In reply to jezb1:
Melting rubber does not work, it doesn't behave in the same way as plastic (but nice idea).
Patching holes never works for very long unless its done properly (i.e. tucked under the sole like the original rand is - hence why I (or other resolers) have to do a full resole to deal with rand holes. It never hurts to try of course but its not something I'd ever offer as a professional service.
Stealth paint ( or Shoe goo, or Black Witch) can work as a temporary measure. It won't last long but if you keep doing it it can help - it depends a bit on the kind of hole. It won't hold the rubber together but can protect the leather/fabric underneath if you've only worn through the rubber.
If they are Evolvs and the split is a horizontal one and just at the rand/sole join then I know lots have failed there and Evolv has replaced some as a warranty issue - at least that is what I've been told by various customers, I haven't dealt directly with evolv so can't swear to it but its worth trying them.
I hope that is of some help, Torquil (Llanberis Resoles)