Harvest, 1910. France. Photo from Creative Commons from collection of postaletrice/flickr
While it is widely assumed that agriculture has been responsible for allowing large increases in human population, a new study of genetic evidence links the rise of agriculture to the timing and scale of large population increases in several regions over the past 10,000 years. The study, which was published March 28 in the Proceedings of the National Academy of Sciences, indicates that the invention of agriculture allowed populations to grow five times faster than the growth rates of ancient hunter gathers. Details:
PNAS PR: via @eurekalert: "Spurts of population growth in Europe, southeastern Asia, and sub-Saharan Africa largely coincide with the dawn of agriculture in those regions, a study finds. Although researchers have long suspected that agriculture drove population growth in different parts of the world, concrete evidence linking the timing and magnitude of population growth with the origin of agricultural practices has remained elusive. Christopher R. Gignoux and colleagues combined archaeological evidence with genetic data from the mitochondrial genomes of more than 400 individuals currently living in mainland Europe to determine whether the adoption of agriculture could be tied to human population size. The mitochondrial genomes, which are inherited solely from mothers, helped distinguish between lineages of people of hunter-gatherer and agricultural origins, and reconstruct a picture of past demographic trends. The authors found that population expansion within the last 10,000 years across parts of Europe, southeastern Asia, and sub-Saharan Africa coincided with the origins of agriculture. Compared with earlier growth spurts among hunter-gatherers, the invention of agriculture seemed to have triggered a five-fold spurt in population growth in all three continents. According to the authors, the findings lend support to one of two competing theories underlying the spread of agriculture: The diffusion of agricultural practices likely happened along with, and not separately from, the migration of people."
Study: Rapid, global demographic expansions after the origins of agriculture
http://www.pnas.org/content/early/2011/03/22/0914274108Abstract: "The invention of agriculture is widely assumed to have driven recent human population growth. However, direct genetic evidence for population growth after independent agricultural origins has been elusive. We estimated population sizes through time from a set of globally distributed whole mitochondrial genomes, after separating lineages associated with agricultural populations from those associated with hunter-gatherers. The coalescent-based analysis revealed strong evidence for distinct demographic expansions in Europe, southeastern Asia, and sub-Saharan Africa within the past 10,000 y. Estimates of the timing of population growth based on genetic data correspond neatly to dates for the initial origins of agriculture derived from archaeological evidence. Comparisons of rates of population growth through time reveal that the invention of agriculture facilitated a fivefold increase in population growth relative to more ancient expansions of hunter-gatherers."
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