Migraine is a debilitating neurological disorder affecting millions worldwide.
The percentage of people suffering from the disorder varies across the human population, but is highest among individuals of European descent, which is also the population with the highest frequency of the cold-adaptive variant, the study said.
The findings, published in the journal PLOS Genetics, suggest that adaptation to cold temperatures in early human populations may have contributed to some extent to the variation in migraine prevalence that exists today in human groups.
"This study clearly demonstrates how the evolutionary pressures of the past can affect today's phenotypes," said co-author Felix Key of the Max Planck Institute for Evolutionary Anthropology in Germany.
Over the last 50,000 years, some people have colonized the warm climate of Africa's colder regions in Asia, Europe and other parts of the world.
"This colonization may have been accompanied by genetic adjustments that helped early humans respond to cold temperatures," said Aida Andres, also from the Max Planck Institute for Evolutionary Anthropology.
To find evidence for this adaptation, researchers investigated TRPM8, a gene that codes for the only known receptor that allows a person to respond to cold and cold temperatures.
They discovered that a genetic variant upstream of the gene that regulates them has become more prevalent in populations living in higher latitudes in the last 25,000 years.
At present, the proportion of people in a population carrying this variant is increasing at higher latitudes and in colder climates, the study says.
Interestingly enough, the scientists had already linked this variant to migraine [1