Harvard biologist Edward O. Wilson and other scientists estimate that half of the current species will be extinct by the year 2100. Many of these creatures are small and don't seem to have a direct impact on humans' everyday lives. Because of the web of life, however, each species has a connection with all the others around it. The extinction of even some of the smallest creatures, such as types of insects and plankton, would have a direct effect on human life.
Food Chain Disruption
The most immediate impact would likely be on the food chain. For example, as sea surface temperatures continue to rise, many species of plankton are beginning to decline. If the plankton, such as diatoms and krill, were to go entirely extinct, it would have an impact on larger creatures, such as fish and whales, who consume it as a major food source. In turn, if those larger marine animals have less to eat, and as their own population declines, it would cause a chain reaction through the food chain, ultimately reducing human food sources.
Many medicines are derived from plants, which rely on insects for pollination. As the insect population decreases, such plants would struggle to reproduce. The fewer plants there are, the harder it would be for the remaining insects to find a food source, creating a cause-and-effect loop that would hurt all species involved. Some medicines are also created from the skin of amphibians, which are also under threat of extinction.
Higher Disease Risk
Some animals are resistant to certain types of diseases, such as the opossum's ability to ward off Lyme disease. Such buffer species help contain outbreaks from spreading to other animals and humans. As buffer species lose habitat space to urbanization or climate-induced ecosystem changes, their ability to create the buffer declines. As they become extinct, the creatures that move in to take their place are often less adept at containing the spread of disease or are more likely to contract such diseases, putting humans at higher risk for disease.
Extinction also has an impact on the world economy. Food chain disruption can lead to job losses as animals such as tuna and swordfish decline, leaving deep-sea fishermen high and dry. The loss of insect life, such as bees, will also have an impact on plant-based industries such as medicine and agriculture, which depend on pollinators. Also, if large animals such as tigers or elephants become extinct despite conservation efforts, ecotourism in certain counties in Asia and Africa may also experience declines.
- World Wildlife Federation: What if Tigers Did Become Extinct?
- EU Observer: EU Study Explores Economic Impact of 'Great Extinction'
- U.S. Fish & Wildlife Service: Why Saving Endangered Species Matters
- Scientific American: Humans are More at Risk from Diseases as Biodiversity Disappears
- The Independant: Animal Extinction - The Greatest Threat to Mankind
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