Essay Sample: Population on Earth, Carrying Capacity, Birth Rate, Death Rate

Introduction

Environmentalists use mathematical models to understand how the size and composition of a population changes with time. These models are common among population ecologists because they describe changes that occur within a population. Also, they help to predict changes that happen in the future. Most of these models include ceilings that result from limited resources. Two main models explain population growth i.e. the exponential growth model and the logistic growth model. Each of these models utilizes the carrying capacity concept and the limited resources concept. This paper seeks to explore the subject of population by examining birth rates, death rates, and carrying capacity.

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Population Growth Models: Exponential and Logistic

Birth rates and death rates are two of the four main variables that determine changes in a population. Populations gain individuals by birth and lose individuals through death. Sometimes, populations may experience more birth rates than death rates or more death rates than birth rates. However, in most cases, the number of birth rates always exceeds the number of death rates. Moreover, the size of a population depends on its capacity to grow. However, there is a limit to population growth. This is because increasing population growth reaches a point where factors such as food and diseases inhibit population growth. These factors help to keep a population in balance. The same applies in birth rates and death rates. According to contemporary literature, any given population should be at equilibrium if its birth rate reflects its death rate.

The interplay between these two variables helps to maintain a population at a maximum number. This equilibrium point is referred to as the carrying capacity. Carrying capacity is normally determined by the amount of resources an area can provide to its species. However, in the case of humans, the definition also includes the cultural and social environments of people. These additional factors help in differentiating a population with exponential growth from a population with logistic growth. In the former, population growth begins slowly, shifts into a rapid phase, and eventually reaches optimum when the populations carrying capacity is reached. In the latter, population growth starts at a rapid pace but decreases as the population size reaches its carrying capacity. The carrying capacity of every species remains constant even as the population of a species expands. This is the reason why animals often kill each other during drought to keep themselves from being extinct.

Birth Rates, Death Rates, and Population Changes

The same applies for humans. Due to the increased birth rates, humans have been able to devise strategies that should help humanity maintain a population that can be sustained by the earth's carrying capacity. For instance, to keep track of the number of people populating earth, nations are encouraged to conduct a census after a given period of years. In the health sector, there have been continued efforts over the years that aim to encourage families to exercise family planning as a way to control the birth rate. This strategy has proven to be successful especially in areas where poverty levels are high. In highly populated countries like China, the government has resulted to using stringent population control laws to reduce its country's population. Also, many developed countries have invested in space exploration in an attempt to establish whether other planets are habitable.

Conclusion

Given that earth's population can only increase with time, individuals are encouraged to heed the advice of environmentalists and population ecologists. This way, earth can accommodate more generations to come.