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Crawling insects (let's call them 2D navigation specialists) on land are prey to flying insects (3D navigation specialists). But these 3D specialist predators r

Crawling insects (let's call them 2D navigation specialists) on land are prey to flying insects (3D navigation specialists). But these 3D specialist predators require more energy to navigate and maintain flying ability. Spiders invert this relationship -- they are 2D specialists that slice a 3D space with a trap, capturing 3D specialists without expending energy to navigate their prey's space. Not quite a free lunch -- it takes some prep work in the lifetime of a spider to survive. Losing your web makes you suspect to getting wrecked by robber flies until you build a new one. On a more science fiction note, I've wondered about generalizing this 2D/3D existence relationship into humans interacting with a hyper-dimensional entity. Will we also have to evolve to build traps against the perception weaknesses of our 4-dimensional invaders? Anyway, I've thought about the level of fidelity of information a spider could get from vibrations on a web. It's probably a function of nervous system ability and sensitivity for the spider to discern frequencies of forces impacted unto it by the web, as well as the frequencies filtered by the web itself. Looking forward to reading the paper.

Gravityloss 5y ago
What a cool thought! What if it takes so much energy to move in the fourth dimension that the entities have to be vulnerable? They might be even easy to catch, or destroy by accident.
fleddr 5y ago
"Spiders invert this relationship -- they are 2D specialists that slice a 3D space with a trap, capturing 3D specialists without expending energy to navigate their prey's space." I think that's a great way to put it, although "spiders" really should say "orb weaving spiders". Jumping spiders don't build a web, they are active hunters in the 3D space with the ability to plan several steps ahead. Although they can't fly, they definitely hunt in 3D and don't really conserve energy. Huntsman spiders are also active hunters, but mostly in 2D and waiting from an ambush position. They don't build a web. Neither do crab spiders, but I'd agree that these two families of spiders are trap-based and largely passive, even if the trap is not a web. Labyrinth spiders (funnel web spiders) are a fun anomaly due to the complexity of their trap, which is 3D, but arguably it's a still a passive way to hunt. My favorite would be the net-casting spider, which builds a tiny web that it holds, and then casts on its prey. The timing and coordination of that is mind blowing: https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s
dTal 5y ago
Not all spiders are 2d specialists who hunt with webs. Jumping spiders display extraordinary spatial reasoning in conjunction with excellent vision, which they use to stalk prey. Jumping spiders have been known to sit motionless for up to half an hour, scanning the landscape to plan the best route to something they can see (the FOV of their hi-res front-facing eyes is quite narrow, so this scanning is necessary to gather the required information).
- egfx 5y ago
  https://arstechnica.com/science/2021/10/spiders-are-much-smarter-than-you-think/ https://arstechnica.com/science/2021/10/spiders-are-much-sma...
- dreamcompiler 5y ago
  Jumping spiders will also follow a laser beam like a house cat (because of their excellent vision). They're fascinating.
recuter 5y ago
We are the 4-dimensional invaders of this planet. :)

Gravityloss 5y ago

What a cool thought! What if it takes so much energy to move in the fourth dimension that the entities have to be vulnerable? They might be even easy to catch, or destroy by accident.

fleddr 5y ago

"Spiders invert this relationship -- they are 2D specialists that slice a 3D space with a trap, capturing 3D specialists without expending energy to navigate their prey's space." I think that's a great way to put it, although "spiders" really should say "orb weaving spiders". Jumping spiders don't build a web, they are active hunters in the 3D space with the ability to plan several steps ahead. Although they can't fly, they definitely hunt in 3D and don't really conserve energy. Huntsman spiders are also active hunters, but mostly in 2D and waiting from an ambush position. They don't build a web. Neither do crab spiders, but I'd agree that these two families of spiders are trap-based and largely passive, even if the trap is not a web. Labyrinth spiders (funnel web spiders) are a fun anomaly due to the complexity of their trap, which is 3D, but arguably it's a still a passive way to hunt. My favorite would be the net-casting spider, which builds a tiny web that it holds, and then casts on its prey. The timing and coordination of that is mind blowing: https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s

dTal 5y ago

Not all spiders are 2d specialists who hunt with webs. Jumping spiders display extraordinary spatial reasoning in conjunction with excellent vision, which they use to stalk prey. Jumping spiders have been known to sit motionless for up to half an hour, scanning the landscape to plan the best route to something they can see (the FOV of their hi-res front-facing eyes is quite narrow, so this scanning is necessary to gather the required information).

egfx 5y ago
https://arstechnica.com/science/2021/10/spiders-are-much-smarter-than-you-think/ https://arstechnica.com/science/2021/10/spiders-are-much-sma...
dreamcompiler 5y ago
Jumping spiders will also follow a laser beam like a house cat (because of their excellent vision). They're fascinating.

recuter 5y ago

We are the 4-dimensional invaders of this planet. :)