Brown algae such as kelp are multicellular, yet not some descendant or ancestor of plants or animals. They are their own thing, just not with the huge variety we can see with plants and animals.
OK there's more, from wiki: complex multicellular organisms evolved only in six eukaryotic groups: animals, symbiomycotan fungi, brown algae, red algae, green algae, and land plants
Anonymous D joined in and replied with this 2 years ago, 32 minutes later, 53 minutes after the original post[^][v]#1,280,503
@1,280,491 (boof)
Silicon based life forms are the next most viable to carbon. Silicon is directly below carbon in the periodic table and so, like carbon, has 4 valence electrons in its outer shell.
boof replied with this 2 years ago, 5 minutes later, 59 minutes after the original post[^][v]#1,280,504
@previous (D)
i know. i was hoping someone would've caught that. many have proposed broadening our search for extraterrestrial life to include signatures of silicon based compounds
boof double-posted this 2 years ago, 1 minute later, 1 hour after the original post[^][v]#1,280,505
also interesting to note that computer chips of course rely heavily on silicon. perhaps life based in silicon will come from a diffent direction entirely and be of entirely terrestrial origin...