Variations in body shape and size arise from the survival nature of different human species. The ecosystem is filled with varying types of people whose body mechanisms are different. The harsh conditions within the environment as well as the increased competition for limited resources results in a scramble for basic needs with the aim of using the available resources to extend their lives. In most instances, the lifestyles led by different individuals demand varying amounts of food and other adaptive characteristics hence the differing heights and body shapes. Such differences represent varying evolutionary forces that seek to make their bodies adaptive to different amounts of basic needs.
Variations in skin color occur due to differences in latitudinal mutations between various communities. Humanity is divided into numerous categories and habitats in line with the people’s seriocomic activities. The southern inhabitants tend to relocate to equatorial regions while the northern ones limit their movements to higher latitude areas (Narvaez 33). It is thus evident that the varying UV irradiation in these geographical locations facilitates the growth of darker and lighter skin in the south and north respectively. The former have vitamin D hence the need for darker skin while the latter are deficient from these nutrients thereby lowering their inclination for similar skin color at such altitudes. It is thus clear that such pigmentation follows this principle.
The sickle-cell allele is a hereditary feature that is transferred from one organism to another through the DNA. Such a phenomenon seeks to herd compatible people together while alienating inferior species as a means of achieving eugenics. In fact, the condition is passed from one person to another when the latter inherits normal and abnormal hemoglobin rather than possess two normal ones. As such, this trait illustrates the co-dominance among species in that the recipient has to rely on external provisions of this vital ingredient in order to remain alive due to a weakening in his/her immune system.
Physical characteristics alone are
not sufficient to categorize human groups into races because cultural
attitudes, skin colors, and height as well as body sizes may correspond with
minimal or no genetic compatibility. As
such, races are meant to show some form of distinctiveness from each other
owing to the different variations that compromise their living cells. It is
however evident that due to migration, some species developed as subsets of
other communities, especially Africa. Such a
continent has little influx. It is the leading contributor to migratory
tendencies by other organisms. For instance, people may be of equal height and
even skin color but belong to different races thereby illustrating the folly of
using general markers to categorize them. Physical attributes are
environmentally defined due to the resultant conditions within the habitat
whereas racial differences can be traced to inherent genetic mutations that
occur naturally (Roberts 49). The transfer of such features facilitates the
adoption of similar beliefs and values hence translating into numerous races
within the planet. The variations are subject to group selections under varying
levels of organizations thereby creating genetic drifts that form unique
organisms. Basing the outcome of such racial characteristics on the physical
appearances alone would be inaccurate since the high number of germinal and somatic
cells can be studied further for better predictions. The human evolution
process is thus complicated by the environmental conditions within which
various species inhabit.
Narváez, Darcia. Ancestral Landscapes in Human Evolution: Culture, Childrearing, and Social Wellbeing. , 2014. Print.
Roberts, Alice M. Evolution: The Human Story. New York: DK Pub, 2011. Print.