Why does it appear that the human population does not follow the logistic growth curve that most other populations or organisms follow? In your opinion, what is the best way to deal with human population growth?
Unlike most living organisms, human population growth is determined by a combination of factors, which are dynamic in nature hence the fluctuations in human population growth curve. Population growth of organisms is mainly determined by the food chain whereby there exists predators and prey (Cunningham, 2006). This cycle helps in checking the population and thus balancing of the ecosystem.
For instance, the mole and wolf population is controlled by the cycle of food chain. It can be said that the wolves ensure that grassland vegetation is not overgrazed by the moles and without the moles; the wolves would probably die (Vucetin & Peterson, 2004). Apart from the food chain, the wolf population, just like other animal population, is controlled by environmental factors like encroachment of the grassland areas and disease. Whereas in humans there is no such thing as a food chain where predators feed on other animals, there are more complex variables that control population growth. These include health factors such as sanitation and medical care.
These two factors have a direct influence on human population in that an improvement in them lowers death rates thus creating an imbalance between birth and death rates hence population growth rate. Where the opposite occurs, both birth and death rate might increase. Other factors influencing human population growth rate include food availability, water supply and environmental conditions like famine and floods.
In my opinion, the best way of controlling population growth is by creating awareness of issues such as family planning. This is the most effective way of controlling population especially in poverty stricken regions where population growth rate is usually the highest.
Extinction is a natural selection process. Should humans strive to preserve a representative sample of all biomes or aquatic zones? Why should humans be concerned with the extinction rate?
High geometrical rate of increase of organic beings results in areas being fully inhabited (Erlich, 1981). As a result, favored organisms increase in number. Consequently, the less favored decrease in number and eventually become extinct with time (Erlich, 1981). This mostly occurs among organisms which are few in number. Factors promoting extinction include unfavorable weather conditions and increase in the number of predators (Erlich, 1981).
But as new forms, favored by the prevailing weather condition, are produced many old forms must become extinct. Species high in number produce favorable variations. Thus, if rare species are not quickly modified, they will eventually be phased out by the modified and improved descendants of the ‘favorable’ species (Erlich, 1981). As new species are formed through natural selection, others become rare and rare and finally extinct (Erlich, 1981).
Given the importance biodiversity in understanding nature humans should preserve representative samples of all biomes. Rapid population increase is forcing man to invade forests and aquatic zones as he searches for land to settle in or build industries. Not only are the indigenous forests at risk, but also the animals like the black and brown bear that inhabit these zones. If man doesn’t preserve samples, these species may become extinct and be long forgotten like they never existed.
Humans should be concerned about the alarming rate of extinction, facing both animals and vegetation. For example, extinction of forestry might have effects like global warming. Consequences of this are already being experienced today in the form of sporadic changes in weather, extreme floods, and drought spells (Cunningham, 2006). Therefore, man should strive to protect the ecosystem and find other ways of dealing with and controlling population pressure.
References
Cunningham, W. P. & Cunningham, M. A. (2006). Principles of environmental science: Inquiry and applications (3rd ed.). Boston: McGraw Hill Publications.
Erlich P. (1981). Extinction: Causes and consequences of the disappearance of the species. New York: Random House.
Vucetin, J. A. & Peterson, R. O. (2004). Long term population and predation dynamics of wolves on Isle Royale. In D. Macdonald & C. Sillero- Zubiri eds. Biology and conservation of wild canids, p. 281-292. Oxford: Oxford University Press.