The Observations of Charles Darwin during the Voyage of the Beagle - Essay Example

?The Observations of Charles Darwin during the Voyage of the Beagle and the Scientific Conclusions these allowed him to make. Introduction Charles Darwin is often considered to be the father of evolutionary theory, determining that all species present on the earth today are descended from a common ancestor. He proposed the natural selection was the process that allowed for evolution to occur and produce the wide range of different types of life that can be observed. The concepts he presented were radical at the time, although natural selection has since become the generally accepted mechanism by which evolution occurs. 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 sunlight. 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 individuals 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 struggle for existence that led Darwin to surmise that more beneficial traits would be preferentially present in the next generation, as individuals with those traits would be more likely to survive and reproduce. The final, and perhaps most important observation that Darwin made was that the survival of individuals differed depending on what traits they had. Some traits appeared more favored, and increased the survivability of the individual, such as an increased ability to absorb energy from food or higher running speed than others of the species. This observation was the final piece of information needed for Darwin’s theory of natural selection and led Darwin to conclude that some traits were beneficial to the survival of individuals and others detrimental. Consequently, those with beneficial traits would be more likely to survive and reproduce, hence increasing the proportion of those traits in the population. Struggle for Existence and Differential Survival Darwin’s theory of evolution was a radical idea that changed the way that people thought about life, painting species as dynamic entities, rather than static in their traits and aspects as had previously been assumed. Darwin theorized that natural selection was the driver of evolution based on four observations that he made during the five year voyage of the Beagle. The first observation was that there was significant variation within species; the second was that some of variation was heritable, third was that there were more individuals produced in each generation than survived, and the final observation was that different traits affected the survival of individuals. The resulting theory predicted that traits are selected for based on their benefit to the species as a whole, with traits that increase the survivability of individuals being more likely to make it into the gene pool for the next generation. Over time, the proportion of these traits in the population increases, while at the same time other beneficial traits are being selected for. The consequence of this selection is that over time species change, with a trait not being represented initially, to being in most or every individual in the population. Darwin theorized that evolution and natural selection explained the large amount of variation present in the natural world. Works Cited  Darwin, Charles. The Origin of Species. London: John Murray, 1859.  Read More