[wruza]

what a billion years of feedback loops and randomness can achieve

Half a billion, afaik. And also how technology matters. Oxygenless ~3.5B years were boring as hell.

For those unaware: Earth not always had O2 in its athmosphere - O2 is a result of one kind of ubiquitous goo that was emitting it as a byproduct. And while it oxidized what it could on the surface, it killed almost every goo, cause it is a poison. Then (and that is still an unproven theory) oxygen-breathing evolved and allowed for fast movement and carnivory, which started arms race of tracking and evasion, coordination, vision, swarming, etc. 0.5B years later here we are.

Btw, there were even higher peaks of oxygen concentration that allowed for animal-sized insects to exist. A time insectophobes wouldn’t want to live in.

Scientists know that dragonflies with wing spans as wide as a hawk's and cockroaches big enough to take on house cats lived during the Paleozoic era (245-570 million years ago). At the same time, mammoth millipedes longer than a human leg skittered across prehistoric soil.

[mietek]

Big millipedes are still around! Although not quite as big as before.

https://youtu.be/oY32HPQrhYg?si=z0QO821u3-E5sJ6l&t=480 (about millipedes from 8:00)