CHARLES DARWIN: BIOGRAPHY AND THEORIES OF EVOLUTION AND SELECTION - SCIENCE - 2024

Charles Darwin (1809-1882) was an English biologist, geologist and naturalist, known for two of the most influential theories in the scientific world; evolution and the process of natural selection. In summary, he proposed that all species of living beings come from a common ancestor and that the species that best adapt to the environment are those that reproduce and survive. Both theories were proposed in The Origin of Species, published in 1859.

Known as the father of evolution, Darwin's theory helped remove old conventions and beliefs that indicated that the formation of various species was the product of a phenomenon caused by a higher being (Wood, 2005).

Darwin's evolutionary theory served science to give a more rational explanation of the formation and existence of new species. This was explained thanks to the concept of natural selection, where several species with a common ancestor can only survive when they adapt to the environment, even when its conditions change.

Those whose variations are negligible will be less likely to adapt, while organisms whose variations give them an adaptive and reproductive advantage will be the survivors.

Biography

Charles Robert Darwin was born on February 12, 1809, in the city of Shrewsbury, in England. The house where he was born was called “El monte” and there he lived together with his five brothers.

Charles was the fifth child of the marriage of Susannah Wedgwood and Robert Darwin. His father was wealthy and worked as a businessman and as a doctor.

The two families from which Charles came were traditionally identified with the doctrine of Unitarianism, which is contrary to the existence of the Holy Trinity.

First studies

From an early age, Charles Darwin showed a peculiar interest in natural history, since since he was 8 years old he liked to review books related to this topic and collect related fascicles.

In 1817 he began to attend the day school, which was a space run by the priest who preached in the church where his family went and participated.

Also in 1817 he experienced the death of his mother. Later both he and his brother Erasmus entered the Anglican school that was located in their city of birth.

Erasmus was older than Charles and brought him to this school to serve as his pupil. Eight years later, while the summer of 1825 was underway, Charles accompanied his father to the county of Shropshire to assist him as a physician in his consultations in that region.

Later he went again with Erasmus, but this time to the University of Edinburgh, where Darwin was not very comfortable, since he did not enjoy the classes, he even said he felt bored.

Instead, he was quite interested in taxidermy, thanks to the link he made with John Edmonstone, a black slave who had learned this trade from Charles Waterton.

Plinian Society

While at the University of Edinburgh he met and enrolled in the Plinian Society, which was made up of a group of students who discussed natural history.

At that time Charles had an interesting link with the researcher Robert Edmund Grant, with whom he collaborated in the study of the invertebrates that made life in the estuary of the River Forth.

Likewise, in 1827 Charles presented to the Plinian Society a work he had done on leech eggs found in the shells of some oysters.

It was at this time that Grant spoke to Darwin about the conceptions related to evolution that were raised by the French-born naturalist named Jean-Baptiste Lamarck. At first, he was very pleased with these ideas, as well as excited.

Cambridge: father intervention

Charles was bored in university classes in Edinburgh, especially those related to the natural history course he was taking, which was taught by the French geologist and naturalist Robert Jameson.

His father noticed and sent him to Christ's College, located in Cambridge, where the goal was for Charles to be received as an Anglican pastor.

Charles came to this school in 1828 and again neglected his studies, dedicating himself to extracurricular activities, such as shooting and horse riding.

At that time there was a fashion that had spread everywhere; collect beetles. Charles embraced this fashion with complete enthusiasm and carried out various investigations, the results of which he was able to publish in the manual written by the English-born naturalist and entomologist James Stephens, called Illustrations of British entomology.

During those years, Charles became close friends with various personalities in the field of naturalism, who indicated that his proposal was demonstrating a kind of natural theology.

In 1831 Charles took his final exam and passed, ranking 10th out of 178 people who had come to be examined.

Stay in Cambridge

Charles Darwin had to stay in Cambridge for a longer time, a period that he used to get closer to reading. At this time he came across a group of works that eventually became an essential part of his thinking.

