Survival of the fittest

Introduction
Hi, I am Nikhil of grade 9. I love to read Agatha Christie mysteries. I enjoy sciences too.

“Survival of the fittest” is a phrase that was first used by the biologist and philosopher Herbert Spencer, and is said to have originated from the evolutionary theory that Charles Darwin has proposed. It was used in reference to the natural selection, a mechanism through which beings capable of reproducing choose their mates, unlike artificial selection- which involves the process of selective breeding.

It is also said that Herbert Spencer first used the phrase after reading Charles Darwin’s ‘Origin of the species’, and used it in his “Principles of Biology” in the year 1864. This phrase basically means that only the fittest organisms(that is, which have adapted to their surroundings) are the only organisms that can survive many generations. Charles Darwin accepted Alfred Russel Wallace’s proposal of using Herbert Spencer’s new phrase, and first used it in “The Variation of Animals and Plants under Domestication” in 1868, and later in the fifth edition of  “On the Origin Of Species”, one of the most revolutionary works of scientific literature.

A common example of a creature that might have evolved through this mechanism is the Giraffe- Giraffa camelopardalis, which is said to have evolved from a species that had short necks. Among these species there might have existed a few creatures that were unusual from the rest- with longer necks than usual, and thus having the advantage of reaching up to taller parts of the plants that they might have fed upon. As the vegetation at lower levels turned scarce, the rest of the creatures with short necks would have had to starve to death, leaving only the tall-necked organisms. As several generations passed, only the gifted varieties of this species managed to survive, resulting in a whole new species. Several generations have had to pass in order to observe these changes as with every generation, a small part of the creature’s genome is modified, and for the rise of a whole new species, this process of genome modification has to occur numerous times.

Another example that I would like to state, which I have observed while watching a documentary on the National Geographic Channel, is that of the ‘Guanacos’, or desert cows. The Guanacos are native of South America- especially the Atacama desert, namely Chile and Argentina. Young Guanacos are known as ‘Chulengos’. Guanacos quench their thirst to the fullest when they arrive at a water body, and while in the desert their only source of water are the flowers of the cactus plant. Due to the circumstances under which they live, Guanacos have adapted a unique ability of balancing themselves on two of their limbs as they try to reach out for the flowers, while making sure they do not go too close to the cactus plant and get struck by the spines- or the cactus’ modified leaves.

According to my interpretation, Guanacos might have originated from a species of desert cows that, at one point weren’t able to reach out to the top most part of the cactus plant- where the flower is usually located. But through several generations and after a long way of the genome

modification, a different kind of the creature with the ability to balance itself on two legs to reach up to the flowers might have emerged. The previous creatures that were unable to do so might have had a very short lifespan, and the new variety of this species would have a considerably higher lifespan, due to their special adaptation. This ability might have been passed down several generations until all of the previous kind went extinct, and a whole new species emerged; named as Lama guanicoe.