Charles Darwin's Natural Selection Theory

Evolution can be defined as “the process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth” (Oxford Dictionary, 2014). The time between the birth of an individual and the birth of that individual’s offspring defines a generation. Three main scientists, Charles Darwin, Jean-Baptist Lamarck and Alfred Wallace have all contributed towards the idea of evolution, that is, all species are related.

Possibly one of the most well known theories of evolution is Charles Darwin’s natural selection theory. Darwin believed that, through “the production of variation in each generation and differential survival of individuals with different combinations of these variable characters.”

He believed that over time these characteristics would spread through the population as their offspring inherit the beneficial genes. Darwin had 5 main theories in which he believed all occurred together to form one master idea. Modification by descent is one of the well-known theories out of his five. Darwin believed that all organisms are connected and have descended from one another and/or have several common ancestors. From this the organisms then diverse and differ from the original organisms. To help him understand the way of nature, Darwin observed life in the natural world surrounding him. Whilst in nature he observed over-reproduction or super fecundity in which “organisms produce more offspring than is required to replace themselves, so population sizes should increase rapidly.” (Stephen D. Nash, 2009)However, he also observed that, even with super fecundity, the population never rapidly increased and stayed around the same. With further research he discovered that resources including food, water and places to mate or take shelter are limited, meaning not every organism had the chance to survive. Darwin then took to breeding pigeons and investigating variability

He believed these pressures forced individuals to diverge to other locations and to adapt to their local conditions. Wallace’s proposal of his theory of evolution prompted Charles Darwin to publish his own theory. Although his theory is very similar and supportive of Darwin’s theory, Wallace advocated a theory of ‘intelligent evolution’. This theory is “of common descent based upon natural selection strictly bounded by the principle of utility” (Michael A. Flannery, 2014). This theory limited the power of natural selection in comparison to biological change. It suggests that beyond the idea of natural selection, some intelligence must be identified to explain organism’s existence. To gather insightful information, Wallace travelled to the Brazilian Amazon to create his own collection of specimens and extensive notes and intended to publish his findings. After compiling articles about what he had observed, he set out to the Malay Archipelago. Here he continued to collect evidence for his theory and describe the Wallace Line. The Wallace Line was “the boundary between Australia and Asia which is marked by a big change in the animals found.” (Stephen D. Nash, 2009). As well as his theory of evolution, Wallace also discovered new evidence for natural selection in which animals used warning colouration. Alongside this he also developed the