Theory of evolution by Charles Darwin

Charles Darwin is a biologist that believed that all living thing rise and develop as a result of a steady process known as the natural selection. This selection is based on the genetic differences between these organisms (Plants and Animals). In his theory, he stated that all life must have originated from a common ancestor. He further proposed the development of life from non-living things or natural forms and the development of humans from animals. His ideas were published in an 1859 article called The Origin of Species. However, his idea was not generally accepted since it conflicted with religious beliefs.

Most religions believed that man was created by God, and that man did not evolve from primates as it is the case in Darwin’s studies (Turner, J.R.).When genetic mutations occur in an organism, the mutations are conserved. Only beneficial mutations in a species are conserved. These mutations are passed from one generation to the next. When these mutations accumulate over a long time, it results in totally different organisms in terms of their genetic composition and observable traits.

The beneficial genetic mutations that develop in an organism are passed from one generation to the next. Offspring which inherit harmful mutations from their parents die gradually, whereas the offspring with useful mutations survive. This process is known as natural selection. This process enables living organisms to compete favorably for the resources in their habitats such as food, water, shelter, mates, and space.

Natural selection is a very important aspect in domestic breeding. Breeders can select domestic animals with useful traits in terms of yield production, i.e. both quality and quantity, and cross-breed them. The domestic animals showing harmful traits are eliminated early during the initial stages of the breeding process. Therefore, the inferior species are removed from a generation gradually (Gliboff, Sander).

Darwin’s theory of evolutions states that evolution is a gradual process. Natural selection takes place as result of several accumulated genetic variations in living organisms observed keenly over a long period of time. These variations in physical, behavioral, and genetic traits enable living organisms to adapt to a particular environment, hence enabling their survival over the ones which lack these traits.

Natural selection can cause variations in members of a particular species in minimal aspects, for example, variations in their body size, shape, and color, a process called microevolution. Also, natural selection can cause tremendous variations in a species resulting in distinct observable traits. This process is referred to as macroevolution. The development of humans from apes, whales from mammals, and birds from dinosaurs was as a result of macroevolution (Igor Tsarkov)

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Darwin’s theory of evolution through natural selection is supported by a great deal of evidence from several scientific fields including, developmental biology, geology, genetics, and paleontology.

Darwin discovered the evolution of a number of organisms. An example is the sea whale. He explained how a land mammal could gradually develop into a sea whale, through the process of natural selection. The whales evolved from the black bears of North America, which used to swim and catch flying insects while swimming in water while their mouths are wide open.

The black bears partly lived on land and in water. These bears through natural selection became more aquatic. They developed structures to enable them to survive in an aquatic environment. Their mouths developed to become wider similar to those of whales. However, this idea was not fully accepted by other scientists and other scholars. This made his idea to be removed from the book The Origin of Species (Kwak, Young Hoon et al.).

Several genetic changes occurred to adapt the whales from land to an aquatic habitat. At first, the whales’ nostrils were placed back on its head, enabling it to breathe even when in water. Later, the nostrils were placed backward from the head. This type of evolution in whales was supported by evidence from some paleontologists in 1994. They found the fossils of Ambulocetus natans, an animal referred to as a swimming whale, but it once walked. Its forelimbs were emanating as small hooves, while its hind limbs were very large in respect to the large size of whales. This animal was adapted to swimming but also capable of walking on land.

Variations in various organisms are a result of changes in environmental and genetic factors. However, genetic changes are the once which result in gradual development living organisms, since they are transmitted from one generation to the next. The selecting force during the slow process of natural selection is the surrounding environment. Charles Darwin explained evolution in biological systems as a slow descent of modification from generation to generation. Evolution within a population depends on the ability of the individuals to reproduce since reproduction is the only means by which genes are transferred from parents to offspring.

There are several basic mechanisms which result in evolutionary changes and modifications. These include; mutation, natural selection (survival of the fittest), migration (gene flow), and genetic drift.

Gene flow is the transfer of genes from one population to another population as a result of migration. Changes in genetic material in particular population are called genetic drift. Mutations are modifications or alterations in the genetic material of an individual as result of errors in DNA repair mechanisms, DNA damage as result of UV- irradiation or exposure to chemical mutagens.

Darwin and Russell Wallace played a great role in the development of foundations of Modern Biology through a better understanding of biological evolution. Wallace collected relevant information on various species of flora and fauna from the islands of Australia and Southern Asia, which he studied comprehensively. He later wrote an article on the evolutionary divergence or these living organisms. The variations in these organisms were a result of changing environmental factors.

The human body evolved gradually from primates to modern human beings. Humans developed from ape-like ancestors. This is due to the fact that all the behavioral and physical traits in human beings are similar to those of the apes. This was through the slow development of human characteristics such as talking and bipedalism. From genetic studies, it has been shown that primates also evolved from mammals.

The human beings that developed from apes had a number of modified morphological features such as increased brain size, decreased sexual dimorphism and lengthy ontogeny. Bipedalism in modern evolved human beings was characterized by modifications and changes in the skeletal structures, for example, the backbone, the skull, the pelvis, legs, and the vertebral column. The developing ape gradually gained stability in walking through the process of evolution.

Darwin made it possible to link human beings to apes in his publication Origin of Species in 1859. He also applied the evolution theory and sexual selection when he published his article in 1871 called The Descent of Man. The evolution of human from apes was illustrated also by other scientists by analyzing the characteristic similarities and differences between the ancient apes and modern beings. However, Darwin’s fellow supporters disagreed his views on the development of mental capabilities from the apes to humans. But this can be explained well by natural selection. This was evidenced when several fossils were discovered in 1960’s around Lake Turkana and Olduvai George.

Genetic material can also provide enough evidence on human evolution and how the past and the present living organisms were related.

Darwin also studied living organisms known as the finches. The finches were found at the Galapagos Islands, which are located in the Pacific Ocean. This was when he toured the islands in 1835. He also had some interest in the local fauna of the islands such as the tortoises.

The finches were very famous birds in the Galapagos Islands. The birds from one island were very different from birds on other islands in terms of their basic features. The variations in these birds included the sizes and shapes of their beaks; depending on the type of food they fed on, for example, seeds or insects, which were available on the islands they inhabited. The finches which fed on seeds had different sizes and shapes of beaks from those which fed mainly on insects alone.

Conclusion

These birds adapted to their different environments. The finches with favorable traits survived from one generation to the next giving rise to more offspring, whereas the ones without these features of feeding died gradually, due to their inability to feed on the food available in their environmental habitat.

Works Cited

Igor Tsarkov. "Sampling Methods Evolution In Problem Of Duration Reduction Of Project With Limited Resources." Russian Journal Of Project Management, vol 3, no. 3, 2014, pp. 14-24. Infra-M Academic Publishing House, doi:10.12737/5782.

Gliboff, Sander. "THE DARWIN CORRESPONDENCE PROJECT: LETTERS FROM 1871." Evolution, vol 67, no. 1, 2012, pp. 303-304. Wiley-Blackwell, doi:10.1111/j.1558-5646.2012.01811.x.

Kwak, Young Hoon et al. "Evolution Of Project Based Organization: A Case Study." International Journal Of Project Management, vol 33, no. 8, 2015, pp. 1652-1664. Elsevier BV, doi:10.1016/j.ijproman.2015.05.004.

Turner, J.R. "Evolution Of Project Management Research As Evidenced By Papers Published In The International Journal Of Project Management." International Journal Of Project Management, vol 28, no. 1, 2010, pp. 1-6. Elsevier BV, doi:10.1016/j.ijproman.2009.10.009.