[qnleigh]

Probably a bit yeah. But there is an argument that it is hard to store a lot of chemical energy without abundant oxygen in the environment. Oxygen stores a ton of energy, and it's quite difficult to achieve comparable energy density without it. This is the basic reason why gasoline has so much more energy than batteries, and people are developing batteries that use oxygen from the air to increase energy density. I remember reading in a Wikipedia article that Earth's atmosphere before it became oxygenated would likely not have been able to support multicellular life with energy-intensive things like muscles and complex brains.

But without knowing if Europa has any life at all this is probably putting the cart before the horse.

[nine_k]

Oceanic hydrothermal vents teem with anaerobic life which uses a lot of interesting chemistries instead, e.g. based on sulfur.

[tivert]

> Oceanic hydrothermal vents teem with anaerobic life which uses a lot of interesting chemistries instead, e.g. based on sulfur.

Yeah, but none of that anaerobic life is "multicellular life with energy-intensive things like muscles and complex brains." It's all bottom of the food chain bacteria.

[nine_k]

Technically anaerobic multicellular life exists [1], but it definitely not comparable with aerobic forms.

[1]: https://en.m.wikipedia.org/wiki/Anaerobic_organism#Multicell...