Skip to main content

Humans: Earth’s Most Invasive Species

Ruth Hopkins column about humans being the most invasive species on Earth.
  • Author:
  • Updated:

I grow wildflowers. Part of the price one pays for enjoying the beauty of an organic flower garden is spending a considerable amount of time pulling weeds.

A weed is any plant that humans consider unattractive, undesirable, or bothersome, that persists in a place where it is not wanted. Invasive weeds all possess the ability to spread rapidly, and are associated with decreasing property values as well as reducing the production of livestock or crops. Most invasive weeds are not indigenous to the locale in which they’ve been designated as such.

While weeds may be classified as invasive, no plant—even ones that are poisonous—are bad, per se. What makes them invasive is the fact that they have been harmful or troublesome to humans or livestock, or are highly competitive with plant species that humans prefer.

Despite the negative connotations associated with invasive weeds, many of the same plants have medicine uses. St. John's wort, (Hypericum perforatum) is classified as an invasive weed in my home state of South Dakota; however, tea made from St. John’s wort has been used by American Indians for centuries as a pain reliever and in the treatment of tuberculosis. Today, St. John’s wort is used as a herbal remedy to treat depression. Hypericin, a complex molecule found in St. John’s wort, is strongly antiviral and is currently being investigated for its ability to inhibit HIV (human immunodeficiency virus) and HPV (human papillomavirus).

Not all invasive species belong to the plant kingdom. Invasive animal species are not indigenous to the habitat where they have become a problem. They upset the natural balance of their new home because natural population controls like predators are no longer present. As a result, invasive animal species disrupt their new environment by essentially taking over, often to the detriment of species native to the area.

Most invasive species have been introduced by humans. History is replete with examples of how humans have brought non-indigenous species to new habitats, often during the process of colonization. The majority of animal species introduced by humans eventually become invasive. Ship rats (Rattus rattus) originated in India, but because of human exploration and colonization via ships infested with rats over the past several centuries, the species has spread to nearly everywhere on Earth. The rat is now classified as an invasive species that has caused the extinction of multiple wildlife species abroad and contributed to the decline of others. In 1854, a mere 24 European wild rabbits (Oryctolagus cuniculus) were released in Australia for the purpose of recreational hunting. Rabbits soon infested much of Australia and are now held responsible for the extinction of a number of species on that continent. They continue to cause millions of dollars of damage a year. In North America, the German cockroach (Blattella germanica) is an invasive species originally from Asia that now infests countless human dwellings.

Scroll to Continue

Read More

Even though plant or animal species may be classified as invasive, they could be viewed as evolutionary successes. They’ve adapted to their environment, and successfully reproduced offspring on a grand scale. What makes them invasive is that we as humans deem them so, and most of the time the species in question became invasive because they were introduced to foreign habitat by humans.

Evolutionarily speaking, human beings (homo sapiens) have been successful too, but not in any romanticized version we might like to imagine. Much like the invasive species we distain, we've thrived at the expense of other species and become adapted to the progressive destruction of our collective environment. We’ve managed to eliminate or weaken most of the natural population controls that kept the human species in check. Thanks to humans, the majority of predators that once preyed upon humans, like tigers and wolves, are either endangered or extinct.

Because of modern humans’ irresponsible management of resources and inability to live in balance with Earth’s natural systems, we could have more in common with invasive weeds, rats, and cockroaches than the majestic endangered animals we admire. We have allowed ourselves to become scavengers and opportunists who strip Earth of its resources at a rate that cannot be replenished, and take from every other species on Earth to our advantage. One can only conclude that there’s been a major oversight on the list of invasive species plaguing natural habitats abroad: humans are the most invasive species on Earth.

That said, if humans were to be classified as invasive, it does not mean that we as a species are all together bad. Like St. Johns wort, we too have medicine. We have the ability to change our behavior and help heal our planet. Unlike the beasts of the field, we can make a conscious choice to start living in balance with Earth. We can choose to respect the laws of nature and life in all its forms.

As indigenous people, natives should reject the slash-and-burn "Drill, Baby, Drill" mentality of many modern humans in western society and instead take a leadership role in showing the entire human race how to live in balance with the earth, our mother. Let us heed the advice of Tatanka Iyotanka, Hunkpapa Lakota Chief Sitting Bull, who said, “It is not necessary for eagles to be crows.”

Ruth Hopkins (Sisseton-Wahpeton/Mdewakanton/Hunkpapa) is a writer, a pro-bono tribal attorney, a science professor, and a columnist for the Indian Country Today Media Network. She can be reached at