When addressing the natural selection of turles and tortoises we must refer back to the year 1831 and the unforgettable journey of Charles Darwin. On this journey Darwin sailed along the Atlantic coast of South America making many stops in order for him to carry out his inland observations. In 1835 Darwin and those that accompanied him on his voyage landed on the island of Galapagos where many interesting discoveries were made.
The Galapagos Island had a very small population of people but here he found a vast amount of turles, tortoises, as well as lizards that did not seem to be afraid of people which allowed Darwin to study them closely.These careful observation allowed darwin to make a very interesting discovery. He found that though the turles and tortoises that were on the Galapagos Island had some of the same characteristics as others seen in South america and other islands, they also had many diferences. He found differences in the shells of turtles, some were softer and some had harder shells. Some had different kinds of mouthes or beaks, as well as different shapes and kinds of feet. After many years of studying and exploring he decided to make a hypothesis on how these differences in the same species came to be. Darwin said that though these turtles may have migrated from the same place, what caused the changes is where they ended up. Some turtles were forced to remain on land and had to adapt accordingly, they developed tougher and harder shells, their feet were shaped appropriately to allow them to comfortably walk on land, and they developed the characteristics necessary to hunt for their prey. Those tortoises that adapted to living primarily in water, also changed over the years. Darwin's observation of the natural selection in turtles was obvious to me upon observing several different kinds of turtles and tortoises and learning how different they are from one another.
During my environmental studies class I was able to observe mnay differnt kind of turles and tortoises and analyze their differences. The one that most shook me was the Snake neck turtle. Over the years this turtle seems to have developed a long slim neck that can stretch out in order to trap prey such as insects, worms, tadpoles and even frogs. Though the shell is a bit rough for protection from other sea creatures, it is also aerodynamic in order to allow for easy swimming. The snake neck turtle has powerful webbed feet to aide in swimming as well as digging and tearing apart prey. The Soft shell turtle is also a water turtle but its shell is very soft ( hence the name) and very different from the snake neck turtle. The shell is very flexible, leathery and flat resembling a pancake. Since this turtle is aquatic its light shell is much easier to swim with. It is also a carnivorous turtle that actually has a pointy sort of beak shaped mouth and nose to aide in the catching of insects which is what they eat most.
I also observed a mud turtle which is not quite aquatic but does like the damp swampy areas and will go in water for a dip from time to time. Mud turtles are small and they are primarily carnivorous which was surprising due to their small size. They eat anything they can catch; insects, worms, tadpoles but they will eat berries and even carrion. My favorite turtle was the box turtle which lives on land. This one had some long legs which are helpful when walking on land .these turtles are omnivorous and vary from eatting insects, worms,fish, frogs, to berries and flowers and carrion. What I found amazing is that this turle had a dented midsection which aides in determining the sex. Usually males have the dent which allows them to mount a female for mating purposes. This turtle was the most outgoing and curious one I observed. Another land turtle is the Redfoot turtle which also has the longer legs in order to comfortably walk on land, thus turtle is not aquatic and therefore does not have webbed feet. We even observed the Central American Ornated Wood turtle which is semi-terrestrial. This kind of turtle can live on land but also needs to go into water. Its shell is strong but not too heavy since the turtle still has to be able to swim comfortable. Thus turtle can enjoy a nice salad consisting of leaves and greens and can also eat worms and insects. Incertain regions the colors are brighter than in others which may have to do with climate and camouflaging.
While analyzing all of these species of turtles my classmates and I now understand Darwin's theory on turtles and natural selection. The physical features and capabilities of these turtles must have changed over time depending on its needs for survival and its sorrounding environment. It is amazing and so very interesting to find that they can be so similar but yet so different. So I recommend take time out and look closely at different turtles and other species and explore the miracle of natural selection!