What is natural selection? What purpose does it serve?
Natural selection is a process or a mechanism in which living organisms reproduce selectively creating changes in genetic constitution or genotype by adapting to the environment and evolve. The individuals thathappen to be well suited to a specific or particular environment survive and further reproduce the offspringsuccessfully compared to others not well adapted, producing descendants of great similarities.In thesebreeding cycles, the better-suitable ones will dominate and the poorly suited ones will be filtered out by nature automatically.
This term is well explained in Darwin’s Theory of evolution also known as Darwinism.
What is this “Darwinism”? This is considered or believed to explain the biological evolution of organisms which is given by Charles Darwin, a naturalist.
The proposal that every species changes with time and also that new species come from the already existing ones and they are a result or outcome of the same ancestor. To further explain this, he developed a model which shows that an individual species consists of some genetic differences in the set where they are unique and slightly different from their great ancestor from where they have accumulated some features and developed over a long time.
The Darwinian theory revolves around or consists of two main points said by Brian Richmond:
- The first point is that this theory explains that various life-forms of the Earth are generally connected and well-related with each other.
- The other major point lies in the fact that the reason for diverse life-forms is mainly due to the further modifications taking place as a result of natural selection where not all populations or not all traits seemed to be favored by the same environment. Some maybe well-adapted or best suited in that particular environment whereas others may not be as they might be affected in some of their physical characteristics or some because the environment could not survive.
What is this natural selection according to Darwin?
According to Charles Darwin, the naturalist believed and even wrote that the phenomenon that is responsible for evolution is natural selection.
Charles Darwin wrote in his theory of evolution that individuals or group of individuals or species that are having physical features that are easily adaptable in an environment have a high chance of living or surviving, protecting themselves from predators, finding food, and,also protecting themselves from various diseases be it severe or not. Such species can very well survive or live in such an environment and can successfully reproduce with their genes passed on to their offspring.
In other cases, if the species or individuals do not have characteristics or features that are suitable or adaptable to a specific environment, they might have very little or no probability of survival and are not even able to reproduce. Thus, such species will not be able to likely pass on their genes to the next generation of species.
With this Darwin concluded his explanation on the term natural selection where in short he stated that “ The species that are best-suited or well-adapted to a given environment will have a great probability of surviving and then the evolution process will gradually take place from the pre-existing species.
Here are the five basic steps that cover Natural Selection:
- Variation
Most of the members of a given species are more or less the same however, they can differ in their color, size, ability to fight off diseases, and so many other traits. The variation usually results from random mutations, or errors while copying arising during cell division for new organisms’ development.
- Inheritance
During reproduction, the DNAis passed on.The traits encoded in DNA are pass to the offspring thus inherit the parents’ traits. For example, tall parents usually have tall children.
- Survivaland Reproduction
Most environments do not supportinfinite populations. The reason is mainly due to very limited resources and organisms that can survive are more in numbers. These organisms that can survive are mainly due to their characteristics which are found suitable for the environment. Such organisms survive, reproduce, and evolve.
- Time
Darwin in his theory stated that with time the species are capable of changing their features.
- Adaptation
The traits which are advantageous do help individuals survive in the environment and reproduce and adapt well in that particular environment.
What purpose does it serve?
Natural selection is a mechanism or process which is believed to be unintelligent which helps in producing and designing populations of species thatare well-suited to a given environment. It causespopulations of organisms to change in characteristics with time and this mainly depends on the selective parameters at a given time and place. Therefore natural selection has mainly two main extremes outcome. One is extinction if the species cannot survive and one is speciation.
For further information in understanding more about the theories of the evolution of life visit a website that contains a lot of informative videos on this.