For today’s biology lesson as I get my teeth cleaned, here’s a 20-minute video lesson about some salticids—the family of jumping spiders—that mimic ants. As you’ll see, this resemblance appears to be a form of Batesian mimicry, in which the spiders mimic toxic, unpalatable, or dangerous ants. The remarkable near-perfection of this mimicry, in which many features of the spiders have been modified to look like ant features, shows how closely natural selection can take an organism to its “optimum” phenotype. (Mimicry is one of the feat aspects of organisms in which you can judge how close they come to the “optimum”: in this case the organism or aspect of the environment they’re imitating.) It also shows the ubiquity of genetic variation, which must, during selection, have been present for every one of the modified features.
And it’s not just morphology that gets imitated, either. There’s chemical mimicry in this case, and behavioral mimicry (e.g., how the spider holds its legs in an antlike position).
The YouTube notes say this:
An exploration of jumping spiders that mimic ants (aka Ant-Mimicking Jumping Spiders) framed around a discussion with spider-scientist Alexis Dodson of the University of Cincinnati’s Morehouse Lab.
h/t: Jacques
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A wasp that mimics a spider…. “All things bright and beautiful….”
For a mimic to be successful it must live amongst the ants. What happens when an ant meets a mimicking spider? Does it perceive the mimic to be a survival threat and attack it? After all, if the predators of spiders cotton on to the deception then this might actually endanger the ants as the predator may start to attack them thinking they might really be a spider…
No, a mimic doesn’t have to live amongst the ants to be a good mimic. All it has to do is encounter a predator who had a bad experience with ants. Read about Batesian mimics; sometimes mimics and models live far apart but are encountered by migrating bird predators.
Also, ants are far more common than mimicking spiders, so your last scenario seems unlikely.
I’ve watched ant-mimicking jumping spiders a lot. They have very good vision and generally hide from any ants that they see. If they chance upon one they retreat very very rapidly. I know that the species that mimics Green Weaver Ants in Australia also targets them as prey but I’ve not observed them so I don’t know how they act. Generally the spiders avoid the ants but live in similar habitats.
Beautifully done! I see a lot of the ant mimicking jumping spiders. Also the putative velvet ant mimics, but I did not realize that about them until this video! 👍
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Pretty convincing to me. I guess that is evidence that the way birds (and mud daubers) perceive arthropods is not radically different than the way we do.
Re those wonderful Spoonerisms: I was delighted to see the full version of the “mystery lectures”. Here is one of my favorites: “Each of us has within us a half-warmed fish”. (I”ll leave readers to do their own transposition).