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.