Darwinism - Theory of Evolution

  • The term "Darwinism" refers to the theory of evolution that originated with the work of Englishman Charles Robert Darwin, especially as expressed in his book “On the Origin of Species”, published in 1859. 

  • Charles Darwin theory argues that the true cause of change is the natural selection of certain species over others: more organisms are born than can live and reproduce, others have features that help them in the ensuing ‘struggle for survival,' and these are winnowed or chosen to be the breeding stock for all subsequent generations.

  • Darwinism is a broad term that refers to all biological hypotheses that explain how organisms evolve by mutation and selection. 

  • Despite the fact that there are many significant discrepancies between Darwin's view of evolution and later theories, the word "Darwinism" is often used to refer to all theories of evolution after Charles Darwin that include natural selection and spontaneous, or nondirected, change as two of the key explanatory elements. 

  • The word Darwinism is often used in a broader context to describe the concept of using Darwin theory to understand cultural traits, cultural behaviour, and human growth.

  • In April 1860, English biologist Thomas Henry Huxley coined the word Darwinism. It was first used to describe evolutionary ideas in general, including those proposed by English philosopher Herbert Spencer.

  • Though the word is most often used to refer to biological evolution, creationists have appropriated it to refer to the origin of life or celestial evolution, all of which are not biological evolution. It is thus described as the belief in and acceptance of Darwin's and his predecessors work over other ideas such as divine design and extraterrestrial origins.

  • Many Darwinists at the time, including Huxley, had concerns about the importance of the theory of natural selection, and Darwin himself supported what became known as Lamarckism. 

  • In the late 1800s, German evolutionary biologist August Weismann's strict Neo-Darwinism found few supporters. 

  • Darwinism was resurrected in a revised form in the early twentieth century with the advent of the modern synthesis, which combined natural selection with population genetics and Mendelian genetics.

  • Although the word Darwinism has remained in common usage among the general public when referring to modern evolutionary theory, science writers such as Olivia Judson, Eugenie Scott, and Carl Safina have argued that it is an inappropriate term. They say that since Darwin was unfamiliar with the work of Moravian scientist and Augustinian friar Gregor Mendel, he had only a hazy and inaccurate understanding of heredity. He had no idea about later scientific advances and, like Mendel, had no idea about genetic drift.


Charles Darwin Theory of Evolution

  • Biological evolution is based on the premise that populations and species of organisms evolve over time. When we think about evolution now, we are most likely to associate it with one individual in particular: British naturalist Charles Darwin.

  • Darwin's theory of evolution and contentious book “On the Origin of Species” was published in the 1850s. He suggested that organisms evolve or, as he put it, "descent with modification," and that all living things can be traced back to a common ancestor in it.

  • Natural selection, in which heritable characteristics that help species survive and reproduce become more widespread in a population over time, was proposed by Darwin as a mechanism for evolution.

  • On the Origin of Species, Darwin's seminal work lays out his views on evolution and natural selection. These theories were primarily based on Darwin's personal observations during his journeys around the world.

  • From 1831 to 1836, he was a member of the HMS Beagle survey expedition, which made stops in South America, Australia, and the southern tip of Africa. Darwin had the opportunity to observe and catalogue the local plants and animals at each of the expedition's stops.

  • Darwin started to see intriguing trends in the distribution and characteristics of species as he travelled. Darwin discovered that neighbouring Galapagos islands had finch species that were related but not identical.

  • He also stated that each finch species was well-suited to its climate and function. Wide, tough beaks were found in species that ate large seeds, while small, sharp beaks were found in species that ate insects.

  • Finally, he noted that the finches and other animals present on the Galapagos Islands were similar to those found on Ecuador's mainland but distinct from those found elsewhere.

  • This pattern, according to Darwin's theory, would make sense if the Galapagos Islands had been inhabited by birds from the neighbouring mainland long ago. Finches on each island may have adapted to local conditions over several generations and over long periods of time. On each island, this phase may have resulted in the emergence of one or more distinct organisms.

  • Darwin suggested that organisms would evolve over time, that new species emerge from existing species, and that all species have a common ancestor. In this model, each species has its own collection of genetic variations from the common ancestor that have accumulated over long periods of time.

  • Branching occurrences, in which new species break off from a common ancestor, resulting in a multi-level tree that connects all living organisms.

  • Darwin coined the phrase "descent with modification" to describe the mechanism by which groups of organisms modify their heritable traits over generations. It's now known as evolution.


Theory of Natural Selection

Darwin did not simply state that species evolved. Darwin instead suggested natural selection as a method for evolution. This process was simple and logical, and it clarified how societies could evolve and descend with modification over time, becoming better suited to their environments.

Darwin's Natural Selection Theory was Founded on Several Core Observations:

  • Traits are mostly inherited. Many traits are inherited or passed on from parent to offspring in living species. Even though Darwin was unaware that traits were inherited by genes, he understood this to be the case.

