The model of complete replacement by Christopher Stringer and Peter Andrew states that 200,000- 150,000 years ago the archaic humans evolved to the modern humans in Africa and then later migrated to other parts of the world replacing the Neanderthals around 60,000 -40,000 years ago. This theory suggests that all people have an African ancestry (Kuklik & Henrika, 28).It also argues that all other forms of Humans like Homo erectus have gone extinct. It suggests that the developments seen in humans today are recent.
Regional continuity model also known as multiregional evolution model by Milford Wolpoff states that evolution was simultaneous in all regions of the old world. This theory observes that the Indians must have evolved from archaic Indians who in turn come from the Homo erectus. Those standing up for this model state that the main human ancestor is the Homo erectus who lived in 1.8 million years ago. Keeping with these Kuklik et al. (129) states that, the theory further implies that there was gene flow between Africa, Asia and Europe preventing distinct species from different regions.
Partial replacement model also known as the assimilation model states that the modern humans originated from Homo sapiens and that they come from Africa and Europe at the same time at about 200,000 years ago. This theory is evidenced by the finding of the Homo sapiens fossils in Europe and Africa (Barrett & Stanley, 109).
A group of distinct people classified in the same category, held together by the same genetic features, history or geography. Most people define race in terms of skin tone, eye color, and hair type. Others go as far as using the body stature, behavior, intelligence or preposition to sickness. Biologist on the other hand define race as on terms of physical appearance, gene frequencies referring to a kind of subspecies (Kuklik et al. 18). Points out that race cannot be simply be defined by appearance and their lucks any biological evidence supporting the argument of race
Early on in the 19th century races were simply categorized as Africans, Indians and Europeans all defined as different species with Africans described as the least intelligent and closest to apes. Keeping with this argues that Rhodes and Dan (201).Race was an ideology spread across the world. Rhodes et al. (10) points out that Adolf Hitler used race ideology to lead to the extermination of people he deemed inferior races like Jews, Africans, Gypsies and homosexuals. Most people today define race mostly in terms of color and location.
Astuti et al. (127) observes that people in the 20th and 21st century no longer believe in a superior instead they probe in to culture and history to define other people. As mentioned biologists have gone as far as to question, the relevance of the term race itself Astuti et al (128) argues that there is no relevant variation, observed in the human population. This argument is made even more compelling, by the discovery that within group genetic variability, it’s greater than the between group genetic variability. In simple this means that Africans, Asians, Hispanics and Europeans are the same since their within group genetic variation is greater than the between group genetic variability.
Lactose intolerance is a selection of symptoms like cramps, flatulence, nausea combined.
When a child is born or any other mammal for that fact it lives on milk for the first few months of its existence. Once the child or the mammal reaches an adaptable age it is weaned. To make this possible is the ability of the small intestine to produce high lactase during the early days of the child and low production of lactase once the child is weaned. Milk contains a chemical known as Lactose a disaccharide of glucose and galactose. For the body to digest Lactose it requires the presence of the enzyme lactase a beta galactosidase found in the small intestine epithelial cells. In the absence of lactase, lactose is metabolized by bacteria causing the aforementioned symptoms.
Ten thousand years ago people that stopped lactase production were seen to be more adapted to their environment. This group of people changed their way of life to hunting for meat and agricultural farming. While those who continued to produce lactase went into pastoralism for milk. Hahn, Robert and Marcia (109) add that for those populations that stopped lactase production they were seen to be biologically advantaged than those who kept on with the production of lactase. It is as a result of this continuous lactase production we see today the culture of dairy farming (Hahn, et al, 29)
According to Nanda, Serena, and Richard (11) the increased rate of skin cancer is a sign of bicultural evolution as a result of weaker Ozone layer which blocks the UV rays. The UV rays are the main cause of skin lesions and skin cancer, which is a way of the skin adapting. Nanda et al (2011) continue to note that the number of teeth in humans today is another example of bicultural evolution. This is as a result to change in the diet in the present.
Work Cited
Astuti, Rita, Jonathan P. Parry, and Charles Stafford.Questions of anthropology. Oxford, UK New York: Berg, 2007. Print.
Barrett, Stanley R. Anthropology: a student's guide to theory and method. Toronto Buffalo: University of Toronto Press, 2009. Print.
Hahn, Robert A., and Marcia C. Inhorn. Anthropology and public health: bridging differences in culture and society. Oxford New York: Oxford University Press, 2009. Print.
Kuklick, Henrika. A new history of anthropology. Malden, MA: Blackwell Pub, 2008. Print. Kuklik & Henrika, (2008)
Nanda, Serena, and Richard L. Warms.Cultural anthropology. Belmont, CA: Wadsworth Cengage, 2011. Print.
Rhodes, Dan. Anthropology: and a hundred other stories. Edinburgh: Canon gate, 2010. Print.
