Evolution: ‘Deadly’ Gene that once aided survival
This gene arose thousands of years ago and provided a survival advantage for individuals living in the Arctic. A CPT1A (carnithine palmitoyltransferase 1A) gene variant that aids the processing of fatty acids provided energy in the form of heat to help regulate body temperature in extreme weather conditions. Dr. Kivisild et al at the University of Cambridge discovered that this gene shows a positive correlation between the likelihood of hypoglycemia (low blood glucose concentration) and infant mortality in today’s northern populations.
25 individuals from Northern Siberia, 25 people from Europe and 11 people for East Asia took part in a scheme in which Dr. Kivisild et al analysed all individuals’ genomes. It was found that a variant located within CPT1A was unique to Northern Siberian individuals. It was also found that 68% of the Northern Siberian population presented this CPT1A variant. Subsequently this shows how initially one gene can possess survival advantages whilst overtime once external conditions have changed i.e. humans are less likely to seek habitat in colder conditions like the Arctic then the role of the gene may display more disadvantages than advantages.
More information: American Journal of Human Genetics, Clemente et al.: “A selective sweep on a deleterious mutation in the CPT1A gene in Arctic populations.” www.cell.com/ajhg/abstract/S0002-9297(14)00422-4