Biology Essay, Research Paper

Are Humans and Beasts Too Close for Comfort?

Are humans and animals in too close contact for disease dispersal? This question that is asked in the May 2000 article, Germs and sickness in a shrinking world, of U.S. News online is one that needs to be looked at very directly. As globalization shuffles more people, animals, and pathogen-contaminated products around the world, biologists say infections are increasing (Tangley 1). This shuffling of cultures occurred early with the Spanish conquistadors traveling to the New World. The lands of America and its native inhabitants would soon be introduced to a variety of new diseases thus creating a virgin soil phenomenon. Measles and smallpox were introduced by the Spaniards leaving the Native Americans too weak to protect their land. The Spanish were descending the disease gradient making them insusceptible to the few diseases that were in the Americas. McNeill s law reveals that as a more diseased experienced population comes into contact with a less disease experienced one; the most common result is the more diseased experienced country will take over. Animals brought over with the Spaniards only complicated matters for the less disease experienced Native society. Parasitic commensalisms (the situation in which the parasite benefits while the host does not, but the host is not harmed) occurring with the livestock or other animals can be directly transferred to human disease if the parasites have the ability to switch hosts. Host specific animal parasites will not be as much of a threat, but will still impede the progress of acculturation. In the case of the Spanish conquistadors, parasites aided them in overpowering the Native Americans.

The domestication of farm animals dates all the way back to the Baktiare nomads of Persia. The Baktiare had domesticated sheep and goats 10,000 years ago. Although the Baktiare were unsuccessful as a tribe, due to the inability for innovation resulting from their nomadic lifestyles, they were beneficial to future cultures in introducing new agricultural advancements.

As society develops, urban living areas become denser. One of McNeill s corollaries states that as urbanization densifies, the new compact conditions invite numerous parasites to prosper. This overcrowding indicates that more people and their pets are sharing the same space. In any situation where both humans and animals share the same living quarters, the chance of shared diseases increases. For example, dogs and humans share 54 diseases. From this cohabitation, different animal to human parasite transfers occur, thus disease pool increases. Disease pools determine how much level of constant infection there is at any given time.

The article describes how the destruction of our world s wetlands and rainforests plays a major role in spawning epidemics. Shrinking habitat is also deteriorating, which promotes growth of bacteria and other pathogens, states Robert McLean, director of the U.S. Geological Survey of National Wildlife Health Center (Tangley 2). As the essential wetlands are being destroyed, the diverse wildlife that live there are forced to evacuate. These assorted creatures migrate towards other areas that provide warmth and moisture. The temperate and tropical climates of civilized communities are home for a wide variety of the disbursed parasites. Human contact is inevitable.

Small insects such as mosquitoes are becoming increasingly dangerous to humans. They have been distributed all over the globe and new epidemics are being introduced to inexperienced countries. The West Nile fever in New York City is a prime example of how the scattering of creatures is very detrimental to the human race. The virus was spread from ectoparasites (mosquitoes) coming from the regions of West African. Last summer, the West Nile killed seven elderly people and afflicted 62 others with body aches, chills, and other flu-like symptoms. Studies showed that mosquitoes were able to survive in the wheel bays of jets traveling thousands of miles between tropical and temperate zones (Morris 2).

As the integration of new humans and the diseases they bring with them occur, we have to be aware of both macro and micro parasitism. Symbiotic relationships between parasites and host have been occurring for thousands of years. Diseases caused by such relationships have woven a complex acculturation of different indigenous peoples. The hunters and gathers switching to the agricultural and domestication of animals brought about brand new introductions of disease which was carried from culture to culture.

Bibliography

http://www.usnews.com/usnews/issue/000403/skeeters.htm

Morris, Jim

http://www.usnews.com/usnews/issue/000522/animals.htm

Tangley, Laura