Concur with you on this, Ken, though I will add another thought on "causation".
There are some who believe the Younger Dryas came about after the antecedents of today's Great Lakes found an outlet and dumped huge quantities of fresh water down the St. Lawrence and into the Atlantic, via the Ottawa River and a stretch called the "French River". Today, the French River flows westward into Lake Huron between Parry Sound and Sudbury, Ontario. The supposition is that during the dump of glacial melt, it flowed in the opposite direction to somewhere near Ottawa and into the Ottawa River.
I wasn't there, so I can't say definitively.
But I do note that mammoths and other megafauna survived quite well in Eurasia, right alongside humans hunting them, until about the same time they disappeared from America. (Even until the time of the Greeks and early Rome, on Wrangell Island.)
Sure, that's the theory of desalinization causing disruption of the Atlantic Conveyor. It was the same concept that was the basis for the movie "The Day After Tomorrow". It fits the Man-Made Climate Change mythology. Consider that all the water previously went down the Mississippi watershed into the Gulf of Mexico, the overall effects could not have been that great, even leading to the facilitation of warming, as meltwater hitting the Gulf may have decreased the strength of the Gulf Stream. This is why our river valleys in the Midwest are so wide, because of the glacial melt.
There were elephants on Sicily well into the historical period. As far as Ice-age species, the modern wolf is descended from the Dire Wolf, modern lions and tigers are descended from sabre-toothed cats.
People also forget the dramatic cultural change that occurred in North America with the reintroduction of the Horse. The plains indian culture was very new, previously not being so mobile, with the perfered method of Bison hunting being to run small herds over "Jumps", as foot-hunting was extremely dangerous.
http://www.history.alberta.ca/headsmashedin/The culture was so fluid and mobile that the concept of "Indian Lands" is very subjective.
