Dragonfly intestines: nature’s Swiss Army knife

“We should be extremely cautious in concluding that an organ could not have been formed by transitional gradations of some kind.  Numerous cases could be given amongst the lower animals of the same organ performing at the same time wholly distinct functions; thus in the larva of the dragonfly… the alimentary canal respires, digests and excretes.”

– Charles Darwin, Origin of the Species, Chapter 6Read More »

Clever little Keas…

Intelligence can be defined as the ability to solve novel problems.  In other words, many examples of “animal intelligence” wouldn’t count because of the limited range of situations within which they are able to act.  Examples might include squirrels caching nuts and finding them again or the ability of drongos to mimic the alarm calls of meerkats to scare them off and steal their food.  A true demonstration of intelligence requires that an animal be able to solve a problem with which it has no familiarity.  The kea is an example of an animal that has a remarkable capacity to do just this (h/t Jerry Coyne):

A trip to Pink Lake, Gatineau Park

Lac Pink and a sweaty Englishman

A few weeks ago I cycled up into Gatineau Park, just outside of Ottawa in Quebec.  It’s nice having wilderness this close to the city, even if I don’t use it enough!  My target was Pink Lake, about 8km inside the park boundary and that made for a 30km round trip.  It’s hard work getting there (the lookout in the photo is about 120m or 400 feet above when I started) but good fun free-wheeling most of the way home.  I didn’t know anything about the lake (there are a lot of them around and I assumed it was just like the others).  However, when I saw the interpretation signs at the site I noticed it was “meromictic”.  What this means is that the lake waters never entirely mix and it produces a fairly special environment for life.  The signs gave some information about the biological implications which I thought I would share.

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In search of Sasquatch

I have been involved in “climate space modelling” for a few years now.  This is an approach that uses observations of a given species to determine the range of environmental variables under which it will occur.  Once you know what the limits of its tolerance are, you can predict where the species will occur.  For example, let’s say that a damselfly (of course I’m using a hypothetical damselfly) can live at temperature of between 10 and 20 degrees and precipitation has to be between 200mm and 500mm per year.  Warmer, wetter, cooler or drier than that and it can’t survive.  We can use these limits to predict (i) where the species currently exists but has not been recorded, and (ii) where the species might exist in the future as the climate changes.

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