Darwin had during the Voyage of the Beagle that led to each of the Essay

Darwin had during the Voyage of the Beagle that led to each of the component parts of his Theory of Evolution (Descent with Modi - Essay Example Darwin’s inspiration came from a five-year voyage of a ship known as the Beagle, during which he was the ship’s geologist. The voyage gave him many changes to observe the distribution of both wildlife and fossils, and he eventually collected these ideas into an extensive theory of natural selection, which he published in his book, The Origin of Species . Prior to Darwin’s theory, the predominant belief was that animals and plants were as God had created them, there were no differences. If change had been observed across time then this was explained that, for example, a generic bird had given birth to a woodpecker, with no apparent reason other than the will of God. Darwin considered that this did not match what he saw during the voyage, and what he considered and theorized over the time following. Darwin’s theory of evolution consisted of four parts, each of which was supported by observations that Darwin had made during the voyage of the Beagle. Variation within Species One of the key observations that Darwin made during the voyage of the Beagle, was the wide ranging variation within members of the same species. There were almost limitless types of variation, such as beak type and size in birds, amount of hair, eye color, and number of offspring produced, ability to conceal and success at mating. Species that had wide ranges, occupied a number of variable habitat types and were common had the most variation. Likewise, species that were in larger genera had more variation than those in smaller genera. Inheritance of Traits Darwin observed that many of the traits that varied among individuals of the same species were passed from a parent to its offspring. For example, a bird with a distinct beak shape passes this on to some or all of their offspring. Not all variation was heritable; some variation was not passed on from parent to offspring, but was a result of environmental changes, such as hair color as a consequence of exposure to s unlight. This was important for Darwin’s theory of evolution, as for traits to change over time; there was a need for the ability for them to be passed from one generation to the next. High Population Growth When individuals produced offspring, they generally produced many more than would survive. Darwin observed this in a wide range of species, including both animals, bird and plant species. The effect was particularly strong in plants which often produce hundreds of offspring, but only a handful survive to maturity due to competition, predation and other externals factors. This led Darwin to predict that the presence of different traits in the individuals in the population would increase the survival of some, and decrease it in others. Struggle for Existence and Differential Survival Darwin observed that there was a constant struggle for individuals and species to survive. Species occupied areas that were not ideal to them in order to avoid competition or predation, and ind ividuals were constantly exposed to a fight to survive. This struggle was not limited to different species, but was equally strong between members of the same species. What species were struggling against, varied widely among species, for example a plant in the desert struggles to acquire enough water to survive, while plants in the tropics struggle for their offspring to acquire enough sunlight and resources due to intense inter- and intra-specific competition. It was this