Darwins Theory of Evolution by Natural Selection Essay Example for Free

Darwins Theory of Evolution by Natural option EssayThe mechanisms for individuals in a population to survive heterogeneous habitats have been a strong pass inside the scientific community. The native European Littorina obtusata are a great model existence to study Darwins Theory of Evolution by Natural Selection. This is because of their vast phe nonypical characteristics, particularly their evolving showcase ponderousness throughout history due to vulturous pressures of the red-hot arrival of Carcinus maenas.Here we test whether L obtusata three most critical tenants of Darwins theory of evolution by natural selection divergence within a population, heritability, and selection. By discover the squeeze thickness of East Coast of N. America L. obtusata where predatory C. maenas are common versus the West Coast of N. America where C. maenas are not found, it will further erect bear witness whether these shell thickness differences are due to natural selection predatory or phenotypic plasticity occurring. This was tested by placing banded crabs in both East and West populations of L. btusata and observing how their shell thickness decreased, further proving that L. obtusata cannot sense or smell the presence of C. maenas. These findings provide further evidence for Seeleys research that the accelerating geomorphologic changes of L. obtusata shell thickness was in response to strong selection by C. maenas and not because speciation occurring.Some believe that Darwins theory of evolution by natural selection is direct the morphological breaks found in fossil records within a population. Darwins book On the offset of Species listed four basic postulates to natural selection there essential be variations among individuals in a population, variations must be heritable, survival and reproduction must be variable and non-random (Darwin, 1859). As a result, every coevals there will be slight changes in the population.One scientist in particular, Robin Seeley, tried rationality Darwins theory of Natural Selection by studying the thickness of shells of flat periwinkles, Littorina obtusata, of Appledore Island and the new arrival of predatory green crabs, Carcinus maenas. Seeley noted acceleration in natural selection that normally is not observed within the L. obtusata population in response to strong selection by C. maenas. This is because shell thickness affects the survivability and reproduction of L. obtusata when C. maenas claws break them to meal (Trussel, 1996).The observation confirmed that when C. maenas were introduced in the East Coast of N. America, L. obtusata range of shell thickness increased compared to the West Coast of N. America L. obtusata populations where predatory C. maenas were not found (Seeley, 1986). These vast morphological differences in their shell thicknesses was thought to occur because of the C. maenas selection for the thinner-shelled L. obtusata. Seeleys research further showed that speciation w as not occurring within the intertidal snails as many previous scientists claimed.