The evidence of wasp evolution around my home is an example of animal urbanization, i.e., how living things adapt to encroaching humanity.
We live in a rural area, and there are quite a few pests. Among the sneakiest are the wasps. They are hard to find but if you get too close, or bump into a shrub that hides the nest, you find them, way too quickly. If you’re lucky only one wasp pops you.
It you’re not, you can end up with a lot of nasty stings.
Fortunately for us, our dog finds most of them. We’ll hear him yelp and then I’ll gently search the area until I locate the nest. Then I spray it. But even once I know where the attack took place, the nests can still be hard to find.
One day I was roughly pulling weeds from the shrubs, and bent back a shrub to get to the roots of a weed, only to discover a paper wasp nest, with about a dozen wasps on it, a few inches from my face. I let go of it, grabbed my little girl who was playing next to me, and ran a few yards away.
Nothing came out.
I was puzzled; as I said, I had been yanking weeds, agitating all of the bushes. I had back the shrub until the nest was almost horizontal, and then I let it go quickly. Any one of those should have brought out the nest en masse, and en colère.
I got some insect spray, gently approached and sprayed, then jumped back, because the spray sometimes elicits an attack.
But nothing happened. They just died.
Several friends have offered various explanations: it was the time of day, or the heat, or the humidity, or the wasps were sick. I don’t buy any of that. I’ve never heard any description of wasp behavior other than extreme, around-the-clock aggressiveness. I’ve surfed around on the Internet, I haven’t found any descriptions or explanation for paper wasps not attacking when disturbed.
After thinking about it a while, I suspect it’s an example of wasp evolution, and the kind of small evolution. I noted that wasp nests are hard to find, and we generally locate them when the wasps sting. The aggressive stinging, or course, warns other animals to stay out of the area.
The problem is, humans are different. We have developed toxic sprays that can kill them. So when wasps sting people, particularly around our homes, they aren’t driving us away.
They’re telling us where they are. And then we come back and wipe them out. It creates pressure for wasp evolution.
So it was only a matter of time before a population of wasps appeared with decreased aggressiveness. It’s an example of animal urbanization, how animals evolve and adapt to the encroachment of humanity. This peaceful wasp behavior may have appeared previously in wasp evolution, maybe even with the earliest wasps and/or their relatives. If so, the peaceful wasps disappeared because the more aggressive wasps won out. Pacifist wasps lose out in the struggle for life.
Or at least they did. Because today, if non-aggressive wasps appear and prefer to nest around people, they may have an advantage. Modern insecticides have created new and very recent pressures on wasp evolution. Suddenly, aggressive wasps are at a disadvantage because they give away the location of their nests. At the same time, perhaps peaceful wasps stand less of a chance of being located, and therefore have a higher chance of surviving.
It’s animal urbanization. Living quietly near humans may give peaceful wasps an advantage. They have access to human waste, which often grows nutritious larvae. They can benefit from the clearings around our homes, particularly since many wasps drink nectar, so they can snack on our lawns and in our flower beds. All the while, we keep many of the wasp’s natural predators in check for them.
This is all conjecture of course. More observations and reports would need to be made of nonaggressive wasps before we could be sure.
But whether or not my particular wasps were selected to behave differently, if there is some advantage to living peacefully around humans, sooner or later wasp evolution and animal urbanization will produce members that are nonaggressive. They will become ‘domesticated’, i.e., they will adapt to live ‘around the home’. It’s an example of how animals and plants can change.
And humans too.
Small evolution is critical for understanding how humanity has changed, and it makes no difference if humanity has been around for many million years, or only a few thousand years. Our biology, and our history, have shaped us.
And if we are to build a better world, we need to build on our strengths, and work around our shortcomings.
As I noted, several people, including some biologists, objected to my thesis here, saying that the wasps didn’t attack because of the time of day, or because the nest was too small.1)If you disturb a tiny fire ant nest, the ants will often flee rather than attack.
But then in October of 2017, we had another nest of non-aggressive wasps. My wife was pulling weeds out of our beds at different times of the day, and although she saw wasps flying out of from somewhere in the vicinity, they never attacked her. This is in contrast to another nest we had a few months ago, that attacked when someone even brushed the branch they were on.
When we finally located the nest of the passive wasps, it was fairly large, maybe 7″ (18cm) across. Unfortunately, I finally decided not to take chances with my family, and sprayed them. But even that supported my thesis. When I have sprayed nests in the past, the wasps fly out and can be aggressive (hence some spray products that can hit a nest from some meters away). But when I sprayed this nest, the wasps did not fly out. They stayed where they were, and died.
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Brown Paper Wasp courtesy of Wikimedia.org.
Footnotes [ + ]
|1.||↑||If you disturb a tiny fire ant nest, the ants will often flee rather than attack.|