Research on natural environments and living organisms is always constrained by exogenous factors(outside influences).

It has the same constraints as an economic model. But, at least, those guys can always start out saying "all other things considered equal". Of course they never are equal and thats what makes economics such an arcane study. They, like weathermen, almost never get it right and none of them agree until after the fact.

Best efforts, best practices, math models and large group statistics are about all you have to go on. No matter what you do there are always those who rush in saying "Yeah, but".

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP Grandpa