Thursday 20 August 2020

CHARLES DARWIN, EVOLUTION & NATURAL SELECTION

Charles Darwin
On a day like today in 1858, Charles Darwin first published his theory of evolution through natural selection in The Journal of the Proceedings of the Linnean Society of London, alongside Alfred Russel Wallace's same theory and The Grandma wants to talk about it.

Because of it is an interesting theme that needs lots of information, The Grandma has received the amazing visit of one of her closest friends, Joseph de Ca'th Lon, who is an expert in Archaeology, Anthropology and Astronomy and a great follower of Charles Darwin's life and works.

Charles Robert Darwin (12 February 1809-19 April 1882) was an English naturalist, geologist and biologist, best known for his contributions to the science of evolution.

His proposition that all species of life have descended over time from common ancestors is now widely accepted, and considered a foundational concept in science.

In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process that he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.

Darwin has been described as one of the most influential figures in human history, and he was honoured by burial in Westminster Abbey.

Darwin published his theory of evolution with compelling evidence in his 1859 book On the Origin of Species. By the 1870s, the scientific community and a majority of the educated public had accepted evolution as a fact. However, many favoured competing explanations which gave only a minor role to natural selection, and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution.

More information: Live Science

Darwin's scientific discovery is the unifying theory of the life sciences, explaining the diversity of life.

Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. Studies at the University of Cambridge (Christ's College) encouraged his passion for natural science.

His five-year voyage on HMS Beagle established him as an eminent geologist whose observations and theories supported Charles Lyell's conception of gradual geological change, and publication of his journal of the voyage made him famous as a popular author.

Charles Darwin
Puzzled by the geographical distribution of wildlife and fossils he collected on the voyage, Darwin began detailed investigations, and in 1838 conceived his theory of natural selection.

Although he discussed his ideas with several naturalists, he needed time for extensive research and his geological work had priority.

He was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay that described the same idea, prompting immediate joint publication of both of their theories.

Darwin's work established evolutionary descent with modification as the dominant scientific explanation of diversification in nature. In 1871 he examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals (1872).

His research on plants was published in a series of books, and in his final book, The Formation of Vegetable Mould, through the Actions of Worms (1881), he examined earthworms and their effect on soil.

The publication of Darwin's theory brought into the open Charles Darwin's theory of evolution through natural selection, the culmination of more than twenty years of work.

More information: Tree Hugger

Thoughts on the possibility of transmutation of species which he recorded in 1836 towards the end of his five-year voyage on the Beagle were followed on his return by findings and work which led him to conceive of his theory in September 1838.

He gave priority to his career as a geologist whose observations and theories supported Charles Lyell's uniformitarian ideas, and to publication of the findings from the voyage as well as his journal of the voyage, but he discussed his evolutionary ideas with several naturalists and carried out extensive research on his hobby of evolutionary work.

He was writing up his theory in 1858 when he received an essay from Alfred Russel Wallace who was in Borneo, describing Wallace's own theory of natural selection, prompting immediate joint publication of extracts from Darwin's 1844 essay together with Wallace's paper as On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection in a presentation to the Linnaean Society on 1 July 1858.

Charles Darwin
This attracted little notice, but spurred Darwin to write an abstract of his work which was published in 1859 as his book On the Origin of Species.

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype.

It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.

Charles Darwin popularised the term natural selection, contrasting it with artificial selection, which in his view is intentional, whereas natural selection is not. Variation exists within all populations of organisms. This occurs partly because random mutations arise in the genome of an individual organism, and their offspring can inherit such mutations. Throughout the lives of the individuals, their genomes interact with their environments to cause variations in traits.

The environment of a genome includes the molecular biology in the cell, other cells, other individuals, populations, species, as well as the abiotic environment. Because individuals with certain variants of the trait tend to survive and reproduce more than individuals with other less successful variants, the population evolves. Other factors affecting reproductive success include sexual selection, now often included in natural selection, and fecundity selection.

Natural selection acts on the phenotype, the characteristics of the organism which actually interact with the environment, but the genetic (heritable) basis of any phenotype that gives that phenotype a reproductive advantage may become more common in a population.


Over time, this process can result in populations that specialise for particular ecological niches (microevolution) and may eventually result in speciation (the emergence of new species, macroevolution). In other words, natural selection is a key process in the evolution of a population.

Natural selection is a cornerstone of modern biology. The concept, published by Charles Darwin and Alfred Russel Wallace in a joint presentation of papers in 1858, was elaborated in Darwin's influential 1859 book On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.

He described natural selection as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favoured for reproduction.

The concept of natural selection originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, science had yet to develop modern theories of genetics.

The union of traditional Darwinian evolution with subsequent discoveries in classical genetics formed the modern synthesis of the mid-20th century. The addition of molecular genetics has led to evolutionary developmental biology, which explains evolution at the molecular level. While genotypes can slowly change by random genetic drift, natural selection remains the primary explanation for adaptive evolution.



A scientific man ought to have no wishes,
no affections, a mere heart of stone.

Charles Darwin

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