It turns out that our reaction to invasive species may have more to do with our fear of the ‘alien’ than environmentalism. Recently I got to listen to an interview, from CBC’s Quirks and Quarks, with ecologist Ken Thompson.
Thompson’s book ‘Where Do Camels Belong: Why Invasive Species Aren’t All Bad‘ lays out the case for the possible benefits of invasive species. He points out that our approach to new species misses some fundamental facts.
First, species have been moving around the Earth for far longer than man has been around. The answer to the question “where do camels belong” is North America. Camels originally evolved in North America 40-50 million years ago and continued to live here until about 10,000 years ago (about 5,000 years after the first aboriginal people’s arrived). It is believed that they migrated across the land bridge the other way and were eventually brought into the Middle East (where they were technically an invasive species).
Second, while it is true that invasive species arrive and spread much more quickly as a result of humans and our transportation systems it is also true that humans are naturally occurring. Just because humans move something doesn’t mean it’s unnatural. This is, after all, our world and there is no part of it we haven’t changed; We’ve changed the climate, mined the mountains, cleared forests, built dams, drained swamps, created man-made lakes and have even altered the chemistry of the Oceans. Manmade and natural are really the same thing at this point or at least two halves of the same coin.
Thompson points out that a thorough analysis of the impact of many (not all) invasive species shows that they are having a benign or even beneficial impact on their new environments. As an example he points to zebra muscles which have provided a new and abundant food source, allowing many native species to increase their population and have served as a pollution filter causing clearer waters in the Great Lakes.
Though I haven’t picked up the book yet, the logic of the argument not only has me re-thinking invasive species it has me wondering if some of our environmental and even regional food shortage problems might not be solved by deliberately spreading certain species.
The full interview with Professor Thompson is below. There is also a panel discussion, which includes Thompson and others on CBC’s Ideas but that conversation does not appear to be embeddable. You can, however, listen to it here.