The Most Invasive Species?
Maybe ten to fifteen years ago I was thinking about the concept of an invasive species. It occurred to me that perhaps we humans are the most invasive species on the planet. We’ve moved out of Africa to nearly every corner of the planet. And, we’ve disrupted nearly every ecosystem along the way.
Recently, I heard an interview with Shane Campbell-Staton, evolutionary biologist and host of two PBS series Evolution Earth and Human Footprint (which are both thoughtful and fascinating shows). The interviewer asked him about a scene in one episode of Evolution Earth where he discusses this idea of humans as an invasive species with another scientist. And she asked him if he thought that humans were the most invasive species. He said he thought so. It was a hundredth monkey moment that confirmed that at least two other people had the same idea.
Hearing Shane Campbell-Staton’s point of view as an evolutionary biologist gives the idea some credence. Also, his research into how human environmental impact affects evolution and the work on his two TV shows (which are really worth watching — can’t emphasize that enough) really highlight the impact we humans have had on the planet we call home.
The interesting thing about the concept of invasive species is that humans are usually the cause of a species’ spread from one ecosystem to another. We have brought non-native plants all over the world for agricultural purposes. We have also done that with animals. And animals (usually rodents) have even stowed away on ships to migrate from one continent to another. Some of our spread of non-native species has been inadvertent.
Even as we ourselves have had such a massive impact on nearly every ecosystem, the fact that we have spread so many invasive species has acted as a force multiplier or our devastating impact. Is that more evidence pointing to our superlative power as an invasive species?
Sometimes I wonder what the earth would have to say about us as the top invasive species if she could speak.