Origins Of The Species By Means Of Natural Selection

On the Origin of the Species by Means of Natural Selection or the Preservation of Favoured Race in the Struggle for Life.

Pigeons and Guatemalan Dogos

One of the differences is that Guatemalan Dogos are mixed with three races: English Bull Terrier, Dalmatian and Boxer. These dogs are still reproducing and also spreading. Those who are reproducing, they already come from the same family but sometimes there are changes, like with the pigeons. In the case of the Guatemalan Dogos, they departed the races that they were most interested in, and joined them to make or to produce one. That’s why many times its very difficult the cross of the animals, because of all the modifications that people make them, and the consequence in the animals is that their reproductive system changes and that’s why sometimes they are infertile. In the book, is explained that pigeons are derived from a version and are almost impossible to be derived from 4 or 5 versions.

Varieties and Species

Variety is not just seeing differences because maybe the phenomenon did exist before or it keeps existing and there are always doubts. It’s very different to say species and varieties. It hasn’t been marked the difference between species and sub-species because they are minor varieties or individual differences. Also, is not supposed to be that all varieties get into the species category. The common species and the extended ones are the ones with more variety. A Guatemalan example of little variety is the “Monja Blanca”, “La Ceiba” or the “Quetzal” because they are in danger but they are classified by species.

Natural selection

Chapter 4 is one of the most important chapters because it talks about natural selection. Darwin explains how the organisms survive throughout natural selection, he says that variations in these organisms gives them an advantage over the others and therefore more chances of reproduction. He talks about the sexual selection that is when the organism with a potential variation allows it to attract females and so therefore he would have more chances of reproducing. After reproduction, the offspring of these organisms would most likely have these characteristics that make him advantaged passed on by heredity. Darwin explains this with many examples of animals but the best example he gives is the one of the bird that says that male birds use to attract females their singing to their mates, showing off various brightly colored feathers to attract attention. If any variation in these characteristics were to give male birds a better chance of mating, that variation would likely spread to the birds’ offspring and, as a result, would become predominant in the population in subsequent generations.

Law of variation

Chapter 5 is a continuation of chapter 4. In this chapter Darwin explains how variations are given. He says that variations do not occur by chance, but they are somehow related to the conditions of life that exist in the species geographical environments. Though actual environmental factors such as the availability of food and the climate of a region do not directly create variations in species, variations will develop in animals and plants that will allow them to better survive in an environment. Darwin gives ideas of how variations produce and one of them is how the organs function. He says that the use or lack of use of the organs produce variations in the organisms. Like, for example he says that there are birds that have wings but they cannot fly or there are rodents that have eyes but are visually impaired. He says

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