Sunday, October 27, 2013

"Something with poison..."

The Wicked Witch of the West had a point. Poison is very handy when it comes to survival, and two recent discoveries have told us more about venomous animals. 
First, an obvious question for paleontologists is when poison first evolved.  The apparent answer popped up in 2009.  (OK, you can argue whether that6's "recent," but I'm working on a theme here.) Half a billion years ago, tiny jawless proto-vertebrates called conodonts evolved strange-looking teeth. (Teeth without jaws were pretty fashionable back then).  Polish scientist Hubert Szaniawski reported, "Many of them are characterized by possession of a deep, longitudinal groove, usually associated with sharp edges or ridges. A comparative study of the grooved elements and venomous teeth and spines of living and extinct vertebrates strongly suggests that the groove in conodonts was also used for delivery of venom." So this poisoning has been going on a long time. (Weird fact: baboon,s which are not venomous, have such grooves for no apparent reason.)
The crustaceans, however, never saw the need for poison, opting to develop better claws and other weaponry.  Or we thought they did. Among seventy thousand species, maybe there had to be an oddball.  London scientists Bjorn von Reumont has found that primitive crustaceans called remipedes, which look a little like swimming centipedes, have, in one species  (Speleonectes tulumensis), developed toxic fangs. The venom is, as might be expected, odd: it mixes a neurotoxin to make its prey helpless and a heavy does of digestive enzymes to get into the prey's body and start breaking it down.
Nature, once again, proves stranger than ...well, anything else. 

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