Example Of Essay On The Four Forces Of Evolution

Introduction

What is evolution?
It is a gradual or a slow process in which organisms change into a different form and mostly the new for is better than the old one. As the organisms respond to changes of environment, they develop features that will enable them survive in the new environment and thus evolving.

In the evolution, we have four forces of evolution, and they are as follows:

1. Mutation; this is by which the genes or chromosome change heritable. The random variation of the genes is due to additions, deletions or substitutions of the nitrogen bases of the DNA sequence.
2. Gene flow; this is whereby two populations exchange their genetic materials; it decreases the gene variation in the two populations involved.
3. Natural selection; is a process where some organisms have better features hence adapting to a new environment and thus having a greater chance of surviving and reproduction than others.
4. Genetic drift; this is where there is a random change of allele frequency and has a more effect in small populations. This happens from one generation to another.
There has generally been no agreed definition of what specie is, however from all the definitions that scientists grapple with, the standard description that arises is that there must be a unique distinguishing factor between one specie and another. In his expansion of how species come about, Charles Darwin accepts that species are not special creations and that they mainly come about through isolation among members of single species.
The population of species is primarily determined by how they adapt to their environment. This is how their genetic structure changes to help them survive in their environment. Hence, species that can quickly genetically adapt in a way that protects it from predators is likely to have a higher population than one that may not change and adapt quickly. Variation, on the other hand, is the genetic difference between individual members of species that helps them adapt flexibly and survive environmental changes.
Natural selection in my view is generally nature taking its course on species. In that, nature will let the individuals with a higher chance of reproduction live while the weaklings die out. Natural selection also looks at species fitness, how it reacts to different changes and how it survives it. That is survival for the fittest. The fitness of species is determined by its genetic flexibility.
Mutation is the change in an individual’s DNA structure that helps it adapt to a new environment. However, for mutation to be equated with evolution, it should not just apply to the single individual but also must be passed down to its offspring. Gene flow occurs when the gene of a particular species is carried to an area where the gene was initially nonexistent. The gene then merges with a different gene with a particular similarity to it and produces entirely new species. Genetic drift is a random process that affects particular species. It mainly occurs in small populations hence particular species is wiped out or depends on another to survive. The dependence on another leads to the emergence of new species.
Isolation is the process in which organisms are prevented from successful reproduction. There is genetic isolation, and this can be through geographic isolation or other isolation mechanisms. Genetic isolation may lead to speciation that is formation of new species thus endangering the species leading to extinction due to a small gene pull. Isolation can be done through crossing of plants leading to production of sterile offspring.
Speciation; this happens during evolution in which new species are formed, and they are distinct from the parent species. It involves the splitting of a single species into two or more genetically independent ones. For example in the eukaryotic species during speciation the genes are separated from two or more gene pool and the diversification of one phenotypic form.

Conclusion

In evolution we can see, organisms evolve so as to have better features so as to adapt to changes in the environment. Natural selection is the main machine in the evolution. Organisms in natural selection strive or compete against each other for survival, and the strongest ones always defeat the weaker ones.