Thomas Malthus lived from 1766 to 1834. In 1798, he published the Principle of Population where he made the observations that the human race would be likely to overproduce if the population size was not kept under control.
Malthus then focused his studies on the human race. His calculations and theories produced an idea that the human population would increase geometrically while the food supply and natural resources would only increase arithmetically. This is a potential explanation for the predicted poverty and famine. He concluded that as more offspring are born, a more competitive nature would arise. As more offspring come into the population, fewer resources will be available for the population. This has the potential for competition between organisms for survival due to lack of resources. This competitive nature would be necessary for survival of individuals within a large population size unable to be supported by the environment. He believed that this uncontrollable population size would eventually be the cause of famine and poverty among humans. His reasoning behind this idea was divine intervention. He believed that this would be the punishment for man if he became too lazy.
Malthus’ Principle of Population caused Darwin to rethink many issues while coming up with his theory of natural selection. Malthus’ work made Darwin realize the importance of overpopulation and how it was necessary to have variability in different populations. Darwin also used Malthus’ ideas to use competition as well as the survival in numbers idea to come up with his full idea of natural selection.
Campbell, Reece. Biology, Sixth edition. Benjamin Cummings. 2001. http://www.ucmp.berkeley.edu/history/malthus.html http://www.blupete.com/Literature/Biographies/Philosophy/Malthus.htm http://geography.about.com/library/weekly/aa033001a.htm