there are plants that may be classified as alpine liveing in certain relativly low spots that escaped bieng glaciated such as pockets in the Cape Breton highlands(max 1200' asl),and preserve species that thrived in much colder, dryer conditions, and who's closest relatives are found thousands of miles away in mountainous regions. Not sure what Darwin would have to say, though he was exceptionaly concervative and precise in detailing and defing his scientific concepts, and prefered multiple proofs of his ideas and was carefull to concider and include all possible counter arguments and deal with them upfront. Reading 'the voyage of the beagle' gives another side of his personality, less constrained by the needs of scientific rigor.