One has to imagine that there were a substantial number of misfires along the way too. Multi-cellular organisms that popped up and died for one reason or another before they had a chance to reach escape velocity. Like an amoeba that eats a bacteria and incorporates it but the mud puddle they are in dried up.
Wouldn’t surprise if for us to know about 50 at this point there were orders of magnitude more that we’ll never know of.
> One has to imagine that there were a substantial number of misfires along the way too.
> Wouldn’t surprise if for us to know about 50 at this point there were orders of magnitude more that we’ll never know of.
Indeed! The Wikipedia article mentions it. To be honest, it's a surprise that we know about 50 cases, given the fact that almost none of them had any hard tissue or structures (like bones or shells) that can survive as fossils. Given those odds, we are likely underestimating the cases by several orders of magnitude.
> I was under the impression that the scientific consensus today was that multicellular life only appeared once.
If that's the case, then the relevant Wikipedia article [1] will need a major correction. They reference multiple sources which are more likely to interest you.
Multiple independent emergence of multicellular life didn't really surprise me, considering how often unicellular life mutates. I'm actually surprised by the suggestion that the opposite is the current scientific consensus. Do you have any sources for that? (Not a challenge. Just want to understand the situation and misconceptions if any.)
You might be thinking of the genesis of eukaryotes, which is thought to be from a specific event where one archaeon incorporated a bacterium, and all eukaryotic organisms are descended from the resulting symbiotic arrangement, with our nuclear DNA descending from the archaeon, and our mitochondria descending from the bacterium.
All multicellular life is eukaryotic, but not all eukaryotes are multicellular, e.g. amoebae.
Perhaps you think about animals, which have appeared only once, i.e. multicellular living beings capable of complex movements.
There are a lot of other kinds of multicellular living beings, which have achieved multicellularity independently, plants and fungi being the most obvious on dry land, but most of these other multicellular life forms had to lose mobility when becoming multicellular.
Only a few have retained some limited mobility when multicellular, e.g. the slime molds, but they are much simpler than those which have lost completely mobility, by having rigid cellular walls, like plants, fungi and several distinct kinds of marine algae.
There are even several kinds of (very simple) multicellular bacteria, among Cyanobacteria (blue-green algae), Myxobacteria (resembling slime molds) and Actinobacteria a.k.a. Actinomycetes (resembling fungi).
