Not much to do but link to this and wait for the paper to appear:
[Jean-Pierre] Bocquet-Appel and anthropology graduate student Stephan Naji analyzed skeletal remains in 62 prehistoric North American cemeteries.
They found that the number of immature skeletons increased by 37 percent over a 600-to-800 year period that coincides with the adoption of farming in North America about 2,500 years ago.
The baby-boom pattern has been observed in African and European cemeteries dating about 5,000 to 7,000 years earlier, according to Bocquet-Appel. This period also coincides with the shift in those regions from foraging to agriculture at the end of the Stone Age.