Alien Biospheres: Part 2 - Early life and Body Plans 

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

"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

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."

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

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.

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

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

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.

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

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

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..😅

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!

"Feel free to use whatever nomenclature makes sense for your project" Me using a nomenclature derived from the language I made with the help of his tutorials: "This guy has made my worldbuilding project infinitely better and he doesn't even know me or what I'm doing"

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*

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

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.

Rewatching in preparation for the release of part 15!

6:45 Urbilaterian are now to be defined as either "Ant Dogs" or "Water Beans", and must be considered as *absolutely precious.* 19:05 (Taking notes)

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.

1:50 It should be noted that radiotrophic organisms also exist.

Getting real “the history of the entire world, I guess” vibes here

Sometimes I just rewatch this series when I feel a creative itch and want to get my brain going. Plus they're really relaxing. Excited for more in the future

Or you could just say “F symmetry” and make a shoggoth... but who am I to judge?

so happy you're doing this! not a lot of good spec evo content on youtube sadly, that could just be me though cause I'm a bio major and a lot of the spec evo videos on here feel like suuuuuper basic biology courses lol but this is good because it does something I don't see a lot of videos shows and and books on speculative evolution do: actually lay out and explain general principles, rules, and driving forces of evolution. so I'm really excited to see more of this!

I feel like you didn’t pay much attention to the amount of sulfur in the ocean. Amazing video anyway! I love these type of evolution videos

"a collection of primitive hearts" sounds like an indie punk album name lol. This series is amazing btw

every single biology and chemistry video I've ever watched, along with the. current chem and bio courses I am taking, has all been for the purpose of following this series. in a selfish way, it feels really good to be able to easily follow along with all the jargon

I guess the Voynich manuscript was just some ancient nerd's elaborate conlang and conworld project.

It is amazing to see the development of life on this planet begun from anemones and sea centipedes, to myriad of "squids" and "spiders". Truly an amazing series.

This is so cool! I love how deep you went into detail!

New video just came out, so I feel like rewatching whole series again

Do a triple person collab with Ewa and Artifexian!

Holy crap I never clicked this fast in my life.

Just found your channel. As a fantasy/scifi artist working on a comic taking place on an alien world I've so far struggled to come up with a diverse ecosystem that isnt just a slightly altered version of earth. This information is extremely valuable, thank you.

Rewatching this series because its just so got dam interesting

Smh, and I hoped you would mention the Avalon explosion. That said, awesome vid. Inspirational.

Great work, can’t wait for continuous episodes! I know it is a lot of work, just know that I am awaiting anything you will put out in this subject and that you should not give up!

Had almost forgotten about this after watching the first episode a few weeks ago. But now I am very excited to see it continue! :D

I used to research all these during my free time and I'm glad I found this series. Thank you making a series like this, it really helps in worldbuilding!

this is one of the most interesting and well presented speculative biology studies ive ever seen - thank you for using your knowledge to create such a thought provoking world! i love the illustration you use as well, it makes it that much more engaging. i didnt have to think twice about subscribing!

This has come far wow never expected this would become so great

I need more. MOOOOOOOOOOOOOOORE.

the best speculative biology/science series I've ever watched on this website. your respect and understanding for biology, chemistry and the fundamental laws of the universe are more than evident. it makes the series so much more interesting than it otherwise would've been because the creations are logical and theoretically plausible, which just blows my mind.

I have been looking for something like this for like 5 years now! Thank you!!

These videos, they are so well executed. It's mentally titillating and you even encourage us, the viewers, to try it ourselves

start of series: radial= sessile ep.6 radial: AND IT'S FLYING HIGHER ! THE KING OF THE SKY!

Fascinating! I could imagine that in the taxon of Anthostoma some species develop their arms into a free swimming sexual stage creating metagenesis (maybe over an autotomic step), while others could achive neoteny in their larvae creating the taxon Anthosoma... Or there could be a taxon in which the Arms of different individuals grow together after breaking off and a short free swimming stage, forming a sexual symbiosis (I think I once read that something a bit similar occures in some species of polychaeta). Speculative biology is always epic!

