I just now took a shower, and when I turned the nob and the water came pouring down, I looked into the tub (we have a shower-tub combo) and saw a spider frantically scrambling to avoid the sudden rushing torrent of water swirling towards the drain, as well as the thunderous downpour from above. This happens a lot. I often find spiders in the tub, sometimes even two or three of them at once. Sometimes, I admit, I squash them with a piece of toilet paper before I step into the shower. This time I was feeling more benevolent and I used the cup-and-paper trick to capture the now somewhat damp spider and throw it out into the yard. While I was doing so (and while I was showering) my mind wandered to the obvious question: why are there often spiders in the bathtub? In my foggy mind the train of thought became a conversation, which I’ll try to reproduce here, with the other character played, naturally, by my friend Benji who is about to start a PhD studying spiders (though he currently has no experience in that field).
Milo: So there are always spiders in my bathtub…
Benji: ALWAYS? You mean there are multiple spiders in there with you any time you take a shower?
Milo: Okay, not always, but often, way more often than you’d expect. And I’m just wondering why they are always there.
Benji: Well maybe they like it there?
Milo: They like bathtubs? You mean they like – well what would they like about them, they’re just smooth white basins… what do you think they like about that?
Benji: Well okay, so I mean they’ve got some instincts that make them prefer that kind of environment, so when they get to a bathtub, they’ve got this real cool feeling like ‘yes, this is just right, this is what I’ve been waiting for, God, I love this.’
Milo: ‘God I love this?’
Benji: Yeah, they probably just love that shit.
Milo. But why love that shit? It’s just a shitty smooth basin.
Benji: Well I guess at some point in their evolutionary history it was beneficial to love that shit – I mean it was beneficial to love being in a bathtub.
Milo: You know there weren’t bathtubs –
Benji: Yeah, okay, fine, it was beneficial to love being in smooth basin in whatever environment they live in.
Milo: And why the hell would it be beneficial for a spider to be in a smooth basin dude?
Benji: I don’t know maybe there was hella (Benji is from Northen California) food at the bottom of smooth basins, or maybe there were spider predators who just hated smooth basins so that was a real good place to hide, or maybe – oh yeah, this is it, okay bear with me here: So there’s this spider, and he, or she, yeah probably she, she has some mutation that just makes her love smooth basins. Like she gets in a smooth basin and she’s like ‘yeah…’ So this spider lady, she also happens to have some mutations that make her super fertile and she survives hella good, so she’s basically super fit. And as a result of all that, in like 20 generations her genes are all over the place. Including this gene that makes spiders love smooth basins – which in the beginning wasn’t beneficial at all. BUT NOW there’s tons of spiders who love smooth basins and they start meeting other spiders in the smooth basins and having sex. So now liking smooth basins makes you more likely to get laid too – if you’re a spider. And those spiders who don’t like smooth basins, they’re alone out there. Cause the party’s in the smooth basin, you know. And so even though being in a smooth basin on it’s own isn’t so hot, liking smooth basins is totally essential now…. Wow, that’ s definitely it, right? Also doesn’t that maybe explain speciation too?
Milo: Well I don’t know, but you totally stole that idea from me, that’s like exactly the same as my “bad party hypothesis” about bird migration. Smooth basins, migration to North America, they’re both bad parties…
Benji: Well yeah maybe I did steal your idea, sorry dude, this is just a conversation in your head. Lay off.
Milo: Oh yeah, my bad man. But still that’s just a story, just like the bad party story. I guess it’s possible but it’s not for sure. I mean, couldn’t it be that the spiders are just in the bathtub because they can’t get out? Like they wander around aimlessly but the probability they’ll go from one place to another isn’t just even all around – the way the world is shaped can mean that moving from some place to another place is more likely or less likely. So maybe spiders are always in bathtubs because it’s like an inescapable state, it’s just a product of the way tubs are shaped and the way spiders move and the whole system of parts. So maybe the spiders don’t like tubs at all, they just end up there by randomly walking around.
Benji: That’s lame though. I mean it’s possible, but what about the whole thing where they’re in the tubs so they can get laid and it’s totally advantageous?
Milo: Yeah, that’s better for sure.
Benji: Alright, then it’s settled.
Milo: Yep, I’ll start writing the paper tonight. I’ll send it to you for edits tonight.
Benji: Sounds good.