Alien Biospheres: Part 2 - Early life and Body Plans

"eventually we come to a critical point in the planet's evolutionary history" banging fists on table, chanting cambrian explosion! cambrian explosion! cambrian explosion!* "the cambrian explosion" wild cheering CANBREIAN EZPOXION

17:28 "How do you find a mate if you can't move?" Yep, that's a very relevant issue right now.

ahhh.... the moment you realize that Humans might actually just be Really complicated Seaweed...

Plot twist: the sessile one evolves into intelligent life.

If you have booth hydrogen sulfide and oxygen present in the atmosphere it would be flammable, makes for some really funny geology. "Here we see another layer where the world caught fire. And just above you can obsere where it rained sulfuric acid for a few weeks."

I would love to see some kind of speculative evolution community similar to the conlang community. Although I can see some problems given that we have about 7,000 languages but only 1 planet with an evolutionary history.

this world building could be great for education: you learn some real theoretical physics, chemistry, biology, linguistics, history, while pursuing your fantasies and learning how to present them in words or visuals. this should be in schools.

I'm a biologist, and I gotta say, this is awesome! Such a good introduction to zoology for non-scientists! The only correction I would make. Insects do not use blood for pumping oxygen. Insect's ''blood" is basically a liquid soup in which their organs sit, they don't have blood vessels, and their hearts are very weak and doesn't move the liquid very fast. The blood really only exists to transport nutrients extracted from the gut. to transport OXYGEN, insects have branching AIR TUBES that run through their bodies from holes in the sides of their abdomens. This is less efficient than the lung/blood combo that vertebrates have, putting a hard limit on how big insects can grow. Some insects can pump their tracheae to increase efficiency. You ever watch a wasp or a bee after it lands from flight? How they pump their abdomens like their shakin what their mama gave them? That's because it's pumping it's tracheae, basically it's panting after the hard exercise of flight.

Nobody: That one bacteria about to trigger the Cambrian explosion: Sunlight’s chill n’ all but that archaea lookin hella thick tho

This is so cool. There's actually a worldbuilding course I am taking for English at school, making maps, languages, planets, geography, and writing stories. It's so cool, didn't think I would learn this sorta thing at school..😅

the hardest rule of the Alien Biospheres drinking game: Every time the Square Cube Law gets brought up, finish your drink

This feels like I'm an alien watching a class about earth. Interesting new feeling.

I can see the Radial design becoming a VERY interesting predator. If they change to me more mobile over time, like their young, they can very quickly become mobile and dangerous. Having some of those 'Feeder Petals' specialize into locomotion and others using concentrated acid from the Sulfur they use for their shell they can go a kind of hybrid Internal/External digestive organism. Now each Radial point would have one 'Mouth Petal' and a 'Fin Petal' as well as a kind of capacity organ for the acid. Things would get... interesting if they get into the trees and still manage to be radially symetrical. Imagine a fast moving creature with eye clusters near their "Hands", which also double as a poison sprayer. These would be pretty amazing ambush predators or active hunters and spawn all kinds of sub species to hunt or be hunted by specific other animals. I do so enjoy these theoretical Evolutionary things, here is hoping to see more soon!

Sort of surprised TierZoo didn't get a crossover. That would have been really fun to see.

I do think maybe you should have mentioned the Ediacaran explosion before the Cambrian. It's not as well known or understood as the latter, and none of the known organisms from that time have a later evolutionary lineage, but it did mark the true transition from simple to complex life.

I want more of this planet. I REQUIRE MORE ANTHOSTOMAE I WANT ONE AS A PET WHEN IS THE NEXT SHUTTLE TO WHAT THIS PLANET IS CALLED

Switching between radial and bilateral symmetry seems less difficult if one thinks about. Radials have a top side and a bottom side that could turn into an anterior and posterior fairly easily. From that one side could be favoured to become the new top/bottom side of a motile.

I learnt more words in this 20 Min video than I did in 5 years of High School English...

17:00 I wonder why hermaphroditic systems aren't as widespread in multicellular organisms, since in theory it allows for even higher rate of gene exchange and mutations during the procreation, compared to defined sexes, since in this case you can mate with any member of your species, instead of only half of the population.

Crazy to look back at the beginning where we only had a little worm thing and a little sea anemone thing