This was amazing!!!! I think I’m just gonna sit here and patiently wait for the next video...

This series is amazing but I have one suggestion: Maybe animate the models as you describe them, I think it would add a nice touch to these videos. Again, just a suggestion, Keep up the good content!

Bravo I did not expect this when I clicked on the video, this is extremely interesting and wouldn't mind trying a project of my own, great job man

oh god i needed this i'm planning on making my own alien biosphere and this is so informative!

Hell yeah! Been waiting for this!

my god i cannot wait for the next episode. this is amazing

This was great! I know biology because I studied it, but this summary for world building purposes is greatly appreciated!

This is all absolutely informative and creative, thank you for such content, please continue it!

I just discovered this channel. With each video I watch here, I am consistently embarrassed by how little I know about the world and slightly gratified to come away knowing a little bit more. I'm not sure if you'll ever read the 986th comment on a video that's nearly a year old, but if you do, then thank you for making these videos. Truly.

this some of the best stuff to watch high

Easier way: Make them in spore

Rewatching all these. Such an amazing project :)

You can see every little detail in making the first animals reflected in the rest of the entire series. It’s great!

omfg i'm so happy i finally found this, i've been stuggling because i don't willynilly wanna make "cool" aliens this is exactly what is needed, thank you so much!!!

Oh my god I love this and I haven't even gotten past the thumbnail lemme at it. Gotta watch the first one first of course tho

this series is gonna blow up i am glad i am here since the start

Your explanation of Convergent Evolution is leaps and bounds more accessible than those I've heard on my own campus. Very well done! (As in, I had understood the concept, but until this explanation there was no 'click')

Great video! I really hope that you can cover non-animal lifeforms similar to plants or funguses? I know plants are simple: cluster of cells got together, formed shapes to maximize sunlight, got on land, got water and nutrient transportation system, got hard and can stand up, got reproductive organs that suit various wet and dry environments, formed cooperative relationship with animals. But they are interesting and are crucial parts of the food web and ecosystem.

A few comments first do note that aerobic photosynthesis wasn't the first form of photosynthesis but yeah oxygen gets you the most energy per reaction. From looking up anaerobic photosynthesis and respiration there is another combination that seems to be nearly as efficient as oxygen, Iron. There are several problems with it namely that it doesn't really permit adaptation to the land since while iron does dissolve into water it doesn't become a gas at hospitable temperatures and that Iron readily reacts with molecular oxygen to form the insoluble iron oxide The main gripe is the role of endosymbiosis getting neglected I mean it literally is the fusion of two organisms into one which is amazing and probably the single most important development in the history of life on Earth! If looking to compare what happened on Earth to interpret how they might effect alien planets is some of the strange and interesting stuff. It should be mentioned that we have no evidence that bilateral symmetry is specifically ideal as it could be a survival bias caused by ancient mass extinctions leaving the survivors to radiate out. So it does seem feasible to pick one of the more exotic symmetries such as the fascinating fractal symmetry triangular symmetry, or chiral asymmetry that evolved within the Ediacarian. Though I would agree that since they were primarily sessile body plans. One fascinating recent discovery that reframes the context of bilateral symmetry in a way that could allow far more exploration of body forms is the discovery that bilateral symmetry was actually ancestral to the last common ancestor between the sister groups bilateria and cnidaria which was a surprisingly complex bilaterally aligned animal with a basic nerve net, simple muscles and a single mouth able to differentiate from two body cavity layers. This is interesting in the context that urbilaterian was surprisingly primitive the main distinction between the last common ancestor of the two clades and urbilaterian being the differentiation of cell types from one body cavity layer into two for a total of 3 altogether. It also adds to the narrative of convergent evolution as ancestral cnidarians secondarily evolved radial symmetry as an adaptive response to a more sessile lifestyle as we now know this has evolved at least 3-4 times Ctenophora, Cnidaria, Echinodermata(echinoderms), and to a lesser extent Tunicata. With exception to the mysterious and ancient Ctenophora, the later 3 groups all shared a common ancestor with a bilateral body plan as they adapted to a slower less mobile lifestyle. The Tunicata are particularly interesting and disturbing as they are chordates meaning they descend from animals with a primitive backbone and a brain. In fact they actually hatch into tadpole like animals with both "brains" and notocords(primitive backbones) which they use to swim find a place to attach to for the rest of their lives and then reabsorb their brain notocord to become fleshy somewhat more radial organisms. Another interesting piece of the puzzle that could be important and interesting to play with is the seeming link between Snowball Earth events and the appearance of multiple lineages of multicellular life which seem to have been deeply linked as both the Paleoprotozoic and Neoprotozoic snowball events are followed by radiations of multicellular life forms with diverse arrays of morphologies and characteristics. Now the first of these on Earth the Francevillian biota failed suddenly as for some reason the Earth transitioned back into a primitive low oxygen state after a few hundred million years of diversification and radiation, followed by the "boring billion" a period of billion or years where life was purely unicellular again. Then you had the Earth froze over again several times in quick succession after which the Avalon explosion and later more familiar Cambrian explosion occurred. The question of why did the first radiation fail and what if it hadn't seems quite a interesting exploration which could allow a far longer period of developing complexity. IRL something caused oxygen to severely diminish but that needn't of happened on an alien world so it could be perfectly reasonable for complex life to arise in such a scenario about 2.3 billion years ago. Given what life has managed to do in the last 600 or so million years just imagine what might come out of two billion years! :D

