Ciro Santilli - we are very far from full understanding. End game is a design system where you draw the body and it compiles the DNA for you.
- some cool mentions of regeneration
How genes form bodies.
This is hot shit, a possible worst case but sure to get there scenario to understand the brain!
Some good mentions at: Video "Where is Anatomy Encoded in Living Systems? by Michael Levin (2022)".
It is quite mind blowing when you think about it, that the huge majority of your body's cells is essentially just there to support a tiny ammount of germline, which are the only cells that can actually pass on! It is fun to imagine the cell type tree for this, with a huge branching of somatic cells, and only a few germline going forward.
One of the simplest known seems to be: en.wikipedia.org/wiki/Trichoplax
www.u-tokyo.ac.jp/focus/en/articles/a_00220.html "The simplest multicellular organism unveiled" from 2013 mentions Tetrabaena socialis.
Then of course: Caenorhabditis elegans is a relatively simple and widely studied model organism.
- youtu.be/1v6cgSkiHik?t=513 multicellularity is polyphyletic, e.g. evolved separately on plants, fungi and animals.
- youtu.be/1v6cgSkiHik?t=668 describes how unicellular organism choanoflagellates form colony, and how animals are characterized by certain key types of cellular interaction: adhesion, communication, regulation (cell differentiation) and extra cellular matrix production
It is hard to distinguish between colonies of unicellular organism and multicellular organism as there is a continuum between both depending on how well integrated they cells are.
From Wikipedia:
Multicellularity has evolved independently at least 25 times in eukaryotesand:
Complex multicellular organisms evolved only in six eukaryotic groups: animals, symbiomycotan fungi, brown algae, red algae, green algae, and land plants.