Yesterday, while doing a bit of yard work, I noticed a largish jumping spider (family Salticidae) on the door of the sun room. I ran and got my camera and took a couple of close-ups. Shortly thereafter, a different (smaller) species showed up on the opposite door, so I took a couple of shots of that one.
I really like jumping spiders, which puts me at odds with all other members of my family. After all, who could like a spider that jumps? Well, I do, because jumping spiders have a bit of personality. When I wiggle my finger at one, it will turn and look at me, almost like a pet dog. Sometimes, I can get them to jump onto my finger.
One reason they're so responsive is that they have pretty good vision. Most species have eight eyes, some of them quite large, and those eyes are capable of image formation, like ours. It's an important adaptation for these spiders because they're tiny little wolves - actively tracking down their food and jumping on it rather than ambushing it or trapping it in a web. Good vision is a prerequisite for such a life; thus their attention to my wiggling finger.
Reflecting on this, I wondered why most of humanity has such a deep, innate fear of spiders. Dangerous spiders are few and far between and are responsible for very few human deaths in any particular year. In our area, I've never seen a dangerous species (black widow - several species; brown recluse - several species) though I suppose the occasional brown recluse could find it's way into a home if someone accidentally brought one with them in a move from the southern U.S. In fact, no one really has a good explanation for this exaggerated fear. One possibility is that a fear of spiders was adaptive in ancestral humans, as people who were so afraid of spiders would make every effort to avoid contact with them and thus avoid potentially deadly bites. But even in our ancestral days, encounters with deadly spiders were likely very few and far between compared with other more significant dangers and an unreasonable fear would have been maladaptive rather than adaptive. It could be a cultural thing, as many humans who live in areas with spiders far more dangerous than any we would encounter regularly catch spiders and use them for food. In any case, the only spiders around here that I kill if they get in the house are large wolf spiders.
