Heinlein's stuff about people wanting to maximize their number of children never sounded right to me in general, but I thought it might be true of pioneers.
The study, published November 4 in Science, analyzed the genealogies of settlers in Canada's Charlevoix Saguenay Lac-Saint-Jean region, northeast of Quebec. Since the colony's initiation in 1608, it underwent several waves of geographic expansion. The researchers, led by population geneticist Laurent Excoffier from the University of Montreal, looked at the colony's marriage and birth records between 1686 and 1960. The analysis found that families living on the edges of the expansions had 20 percent more children than families living at the core of the settlement. They also married one year earlier, on average, and contributed up to four times more genes to the region's current population.
I'm surprised, though, that the effect isn't huge in the short run-- only 20% more children. It's not something like having seven kids instead of four.
Link thanks to Marginal Revolution.
This entry was posted at http://nancylebov.dreamwidth.org/510965.html. Comments are welcome here or there. comments so far on that entry.