Milking created selection pressure that extended lactose processing past infancy.

Evidence

Though many factors have shaped the distribution of these regulatory genes, there are two key culturally evolved packages that have driven this bit of genetic evolution. First, it’s only in the last 12 millennia that humans have domesticated animals like cows, sheep, camels, horses, and goats, which can potentially provide milk for adults to drink. So some populations adopted cultural practices that permitted them to keep animals and milk them. Such animals provide meat and hides, if nothing else. Initially, the extra milk would have been useful only for young children and infants. However, its presence would have created a genetic selection pressure for extending this lactose-processing ability into middle childhood and beyond. — Joseph Henrich, The Secret of Our Success, 295

Categorization

• XREF: connects to: Natural selection independently produced five distinct lactase-persistence mutations across herding populations — Joseph Henrich, The Secret of Our Success: How Culture…, 299; Culture-fueled lactose persistence spread to a third of humanity in ten millennia — Joseph Henrich, The Secret of Our Success: How Culture…, 299; Adopting cheese technology can halt a population’s lactase gene evolution — Joseph Henrich, The Secret of Our Success: How Culture…, 295 (+4 more)

Broader Connections

• Cultural evolution can create selection pressures stronger than natural ones #exemplifies (0.90) — Joseph Henrich, The Secret of Our Success, 282
• Natural selection independently produced five distinct lactase-persistence mutations across herding populations #corroborates (0.88) — Joseph Henrich, The Secret of Our Success, 299
• Culture-fueled lactose persistence spread to a third of humanity in ten millennia #expands (0.85) — Joseph Henrich, The Secret of Our Success, 299
• Cultural adaptation enabled people to eventually drink cows’ milk without illness. #corroborates (0.82) — Neil MacGregor, A History of the World in 100 Objects, 167
• Cooking evolved culturally and reshaped human digestive anatomy and function #exemplifies (0.80) — Joseph Henrich, The Secret of Our Success, 224
• Adopting cheese technology can halt a population’s lactase gene evolution #complicates (0.75) — Joseph Henrich, The Secret of Our Success, 295
• Lactase persistence varies dramatically even among neighboring African ethnic groups. #expands (0.75) — Joseph Henrich, The Secret of Our Success, 294