Lizard Physiology
Derrick Keyser
BIO/101
March 17, 2014
Brian Fox

Lizard Physiology
Lizards once ruled the earth as massive beasts, but over the course of time, evolution has changed them to be much smaller than they once were. While these creatures have been around for millions of years, they’ve had to change to become better suited for the environments that they currently inhabit.
The lizards that I am the most familiar with are now living in developed areas, such as rural neighborhoods and urban sprawls. While walking around my house or place of work, I often see the little green Anole lizards scurrying about. These little guys are small because they are naturally inclined to hide from danger. If I move slowly enough, I can catch them out on the sidewalks or the sides of trees sunning themselves. But if I get too near, they hurry away to the nearest hiding spot; under a bush, into a hole in a brick wall, whatever happens to be nearby. If these creatures haven’t evolved to become smaller, they wouldn’t be able to fit where they can now.
According to the website published by Joanides (2011) there are upwards of 3000 different types of lizards, each varying in color, size, and location. Many of these lizards primarily eat insects, which helps to keep the insect population under control. Since insects are available virtually everywhere, I can imagine that the Anole lizards in Florida have plenty to eat, even in the urban areas.
The majority of lizards are found in tropical areas, and since they are cold-blooded, they need heat to survive. The tropical climates of Florida most likely keep the Anoles comfortable most of the year. However, even tropical areas can have cold snaps. This would be where the urban areas can help the smaller lizards survive, as they would be able to take shelter inside of a building with heat. Since the Anoles are smaller, they can get into tiny crevices that most things cannot. Because of that ability, they can get into many urban buildings to keep themselves warm when they need to be.
The urban environment is also useful for the lizards on the extremely hot days. Because of the nature of the urban environment, there is plenty of shade to help cool them down if they begin to overheat. Many buildings also offer air conditioning to help speed up the process. This again goes back to their ability to reach very small spaces that most creatures cannot reach.
The small lizards also have to worry about predators in the urban environment. Stray cats and dogs can find them. According to the page by Joanides (2011) lizards also have the ability to lose a significant portion of their tails under duress, a tool used to distract predators. After they have utilized that method while trying to escape predators, the lizards in the urban environment also have another advantage over their attackers: they can hide in the crevices found along buildings, in a small enough space that a cat or other predator cannot reach them. Because of this advantage, there are a high number of lizards found in my area.
As I mentioned earlier, the majority of lizards primarily eat insects. Because of their diet, the insect population where lizards are found is kept under control. As insects are considered pests to the majority of people, anything that can help take care of pests is welcome in our surroundings.
The lizards found today are much smaller than those found in the age of the dinosaurs. Of course, the reason for that is the fact that the environment has changed greatly. There are significantly less open areas for the lizards to inhabit, meaning that the lizards now do not need to cover nearly as much ground in order to find their food. The jungle has been replaced by concrete, meaning that they do not need to travel as far to find a good patch of sun to keep warm. Instead, the concrete itself warms up in the sun better than the jungle floor, so all that the lizards need to do now is just simply go out to it and rest. Of course, if the small lizards are not careful, they could be trampled by people walking on the sidewalk, but since most of the sidewalks are in very close proximity to ideal lizard hiding spots, there isn’t much for one to worry about anymore. Their quick reflexes and lightning fast agility keeps many of them alive.

Reference
Joanides, S. (2011). Ranges of Reptiles. Retrieved from http://rjfisherjoanides.pbworks.com/w/page/36530159/Reptiles%205