Merlin, if he ever existed at all, lived within the Christian era; the kind of thing I am talking about appears to have died out altogether about 2500 years ago and was in its heyday before the flood, 3500 - 4000 years ago.
That's no more weird than believing, for instance, that the Earth once orbitted Saturn...
So what did this force/power/agent consist of? I have seen/read about some expirements with UV depravation resulting in much larger (giant-man species explanation was the purpose if I remember) and robust animals. But I've never seen anything scientific related to what you are putting out here. Got any data for me to look at?
EBUCK