Stages Of Human Development Essay

The phases of human development can be culturally defined. In fact, an individual's culture, or environment, plays a huge role in the developmental process. These influences are present even in the embryonic stages of development. For example, if a pregnant woman is a part of a culture or group which places a value on smoking or burning incents, than the mother is likely to inhale a large amount of smoke. The toxins from the smoke could have adverse effects on the baby's development which could lead to a deformity or birth complication. Another example could be a young child, say 5 years old, who is a part of a culture who only eats plants. The human body requires a balanced diet consisting of grains, dairy, fruit, meat etc. in order to be
The evolutionary relationship between vitamin D, folate, and sunshine all relates to skin pigment. "Melanin, which is responsible for skin pigment, can be advantageous or nonadventageous. That is, because melanin provides protections from solar radiation, substantial amounts of this pigment can inhibit vitamin D production." (Our Origins p. 139). Therefore, the more melanin an individual has, the more protection from the sun he has. So, at the equator, we tend to see people with darker skin because they are exposed to more sun than in other parts of the world. This demonstrates a strong correlation between distance from the equator and degree of skin color. In our book, it discusses how scientists have hypothesized how human ancestors migrated from Africa into northern latitudes. At these latitudes, there is less UV radiation, so populations with dark skin were not be able to create enough vitamin D to thrive. This meant that lighter skin in humans at the northern latitudes was more favorable and had a selective advantage. As a result, the fitness at the northern latitude corresponded with a lighter skin tone. So, naturally, human populations selected for lower melanin levels, and eventually evolved lighter skin in northern latitudes which explains the relationship between vitamin D, folate, and