It is very well known, though there are other points of view regarding this issue, that evolution is what made us what we are. We developed out of much simpler life forms, as well as other animals. But what is important to understand is how and why the evolutionary processes work. And though there are different approaches to this problem and different ways to look at it, there is one, a conventional way of seeing evolutionary process, which will be briefly discussed within the limits of this paper.
The evolutionary process is gradually taking place as the generations change. This process changes the traits and, as a result, not only do the species change their characteristics, but the population becomes diverse. Each individual is very different from other individuals, though the characteristics of the species remain. At this point it seems to be reasonable to define a concept, which has just been applied. Population is a population is a set of organisms, which share the same area, within which they live and interbreed. The organisms within the population belong to the same species. The concept of species also requires being defined. The species is the largest group of biological organisms. It is characteristic of such a group that hybrids within it are able to interbreed.
New species constantly appear. But for a species to appear the process of speciation – development of a new species – needs to take place. The process of speciation is usually caused by certain factors from outside. Such factors may be different. But as a result two or more groups are separated from within one species and begin developing in different natural conditions. Due to the fact, that they have to adjust to such conditions they are obtain different biological characteristics, different from the original species. And thus turn into different species. One of the most common factors which cause the process of speciation is a geographical change. For instance, as natural geological processes take place, a population of one species may appear to be separated with a large hill, and thus the representatives of two groups lose the ability to interbreed. Thus, they begin developing by different patterns, independent from one another. This may cause significant changes between two groups to develop. However, it is possible for the speciation to take place even within the same territory. Even though the population still shares the territory, its part may change their habits and due to that and the need to adjust to the new way of living they may develop different characteristics. Such habits may include consumption of different sort of food as an example.
Traditionally scientists speak of four forces of evolution (Haviland et al, ND). These are the factors, which make the evolutionary process possible, the driving forces, so to speak. These factors are gene flow, random flow of genes, natural selection and mutation. In order to understand the very essence of evolution it is important to at least briefly discuss these factors and explain them.
Due to natural selection the best representatives of the species are able to produce common offspring. Thus, they are capable to “send” their genetic material, their best features to the future generations.
Due to geographic relocation of species or their representatives the process of genes flow takes place. Due to it the genetic material is introduced to the areas, not typically inhabited by the representatives of this species.
Two other forces are random by their nature. Genetic drift is one of them. Due to this process some genetic combinations receive a chance to survive, while others disappear, though one may not say that one of the combinations was preferable compared to the ones, which failed to survive.
Mutation is another random force of evolution. Mutation is, basically, an alteration in the DNA of the organism. This alteration is then redelivered to future generations and thus the entire species obtains new characteristics. It is also very important to note, that DNA is responsible for a number of factors, such as behavior of the individuals, belonging to the species, for their immune system, for their looks, size and color, etc. Thus, though random, mutation is still a very strong force of evolution.
Evolution is a strong power, which at first allows the populations adjust to new living conditions or develop resistance to their natural enemies or unfavorable living conditions. But in the long run evolution is what leads to development of new species. In the very long run evolution has led to development of such a great variety of species, that from looking at them in their integrity it becomes nearly impossible to believe that they all had common ancestors. These species live in entirely different conditions – some can survive only in water, while for others water is not possible to survive in long. Some species are capable of flying, while others have adjusted to living on solid ground. There are those who live under ground. And they all completely different.
However, it is reasonable to note in conclusion, that the evolutionary theory is not the only possible way of looking at the development of all the species on Earth. There are other ways to explain the variety of living organisms on our planet. However nowadays the evolutionary theory remains to be the most popular and the most trustworthy from the point of view of the majority of scientists.
- Haviland, William, Prins, Harald E.L., Walrath, Dana, & McBride, Bunny. “The Essence of Anthropology. Third Edition”. Wadsworth Publishing; 3 edition, 2012.