Wednesday, August 29, 2012

Speciation

En route, Lake Champlain
44 29.87 N 073 19.50 W


We were asked if we have seen evidence of global warming while cruising the past seven years. We say no. Distinguishing weather from climate is very hard. If you can do it at all, it is best done from a fixed location you've lived all your life. We can however, see evidence of Darwinism as we travel.


The evidence I speak of has to do with the differences in dolphins, flies and mosquitoes we see up and down the coast.


We see dolphins almost everywhere we sail except on Lake Champlain. We see them in salt water and fresh water. The biggest pod of dolphins (~300) I remember seeing was near Cape Charles at the mouth of the Chesapeake. Very noticeable is the gradual change in size and shape of the dolphins as we move north ans south. They are biggest in southern waters. I estimate that Florida dolphins are about three times heavier than Maine dolphins.


Mosquitoes too vary greatly from one place to another. They vary in size, in speed, in voraciousness, in determination to find their way inside, and in their skill at avoiding being killed. It starts with the notorious no-see-ems in Florida. They are small enough to go through most screens and too small to see for swatting purposes. Technically, they aren't mosquitoes at all.


Of course, the worst mosquitoes are the ones most successful in biting us. I hate it when I swat 10 of them and find that 8 of the, are already engorged with my blood.


We are bothered by flies less often than mosquitoes, but when they do it is worse. Fly bites hurt. Flies draw blood like mosquitoes. Some flies are so wary and so fast that they are very hard to kill. The worst flies ever we encountered on the ICW in Georgia in the month of May. They came by the hundreds. 

If we must have flies and mosquitoes, why can't they all be big, fat, slow, and not hungry.  
Anyhow, these obvious variations in species characteristics are similar to those that Darwin himself noticed in The Galapagos. Changes are gradual. Interbreeding with neighbors prevents drastic step changes. Over great distances over a great time, drift in the genes can give rise to an entirely new species. Cool.

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