  • Organisms have the ability to produce more offspring than their surroundings can sustain. As a result, each generation competes for limited resources.

  • Heritable characteristics in offspring differ. Each generation's offspring may vary slightly in terms of traits (colour, height, form, and so on), and several of these characteristics will be heritable.

Darwin Deduced the Following from His Basic Observations on the Theory of Natural Selection: 

  • In a population, certain individuals may have inherited characteristics that help them survive and reproduce. Since the traits make them more successful at living and reproducing, individuals with the helpful traits may leave more offspring in the next generation than their peers.

  • Since beneficial traits are heritable and species with these traits produce more offspring, they will become more prominent in the next generation.

  • Individuals with traits that are beneficial in that environment have significantly higher reproductive success than their peers, so the population will become adapted to its environment over generations.

Criteria for the Theory of Natural Selection to Work:

  • Natural selection does not choose traits that are inherently superior. Instead, it prefers beneficial traits, such as those that help an organism live and replicate more successfully than its peers in a given environment. Characteristics that are beneficial in one setting can be undesirable in another.

  • Natural selection requires some starting material, and heritable variation is that material. There must already be variance in a trait for natural selection to work on it. Furthermore, the variations must be heritable, as determined by the genes of the species.

  • Random mutations, such as variations in DNA sequence, are the original source of new gene variants that create new heritable characteristics, such as fur colours. Random mutations that are passed onto offspring usually happen in an organism's germline, or sperm and egg cell lineage. To increase diversity, sexual reproduction mixes and matches gene variants.

Scientists believe that this form of mechanism has occurred several times in the history of life on Earth, based on different lines of evidence. Natural selection and other processes are responsible for the remarkable diversity of today's life forms, and natural selection may clarify how species and their environments work together.


Social Darwinism

  • Various ideas that originated in Western Europe and North America in the 1870s that applied biological principles of natural selection and survival of the fittest to sociology, economics, and politics are known as social Darwinism. 

  • According to Social Darwinism, the wealthy and powerful gain wealth and power, while the poor lose wealth and power.

  • Joseph Fisher's article The History of Landholding in Ireland, published in the Transactions of the Royal Historical Society in 1877, was the first to use the term "social Darwinism."

  • The extension of Darwin's biological theories to the social and cultural realm is known as social Darwinism.

  • In fact, rather than arising from biological theories, sociocultural evolutionary theories evolved alongside them.

  • Social Darwinism is a catch-all concept that has been applied indiscriminately to a wide range of late-nineteenth-century social theories, many of which bear no resemblance to Darwin's original theories.

  • There is no simple collection of ideas that can be described as Social Darwinism because science cannot easily be isolated from cultural factors.

  • There's reason to doubt whether the label referred to a real social movement or was merely a construct invented by historians and projected into the past.

  • The term did not become common until the turn of the century, and it has a negative connotation. Social Darwinism has been associated with racism, Nazism, and the eugenics movement in the twentieth century, which may explain why more recent involvement with evolutionism has been limited to human geography.


Conclusion

Charles Darwin proposed the Darwinism theory of the evolutionary system as an explanation for organic transformation. It refers to Darwin's particular viewpoint that evolution is primarily influenced by natural selection. Neo-Darwinism has superseded the earlier definition, purging it of Darwin's residual connection to the Lamarckian principle of acquired characters, based on newer experience. Modern scientists can differentiate between non-inheritable bodily variation and variation of a truly inheritable nature more satisfactorily than Darwin because they have a better understanding of the processes of inheritance.

FAQs (Frequently Asked Questions)

1. What is Darwinism?

Ans: Following Darwin's publication of On the Origin of Species in 1859, Darwinism became a generic term for all biological hypotheses regarding the evolutionary diversification of species by mutation and selection. The word Darwinism is often used in a broader context to describe the concept of using Darwin's mechanisms to understand cultural traits, cultural behaviour, and human growth.

2. What is the Theory of Evolution?

Ans: The term "theory of evolution by natural selection," coined by Charles Darwin and Alfred Russel Wallace in the nineteenth century, is simplified to "theory of evolution." "Evolution is a change in the heritable characteristics of biological populations over successive generations," according to the theory of evolution. These traits are the expressions of genes that are passed on from one generation to the next during reproduction. As a result of mutation, genetic recombination, and other causes of genetic variation, different characteristics appear to occur within any given population.

3. What is Social Darwinism?

Ans: Individuals, classes, and peoples, according to social Darwinism, are subject to the same Darwinian laws of natural selection as plants and animals. In the late 19th and early 20th centuries, social Darwinism was promoted by Herbert Spencer and others to justify political conservatism, imperialism, and colonialism, as well as to discourage intervention and change.