We did note that humans are the most invasive species at all. We are often the ones who bring damaging species into an ecosystem as we travel.
Sometimes invasive species are introduced purposely but have unintended consequences, as when cane toads were brought to Australia in an attempt to control the bugs in the sugar cane fields.
There are other instances when the travel of species is not considered a problem. I mentioned the Columbian Exchange, which caused potatoes, tomatoes, and cocoa to spread outside of the Americas, and diversified food without causing huge disasters.
Plants can be invasive. Kudzu vines, bamboo, and pampas grass are examples of problem plants. Eucalyptus trees were brought to America because they grew fast and people hoped to use them to make railroad ties, but they brought a soft-wood species rather than a hard-wood species. Now those trees are all over... but are generally not thought of as damaging.
When you bring a foreign plant into a new ecosystem you can get the "silent forest effect," which is where none of the local insects or birds are able to interact with the foreign species and so the ecosystem's diversity becomes suppressed. This has happened sometimes when forest-planting charities have planted non-suitable trees.
We asked, "Would we survive on another planet? Would our crops interact well with bacteria and fungi?" I mentioned the case of Chris McCandless, who was poisoned when he ate the wrong kind of grain in the wilderness of Alaska. Che suggested that we might not survive unless we terraformed from the ground up.
Whales eat krill which in turn eat phytoplankton, but if you try to remove whales from the web so you can use the krill yourself, you forget what the phytoplankton survive on, which is the fecal plumes of the whales.
Sometimes we don't realize what impact a species can have on its ecosystem, and only discover it later after it has been lost and then reintroduced, like wolves in Yellowstone. What would happen if beavers returned to California?
What if a species on another planet died out but could somehow be replaced by a species from our planet?
What if you introduce something invasive accidentally - should you bring something else to keep it under control? What kind of trouble would that creature cause? What kind of research might prevent the problems?
Two stories that deal with these questions are "Contaminated" by Jay Werkheiser (Analog) and the novel Archangel by Marguerite Reed.
As a group, we had seen instances of invasive species less often in fantasy in science fiction, though the phenomenon happened as soon as sailors would start landing on islands with things like goats that endanger tortoises, rats that endanger insect or bird species, etc.
The water buffalo is an invasive species in Australia. Australia has many examples of harmful invasive species in part because it is a (large) island that separated off from the other continents very early. People who traveled did so without any concern for people already living there, and even less for animals already living there.
In my current novella, I'm working with a transplanted species called haali (a flower bush), but it is not invasive, needing tending in order to survive. I mentioned how when I was weeding in my yard over this winter and spring, I left some areas wild in order to preserve the insect population of the yard. Morgan said she had deer in her yard!
There are wild parrots in Britain (more invasive) and a flock of parrots in SF that seems relatively stable. They affect the grape harvests.
Mint will take over your yard. Blackberries are a scourge from Northern California up into the Pacific Northwest, and gorse is a problem in Oregon.
We imagined what it would be like from a dragon's perspective, seeing humans as an invasive species. We also wondered what ecological effects would have cascaded from the genetic engineering of fire lizards into dragons on Pern.
If you took invasive species into fantasy, they might cause change in magic systems as well as physical ecology.
We saw invasive buzzy cute critters in My Little Pony. There were also green Smurfs.
Morgan suggested that it would be interesting to consider the introduction of magical species where there was no magic, which made me think if the changes in Jeffe Kennedy's novel world. You could easily see a magical imbalance grow out of that.
Thank you to everyone who attended! Next week, on October 19th, we'll be discussing Social Class and its values. Our next guest, Marshall Ryan Maresca, will be joining us on November 9th to talk about his latest novel. More on that soon!