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Comment by MrArtichaut | Hacker News Reader

"The new organisms are multicellular but mostly non-symmetrical"

So it's not really a new branch of life if it's multicellular but just non-symmetrical ...

Maybe a new sub-division in the multicellular kingdom but not a whole new branch at the same level as bacteria, archaea and multicellulars...

edit : bacteria, archae and EUKARYOTE not multicellular

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You are describing domains, and neither the article nor its title suggested the discovery of a new domain. There's no technical reason I'm aware of for "branch" to be restriced to describing domains of life.

This case appears to demonstrate a new phylum, which is two steps below domain, so it's still significant in terms of classification. The fact that the organisms resemble some others we thought died out long ago is also important for evolutionary biology.

What's fascinating is that finding new animal phyla is apparently something that has happened a few times in the last century, and they aren't able to place this creature into a phyla yet - it's close to a jellyfish and comb jellies, but not close enough to be included in the Cnidaria or Ctenophora phylum.

I don't deny the importance of the finding. Bilateria and non-bilateria are huge groups in the animal kingdom and if this animal doesn't fit in one of them is really something.

But (for now, without ADN analysis) it's just a new structure plan. I just find the title about "a new branch of life" a little sensationalist :)

I think the article was using "branch" colloquially, rather than in some technical sense. And it's saying "may be" rather than "is".

The problem is that it's an exaggeration like: "New article title may be a new branch of linkbait art"

A better title is "Deep sea 'mushroom' may be new branch of animals" or "Deep sea 'mushroom' may be new branch of animal kingdom".

I'm still not 100% happy with the proposed title, but it's more realistic. One of the problems is that it's not a mushroom nor mushroom related. It's only a weird animal with a strange shape that looks like a mushroom.

Wikipedia (bless it's soul) has an update on this - clearly in the kingdom Animalia, http://en.wikipedia.org/wiki/Dendrogramma, they are just trying to figure out which phylum to place it in.

I wondered the same - symmetry seems quite an arbitrary criterion to me, especially because, for example, humans are not really symmetric once you look at the placement of organs. But I could imagine that the mechanism that causes bodies to grow (almost) symmetrically has some deep and unique genetic and biochemical reasons and therefore justifies this classifications.

If archaea are a new branch on the same level as bacteria, why can't new multicellulars be a new branch on the same level as modern multicellular life?

They may be unrelated and different enough - this is one of the ideas about Edicarian fauna.

My mistake : I meant Eukaryote not multicellular.

Archea are less related to bacteria that we thought some years ago. They are as different from bacteria that eukaryotes are different from bacteria. So a new branch of life is justified here since the basic parts of the cell are differents.

You're right in this regard, but they still may become a new kingdom (akin to plants, fungi, animals).

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