Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Friday, January 27, 2023

The swamps of Canada

Ellesmere Island would be high on the list of the Earth's most inhospitable places.

It's huge, only slightly smaller in area than Britain, and is part of the territory of Nunavut in Canada.  It is entirely above the Arctic Circle.  The record high temperature there was 15.6 C (60 F); the average high is 7 C (45 F).  The record low, on the other hand, is -47 C (-52.6 F).  It's also exceedingly dry, averaging a little over six inches of total precipitation a year.  It's no wonder that although the Inuit use some of it as summer hunting grounds, the permanent resident population stands at 144 brave souls.

Honestly, I'm a bit mystified as to why anyone lives there.

It wasn't always that way, though.  As hard as it is to fathom, Ellesmere Island used to be a swamp, back during the Paleocene-Eocene Thermal Maximum, a period about fifty-five million years ago during which the global average temperature was about eight degrees hotter than it is now.  The reasons it occurred are still a matter of discussion amongst climatologists, but from the chemistry and deposition of sedimentary rocks, it clearly came from a massive increase in the levels of atmospheric carbon dioxide, and was accompanied by the sea levels reaching levels between three hundred and four hundred meters higher than they are today.

If that happened now, where I'm currently sitting in upstate New York would be beachfront property.

What's most interesting about the climate of Ellesmere back then is that even though it was a warm swamp, it was pretty much located where it is today (i.e. above the Arctic Circle).  But even though for a couple of months of the year it was plunged into darkness, there were still trees -- fossils of the conifers Metasequoia and Glyptostrobus have been found in regions that now host little else besides mosses and lichens.

And a paper in PLOS-One this week showed that it isn't just subtropical trees that used to live on Ellesmere -- so did some long-lost cousins of primates.

We usually think of primates as being tropical, and for good reason; most of the primate species in the world live in areas not too far from the equator.  We originated there, too, of course; the ancestral home of Homo sapiens is Kenya and Tanzania (that's all humans -- sorry, racists).  We've since expanded our territory a little, but our relative hairlessness is a good indicator that we originally came from warmer climes.

But back during the PETM, Ellesmere was a warmer clime, and paleontologists have found in sedimentary rock strata the fossils of two proto-primates, Ignacius mckennai and Ignacius dawsonae.  The genus Ignacius is part of a much larger group called the plesiadapiforms, who are all extinct but whose closest living relatives are modern primates.  Ignacius was a genus confined to the northern half of North America, and when the temperatures warmed up and the forests spread north, Ignacius followed them.

This makes these remains the northernmost primate fossils ever found.

A reconstruction of Ignacius dawsonae [Image is licensed under the Creative Commons Kristen Miller/Biodiversity Institute/University of Kansas (CC-BY 4.0)]

What is amazing to me about this is... well... everything.  That trees could flourish in a swampy environment well above the Arctic Circle.  That non-human primates ever got this far north.  And most especially, that the Earth's climate was this drastically different, only fifty-five million years ago -- a long time ago on our usual timeline, but pretty much day before yesterday on the geological scale.

Of course, this should be a cautionary tale for us cocky humans, and probably won't be.  Things can change drastically.  Have changed drastically, and will again.  What we're doing right now is spiking the atmospheric carbon dioxide levels, and thus the temperature, at a far faster rate than just about anything in the geological record -- perhaps even exceeding the carbon dioxide pulse that set off the Permian-Triassic Mass Extinction.

And that cataclysm killed an estimated ninety percent of life on Earth.

All I can say is, we damn well better start paying attention, or else we'll find out that Santayana's famous quote about not learning from history also applies to not learning from prehistory.  Or, put more succinctly, that the best strategy is not "fuck around and find out."


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