Modern man has built an empire. As a species, humans have made it to every continent, every ocean, and even space. The species did not begin this way; in fact, all modern humans can be traced to Homo erectus, a species that originated in Africa roughly 1.7 million years ago (Ayala 1995). Slowly making their way out of Africa, H. erectus introduced themselves to new environments, where they dominated the native species. 1.3 million years after migrating out of the African continent, the H.
erectus slowly gave way to H. sapiens, more commonly known as humans (Ayala 1995). Charles S. Elton, hailed as the father of invasive ecology, first used the term ‘invasive species’ in 1958. His book, titled The Ecology of Invasions by Animals and Plants, foreshadowed the invasion of nonnative species that plagues the modern world. Since then, many different definitions have gained popularity.
For the sake of simplicity, it is common to use the definition found in the United States Executive Order 13112. The document establishes that an invasive species is one “whose introduction does or is likely to cause economic or environmental harm or harm to human health” (Exec.
Order 13112, 1999). Many animals fit this description; common examples are the mosquitofish, the common goldfish, and the Sambar deer (Colautti & MacIsaac, 2004). The list, however, seems to be forgetting the animal with the greatest threat to the economy, the environment, and human health: Homo sapiens. An economy can best be defined as, “the system of trade and industry by which the wealth of a country or region is made and used” (Cambridge University Press, 2008).
According to the American government, invasive species must be inherently damaging to the economy. Humans damage the economy periodically, due to the nature of the business cycle.
The Great Depression and its causes exemplify humans damaging the economy. Before the crash of the stock market, investors began getting involved in what is known as speculation. This caused a market bubble, which led to the crash in 1929, preceding the worst economic situation the country has ever seen. It is evident then, that human activity in this case, the investors’ speculative tendencies) is damaging to the economy. An invasive species must also have adverse effects on the environment. Humans fit this description far too easily. The greatest impact humans have made is on the land. Transformations of the terrain (executed by humans to better suit their purposes) began at least 10,000 years ago, with the beginning of agriculture (“Our Imprint Deepens” 1996).
However, the composition of the terrain is not the only component of the Earth to suffer from human activity. The atmosphere, composed of nitrogen, oxygen, and minute traces of other gases, has also been negatively affected by humans. The United States alone produces two billion tons of carbon dioxide every year via coal-burning power plants and transportation. These emissions lead to global warming, a phenomenon that despite clear evidence-many people have yet to believe. According to the Natural Resources Defense Council, “over the past 50 years, the average global temperature has increased at the fastest rate in recorded history” (MacMillan 2016). This trend is accelerating, not coincidentally, with the increased rate of carbon dioxide emissions. A 134-year record of average annual temperatures has seen all but one of the 16 hottest years to have been recorded since 2000 (NOAA 2016). Humans have evidently changed the Earth, and not for the better. Lastly, invasive species must pose a threat to human health. Every negative effect imposed on human health can be traced to human activity.
The most obvious examples include lung cancer developed from smoking (cigarettes were not only invented by man, but so was the machine that makes them today), and alcoholic liver disease due to overconsumption of alcohol (“Cigarettes and Cancer” 1953; “How Does Alcohol Damage the Liver?” 1978). As an invasive species, humans have caused more damage to the economy, environment, and human health than any other similarly classified species. Acknowledging humans’ status as an invasive species is only the first step. It is of utmost importance to lessen the impact on the three components that make humans an invasive species.