Got Lactase?

A population that raises wheat and sheep.

Suppose that a mutation for lactase persistence occurred in each of the pastoral populations described below. In which population would the mutation be more likely to increase in frequency over time due to natural selection?

Peter and Sarah, because their glucose levels increase dramatically after drinking milk.

Four individuals measured their baseline blood glucose, then quickly drank a liter of milk. They then measured their blood glucose levels at regular 15-minute intervals for 60 minutes. The results are shown in the graph. Which individual or individuals are lactase persistent, and how do you know?

Milk could have been a critical food source during times of famine. Milk is generally safer to drink than water. Milk is rich in proteins and fats.

How could milk drinking have provided strong favorable selection for lactase persistence? Select all that apply.

Someone who is able to digest lactose as an adult.

How would a biologist describe someone who is "lactase persistent"?

glucose and galactose

The primary sugar in milk is lactose. The enzyme lactase breaks lactose down into which compound(s)?

They are found in a noncoding regulatory region (a "switch") near the lactase gene.

What did researchers discover about genetic mutations that cause lactase persistence?

Ancient pots used to hold milk are about the same age as the lactase-persistence mutations.

Which discovery best supports the hypothesis that evolution of the lactase-persistence trait was driven by dairying, the use of milk as a source of adult nutrition in pastoralist cultures?