All living beings are able to pass on certain features and characteristics to their descendants. It is the ability due to which scholars explain the similarity between the child and his parents called human heredity, the discovery of which was primarily attributed to Gregor Mendel (Muehlenbein 48).
At the same time, child’s qualities, peculiar to each of the parents, are manifested differently. For example, the child may outwardly resemble the father, but his behavior would be transferred from his mother. It occurs because there are two types of genes – dominant and recessive (Emery and Emery 43). The first of them would appear in the course of a child’s development by inhibiting the action of the latter. Heredity reflects on man’s mental and physical development. However, one cannot judge the potential of the child only according to his parents. It is possible that the child would inherit the dominant qualities of one of the remote ancestors. In this sense, it goes without saying that heredity and inheritance topic applies to real life playing an important role as for genetics as well as for every man. One of the interesting studies of inheritance is drawing a family tree. It allows following the dominant features in related entities within a few generations in each particular family. From a practical point of view, such study is very significant to identify the different transmitted diseases as a result of the influence of heredity on human. Therefore, it is achievable to develop methods for diagnosis and prevention of possible pathology in some cases. Let us take the following example. There is a married couple. The woman has a recessive gene responsible for predisposition to diseases of the respiratory system. If this gene interacts with a man with a dominant gene, both features would be presented in the genetic code of their child, but the gene of the respiratory system diseases would be suppressed by the dominant gene of a man. As a result, the disease would not manifest itself in a child with a high probability.
It should also be noted that inheritance represents the process of the genetic trait from a parent to offspring. There might be several types of human inheritance among which dominant-recessive, incomplete dominance, co-dominant, sex-limited, and sex-influenced are. The bright example of a sex-influenced inheritance is baldness. “Two of every three American men will develop some form of balding,” states Chiras (350). The other example is skin color that has a genetic basis as “more that 100 gene products are involved in the synthesis of melanin, and the formation and deposition of melanosomes” (Starr, Evers, and Starr 204).
In the recent research, Jablonka and Raz distinguished so-called epigenetic inheritance that is “the inheritance of developmental variations that do not stem from differences in the sequence of DNA” (132). For instance, the impact of living conditions in early childhood reflects the picture of epigenetic modifications and accompanies the person for all his life. Moreover, a new study provided by specialists of the Zurich University (Switzerland) helps to clarify the situation with the epigenetic inheritance. Gapp et al. studied the molecular mechanisms of inheritance behavior in mice. In order to do this, they caused animals’ childhood trauma: they were taken away from their mothers during two weeks at a time (Gapp et al. 667). This unpredictable stress influenced both cubs and females who were also imprisoned for a time in a close tube. According to the research, when the stressed cubs grew, the researchers noticed that they were indifferent to the danger: for example, they were less afraid of open and well-lit spaces (normal mouse, of course, is to avoid such places) (668). However, precisely speaking, changes in behavior and metabolism were inherited by their descendants as well. Therefore, some epigenetic features might be inherited by offspring.
In conclusion, heredity and inheritance occur as an integral and substantial part of all living creatures.
References
Chiras, Daniel D. Human Biology. 7th ed. Sudbury, MA: Jones & Bartlett Learning, 2012. Print.
Emery, Alan E. H., and Marcia L. H. Emery. The History of a Genetic Disease: Duchenne Muscular Dystrophy or Meryon’s Disease. 2nd ed. New York: Oxford UP, 2011. Print.
Gapp, Katharina, Ali Jawaid, Peter Sarkies, Johannes Bohacek, Pawel Pelczar, Julien Prados, Laurent Farinelli, Eric Miska, and Isabelle Mansuy. “Implication of Sperm RNAs in Transgenerational Inheritance of the Effects of Early Trauma in Mice.” Nature Neuroscience 17.1 (2014): 667-69. Print.
Jablonka, Eva, and Gal Raz. “Transgenerational Epigenetic Inheritance: Prevalence, Mechanisms, and Implications for the Study of Heredity and Evolution.” The Quarterly Review of Biology 84.2 (2009): 131-76. Print.
Muehlenbein, Michael P. Human Evolutionary Biology. Cambridge: Cambridge UP, 2010. Print.
Starr, Cecie, Christine A. Evers, and Lisa Starr. Biology: A Human Emphasis. 8th ed. Belmont, CA: Cengage Learning, 2011. Print.