The Basics of Evolution

Today’s post will make an attempt to explain the very basics of evolution, how these animals with remarkable mimicry and deception techniques came to be. Basically, there are three essential parts to evolution. It is possible for the DNA of an organism to occasionally mutate. The change due to mutation is either beneficial, harmful or neutral and lastly the mutations occur and spread over long periods of time resulting in new species.

DNA is the hereditary material of life, it affects how an animal looks, behaves as well as its physiology. Page & Holmes (1998) state that DNA sequences are valuable pieces of information, that they provide the most detailed anatomy possible for any organism. Therefore, it can easily be seen that a change in its DNA can change other aspects of its life. Mutations can either be neutral, beneficial or harmful. These mutations can give it an advantage other others, make it harder for them to survive or have no effect on their lives at all. However, mutations are completely random, whether the mutation is beneficial or not as well as how useful it is to the animal is unrelated and random. If the mutation is beneficial to the animals, then it has a higher chance to reproduce and hence pass on the beneficial genes. This process is repeated over a long period of time until the species all have gained the beneficial mutation as those with it were more successful than those without.

For example, the Common Mormon (Papilio polytes) may not have looked like the Common Rose (Pachliopta aristolochiae) originally. However, a mutation may have given one individual a red spot on its wing. This single red spot confused predators and deterred them from consuming the mutated individual. This gave it an increased chance to breed and pass on the mutation that gave it a red spot. This process was repeated and over time the species developed multiple red spots that mimicked the distasteful poisonous Common Rose. This is an example of visual evolution but can occur in all aspects of an animal such as behaviour and body movement as well in earlier posts.

Figure 1: Comparative photo of Papilio polytes(top) and Pachlio aristolochiae(bottom). Photographer: Kunte (2014)

Hopefully this snippet gave you some idea of how evolution works, more examples as well as a deeper understanding will be attempted in the next post.

References:

Kunte, K. (2014) Comparative photo of Papilio polytes(top) and Pachlio aristolochiae(bottom). http://www.natureasia.com/en/nindia/article/10.1038/nindia.2014.29. Retrieved: 24/05/2015

PAGE, R. D. M., & HOLMES, E. C. (1998). Molecular evolution a phylogenetic approach. Oxford, Blackwell Science. http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=51693.