Very excited to see where youll take this

I’m so exited for the next episode,

15:01 That kinda looks tasty. If i were a predator on that planet i know what i'd eat..

This taught me more about biology than school did...

absolutely love this series, its awesome

It's been two years and i only just realized the sessile creatures have an armour of essentially plaster or gypsum

I like how the spores have mobility as a trait 😍 It would be interesting to see them develope mobility in their later stages as well.

A new vid of biblaridion. *click immediately* *pause* *writing a comment saying what i did and am doing*

Crystal clear and utterly fascinating. Subscribed at episode one. Looking forward to more.

this series exemplifies why things on earth are the way they are so effectively

Where did you make/get the designs for the early life body plans? I'd like to try and make my own but I'd like to see if there's a site or a template I can use for reference.

Hell yea dude hell yea this is so up my alley I'm wondering how you even found my address

This series is great so far.

just started this series, this is just amazing

🎵🎶it's 🎵🎶the 🎵🎶Cambrian 🎵🎶explosion!! 🎵🎶

Well, just finished the new video, time to restart the series from the beginning. Again.

Very good information, thank you bib

This is awesome, it is really helping with a project I am working on! Keep it up!

Are you going to cover plant evolution in this series as well? Do you think it would be feasible for this world's analogue of eukaryotic plants to have evolved symbiosis with both the analogue of the cyanobacteria (as Earth's plants did) and the chemotrophic bacteria so as to have two energy sources or would this be inefficient? Also I grin in the general direction of the organism with the plaster of paris exoskeleton.

Not gonna lie I'm excited to see if there is any advanced civ that develops

i so hope there's a part three.... this is amazing

this is well made. thank you for posting this

How did you model the animals? I would love to maybe make my own Speculative Evolution stuff.

The guy: * Explains his context of the life on a planet * Me: I like your funny words magic man.

Awesome video! I learned so much

Someone should show this series to the people, who deny evolution, because they think of it being "illogical". It is pretty inspiring to see a theoretical alien world evolve and I am eagerly looking forward to the next video in this series.

Awesome video! What did you use to draw the creatures? Google Sketch-Up?

Very nice work!!! At minute 3.10 there is a confusion between aerobic celullar respiration (glucose oxidation) and breathing/ventilation (oxigen and carbon dioxide exchange with the atmosphere)

I don't know how I got here but I found this interesting so I am staying. Good vid nice to see science done simple.

I remenber the first time I saw this video. I didn't understand nothing, my English isn't perfect even more in the past. It''s a amazing serie about alien life planets, It's very interesting. Keep making other videos like this and I will be happy.