Yes, it's the leading theory. That doesn't mean is true, just the most likely explanation for the data we have now. Hardly anything is "conclusively proved", a

Yes, it's the leading theory. That doesn't mean is true, just the most likely explanation for the data we have now. Hardly anything is "conclusively proved", although theories we can design experiments for are much more robust than theories about historical or geological events where we don't have that luxury.