Anthropology - Reproductive Isolating Mechanisms - Article Example

1. Discuss four of the reproductive isolating mechanisms in regards to speciation and macroevolution. For each of the four terms you select, give thevocabulary word from the list and a nonhuman example to illustrate your example. Speciation occurs when gene exchange become restricted. Thus, one of the isolating mechanisms with regard speciation and macroevolution is temporal isolation in which species show activity at different times or different seasons and thus, species avoid mating. One example of this is the temporal cicadas. In ecological isolation, species mate in the habitat and environment they desire and as a result, fail to copulate with the individuals of the same species. This is evident in the disparate species of Manzanita shrubs, which thrive, in different altitudes. Another one of the isolating mechanism is behavioral isolation in which potential mates converge but refuse to mate, as they prefer individuals from their own species as evident in the mating rituals of the albatross. This is in contrast to mechanical isolation where mating and copulation is attempted but sperm transmission does not occur. The two-lipped flower, a species of sage, found in California is an example of this (Calow 379-380). 2. Define cephalic index and explain how it originally was used in an ethnocentric manner. Define eugenics and explain two specific ways (one human, one nonhuman) in which it can be used in a non-ethnocentric manner. Explain the relationship between polytypic, continuous variation and the vitamin D hypothesis. The cephalic index was used to determine the intelligence of a person or her behavior based on the measurement of the skull or the cranium. The size of the cranium determined the superiority of the race. Proponents of Eugenics utilized this idea to forward race improvement through government control on marriage and family. The principles of eugenics can be used in non-ethnocentric manner, as to prohibit the marriage of two groups of populations that increases the possibility of genetic diseases (Jurmain and Nelson 118). In dogs or other mammals, such as race horses the principles can be applied for stronger breed. Yet, eugenics limits the freedom of the genes to function freely (Jurmain and Nelson 112). Polytypic species is composed of one population of species and homosapiens are one of them. Phenotypic variations are evident among humans as they exhibit differences in skin color for instance base on the environment or circumstance in which they live. One of these hypotheses the lightening of the skin color in higher altitudes, which cause the body to generate more Vitamin D said to prevent diseases such as rickets (Jablonski 585 - 623 ) 3. Explain how the Hardy-Weinberg theory is related to both polymorphisms and balanced polymorphisms. Explain how the terms prions and BSE are related to the terms vector and pathogen. The Hardy Weinberg theory or equilibrium is one of the main theories in population genetics, which also states that relative gene frequency stay constant from generation to the next. This is based on a mathematical model. This theory is related to polymorphism, as this is typified by the constant equilibrium with disparate alleles of the genes which at unvarying relative frequencies in a certain population. Prions are like pathogens because they result to diseases such as the bovine spongiform encephalopathy (BSE). Hence BSE is a prion, which could be transmitted through a vector, contact or bite of an animal. 4. Explain the difference between acclimatization and adaptation, giving one example in humans for each. Explain Bergmann's Rule and Allen's rule and how they are related to high altitude and ossification of epiphysis/diaphysis. Define biocultural evolution, explaining both the example of lactose intolerance and sickle cell anemia for this term. What are pleiotropic genes and how do they affect sexual dimorphism and transgenerational problems Adaptation is the means humans utilize to meet the challenges of their environment whereas acclimatization is how an individual or organism react to specific changes to the environment. An example of adaptation is genetic mutation or evolution and an example for the latter is the changes in skin color, which is a phenotypic transformation (Jurmain and Nelson 140-141). Bergmann's rule refers to the relationship of mass relative to the surface area. This is also explained through variations in height and weigh in humans. For instance, people who dwell away from the equator tend to be larger. Allen's Rule refers to the shape of the body in relation to the climate. In colder circumstances for example, humans have shorter appendages to generate more body heat. These rules are related to or the process of bone formation ossification of epiphysis/diaphysis because the bone structure tends to be of rounded end (epiphysis) or diaphysis, the main mid-section of the long bone. The environment according to the aforementioned hypothesis influences these bone structure. Biocultural evolution is the physical changes which occur on human beings as a result of cultural variables 148. For instance, lactose intolerance transpired when some populations in the Stone Age lacked access to milk in the hunting and gathering societies. The absence of lactose in their diet caused some necessary enzymes, which help to digest milk, seemed to have halted in production. When the red blood cell, normally disc-shaped changes to crescent shape, they result to an abnormal function and results to clotting of the blood. This inherited disease is called sickle cell anemia, common in ethnic groups found in Africa or individuals who traced their roots in that area of the globe. This is said to be carried in the genes of by people who survived the malaria outbreak in Africa (Jurmain and Nelson 178). A pleiotropic gene is a gene that influences more than one phenotype traits which results to male and female difference that are quite marked, also referred to as sexual dimorphism. The genotype based on gender also affects behavior. The effect of the genes on individuals could be striking and could cause problems if abnormality in the genes occurs such as females exhibiting more facial or chest hair. 5. What is the main difference between undernutrition and malnutrition Explain the causes, symptoms and associated cultures for: beriberi, marasmus, goiter, scurvy and rickets. Which of these can be found in paleopathology and why What is the starvation gene and what is its function What is the genotype for rh disease for the mother and for the fetus What is the cause of rhe disease Undernutrition is a diet lacking in quantity such as calorie to maintain normal health while malnutrition is a diet lacking in quality as for instance, essential nutrients to maintain health. In paleopathology, certain diseases such as: beriberi, marasmus, goiter, scurvy and ricket used to affect human populations as evident in anthropological findings. Some cultural behavior and diet also cause these certain diseases. Many populations in the past suffered from beriberi as a result of deficiency in Vitamin B as their diets lacked this Vitamin supplement. Marasmus was found to be caused by protein deficiency in the diet. Goiter was a result of potassium lacked diet while scurvy, a disease caused by Vitamin C deficiency and Vitamin D deficiency for rickets, were a consequence of the earlier populations diet and the environment in which access to these supplements were difficult or even impossible (Jurmain and Nelson 154). The Rh disease occurs when the mother of a fetus carries and Rh genotype while the conceived fetus has a positive genotype. The incompatibilities in blood cause diseases such as jaundice, anemia and heart failure. WORKS CITED Calow, P. (ed.) Encyclopaedia of Ecology and Environmental Management. Blackwell Press, 1998 pp. 379-380 Jablonski, N.G. The evolution of human skin and skin color. Annual Review in Anthropology 33:585-623, 2004 Jurmain, R., and Nelson. Introduction to Physical Anthropology. 6th ed.. St. Paul MN: West Publishing Company, 1994. Read More