Human Genetics 34 Points Total Essay

Geographical isolation in the past has caused a variation in skin color; natural selection selected specific skin pigments depending on environmental factors. Early humans who moved to Europe were introduced to a place that had less sunlight than their former place of residence. Overtime, light skin (skin with lower levels of melanin) was selected for since there were not as many UV rays that the skin needed protection from. But, what was wrong with having dark skin in Europe? How is extra melanin a disadvantage in this case? One thing to remember is that even though the sun can provide UV rays, sunlight is also a great source of natural vitamin D (Jablonski; Kirchweger). Vitamin D helps bones absorb calcium and is particularly essential for developing embryos in pregnant women. The adaptation for lighter skin was important because the skin needed to absorb as much sunlight as it could in order to receive optimal amounts of vitamin D (Kirchweger). However, too much vitamin D can be fatal. So as high amounts of melanin protected the skin from excessive UV rays in Africa, they also protected it from excessive vitamin D (Kirchweger).

Anthropologists and geographers have studied and overtime come to the conclusion that distribution of skin color is not random. Darker skin color has been found to typically come from near the equator and lighter skin colors are typically coming from closer to the north and south poles. Over the years, researchers have found that darker skin colors has protected the

Caucasians have the lowest amount of melanin in their skin cells when being compared to other cultures. Melanin is crucial to protecting our skin from UV rays, and so someone with a darker skin tone is better protected.

5. In the film, Dr. Jablonski explains that melanin, located in the top layer of human skin, absorbs UV radiation, protecting cells from the damaging effects of UV. Genetics determines the type of melanin (i.e., brown/black eumelanin or red/brown pheomelanin) and the amount of melanin present in an individual’s cells. Based on this information, write a hypothesis for where in the world you would expect to find human populations with

How does the change in the alleles affect the pigment in the alligators; which also affects the fitness of the animal?

This is interesting to me in that though everyone looks different, we are al vary similar at a the DNA level. Our differences are not so great. There are two historical perspectives on race and ethnicity among geneticist. One is that is a cultural and historical construct with no biological significance, meaning that there is entirely unique to a particular ethnicity. The other argument is that there are biological differences between different ethnicities. As the human genome was being sequenced, different frequencies of genes variants related to disease susceptibility, drug metabolism, and environmental response were found among different populations (). Even though there is a small difference in DNA from person to person, there is some biological distinction. The variations of these genes tend to be similar among certain

The PBS series “Race: The Power of an Illusion” effectively works to expose race as a social construct and deconstructs the false notions that race is a biological marker. The series first discusses that all human beings originated from Africa but dispersed about 70,000 years ago to various places in the world. As a result of this migration, people were spread to different locations throughout the world with different environmental conditions that affected their physical traits. It was many years after the migration in which people began to display these new physical traits such as slanted eyes, fair skin, and differing hair textures. While the series notes the physical changes that occurred during the migration it also emphasizes that race while it may seem apparent in skin color and other physical features has no real biological basis.

As the research continues it becomes ever more important to discuss how exactly the differing pigmentation of one race of people actually occurs, because I feel that it has an effect on the way colorism is handled throughout the African American community. There are two ways in which a person of African descent can be of a lighter complexion; the first being amalgamation, which is the coming together of both the black and white races and reproducing to make a mulatto or mixed race child and the second is the use of cosmetic creams in attempt to bleach one’s skin until they too appear mulatto (Dorman 48). This is relevant because, it shows the extremes that people are willing to go to reach the highest plateau of social acceptance. Many of these creams were painful acidic chemicals slowly burning away the pigmentation as people slept, while others were considered mild abrasive materials used to “gently” scrape away dark pigments (Dorman

Melanin has played a significant role in human evolution. In this paper I will discuss the importance of melanin in its role in the human biological system and how it relates to the natural selection of suitable human life according to geography and environment.

We often connect ourselves to the world through our appearances. One of the first characteristics we notice about another human is the color of their skin. It is unavoidable, as the largest organ of the body, it covers and highlights our individual features and forms a protective wall against the elements. There is no escape from the social repercussions our pigmentation causes no matter what range of the very broad spectrum of color we fall into. I have never thought so much about the genetic and social evolution of skin and its properties until I read Nina Jablonski’s Living Color: The Biological and Social Meaning of Skin Color. This book encompasses, in great detail, how our skin has evolved, adapted and mutated throughout time and in what

The world of Genetics is one that is both fascinating and interesting. When tackling how genetics plays a role in behavior, one must look within the scope of what genetics is before dealing with how it plays a significant role in one’s behavior. Simply put, genetics is the study of genes. It is a biological component within the entire study of biology itself. Scientists who study genetics and perform research do so with the intent to learn more about how genetics affects the overall attitudes, behaviors and dispositions of individuals. It could be said that genetics is somewhat of a psychological-biological science as researchers look at the underlying patterns within the genes that cause

Due to scientist’s interest in human genetic variation, human racial classification became a focus of scientific investigation by evolutionary biologists attempting to categorize individual humans based on presumed patterns of biological difference. Scientists had hoped to classify humans in the same way that they classified other species. These scientists attached hierarchical titles to these categorizations; they claimed that differences in skin color, physiognomy, and geography were associated with scientifically measurable differences in character, aptitude, and temperament (Smedley, 1998). However, studies supporting these claims have been unsound (Gould, 1981). Categorization of humans by racial and ethnic groups continues, as researchers must remain aware of this historical legacy of the science of heredity as the genomic era continues to develop (Bonham et al., 2005).

Population demographic factors such as age, sex, diet and ethnicity explain the largest proportion of genetic variation between human populations (Fumagalli et al., 2011). Infectious agents including viruses, bacteria and protozoa are likely one of the strongest evolutionary drivers of the remaining genetic diversity within and between populations, as a result of the selective pressure they inflict in regions where infection is endemic. Mortality is the strongest selective pressure which is imposed by an infectious agent. Any genetic variant associated with an improved response to that pathogen is likely to be a target for selection (Fumagalli et al., 2011). Positive selection results in the increased frequency of a beneficial allele. Balancing selection maintains diversity, while negative selection eliminates deleterious variants. This process of natural selection leaves behind distinctive signatures of selection that can be exploited to identify regions of the genome under selection (Karlsson et al., 2014). Signatures of selection are distinctive because they reflect uncommon patterns of allele frequencies at a particular locus when compared to the underlying genetic variation. Candidate based gene approaches, Genome wide association studies (GWAS), haplotype based methods and various statistical tests such as Tajima’s D statistic are used to detect these signatures of selection within the human genome. This essay uses specific examples to discuss the evidence of

The human race has been distributed in different geographical locations with a particular physical feature. Below are some of the races found in various parts of the world? The Natural habitat Caucasian from North Africa, the Indian, Southwest Asia, and Europe. The group is made up of Nordic, Alpine, east Baltic, Mediterranean among other groups. These groups of people are different from other groups significantly more so the high profiling individuals. Natural habitat in East and West Africa, present with curly hair, dilated nostrils, dark skin. As long as the round-headed, Negro type and middle-sized. Pygmies in the central and western part of Africa are unusual to note. The pygmies are about 144 to 150 cm for men, curly hair, skin light brown, massive torso, legs and arms are short. There are about 200 thousand people.

1.     The colours would be adjusted to this type of skin( a wide variety of darker colours )