Amol Rajan: Thumbing through the pages of human evolution

Aside from a large brain and ample stomachs, the chief glory of being an ape is largely due to our opposable thumbs.

 Darwinists have long known that evolution sped up when our mammalian ancestors developed fingers arranged in such a way as to make picking up objects and gripping things generally, much easier; and indeed, the fact that apes can manipulate their environments using opposable thumbs is one of the main reasons homo sapiens have distanced themselves from the rest of the animal kingdom, developing fine motor skills and inventing tools.

In the past few decades, advances in technology haven't caused evolution to accelerate again – it seems, alas, to have stopped altogether – but afforded us new motor skills and new tools dependent entirely on the proficiency of the thumb. So much so, in fact, that while batting during a cricket match this weekend, I took a nasty knock on my right thumb from a delivery bowled by Jo Johnson MP, and soon had cause to realise something curious about my generation.

We're Generation Thumb.

The realisation came when, back in the dressing room, I took out my iPhone and tried to send a text message. Have you ever tried to send a text message with a badly bruised thumb? Or send an email from your BlackBerry? You'll find a sore thumb is a reliable way of getting your phone bill down, I imagine.

It's not only mobile phone technology. The rise and rise of doorbells – which admittedly got going over a generation ago – and with it the gradual demise of the old-fashioned, index finger-deploying door-knock has given thumbs a greater role in opening doors, in every sense of that phrase. Finger-printing, now more prevalent than ever because of biometric technology and security paranoia, is another source of increased labour for thumbs.

Then there are computer games consoles. For children of the 1990s, reared on Mariokart and Sonic the Hedgehog, the Nintendo or Sega Mega Drive controller was a source of endless happiness. Now, in the age of the Xbox, children and young adults are using their thumbs at home much more than, say, the post-war generation who idled away their childhoods reading Thucydides and flirting with Patricia Robinson at No 32.

Human evolution may have stopped, but technological evolution is only just beginning.

With it, different parts of our anatomy are being deployed in ways our distant ancestors would have found unimaginable. On the whole, this deserves a thumbs-up from Generation Thumb.