Evolution

Evolution is described by Darwin as the diversity between biological populations that exists because of different characteristics that are passed down through generations. All life on Earth originated from one common ancestor about 4 billion years ago (Wikipedia, 2013). A lot of controversy surrounded Charles Darwin when he first published his theories on evolution over 150 years ago. Nowadays, there is widespread support for his theories and much evidence to support them. Darwin’s theories existed long before he was born; however, he was the one that carried out necessary research to make it a valid scientific theory so it could be accepted into the scientific world (Ker, 2012).

When Charles Darwin first landed on the Galapagos Islands in September 1835, he established the theory of natural selection. This theory proved to be the pinnacle of Darwin’s research into evolution. One of the major points of natural selection is that it assumes that the primary objectives of all species are to reproduce and pass on the genetic information to the next generation. The lack of resources produces competition between individuals, which leads to selection for the individual best suited to the environment. From these observations in the Finches of the Galapagos Islands, Darwin determined that the most desirable characteristics of a species were favored and were passed onto the next generation. Different characteristics will be more favorable in a changing environment, which means that species evolve to suit their environment for the best chance of survival. As a result of this, more favorable characteristics become more frequent in the population leading to a change in the gene pool of the species (Biology Online, 2013). This theory is named by Darwin as decent with modification meaning that different species inherit traits from common ancestors and these traits can be changed over time so that the descendants are completely different to their ancestors (Ask.com, 2013).

While on the Galapagos Islands, Darwin’s theories originated from his studies of the finches, a bird native to the Galapagos Islands preserved without outside interference. Darwin noticed that these finches showed great variations in characteristics. The main characteristic that Darwin looked at was their beak size and shape from finches on different islands. Darwin suggested the difference in beaks enable the finches to be better suited to take advantage of their niche. One species of finch evolved with thin sharp beaks that are used to eat insects and grubs while another species has large claw shaped beaks whose diet was mainly nuts, buds and fruits. From these observations, Darwin concluded that on each island, the beak suited to that niche prevailed and was naturally selected for over other beaks, resulting in the variation in different finches in the Galapagos Islands. Natural selection then occurs as these individuals will grow and reproduce more successfully,