Tareas

Evolution of species.

Charles Darwin, the British naturalist who lived between the years 1809 and 1882. His work "On the Origin of Species by Natural Selection or the Preservation of Favored Racesin the Struggle for existence" published on November 24, 1859, has revolutionized the concepts of time and opened a field of controversial discussion.

His thought influenced by the text ofMalthus' First Essay on Population "(1798) and the Scottish Charles Lyell Principles of Geology" (1830) emerged after observing the flora and fauna of the Galapagos archipelago, a trip made on the ship"Beagle," tour that lasted five years, between December 27, 1831 and October 2, 1836. Darwin observed this trip birds called finches, which found seven different species, but with a common trunk, whichwere separated in adapting to different environments.

Charles Lyell, enrolled in the current, had argued that it should not be resorting to evolution in terms of catastrophic events such as floods,but the same causes that have acted over long time periods.

Darwin, in his book, tells us that in every generation gaps are inherited without apparent explanation, that make organisms evolve bynatural selection. Species with greater adaptation to the environment are those that are increasing, while the rest is moving towards its demise, which would mean a rate of survival.

It is proved byfossil remains, that many ancient species have become extinct, and others were taking on new forms.

For about four billion years ago came the first signs of life through rudimentary cells. Is aboutseven hundred million years of multicellular organisms appeared. Invertebrates were nearly six hundred million years and the fish, the first vertebrates, were 450 million years ago. Flora originateda hundred and fifty million years.

Thus, the fish were adapted to aquatic life, terrestrial animals to life in that environment, as did the flying. But the atmosphere changed, and these living...