These books were Journey to the Equinoctial Regions of the New Continent, by Alexander von Humboldt; Natural theology, by the theologian and philosopher William Paley; and A preliminary discourse in the study of natural philosophy, by John Herschel.

These publications caused Darwin to want to contribute to the discovery and understanding of natural history, so he immediately decided that he would travel to Tenerife, a Spanish city, together with other colleagues with the intention of studying the poles in detail.

After these events, Charles returned home to find botanist John Stevens Henslow, with whom he had become close friends, offering to be a naturalist for Robert FitzRoy, who was an officer in the British Royal Navy.

The intention is for him to be the captain's companion and to contribute to the objective of the trip, which was to map the coasts of South America.

Charles's father did not agree to this trip, as it would last about two years and, for him, it meant a waste of time for his son. However, he eventually agreed.

HMS Beagle

The ship in which Darwin enlisted was called HMS Beagle and made a journey that took about five years. Most of the tasks that Darwin carried out on this ship was to be on land, doing geological investigations, as well as collecting various specimens.

Charles was always characterized by being extremely meticulous. It is therefore no wonder that, during his first voyage on the Beagle, he had documented every element of the journey very well.

These documentations were sent immediately to Cambridge. Charles also sent many family letters, which later became the memory of this adventure of the scientist.

Darwin's primary intention was to collect as many specimens as he could carry, so that when he returned home they could be reviewed by naturalists more expert than himself.

During that trip Darwin had the opportunity to marvel at spaces such as the Amazon rainforest, and the flora and fauna of regions such as the Galapagos Islands. The finch species on each island in particular helped him develop his theory of natural selection; depending on the island, there was a different species of finch, with a beak adapted to the particular environment.

Return

The Beagle returned on October 2, 1836. Already at that time Darwin's notions had become popular within the field of science thanks to the intervention of Henslow.

As soon as Darwin arrived, one of the first things he did was visit Henlow to seek advice on the specimens he had collected.

Henslow immediately recommended that he find some other naturalists to help him classify the specimens, and told him that he would take care of the botanical elements himself.

Some time passed and Charles still couldn't find experts to help him. At the same time he had become a prominent figure in the field of science, partly also because of the investments that his father constantly made.

On October 29, 1836, Darwin met anatomist Richard Owen, who ran as a candidate to be the one to review several fossilized bones that he had collected. Owen's advantage was that he could use the facilities of the Royal College of Surgeons of England.

Sure enough, Richard Owen started working on these specimens and got great results.

Presentations

In January 1837 Charles Darwin began to divulge all the discoveries he had made. In this context, he was appointed a member of the Geographical Society on February 17, 1837.

After this appointment he moved to London, with the intention of living in an area close to the place where he worked. In 1839 he published his The Voyage of the Beagle, which was a true best-seller and became a very popular work.

It was at this time that he began to worry as a result of a chronic disease that he had been developing.

The origin of species

In 1859 he published The Origin of Species, a work in which he explained his theory of evolution and the process of natural selection.

Death

Charles Darwin's last years were full of severe ailments, which flared up in periods of increased stress. However, he continued to work until the end of his life.

He died in the county in Kent, England, on April 19, 1882. He was offered a state funeral inside Westminster Abbey. There he is buried next to Isaac Newton.

Theory of evolution

In 1859 Darwin's most famous work, The Origin of Species, was published. In this book he defended two theories;

• The common origin, in favor of evolution.
• The theory of natural selection.

To begin with, there is an important difference between evolution and the theories proposed to explain its causes and mechanisms.

In a simple way explained, the theory of evolution is the one that explains that men come from monkeys. Natural selection explains why Homo sapiens survived and Homo neanderthalensis became extinct.

Evidence

Evolution is defined as the genealogical connection existing between all living organisms, based on their descent from a common ancestor. This claim is based on evidence.

