Different people have different types of eyebrows. Some have arched ones, some have clocked shadows, some have furry unibrows.
There has been a new study that shows the roots of the hairy variation. It found how genes can cause curly versus stick-straight hair, as well as the tendency to become bald or go grey.
The researchers involved analysed 6,630 people and their DNAs, and the sample group included a mix of Caucasians, Africans, and Native Americans.
Kaustub Adhikari, the lead author of the new study and a biologist at the University College London, says, “We already know several genes involved in balding and hair colour, but this is the first time a gene for greying has been identified in humans, as well as other genes influencing hair shape and density.”
They found out why some people have sport thick, luxuriant heads of hair, but have thin eyebrows or smooth baby faces. The answer lied in separate genes that affected the hair type, beard thickness, eyebrow thickness and unibrow presence. They also found out that the hair types and thicknesses were not just a random accident, but instead evolution where people preferred long, straight locks, hairless faces or silver foxes.
Adhikari mentions, “It has long been speculated that hair features could have been influenced by some form of selection, such as natural or sexual selection, and we found statistical evidence in the genome supporting that view. The genes we have identified are unlikely to work in isolation to cause greying or straight hair, or thick eyebrows, but have a role to play along with many other factors yet to be identified.”
The findings also have a great implication for forensics. This can allow police force to use genetic data from a bit of hair left at the crime scene.