Natural Selection

Evolution is a long-term process and during that long period, the organisms which prove to be the fittest survive in this environment, and later they adapt themselves according to nature. Evolution is the combined change in the qualities of a living being or a population over the following ages. It is sometimes summed up as descent with change. Natural selection is one of the mechanisms that drive evolution.  

To be an active character or quality causing natural selection to take place, the trait has to have the following features:  

• Heritability: A character can only impact evolution through natural selection if it is passed on from parents to offspring.
• Functionality: The characteristics must have a function. Qualities must do something for natural selection to happen.
• Advantage: To be selected for passing on to descendants, the trait must confer a benefit on the organism that has it or make the organism more fit for survival in its environment.
• Origin: The trait must have caused the organisms to develop because it made the organisms that had it more fit for survival. If the organisms changed due to another mechanism, such as genetic mutation, it was not due to natural selection.

Since Nature is the superpower, it selects only the organisms which become different species with the accumulation of variations. The theory of evolution portrays what occurs as the qualities of certain people of a species become predominant, and natural selection describes how this predominance comes about. Darwin studied natural selection in finches. Even when another mechanism such as mutation changes a population, if the mutation does not confer a natural advantage, it may die out due to natural selection.

Examples                                                                                                                                                                                    

Bacteria

Populations of bacteria show very strong natural selection because they can increase quickly. They normally increase until they reach a limitation such as the absence of food, space, or other resources. At that point, those bacteria best suited to their current circumstance will survive, while the rest will die off.

One example of natural selection in bacteria is the improvement of antibiotic resistance. When bacteria cause an infection or disease and the individual is treated with antibiotics, any bacteria that have the antibiotic-resistance trait will survive while all others will die off. The proliferation of antibiotic-resistant bacteria is a major medical problem.

Plants                                                                                                                                                                                                                              

Plants develop to become fit for their environment through natural selection. Some plants develop flower colors to attract pollinators of a particular kind, and develop unique mechanisms to spread their seeds. They have to adjust to more or less sunlight and fight off pests.

Cacti or the desert flora are an example of natural selection in plants. In the desert where they live, there is more sunlight, little water, and occasionally an animal that would love a juicy bite. As a result, cacti have developed compact bodies or small, succulent leaves with thick skins to safeguard against the strong sun and minimize water loss. They can also store water and have sharp spikes to discourage animals. The cacti with these traits were the fittest, and they are still developing.

Another example is the adjustment in the field mustard plant caused by the drought in Southern California. To survive a drought, plants must grow, flower, and distribute their seeds quickly. The Southern California field mustard plants that flowered early became dominant, while those flowering later died out.

Also Read:

• Lamarckism
• Speciation
• Microevolution

Charles Darwin was a British naturalist, biologist, and geologist during the nineteenth century. He is generally known for his 1859 book “On the Origin of Species”.

Charles Darwin, in full Charles Robert Darwin, was an English naturalist whose scientific theory of evolution by natural selection became the foundation of modern evolutionary studies. However, his nonreligious biology appealed to the rising class of professional scientists, and by the time of his death evolutionary imagery had spread through all science, literature, and politics. Darwin, himself a rationalist, agreed on a definitive British honor of entombment in Westminster Abbey, London.

Darwin formulated his theory in private in 1837–39, after returning from a voyage around the world aboard HMS Beagle, yet it was only after twenty years after the fact that he at long last gave it full open articulation in On the Origin of Species (1859), a book that has greatly impacted today’s Western culture and thought.