Arthritis is a medical condition that many people world-wide suffer from. A science magazine has recently published an article in which arthritis might have been the medical condition, which helped the early Europeans survive the harsh conditions of the Ice Age.
How was this possible?
It seems that the achy joints helped the early settlers to survive frostbites and the arthritis prevented them from getting fractured during the cold climate. The chances of having arthritis is nearly double for those carrying the GDF5 gene, a gene common to more than one-half of Europeans. This GDF5 gene, also seems to shave 1 cm in height, fact which might have also been an advantage for early Europeans.
By having arthritis and being shorter, the early Europeans survived the cold weather, because their bodies would lose less heat and also because they had less chances of falling and fracturing their bones (the short height). Breaking a bone or having a fracture back in those days could have been the difference between life and death.
The arthritis develops later in life, passed the reproduction age and nowadays billions of people suffer from this condition. The first link between the gene and arthritis was found in the 90s and its expression has since been linked to GROW1 (a genetic mechanism which commands the gene to shut down bone growth).
The researchers analyzed the genomes of people across the world (1,000 Genomes project) and they have concluded that the GDF5 gene and the switching off of bone growth were more common on Europeans, rather than Africans or Americans. The Neanderthals and Denisovans also carried the gene and the explanation is that they have inhabited Europe and Asia 600,000 years before the arrival of modern humans.