Major Principles of Evolution - Essay Example

The Theory of Inheritance of Acquired Characteristics put forward by Jean-Baptiste Lamarck in 1809 states that modifications acquired during one’s lifetime are inherited by the next generation. “Ex. giraffes acquired a long neck slowly over time as each generation of giraffe stretched its neck slightly longer in trying to reach leaves high in trees” (Principles of Evolution, n. d). Lamarck’s theory seems to agree with the Darwinian Theory which states that evolution produces life forms adapted to their environments. However, Lamarck argued that the organism itself can control the direction of change whereas Darwin did not agree with that postulate.

“For a long time, it was mistakenly thought that evolution was a simple linear progression, with humankind at the top of the ladder. We now understand that evolution proceeds with species on one branch giving rise to other branches and so on” (What is evolution? n. d). We have a lot of animals in this world which like the leaves in big trees. For example, elephants, cattle, etc like the leaves of some big trees. However, these animals do not have such big necks as giraffes. These animals also should have tried a lot in the past to reach out to the higher branches of the trees. But they never got their neck extended just like giraffes. Humans always like to fly like birds. It is easy for humans to access the resources in this world more easily if they would have wings. After watching the birds fly, even the ancient human should have wished for wings. However, we have no history which shows any of the humans in the world has developed wings naturally. In my opinion, neither the Lamarck theory nor the Darwinian Theory gives a satisfactory explanation for the doubts.

We know that individuals within a species vary considerably. Africans and Americans vary extensively both in physical and mental make-ups. Genetic information is passed from one generation to the next. However, these genetic traits have been modified continuously because of the advancements in living standards based on the advancements in generations. The challenges faced by the ancient generation are different from those faced by the current generation and hence the genetic traits are also undergoing constant changes. For example, it is not necessary that the children of a thief in the past became thieves at present even though the genetic traits for becoming a thief are there in the blood of the children. A thief in the past became a thief because of the circumstances in the past. Such circumstances may not exist today and hence it is not necessary that the children may also become thieves today. In short, genetic traits could be changed or modified based on the circumstances or the environment.

To conclude, even though the theories of evolution increased their credibility in the recent past, still many unanswered questions are there.