“I used to think growing up that the biggest thing I had to worry about was an invasion from outer space. I love those Hollywood movies where a flying saucer would show up and all of a sudden zap forests and people. But I’m going to talk about a different kind of UFO today ...
“When I got out of school and started hiking around national parks, I was alarmed, for example, that in the U.S. I saw Europe everywhere I went. In Grand Tetons National Park in Wyoming, the valley floor takes on many colours during the spring and summer — because of the musk thistle from Europe, the red bronze from Europe, and the yellow sweet clover from Europe.
“Well, I don’t go to my national parks to see Europe. When we lose a little bit of our biological integrity, we lose a little bit of our cultural integrity. It’s no longer just us. Some of these things are outcompeting native species, and I’m convinced native species are worth saving. To do that we have to take a far better look at the UFOs: the unwanted foreign organisms that have come in and are changing our world ...
“When the continents were far apart, our species were somewhat isolated. They were living the good life. But something changed. We had an age of exploration. Columbus started sailing around the world.
“In the last 150 years, more and more boats have gone around the world, and we brought back all kinds of things. And in the last 60 years, we’ve had that exponential increase in trade and transportation. Now we’re all trading around organisms left and right ...
“We brought the continents back together again, and now we have a sample size of one — one globe. We have changed the way plants and animals have to do business. We’ve changed food webs. We’ve changed ecology. And it’s no mystery that founding populations are enough to drive species into extinction ...
“So what are we going to do about this? If these invasive species are harmful somehow to the economy, to the environment or to human health, we want to minimize their effects ...
“Climate change may move a species at five kilometres a year, but a Walmart truck can move it around at 500 kilometres a day. It’s us. It’s trade and transportation that moves things around. It’s getting on a website and ordering something. It’s going to your local nursery and buying something that maybe shouldn’t be in your area ...
“Why am I not worried? I’m a total optimist, and I’ll tell you why. Because we have the next generation of scientists who are a lot smarter and faster than I am, and than we are collectively. We want to encourage that next generation. No matter how young they are, encourage the science — the technology, the engineering and the mathematics — and have them put it to a purpose. Have them prove at the end of the day that they helped save the world.”
TOM STOHLGREN, PhD, is a leading authority in the field of biological invasions, senior scientist at the Natural Resource Ecological Laboratory at Colorado State University and director of the National Institute of Invasive Species Science. On March 12, he brought his signature humour and engaging style to the University of Waterloo for the 2015 TD Walter Bean Lecture, “Invasions from Inner Space: Species Invasions and Extinction.”
