Thumbs up (and over)
![](https://natalieparletta.com.au/wp-content/uploads/2021/02/hand-1-1440x878-1-1024x624.jpg)
Dexterous thumbs – considered a hallmark of being human – were present two million years ago, according to a study published in the journal Current Biology.
This was around the time that more systematic tool production and complex cultural developments emerged and our large-brained Homo erectus ancestors appeared on the scene, highlighting the pivotal importance of thumb evolution.
Published by Cosmos.