The major understanding of biomedical examination and extensive knowledge on the science of genetics are exceedingly significant nowadays. A branch in biological science that deals with heredity and genes is popularly known as genetics. Humans began applying knowledge of genetics in prehistory with the domestication and breeding of plants and animals. In modern research, genetics provides important tools in the investigation of the function of a particular gene; an instance is the analysis of genetic interactions (Scheinfeld, 8).
To gain supplementary insight on the transfer of traits and findings on the source of illness and physical appearance is through the tracking of human genes or the study of genetics. To further explain this, the predisposition of persons to acquire the traits of parents or ancestors is called heredity. The eye color is a genetic information that is inherited from one’s parents. The union of genes of parents is the determination of the physical characteristics of an individual. Eye color is an concrete example of a physical trait determined by heredity.
46 chromosomes of every parent are split into 23 pairs. In simpler terms, the baby acquires 23 chromosomes from the father and the remaining 23 from the mother. This illustrates a brief explanation of dominance and recessive traits in humans. If the father’s blue eye is the dominant gene and the brown eye of the mother is the recessive trait, then the color of the baby’s eye is blue. Recent studies showed that this type of inheritance pattern does not apply to the genetics of eye color. The hereditary foundation for eye color is full of twists and turns.
According to the Queensland Institute of Medical Research and the University of Queensland’s Institute for Molecular Bioscience (IMB), the theory of dominant/recessive inheritance which was famously performed by the Father of Genetics, Gregor Mendel does not apply for the passing of genetic trait which is eye color. The research on the genetics of eye color concludes that there is no single gene for eye color. The model of eye color inheritance using a single gene is insufficient to explain the range of eye colors that appear in humans such as blue, green, brown, black, hazel and pink.
It is believed instead that there are two major genes – one that controls for brown or blue, and one that controls for green or hazel – and others that modify this trait. So contrary to what used to be thought, it is possible for two blue-eyed parents to have a brown-eyed child, although this is not common. The study was carried out to clarify the role of the OCA2 gene in the inheritance of eye color and other pigmentary traits (“No Single” 1). Aside from the genes, melanocytes also served to be another physical basis.
Melanocytes greatly influenced the formation of the dark pigments in the skin, also called melanin. These biological pigments produce coloration to skin, eyes and other tissues. The amount and placement of the melanin produces the different eye colors that we see. Melanin is a dark brown pigment that is placed in the iris. The more melanin used in the iris means the darker the eye color will appear, the less melanin used means that the eye color will be lighter. The genes tell the enzymes how much melanin to deposit in the iris.
A newborn’s eyes appear blue, but may darken over the next few years. Melanin production has not begun at the time of birth. A child’s true eye color cannot be determined until the age of three. Black and brown eyes are usually of the ethnic region or the Asians and Africans. While very relatively different and abnormal color which pink, may be seen in Albinos due to lack of melanin. This suggests that there are other genes, yet to be discovered, that determine eye color and the fact that melanin also affects the color of the eye (Guttery, 1).
Works Cited
Guttery, Linda. “The genetics of Eye color” Sewanee edu. 2003. Sewanee. 23 May 2008 <http://www. sewanee. edu/chem/chem&art/Detail_Pages/ColorProjects_2003/Guttery/>. Scheinfeld, A. You and Heredity. New York: Frederick A. Stokes Company, 1939. University of Queensland. “No Single Gene For Eye Color, Researchers Prove. ” ScienceDaily. 25 February 2007. 23 May 2008 <http://www. sciencedaily. com /releases/2007/02/070222180729. htm>.