Evolutionary Weaponry -- Venom

"If I spit, they will take my spit and frame it as great art." - Picasso

His modesty is commendable, but really humans are millions of years behind other animals in terms of the quality of their spit.

There are many animals in the world today that utilize a variety of venoms to incapacitate prey. Most notable of these are snakes, lizards, spiders, and jellyfish. Few people are aware of the venoms that some mammals have, such as moles and shrews. But if the evolution of venoms occurred in multiple kingdoms at different times, where did they all come from?


The answer is ever so cleverly concealed in the opening quote of this article. Primitive forms of venoms usually are found in the saliva of organisms. This is evident even today in a number of monitor species and some fish. Scientists who specialize in the application of venoms for medicinal research have been studying the make up of various venoms and have reached a few conclusions through the use of DNA analysis. Namely that many of the enzymes and proteins that are found in venoms of a particular species are also found in other organs of their digestive system. This has lead researchers to believe that venoms started out as "strong" salivas.

Venom typically is made up of one of three (or some combination of) toxin classifications: cytotoxins, hemotoxins, and neurotoxins. The makeup of the venom is usually influenced by the hunting styles of the animal in question. Sea snakes for example require incredibly powerful venoms to kill fish almost immediately, otherwise they would not be able to catch them.

INTERESTING SIDE NOTE: the king cobra has venom potent enough to kill an adult elephant. But the strength of it's venom was only increased because it hunts other snakes, which had developed a resistance to it's venom.

Cytotoxins are considered the most primitive. They initiate the digestion of tissues before being swallowed. Most salivas do something similar, for instance in humans, we have enzymes that help us break down carbohydrates and sugars before it even gets to the stomach. Venoms simply have specialized enzymes and proteins which do essentially the same thing on living tissues. Cytotoxin venoms are also utilized by a number of species for defensive purposes, which sufficiently irritate attackers to allow for a hasty escape. Cytotoxins usually don't kill the prey, but can wound it sufficiently to make it easier to catch. Some cytotoxins can be incredibly potent and lead to deformities, such as those found in the brown recluse spider (Pictures of brown recluse toxin effects on humans. WARNING: graphic content.)

A more advanced toxin are the hemotoxins. Hemotoxins attack circulatory systems, usually preventing the coagulation of blood thus preventing the victim from being able to stop bleeding after the strike. However some more advanced hemotoxins do the exact opposite, and actually rapidly clots all the blood throughout the body of the victim.

The most frightening toxin, at least to me, are the neurotoxins. These toxins work between the synapses of the nervous system. Basically the eliminate the singles being sent from the victims brain stem to the muscles. In essence the victim is still alive when it begins to be eaten.

The evolutionary history of venoms in snake species is particularly interesting. Much to the dismay of my mother, snakes have also become a small obsession of mine. DNA researchers have determined that the ability to form these venoms, in snakes, arose from a single evolutionary branch over 100 million years ago in one of the earliest ancestors of modern snakes. All of the modern snakes of today have venomous potential, however only tree taxonomic families are now considered poisonous.

And now after convincing you all that snakes are terrible animals to have around the house, I would like to encourage everyone to visit the New York Reptile Expo on Wednesday January 20th at the Westchester County Center in White Plains NY. I went last year and had an absolute blast. They have vendors there selling all sorts of reptiles. Monitors, snakes, geckos, chameleons, frogs, turtles, they literally have it all. It was that show where I bought my first corn snake, they make for great pets. Everyone should check it out, $10 to get in and see some of the craziest animals and people the greater New York area has to offer!