High frequency of lactose intolerance in a prehistoric hunter-gatherer population in northern Europe.
BACKGROUND
Genes and culture are believed to interact, but it has been difficult to find direct evidence for the process. One candidate example that has been put forward is lactase persistence in adulthood, i.e. the ability to continue digesting the milk sugar lactose after childhood, facilitating the consumption of raw milk. This genetic trait is believed to have evolved within a short time period and to be related with the emergence of sedentary agriculture.


RESULTS
Here we investigate the frequency of an allele (-13910*T) associated with lactase persistence in a Neolithic Scandinavian population. From the 14 individuals originally examined, 10 yielded reliable results. We find that the T allele frequency was very low (5%) in this Middle Neolithic hunter-gatherer population, and that the frequency is dramatically different from the extant Swedish population (74%).


CONCLUSIONS
We conclude that this difference in frequency could not have arisen by genetic drift and is either due to selection or, more likely, replacement of hunter-gatherer populations by sedentary agriculturalists.
Malmström
Helena
H
Department of Evolutionary Biology, Uppsala University, 752 36 Uppsala, Sweden.
Linderholm
Anna
A
Lidén
Kerstin
K
Storå
Jan
J
Molnar
Petra
P
Holmlund
Gunilla
G
Jakobsson
Mattias
M
Götherström
Anders
A
D000383:Agriculture; D005787:Gene Frequency; D006801:Humans; D043322:Lactase / Q000235:genetics / Q000378:metabolism; D007787:Lactose Intolerance / Q000201:enzymology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012537:Scandinavian and Nordic Countries; D012641:Selection, Genetic
D043322:Lactase