Lactase Persistence and Evolutionary Adaptations

Flashcards based on lecture notes about lactase persistence, evolutionary adaptations, and cultural influences on diet.

What is the role of the lactase enzyme in humans?

It is necessary for the digestion of lactose (milk sugar).

What happens to lactase production after weaning in most mammals?

The gene for the lactase enzyme is down-regulated, leading to a decrease in lactase production; approximately 90% decrease in humans by age 4.

What percentage of humans continue to produce lactase into adulthood?

About 30% of humans continue to produce lactase into adulthood.

Which populations tend to have high rates of lactose intolerance?

Most African and Asian populations.

Why is lactase persistence hypothesized to be high in European populations?

It is related to the cultural invention of dairying.

What is a likely evolutionary advantage of lactase persistence?

It allows individuals to digest lactose, particularly in cultures with a history of dairy farming.

What is the significance of minichromosome maintenance 6 mutations in lactase persistence?

These mutations occur in regulatory regions that influence lactose tolerance.

What is the frequency of lactase persistence among the adult population in general?

Only about one-third of adults produce the lactase enzyme.

When did dairying first occur in Europe according to pottery evidence?

Around 6500 BCE.

What evidence does ancient DNA provide regarding lactase persistence?

It suggests that the LP allele necessary for digesting lactose didn't become common until around 3500 BCE, it was not high in frequency.

What are fatty acid desaturase enzymes important for in the diet of the Inuit?

They process fatty acids from a high-protein, high-fat diet primarily consisting of fish and marine mammals.

How have FADS alleles shown changes consistent with natural selection?

There is significant frequency change of alleles associated with reduced weight and height in Greenlanders.

What dietary adaptation is indicated by the FADS allele frequencies among different populations?

They demonstrate extreme differences related to dietary intake of fats among Europeans, Greenlanders and Chinese. Green land differed way more than chinese and Europens.

What types of metabolism phenotypes are associated with European FADS mutations?

They are associated with pulse rate, standing height, asthma, and lipid metabolism.

How does climate influence dietary adaptations in populations like the Inuit?

Their diet, which largely consists of marine animals, influences genetic adaptations for processing high-fat diets.

Why can greenland digrst so much fat and protein with the FADS GENE ?

A LOT OF NEW MUTATIONS THAT HAPPENED IN THE GREENLAND FADS GENES THAT ENABLED THEM TO PROCESS LARGE AMOUNTs OF PROTEINS AND FATS.

what is the name of the allele that enables high processing of the FAT AND PROTIEN IN GREENLAND.

T ALLELES

THE ABILIT OF THE EOUROPENAS TO FADS DIGESTION IS ?

CENTRAL AND SOUTH AMERICA HAVE SAME ALALELE FREQUENCY AS GREENLAND BECAUSE OF THE CARRY OVER OF A MIGRATORY THROUGH THE BARIGN LAND STRAIT.