Sunday, December 28, 2014

My Year of Darwin 12/28/2014: Pleistocene refugia

 Charles Darwin

"At this period of extreme cold, I believe that the climate under the equator at the level of the sea was about the same with that now felt there at the height of six or seven thousand feet. During this the coldest period, I suppose that large spaces of the tropical lowlands were clothed with a mingled tropical and temperate vegetation, like that now growing with strange luxuriance at the base of the Himalaya, as graphically described by HookerCharles Darwin, Origin of Species 1st edition (on Kindle)

This sounds much like the Pleistocene refugia hypothesis for explaining the incredibly high tropical diversity. This hypothesis posits that the tropics, particularly South America (might apply to other tropical sites but I'm not familiar with that literature) was broken up into islands of tropical habitat with the intervening matrix being composed of grassland and scrub. There are nice descriptions of PRH here and these lecture notes. My understanding of the PRH is that is has some strong support but some conflicting evidence. This probably means that the PRH is a good description but does not capture the full dynamics and habitats merged and diverged like gobs in a lava lamp. 


Aubry remains stable. I just hate she's on cold steel with a bunch of strangers. I know they're taking great care of her. 

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