How the Environment Influences the Body Plans of Organisms

The body plan of an organism is the most basic arrangement of the tissue layers in that organism without any details concerning the arrangement of its internal organs and the most basic and greatest influence on the body plans of organisms is the environment. The fundamental body plans such as the size of an organism can be determined by the environment in which it lives. According to Fastovsky and Weishampol (2005), all organisms are subject to design constraints. Organisms that live in the air or in water are acted upon by gravity and this causes their ancestry to limit the structures that they can evolve. For example, you will never find a propeller on the nose of a bird, even though that would be the most efficient way to propel the animal, because the evolutionary process works by descent with the modification of existing structures and not the wholesale invention of new ones.

Hoffmann and Parsons (1997) state that the body plans of organisms can be influenced by the types of landscapes encountered by them.  It is very difficult for a population to move from one environment to another when natural barriers such as mountains and seas because there are large differences between their current forms and the alternative forms which they would need to cross these barriers. Therefore, these natural barriers keep the organisms within one environment and in order to survive, they will have to develop the essential body plans to suit that environment. In other words, their inability to move from this environment will lead to a stasis in the development of their body plans and these will instead remain in their current state with little or no change over a long period of time.

Tobin and Dusheck (2005) declare that the body plans of organisms such as the particular arrangements of bones in the limbs of horses, whales, and humans may simply be a case of organisms making do with what they have. Organisms tend to reuse the same parts and materials, reshaping them for new purposes. A good example of this would be when one considers the whale which, although it is a mammal, lives in the ocean. Unlike other mammals, it does not have the legs it would normally have had if it had been living on land and instead, those limbs that would have formed legs on land have instead developed into fins to enable it to survive in the ocean efficiently. Furthermore, the body of the whale is too big to survive on land and it is instead adapted to life in the ocean because the water can not only support its weight, but there is also enough space within it to ensure that the whale is able to navigate within it.

In conclusion, different environments influence the development of different body plans to adapt to them. For example, the camel is very well adapted to life in the desert because it has developed padded hooves to be able to walk on the desert sand, long legs and neck to keep it from sinking into the sand and enable it to breath respectively, and a hump to store water because of the scarcity of this resource in the desert. Examples of other body plans include camouflage to avoid predators and the extreme height of some trees in forests in order to gain light for photosynthesis.

References

Fastovsky, D E. & Weishampol, D B. (2005). The Evolution and the Extinction of the Dinosaurs. Cambridge, United Kingdom: Cambridge University Press.

Hoffmann, A A. & Parsons, P A. (1997). Extreme Environmental Change and Evolution. Cambridge, United Kingdom: Cambridge University Press.

Tobin, A J & Dusheck, J. (2005). Asking About Life. Andover, United Kingdom: Cengage Learning.