A lot of things associated with ESP can be explained by the neural networks in our (and animals) brain being trained to patterns that we consciously don't observe. For example, people say dogs have a extra sense that their owner is coming home, but its pretty much as a result of many and many repetitions of the owner coming home, with all the rather insignificant events that happen before the owner comes home - sun shining through the window a particular way, the noise of the schoolbus that arrives 30 minutes before the owner comes home, activity of neighbors or other people that take out the trash or park their car at the same time.
Humans do this as well. If you play a video game a lot with a lot of repetition, like Counterstrike for example, you can close your eyes and play an entire random match in your head, all because your subconscious learned several patterns that result in certain things.
A mutation in the genetic code that allows for extra sensory abilities. Like added retina sensors that allows you to see infrared or something. This would take thousands of years however and I think it would be in a way that people won't even notice. A good example of a similar mutation is lactose tolerance. But I'm not sure how ESP would develop given the lack of necessity extra sensory in our survival/natural selection.
[–] mAineAc 0 points 1 point 1 point (+1|-0) ago
I think that if it does happen it may be related to the process of quantum teleportation.