Darwins theory of evolution
All living organisms are related in one way or another and they originated from a common predecessor.
Darwins theory of evolution
Going by the Darwins theory of evolution, it brings about the idea that all life on earth is not only related but started from one common ancestor the fishes, the birds, the flowers and the humans are all related and have the same origin. The general theory of Darwin presumes that life developed from non-life. The theory therefore suggests that living creatures must have evolved from ancestors that were more simplistic than them. Within a nutshell, where random genetic mutations take place within the genetic code of a living organism, the most important mutations are usually preserved naturally since they are essential in assisting in survival, through a process that is commonly referred to as the natural selection. These important mutations are in turn passed to the subsequent generations. As these mutations are passed to these generations, they accumulate over time and they eventually lead to the emergence of completely different types of organisms. The new organisms do not only vary from the original organism, but they can actually be a completely different creatures from the original one.
In his assertion that life began from non-life, Darwin suggests that organisms with simple forms of life evolved from garbage. These simple forms of life then evolved over time as they underwent genetic mutations and transferred some of their traits to other generations thus bringing about other living organisms that were completely different from the original creatures. Biological research further indicates that the fossils that have been found in various sediments and trapped in bedrocks had a common ancestral background. Some of the fossils that have been discovered show that they belong to certain species that are found not only in the continent where the fossil was discovered but also in another continent. This implies that these organisms once lived in a super continent that was not split, but as the massive continent split into several continents, these organisms were separated and had to evolve independent of the others thus resulting into different species depending on the ecological and climatic conditions of its environment. The important mutations that are passed onto the subsequent generations are very important and they assist in an organisms survival. There are several organisms that have either been eliminated or flourished due to these beneficial mutations. Thus if an organism does not undergo beneficial mutation, it will simply be eliminated by its immediate environment.
Personally, I believe that evolution takes place and that all the living organisms have a common ancestral origin. This is quite evident from the great similarities between different species which have evolved in order to survive in their ecological environments. A close examination of most organisms that are found in Australia shows that these species were separated from the rest before they had substantially evolved. Australia got separated from the rest of the land mass before any other continent. Therefore, the living organisms on it were completely separated from the others and thus evolved independently. This is evident from the species that are found in Australia which are much more primitive as compared to the organisms that are found in the other continents. However, I do not concur with Charles Darwin on the assertion that life developed from non life as there is no sufficient prove to this effect. The theory is also not clear on the exact form of non life that brought about life, but only talks about garbage without specifically stating the components of the garbage.
Natural selection was also discussed extensively by Darwin as part of the evolution theory. It was illustrated as a process through which the heritable traits of an organism can increase or lower its chances of survival. The genetic natural variation within a certain population of living organisms implies that some members of the population will reproduce and survive while others will be eliminated. The natural variations take place among the members of any given population. Several of these variations have no effect on survival, but there are certain variations which may enhance the survival chances of some members of the population. A prey that is able to run much faster than others, is more likely to escape from being predated on and thus this particular trait will improve its survival chances as compared to the members of the same population that cannot ran very fast. Again, for the algae that are more efficient in extracting solar energy will not only grow much faster than the ones which cannot be able to extract solar energy, but will also increase its population size very fast. In this case, the living organisms with the heritable traits that enable them to adapt better to their environment usually have better chances of survival as compared to their counterparts lacking such traits or whose traits are weak. The living organisms without such traits will not survive for long as they will soon be eliminated and thus cannot pass on the undesirable traits to their subsequent generations and they can therefore be said to have been selected against naturally. On the other hand, the living organisms with the desirable traits will have greater chances of surviving and reproducing and thus will pass on these desirable heritable traits to their subsequent generations and thus the natural selection can be said to be in their favor.
A good example of a population that has undergone natural selection is the England moths during the period of industrial revolution. During this era, there were mainly two types of moths, the light colored and the dark colored. The dark colored moths were rare whereas the light colored were very common. However, as a result of the dark soot together with other dark industrial wastes killed the lichens and darkened trunks of trees. The light colored moths could be easily spotted by predator birds which led to a sharp decrease in their population whereas the dark ones flourished under the same environment since the predator birds could not easily spot and predate on them. This example indicates that the traits of the moths of being light colored made them to be naturally selected against while the dark ones were favored by the environment that resulted from the industrial revolution.
According to me, natural selection is very true and the organisms with certain traits that make them to survive better in a certain environment will therefore reproduce and increase their populations and thus such heritable traits will be more common. On the other hand, the organisms with undesirable traits will be naturally selected against and will thus reduce in population which also implies that such traits will slowly be eliminated and hence evolution will have taken place. It is true that the natural environment will favor the survival and reproduction of organisms with traits that enable them to adapt much better to the environment as opposed to those organisms without such traits.
Conclusion
Evolution is a continuous process and has taken place throughout the history of living organisms. According to the Darwins theory of evolution, all life share a common origin and ancestral backgrounds. This explains why despite the fact that different species are distinct from each other there are some remarkable similarities between various species, indicating that they originated from a common ancestor. Evidence of evolution is largely provided by the fossils which have been found in different parts of the earth trapped in bedrocks and sediments. These fossils show how the early forms of life looked like and its relationship with the current ones. The natural selection is yet another means through which evolution is extensively explained. It shows how certain heritable traits of an organism within a population can either increase or reduce its chances of survival, depending on the manner in which the specific trait enables the organism to adapt to its environment.
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