Our thumbs are our special fingers. Their muscles and bones are set up in a way that give them abilities the other fingers don’t have, making them useful in ways the others aren’t.

The motion of the thumb opposes the motion of the other fingers, which makes it possible for the hand to hold and grasp things. If you’ve ever tried getting dressed without the use of your thumbs, you realize how important they are.

Thumbs are now considered the new fingers for the texting generation, but it’s more than that. The thumbs on humans are evolving. New research shows that the relationship between thumbs and technology is on its way to causing mutations in our anatomy.

Dr. Sadie Plant, founder of the Cybernetic Culture Research Unit at Warwick University spent six months collecting data on hundreds of mobile device users in nine of the world’s largest cities. She found that thumbs are increasingly being used as the favorite digit for tasks traditionally carried out by the other fingers. “The relationship between technology and the users of technology is mutual: they are changing each other,” Plant said in a Time Magazine article written by John Armitage.

The changes affect those who have grown up with hand-held devices capable of text messaging and accessing internet services. Mobile devices are now our essential props and thumbs operate them almost exclusively. As they become stronger and more dexterous, the younger generation takes to using them instinctively in ways they previously weren’t.

Plant believes there’s no question thumb preference is having a clear effect on physicality. “The fact that our thumbs operate differently from our other fingers is one of the main things that define us as humans,” Plant says. She finds it particularly interesting how thumbs are taking over jobs previously accomplished with index fingers.

So what does this mean for the next stage of Homo sapiens? As our thumbs overtake the importance of the other fingers will they also become longer and more prominent, like tendrils? I’m not sure how I’d react to seeing something looking like a praying mantis ringing my doorbell, with its overdeveloped thumb.

The social life of 20-year-olds now includes impressing their friends with the advanced technology of their phones. The rapid thumb motion is like part of a mating display. In Japan, the trend is particularly marked. People there under the age of 25 refer to themselves as oya yubi sedai – the thumb tribe.

Although they’re useful, being all thumbs has never been thought of as a good thing. Their main job was to help us get a grip on things like prey.  Now it’s on its way to becoming the hand’s most muscled and dexterous digit.

The thumb has plenty of importance before without being the go-to digit for technology interface. When we’re little, we suck on it. Later on, it’s an essential tool for hitching a ride. And when we’re counting on our fingers, the thumb holds down the other fingers that haven’t counted yet.

Because more and more is always required of thumbs, things like thumb twiddling and thumb wrestling are now activities that my thumbs are too tired to enjoy.

The most muscled and dexterous digit might sound impressive, but the thumb’s new status comes from being turned into input apparatus for commercial products. Its evolution is occurring under the thumb of our marketable gadgets.