Got Lactase? The Coevolution of Genes and Culture

Galactose

Glucose

Lactose

Maltose

The milk is fully digested and absorbed for energy.

The undigested lactose travels to the large intestine, causing digestive issues.

The lactose is broken down into glucose and galactose in the small intestine.

The mammal develops an increased ability to produce lactase.

They are unable to digest lactose as an adult.

Their body continues to produce the lactase enzyme beyond childhood.

They can only digest milk from specific animal species.

They experience severe digestive issues after consuming milk.

Yes

No

A single, universal mutation is responsible for lactase persistence across all populations.

Lactase persistence is caused by different, independently evolved mutations in different populations.

The ability to digest lactose is not genetically determined.

Lactase persistence is only found in populations that traditionally consumed dairy.

They were primarily hunter-gatherers.

They relied heavily on agriculture.

They were pastoralists, domesticating animals for food.

They lived in large urban settlements.

They are primarily used for transportation and labor.

They are considered sacred animals and are never consumed.

They represent wealth, social status, and are central to their culture.

They are mainly hunted for their hides and horns.

By analyzing the DNA extracted from the pottery.

By observing the physical appearance and texture of the fragments.

By comparing the ratios of carbon isotopes in fat residues.

By using X-ray imaging to detect organic compounds.

Ancient oral traditions and mythological stories.

The study of ancient architectural designs and building materials.

Archaeological findings of milk fats in pottery and genetic analysis of DNA.

Historical documents and written records from early civilizations.