A new research study has shown that the number of red hair is increasing due to natural selection.
A team of Harvard University researchers assessed the ancient DNA of approximately 16,000 people spanning more than 10,000 years in western Eurasia, including the Middle East, the Caucasus, Europe, and parts of Central Asia and North Africa.
The study found that some genes became more common because they potentially provided some kind of benefit or were affected by the changing environment.
According to the researchers’ findings, genes related to red hair, lighter skin tone and celiac disease are becoming more common.
“Perhaps having red hair was advantageous 4,000 years ago, or perhaps it came with a more important trait,” the study published in the scientific journal Nature suggests.
The findings also show that natural selection has played a larger role in shaping the modern human genome than previously understood.
The study also doubled the existing library of ancient human DNA, adding 10,016 new ancient DNA sequences and bringing the total dataset to more than 22,000 individuals.
“With these new technologies and a huge amount of ancient genomic data, we can now see how selection shaped biology in real time. Instead of searching for traces of natural selection in current genomes using simple models and assumptions, we can let the data speak for themselves,” said study author Ali Akbari, senior staff scientist in the laboratory of Harvard geneticist David Reich.
Furthermore, natural selection appears to have increased the prevalence of variants associated with celiac disease and Crohn’s disease.
Development has also supported traits that confer resistance to leprosy and HIV, including reduced risk of bipolar disorder, alcoholism, and schizophrenia.
The study also suggested that low BMI, waist-to-hip ratio and low body fat are also associated with DNA changes.
According to the researchers, the study’s findings could also help scientists identify new genetic factors in health and diseases, which would revolutionize medical science.
