Human Effects on Other Species, Essay Example

The Industrial Revolution’s Evolutionary Effect on the Light-colored Moth

In his theory of Natural Selection, evolutionist Charles Darwin posits that living species undergo constant biological mutation, so as to adapt to changing environmental conditions. In what he termed as ‘survival for the fittest,’ he further argued that those species which fail to adapt die and eventually get extinct, while those that adapt survive to give rise to future generations of their kind.  Nonetheless, human activities can cause environmental change and in turn trigger the metamorphosis of certain species. The essay examines how the industrial revolution in Britain led to the evolution of the light colored Biston betularia moths.

Before the industrial revolution in Europe, there were a lot of light colored Biston betularia moths (also known as typical), as compared to the dark colored ones (melanic) (Allaby, 2002, p. 298). The light-winged moths were difficult to spot on whitewashed buildings and tree barks, hence, were safe from bird predation. However, following the industrialization of England in the early 19^th century, pollution caused by coal burning and industrial emissions darkened the environment, including buildings and trees. Consequently, the light colored moths were conspicuous in the darkened environment and made easy targets for preying birds (Allaby, 2002, p. 298). On the other hand, the dark colored moths became well camouflaged, and their numbers increased, especially around the city of Manchester. By the mid 19^th century, 90% of the moths in the industrialized areas were melanic.

Nonetheless, when pollution decreased as a result of the introduction of Clean Air Laws, there were reverse trends: the light colored type once again became camouflaged in the new environment, while the melanic type became conspicuous and vulnerable to predatory birds (Miller, 1999).  It led to their decline, just like before the industrial revolution. Thus, it is evident that human activities contribute to the evolution of other species.

References

Allaby, M. (2002). Encyclopedia of weather and climate, Volume 1. New York: Infobase Publishing.

Miller, K. (1999). The Peppered Moth- An Update. Retrieved October 28, 2010 http://www.millerandlevine.com/km/evol/Moths/moths.html