list as HTML and as PDF.
Although Verd et al. do note the possibility of their result being purely cultural, they strongly play it down. To me it’s obvious that what they see here is a group more prone to letting themselves be browbeaten into publicly approved correct behaviour than others and that this influences their salt intake more than their breast feeding.
It would be possible to comment on Goldstein & Leshem if they were to show the cluster of real data, but regression lines alone, without even their, in this case considerable, error margins for slope, are meaningless. Their hypothesis is very plausible, though. Given the proven efficacy of Lithium, it’s only reasonable that the most similar of the other elements too produces a small effect.
It seems, according to Araus et al., that climate conditions were far better than today around the beginning of agriculture. The yields may have been as high as today’s are, and thus far higher than current estimates based on ancient cereal strains and methods have led us to believe, right around the time when agriculture began to spread.