Jean Baptiste Lamarck’s theory of evolution

Jean Baptiste Lamarck’s theory of evolution

Jean Baptiste Lamarck’s theory of evolution stated that organisms change during their lifetime, and then their offsprings inherit these changes. For instance, he had a belief that the giraffe is a long-necked animal because it elongated while trying to reach leaves that were in higher branches. It thus meant every generation of giraffe had a more elongated neck than the preceding one.

Darwin, on the other hand, did not agree with that theory and thus originated the theory of natural selection, which stated that organisms had variations. It, therefore, meant that each individual had a slight difference from the other, and this determined who was more likely to survive and reproduce. These features were, therefore, more likely to appear in each generation of that species. Darwin thus believed that longer necked giraffes had higher chances of survival as they would reach the farthest leaves and thus the increase of longer necked giraffes, and finally, all giraffes would be long-necked. It is where the phrase ‘survival of the fittest’ originated.

Charles Lyell, in his book ‘Principles of Geology,’ argued that geological processes on earth occur very slowly. Therefore this meant that the universe is older than most people thought (Darwin 38). The book thus helped Darwin to realize that living things had much more time to evolve and, therefore, room for greater diversity.

Thomas Malthus’s essay regarding population stated that human societies have a likelihood of growing faster than the available resources, and this would lead to famine and diseases. It is from this idea Darwin realized there would be a scuffle for resources if offsprings were too many, leading to the survival of the fittest.

A comparison of the parts of the body of diverse species can, at times, disclose proof of evolution. For instance, mammals have anterior appendages that look different and are used for various purposes.it is their bone structure that shows that they have a common ancestry.

Embryos of different species may show similarities, but when the species take the adult form, they look dissimilar. For example, the nuclei of pigs, turtles, chickens, and human beings show resemblance, which therefore provides the evidence that the four species are related.

Species that diverged a long time ago usually have a more significant difference in their DNA than those who are closely related because those that are strictly related have not had time to accumulate random mutations in their genetic codes.

The anole lizards were initially about 150 and were closely related. They evolved in the past 50 million years through a colonizing species on each island ( Pontarotti 20). The processes that led to the speciation include; geographical isolation, reproductive isolation, and adaptation to other environments.

Convergent evolution is the process in which organisms with different ancestry develop similar features. It happens because they live in the same habitats, and all acquire natural selection for their environment (Pontarotti 26).

Coevolution is the influence that closely related species have on each other during their evolution. It usually occurs because of natural selection, and the species involved create a symbiotic relationship. For example, flowers rely on bees for pollination, while bees depend on them for nectar (Pontarotti 30).

Works Cited

Darwin, Charles. The Voyage of the Beagle. The Floating P, 2009.

Pontarotti, Pierre. Evolutionary Biology: Genome Evolution, Speciation, Coevolution, and Origin of Life. Springer, 2014.