A simple change in our ancestors DNA that happened in Ice Age might have been a way to survive the cold temperatures and made us shorter and prone to arthritis. The new study that researched genetic mutations showed that the gene called GDF5 has a mutation which resulted in shorter bones. This, on the other hand, impacted our growth and made us compact and reduced the risk of bone fracture caused by falling.
This little, almost insignificant change in nucleotides has resulted in the fact that people were then better equipped to handle extremely low temperatures that are accompanied with frost bite and made the migration from Africa to the northern climates possible. This early migration happened 50,000 to 100,000 years ago and it was a crucial part of human history.
Although the genetic mutation was also linked to an increased risk from osteoarthritis, but it seems that the advantages of a shorter growth that help with cold temperatures might have outweighed this threat as it was a more important characteristic.
Terence Capellini who is an Associate Professor at the Harvard University said: “The variant that decreases height is lowering the activity of GDF5 in the growth plates of the bone. Interestingly, the region that harbours this variant is closely linked to other mutations that affect GDF5 activity in the joints, increasing the risk of osteoarthritis in the knee and hip.”
This study, which was published in the journal Nature, was conducted by a team of researchers who were examining the specific single gene GDF5, that was first linked to skeletal growth in the early 1990s. This study was primarily done in order to learn more about the ways the DNA sequences that surround the aforementioned gene GDF5 might impact the gene’s expression.
The research team has identified a nucleotide change that is responsible for all of this. It seems that this specific DNA mutation is highly present in the DNA of Europeans and Asians, but interestingly, is very rare in Africans. When the nucleotide change was introduced to laboratory mice it showed that is decreased the activity of the GDF5 in fetal mice.
According to David Kingsley, Professor at the Stanford University “this is an incredibly prevalent, and ancient, variant. Many people think of osteoarthritis as a kind of wear-and-tear disease, but there’s clearly a genetic component at work here as well. Now we’ve shown that positive evolutionary selection has given rise to one of the most common height variants and arthritis risk factors known in human populations.”