Energy expenditure IS significantly affected by training. An out-of-shape cardiovascular system uses a lot more energy to get the same job done as an in-shape one, and that applies to handling extra load, too.

So two animals with genetically-programmed (and environmentally-massaged) reflexive behavior, and with different genes (and environments) from one another, behave differently from one another. That is incredible.

But in Star Wars, all of those races, worlds, cultures and quirks are on display in about 12 hours of screen time (6, if you're just talking original trilogy, which Robot Chicken largely limits itself to). Star Trek's races are spread out over hundreds upon hundreds of hours of episodes and movies, and a great many…

". . . if that doesn't describe good tool use, I'm not sure what does."

While jaws didn't give them a better hand, it let the jawed fish play an entirely different game. "Didn't out-compete" means that jawed fishes weren't eating the same food as jawless fishes . . . they were eating new, different food that jawless fishes couldn't possibly hope to eat.

The arrival of fur, placental birth and milk-production didn't cause mammals to immediately out-compete their reptilian/archosaurian competitors, either. And most of the placental mammalian orders were already established 20-40 million years before the ruling reptiles (pterosaurs, non-avian dinosaurs, mosasaurs,…

Yeah, but car lights are limited by their angle and how bright they can safely be (you don't want ridiculously bright headlights because then you start blinding oncoming drivers).

It'd be interesting to see a 2nd-tier superhero movie where the superhero was 2nd-tier even in their own film. Like an Aquaman movie, where Aquaman gets to help dolphins caught in nets or the occasional submarine, but Superman, Batman or Wonder Woman (or Flash or Green Lantern or . . .) swoops in and saves the day…

I wonder if the researchers considered that the older spider is substantially larger and heavier than the younger one. That's got to throw off a number of sensory cues that spiders might rely on to construct their webs. The appropriate distance between spiral loops is a smaller fraction of the spider's body width,…