It’s weird that for two days I have been having the same dream about me escaping a Python. In the dream, I see it right beside me and as soon as I think that I am safe, I try to run away from it but it’s too late and it raises its head, recoils a bit; just sweeps towards me with its full impact; bites on my shoulder to injects its venom and paralyzes me. I somehow have a sense that I am dreaming and so I try to wake myself up because I know that if I don’t wake up, it would just wrap itself all around me; suffocate me and crush my bones to death to eat me.
The above dream could be because I have always feared snakes. I think they are the most paranoid creatures of all- they have little brains and they think that everything that moves and breathes is trying to kill them and so they attack. It’s good that not all snakes are poisonous but for a person like me…a pair of fangs or the concept that they bite is enough. But just for the same reason (my fear for them ) snakes also fascinate me. I think I have seen every freaky-deaky documentary that has ever been shown on snakes on discovery channel & national geographic. This is a part of my research on snakes. Let’s start with their evolution.
Starting from the first cell, we all know that evolution began in water. The first blue-green algae started producing their own food with the help of sunlight and started releasing oxygen which made the oceans and seas conducive places to give rise to diverse life forms. Gradually, different parts of cells started organizing themselves into complex structures such as internal membranes and DNA strands coiled up in a nutritious nucleus which marked the emergence of the Kingdom Animilia (Eucaryotes- if you really wanted to know what the first animals forms were called 
).
As more and more complex life forms evolved life saw the most dramatic evolutionary step that is the development of a structure called a notochord. A notochord is the vertebral axis that- when developed- gives support to an animal and helps give it a strcutre that makes complex movements possible. (This is a gross generalization of the meaning of the term notochord)
Supported by the strength of a vertebral axis(chordates) and primary limbs; life jumped media- from water to land in the form of amphibians. Amphibians could live on land, but had to go back to water to lay their delicate eggs which remained more protected there. The delicate eggs started developing into shelled eggs and that allowed these animals to remain on land for progeny. This happened nearly 245 million years ago and marks the beginning of a class of chordates called reptiles.
Reptiles are Amniotes which means that their embryos are surrounded by a nutritional medium called amniotic fluid (just like humans). They are also tetrapods that is, they have 4 limbs/legs to move- e.g., lizards. The earliest reptiles were Cotylosaurs who later on diverged into three different groups based on how the relationship between their jawbone and skullbone developed. This combination was called Quadrate Bones.
First ones (the ancestors of present day turtles) developed no arches in the skull-bone and no movement was possible between the jawbone and skull-bone. Second ones that evolved into the ancestors of today’s mammals had an arched skull-bone and had some gap between the jawbone and the skullbone which allowed jaw muscles to pass through them making some movement between the two bones possible.
In the third category, to which dinosaurs, lizards and today’s snakes belong, development of the Quadrate bone happened in the most interesting way such that it was possible for them to move their jaws a lot more than relative to the braincase (the skull-bone). The jaw muscles and the bones developed in such a way that these animals could open their mouths and engulf a prey way bigger then the size of their mouth.
The common belief is that snakes evolved from lizards but no one is sure about which family of lizards evolved into snakes. Some believe that the ancestors of today’s monitor lizards started burrowing into loose sand and developed a sub-terranian life which required them to shed their legs; have specialized eyelids as eye covers and caused loss of ears. Another theory purports that their lack of legs; eyes and ears maybe due to the fact that they evolved directly from their aquatic ancestors.
Whatever it is, first of the modern snakes were like Pythons and boas(Boids)- they were large; had huge muscles and had tiny limbs (a probable relic of their lizard ancestors). These were dominant during the times when dinosaurs had become extinct. 36 million years ago, a swifter and smaller species of snakes evolved which we call the typical snakes (Colubrids). The boids were the rulers of the earth until the continents started shifting and the temperatures fell. Boids could not survive the cooler climatic conditions and the colubrids soon started dominating the snake world.
Some Colubrids started developing enlarged teeth at the rear of their jaw (e.g., queen snake, African twig snake). These enlarged teeth had grooves in them and when a prey was partially swallowed a highly modified version of saliva (venom) was injected into the prey to subdue it. Since the teeth were too far behind, this could not have been a defense mechanism.
More groups of snakes evolved as the venom apparatus in them evolved (Elapids). The shortening of the maxillary bone (the upper bone that holds the teeth in humans – the palate) helped the migration of the fangs (enlarged teeth) to the front and thus could be used to inject venom into enemies skin and also kill the prey. The cobras and sea snakes belong to this category.
The fangs grew larger and larger and finally, nearly 10 million years ago a species of snakes evolved which had such long fangs that they could not even close their mouths. These were called Vipers. Some Vipers later on developed heat sensors located in pits on the sides of their face which helped them sense living creatures in the dark and became pit vipers and a few million years ago, a class of pit vipers developed a certain structure on their tails that they could rattle and warn the approaching enemy with and formed the most specialized species of snakes found today, called rattle snakes.
Presently, there are about 2,400 species of snakes in the world and they live almost everywhere, in deserts, forests, oceans, streams, and lakes. Snakes have a history that goes back more 300 million years which is way before early humans started walking on earth. Snakes may have reduced to just an object of study or slithering creatures fearfully wrapped up in myths, stories, art and religions- but to me they seem like the fore bearers of an ancient wisdom that earth divulged into them…a secret that we seek so arduously…an important piece belonging to the puzzle of our very own evolution.
