Darwin’s Theory Of Iq The famous naturalist Charles Darwin presented the theory of natural selection. He went on many journeys on sea and on land, following his interests of the nature and the change that happens in the nature, i.e., the change in species. Following his exposure to many different kinds of birds, insects and animals, he explained Natural Selection as presentation of favorable variations and the rejecting of injurious variations.(131). Darwin used analogies and metaphors to demonstrate that different alterations occurred in the same specie, which helped them to adapt to their surroundings. Darwin’s theory of natural selection was based on the following facts: 1) organisms increase more rapidly than their food supply. He quotes that there are finite number of resources, therefore making him a Neo-Malthusian.
2) Due to natural selection, there is never overpopulation in animals, because some of them will be eliminated at a young age due to unfavorable environment. 3) Due to limited resources, all life forms struggle to survive, but only the superior ones survive. 4) Those individuals that possess some characteristic that are useful in adapting the environment increase their chances of survival, and produce more offspring with the favorable characteristic and pass them to the next generations. Due to the variations in characteristic and physical changes, the new individual will eventually become so distinct that they will constitute different specie. Sexual competition is an important aspect that depends, not on a struggle for existence, but on a struggle between the males for the possession of the females (136).
It does not affect the death of the recessive individual, but it results in fewer or no offspring for that male. Victory depends on special traits. For example: a hornless stag or spur less cock would not have a good chance of leaving offspring. Darwin provides graphic examples of species warfare by saying male salmons have been seen fighting all day long; male stag-beetles often bear wounds from the huge mandibles of other males (136). These weapons and shields of animals are as important for victory as swords or spears, are for humans.
Sexual selection also involves attracting females by show or aesthetics; some birds as Guiana display their gorgeous plumage and perform strange antics in front of the females, who choose the most attractive partner for them. Darwin believed that when the males and females of any animal have the same general habits of life, but differ in structure, color, or ornament, such differences have been mainly caused by sexual selection (137). Darwin illustrates the action of natural selection in various ways. A weak wolf can still survive, if the number of dear increase in its territory. Cats have a tendency to catch rats rather than mice, because that characteristic is inherited is inherited. Even if a slight difference in the habit of an individual can better suit the individual for survival.
Darwin says, if any slight change innate change of habit or of structure benefited an individual wolf, it would have the best chance of surviving and of leaving offspring (139). Darwin compares natural selection to animal husbandry by saying, a breeder selects for some definite object, and free intercrossing will wholly stop his work. (148). He explains intercrossing that it affects those animals, which do not breed at a quick rate. Darwin gives a real world example of a breeder, who selects for distinct objects in specie, resulting liberated intercrossing to stop.
The new animals do not cross with the inferior ones. There would be an improvement and alteration in the animal, if many men have the same standard of exactness. As Darwin says Intercrossing plays an important part in nature in keeping the individuals of the same species, or the same variety, true and uniform in character. (149) Darwin used a daily life example of a nurseryman, who prefers getting seed from large body of the same variety that results in decreasing the intercrossing with other varieties. Isolation is a method that acts efficiently in checking the immigration of better-adapted organisms, after an alteration in the climate. There are more chances of modification and of spreading widely on a large area then on a small area. Darwin presents his theory of Extinction as: each favored and selected form increases in number, the less favored form decreases and eventually becomes rare.
As he explains rarity is the precursor of extinction.(153) Because of the small number of the original form, there is a smaller chance of adapting, which ultimately leads to extinction. Darwin gives examples of new breeds of cattle, sheep and other animals that replace the older and substandard kind. To be precise, he presents example of ancient black cattle, which was displaced by the longhorns. Darwin gives importance to divergence of character within specie. He explains that even a slight difference in the characteristic of specie could make a gigantic difference.
He presents with an example of some men in early period, which preferred fleeter horse, but the others liked bulky horses. The difference becomes greater and greater forming two sub-breeds. The favorable variation slowly becomes so different that it would be a lot different from the original. Charles Darwin has explained his theory of natural selection in a very straightforward way. He went by stating theories and giving general life examples, to help understand them better. Darwin’s theory is written step-by-step giving a very good explanation of evolution.