First, there is the direct evidence product of the manipulation of species of domestic animals and plants for hundreds of years, with the aim of domesticating certain wild species and developing better crops, showing the existence of small gradual changes over time. This is called artificial selection.

On the other hand, natural selection was observed by Darwin in the finches of the Galapagos Islands, which presented changes in the shape of the beak due to general environmental conditions, the availability of food and the presence of other animal species and bacteria..

Fossil finds

Biological changes that take place in species can be recorded and traced in fossil finds. In this way, paleontologists have found multiple evidences and examples of sequential changes in ancestral species of living beings.

Common features

Finally, the theory of evolution can be evidenced when common characteristics are found between different species, all of them coming from a common ancestor.

In some occasions, these similarities can only be explained as vestiges that remained in the species. In this way, Darwin believed that human beings have a series of physical characteristics that are only possible thanks to the fact that they come from a common ancestor: fish.

Common ancestor

Almost all organisms share a common ancestor. According to Darwin, all organisms shared a single common ancestor that over time evolved in different ways, branching out the species.

In this way, Darwin's theory of evolution supports divergent and convergent theories of evolution.

Idea of ​​"Species do not evolve, but species do"

Darwin believed that evolution is a slow and gradual process that takes place over a long period of time. The biological change from one generation to another within the same species can take millions of years, since it is a slow process of adaptation and stabilization.

Darwin understood that within each population of animals there were specimens with differences that allowed them to better adapt to the environment, reproduce and transmit those traits. In this way the population evolves; the traits of the best adapted individuals are transmitted to subsequent generations.

Natural selection

Natural selection is the phenomenon of evolution that explains why some species become extinct and others survive.

For example, the finch species Geospiza fortis is adapted to the island of Santa Cruz in the Galapagos, with a natural habitat of tropical or subtropical forests. Those adaptations gave it a reproductive advantage, allowing it to survive and not go extinct.

Other species of finches, such as Geospiza fuliginosa, Geospiza conirostris, Geospiza scandens or Geospiza difficilis adapted to other islands and also survived.

Therefore, it is a selection of nature, no supernatural force intervenes that chooses which species survive and which do not.

Darwin observed species from all the areas he visited, including South America, the Galapagos Islands, Africa and the islands of the Pacific Ocean, always keeping a record (Browne, 1996).

He was able to observe many natural phenomena such as earthquakes, erosions, volcanic eruptions, among others.

Adaptation of the species

All species are in a constant process of evolution over time. As the environment changes, the needs of organisms also change and they adjust to their new environments in order to survive.

This phenomenon of changes within a certain margin of time in order to survive is known as adaptation.

According to Darwin's theory, only the species that presented higher changes could survive, while the others were doomed to disappear.

These changes do not necessarily imply an improvement of the species, they simply give them an advantage to be able to survive in a given environment.

Plays

Darwin's most influential works were The Origin of Species (1859), The Voyage of the Beagle (1839), The Origin of Man (1871) and The Expression of Emotions in Man and Animals (1872).

References

1. Browne, J. (1996). Biology Reference. Obtained from Darwin, Charles: biologyreference.com.
2. (December 11, 2015). By Ju's. Obtained from Darwin's Contribution: The Theory of Evolution: byjus.com.
3. College Term Papers. (December 31, 1969). Obtained from Charles Darwin and his Contribution to Biology: collegetermpapers.com.
4. Darwin, C. (1998). The Expression of the Emotions in Man and Animals. New York: Oxford University Press.
5. Stark Effects. (April 27, 2017). Obtained from Charles Darwin and the Theory of Evolution: starkeffects.com.
6. Wood, B. (2005). Human Evolution: A Very Short Introduction. New York: Oxford University Press.
7. Your Dictionary. (April 27, 2017). Retrieved from What Did Charles Darwin Discover ?: biography.yourdictionary.com.