Tag: theories of evolution

Darwin developed a theory of biological evolution in which by observing a different type of finches in the Galapagos islands. He observed 15 species of passerine birds and they varied island to island. This observation helped him to give a theory on natural selection and that lead to evolution to Finch species. 

Charles Darwin was influenced by Thomas Robert Malthus, a late-eighteenth century economist. Malthus wrote "Essay on the Principle of Population" (1798), which Darwin read and was inspired by. The central theme of Malthus' work was that population growth would always overpower food supply growth, creating perpetual states of hunger, disease and struggle. The natural, ever-present struggle for survival caught the attention of Darwin and he extended Malthus' principle to the evolutionary scheme. 

Charles Darwin went on a trip aboard HMS beagle as a naturalist. The purpose of this voyage was to map the uncharted areas of south Americal coastline. Darwin observed unique species of plants and animals in South America like finches and iguana. He noticed that the temperate South American animals closely resembled the tropical South Americal animals as compared to temperate European animals. Some of the characteristics of fossils observed by him in South America were similar with the contemporary South American characters of organisms.

The Descent of Man and Selection in Relation to Sex is a book by English naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection. The book discusses many related issues, including evolutionary psychology, evolutionary ethics, differences between human races, differences between sexes, the dominant role of women in mate choice, and the relevance of the evolutionary theory to society. Thus, option A is correct.

Darwin proposed the theory of natural selection to explain the process of evolution. According to Darwin’s theory of natural selection, all organisms have the potential to reproduce limitlessly irrespective of the fact that each species maintain a constant density over time. However, the struggle for existence, i.e. the competition among individuals for available resources to survive and reproduce, put a check on species density and maintains it at a constant level. Survival of fittest is unequal ability of individuals to survive and reproduce based on suitability of their inherited characters to prevailing environmental conditions. It imparts the reproductive advantage to certain organisms which account for major part of the gene pool of the species. Thus, natural selection favors the individual with survival and/or reproductive advantage over others under existing environmental condition. Thus, the correct answer is option D.

Charles Darwin visited Galapagos islands, the chain of 22 islands located in the Pacific Ocean on the west coast of South America, during his voyage on HMS Beagle. Since Galapagos islands were once connected with South America mainland, many birds of the island resembled those of mainland. This observation laid the foundation of his concept of adaptive radiation and his theory of evolution. Thus, the correct answer is option B.