You can't even begin to grasp biology, you cannot perceive life unless you perceive what it's all there for, however it arose - which means that evolution.-- Richard Dawkins.

So when a group of scientists questions the re-appearance of a tiny bone in the human body, you know that evolution is at work. A tiny bone hidden in the tendon of the knee started to disappear over the course of human evolution or so scientists thought. A new study finds that tiny hidden bone, this so-called fabella (Latin for "little bean") is making a comeback. The bone is embedded in tendons (thus the term sesamoid bone), is three times more common in humans now than it was a century ago, scientists reported in the Journal for Anatomy.

Results from X-rays, MRI scanning and dissections - from over 27 countries and over 21,000 knees were collated and studied by a group of Imperial College London researchers. By combining their data and creating a statistical model that estimated the prevalence of this tiny elusive bone across time, the researchers found out that the bone seems to be slowly vanishing. This was from 1875 until 2018. Initially, the tiny bone served a purpose similar to that of a knee cap for Old World monkeys. Back in 1875, the fabella was found in 17.9 percent of the population, in 1918 it was found in 11.2 percent, and by 2018 it's hidden in the tendons of 39 percent of the population.

According to a statement from the Imperial College London, it has been linked to several knee problems such as arthritis and joint inflammation. They stated further that the bone is more likely to be found in people with osteoarthritis of the knee than in people without.

"As we have a tendency to evolved into nice apes and humans, we appear to have lost the need for the fabella," lead author Michael Berthiaume, an anthro-engineer at the Imperial College London, saidin the statement."Now, it simply causes USA issues - however the attention-grabbing question is why it's creating such a comeback."

The development of sesamoid bones, much like the fabella, is usually in response to mechanical forces, and nowadays, due to the change in diet and the environment in general, humans are heavier and taller putting more pressure on the knees. Berthiaume said. "This could explain why fabellae are more common now than they once were."