We don’t use our toes to climb trees, but we use our fingers for typing on our keyboards every day.
Evolutionary speaking (or rather it's adaptation), will humans lose their toes, but gain more fingers?
Apparently, it’s predicted that humans will eventually lose their pinky toes.
This prediction is made on walking patterns, and how we now use our feet and toes in this current era compared to how we used to use them before (millennia ago). Like primates, we used to use our feet to grab things, to climb trees and hop around. Nowadays, we no longer use our toes as much as our ancestors used to, so the need to have a pinky toe isn’t really there anymore.
We evolved to rely on the metatarsals and heel of the foot for balance, which means toes in general, and pinkies in particular, are not essential for balance. Our ancestors used to walk and balance more readily on the midline of their feet, however humans have now gradually transferred to balancing more toward the side of the big toe, and that midline, or the balance centre is shifting rather inwards. Humans who used to once rely on their 5th toes for walk and balance don’t now, which could mean we might no longer need our 5th toes.
However, if we do get to lose our pinky toes due to not needing them, this won’t be due to “adaptation”, but it will rather happen in the context of genetic drift. “Adaption” is wrongly understood as the mechanism that eliminates traits that are no longer needed. That’s not true, because neutral or unnecessary traits don’t play such a big role in natural selection.
As for our fingers, I don’t know… Do we really need more of them to type?
Thing is that the same genes that express to give us toes, are also giving us fingers. We might not need all or toes, but they’re also not really bothering us that much. This means, I think, that as long as we have fingers, we’ll have toes. If anything happens to our toes and our fingers in terms of how many there are, it’s more likely going to be because of human intervention and future genetic manipulation, rather than adaptation or evolution.