HUMAN VARIATION

Human Variation

Human Variation

Introduction

Human variation has played a significant role in human evolution. Cultural variation has also refers to no biological responses of individuals or groups to alleviate environmental stress. It is an important mechanism that allowed humans to survive and colonize relatively inhospitable areas until physiological adaptations could occur. All the evidence to date suggests that hominids evolved in the hot savannas of East Africa. Humans today cope better with heat than they do cold, illustrating the long-term adaptations to heat that developed in our ancestors. As humans migrated to colder environments, they invented fire, clothing, and shelter to survive. (Williams, 2009)

The study of human variation and adaptation is useful in a various stages of life. The broad field of biological anthropology, also called physical anthropology, studies the mechanisms of biological evolution, genetic inheritance, human adaptation and variation, and primatology. The objects of study range from fossils and bones to living populations. In addition to researching and teaching in the anthropology department of a college or university, there are many situations that require the study of human adaptation. (Wright, 2003)

A key opportunity to study human variation appears in biomedical research. Biomedical scientists focus on issues related to public health, including growth and development, nutrition, aging, disease, genetics, epidemiology, physiology, and forensics. (Stock, 2002)

Comparison (Global)

Environmental conditions vary greatly around the world. Over thousands of years, human beings have varied themselves to living with extreme heat, extreme cold, high altitude, dietary limitations, and more. While human populations have a variety of cultural or behavioral methods to combat exposure to environmental stressors for rapid acclimation, the actual physical changes in over hundreds of generations can be seen in those native to a region. While demonstrating direct effects of natural selection is difficult, humans do show physiological differences in response to their environment. The question is whether these changes were due to variation through natural selection, or would any population of humans have the same physiological ability (plasticity) to adjust to that environment, given enough time? (Wright, 2003)

Nutrition

There are vast differences in the types and availability of food resources around the world. During human infancy, childhood, and adolescence, much of the energy provided by nutrients is devoted to growth. Too few calories can result in a reduction in size and a delay in maturity. Too many calories, on the other hand, can result in fat accumulation and acceleration in physical maturity. Neither result is ideal. Inadequate nutrients can impact basic biological processes and lead to disease susceptibility. (Wright, 2003)

The development of agriculture had a profound impact on human development and variation. The domestication of crops provided an increased concentration of food, which expanded permanent settlements and increased population growth more rapidly. These factors, in turn, increased the spread of disease. Climate, resources, and level of technology all influenced food quality and quantity. (Stock, 2002)

The rise of agricultural societies created an increase in food production, but resulted in more restricted diets. Agriculturalists tend to rely on one or very few staple crops, ...