Anthropology. DNA Essay Example | Topics and Well Written Essays - 750 words

Anthropology. DNA - Essay Example A chromosome is thus a structure that has DNA molecule that consists of many genes. According to Mendel, offspring receive their genes from the parents. Half of the genes are inherited from one parent and the other half from the other parents. Both parents are thus responsible for the traits displayed by the offspring. In mitosis, the daughter cells are identical to the parent cells without any differentiation (Ridley, 25). In meiosis however, due to the crossing over during the metaphase, mutation occurs. It can thus be concluded that the traits that are inherited form both parents and genetic mutation that may take place during crossing over in meiosis are accountable for the characteristics found in offspring. Question 2 Hardy-Weinberg principle is based on the fact that genetic variation is constant through generation in absence of other evolutionary forces. For these variations to remain constant there are some limiting factors that should be in place. One of the factors is the existence of random mating. According to him, populations have specific genes frequencies. If random mating does not take place then the proportions that Hardy proposes cannot be achieved. An example of non-random mating could be through inbreeding where homozygozity of genes in the population is achieved. Selection is another factor which leads to rapid changes in allele frequencies where the desirable characteristics are favored. This can be changed through artificial breeding where all the traits are maintained. Mutation has minimal effects on allele order. However, it can cause remarkable changes in the population if it is recurrent. Migration also affects allele’s frequencies (Ridley, 84). With migration homogeneity of genes within the population is increased since it causes random mating. Lack of migration would result in a certain population having almost homozygous traits. Genetic drift is another factor. This occurs in small sized population and this causes swift cha nges in gene frequency. This is not applicable in large sized population. Question 3 Natural selection is the process through which organism that is best adapted to live in a certain environment survives while the organisms which have weak traits die out or migrate. It is nature’s way of retaining organism with the best trait on the planet while the weaker genes die out. The process of natural selection has been cited as an important stage in evolution. Darwin supported the theory of natural selection using several premises. One is that natural selection comes as a result of existence of variations in organisms. You will find that a certain trait will be displayed over a range of characteristic s within the same species. For instance there is a wide range of skin completion in man. These differences allows for the creation of new traits in the next generation when parents with different traits mate. This creates a room where the trait that is best suited for a certain environ ment to be favored bringing about natural selection. There are however other traits that do not show variation such the number of eyes in mammals. Moreover, some traits that organism have are acquired from the parents while others are obtained from the environment. The traits acquired from the environment are passed to the next generation bringing about differentiation. Another factor that brings about natural selection is high levels of population growth rate. The population of organism increases when the conditions are favorable for example vegetation population in the forest during the heavy rains. Drought causes the organism to compete over limited resources. The organisms that survive during such conditions are the ones that have been adopted to survive with less water