It might allow more fine manipulation with different types of grips. Like, if you're trying to reach into a tight spot to put a screw into a slot (no dirty minds, I'm thinking of furniture construction or the like), sometimes you have to either strain or switch to the opposite hand to get the right angle. Part of that strain is the lack of leverage and fine manipulation capability from that angle. With the thumb, you wouldn't have to switch hands.
My guess would be that tool usage would have ramped up considerably early on, since my understanding is that early development in tool using is a trial and error affair -- and there'd be fewer errors before a success if you had two different ways that were BOTH the right way to hold a tool. I don't know that we'd be any further along, but I suspect we'd have reached our current tech level a bit faster -- an accelerated development cycle very early in tech development, which then becomes more normal once the thumb is no longer the limiting factor (and things like material supply are).
If a double thumb actually helps the grip, evolving primates might not have left the "young clings to the mother/father" system, which would mean that modern man would have more hair.
People have brought up typing, but to extrapolate further back, I can imagine that with only 6 normal fingers and 4 thumbs, writing itself may have changed. For early cuneiform, the ideal structure might not have been flat tablets but cylinders that let the author write on both sides. Fast-forward a few thousand years, and modern keyboards might look like cylinders with keys all along the outside -- a lot of keys along the front, where the 6 fingers will type, and several important keys along the back, where the 4 thumbs type.
And factoring THAT in, writing would have been a ton more expensive to transport, until someone thought of having cylindrical pieces of wood or stone around which pieces of paper were fastened for early writing.
But I'm ranging pretty far afield.
My guess would be that tool usage would have ramped up considerably early on, since my understanding is that early development in tool using is a trial and error affair -- and there'd be fewer errors before a success if you had two different ways that were BOTH the right way to hold a tool. I don't know that we'd be any further along, but I suspect we'd have reached our current tech level a bit faster -- an accelerated development cycle very early in tech development, which then becomes more normal once the thumb is no longer the limiting factor (and things like material supply are).
If a double thumb actually helps the grip, evolving primates might not have left the "young clings to the mother/father" system, which would mean that modern man would have more hair.
People have brought up typing, but to extrapolate further back, I can imagine that with only 6 normal fingers and 4 thumbs, writing itself may have changed. For early cuneiform, the ideal structure might not have been flat tablets but cylinders that let the author write on both sides. Fast-forward a few thousand years, and modern keyboards might look like cylinders with keys all along the outside -- a lot of keys along the front, where the 6 fingers will type, and several important keys along the back, where the 4 thumbs type.
And factoring THAT in, writing would have been a ton more expensive to transport, until someone thought of having cylindrical pieces of wood or stone around which pieces of paper were fastened for early writing.
But I'm ranging pretty far afield.
