Evolution Intelligent Design

Sponges really are older than comb jellies, researchers say

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Researchers’ data favors sponges as sister group to all existing animal lineages/Professor Gert Wörheide, LMU

There’s been a bit of a jostle recently between claims made for sponges vs claims made for comb jellies as the first significant complex life. Both types of life forms are at least 500 million years old. Using a bigger data set, this group of researchers favors the sponges. From ScienceDaily:

Of particular interest among these animal phyla are the sponges (Porifera) and the comb jellies (Ctenophora), as it remains unclear which of these groups represents the sister group to all other animals. “Irrespective of whether we include paralogs or not, our results are consistent with the classical view of animal phylogeny in that the sponges are the sister group to all other extant animal lineages,” says Wörheide. Analysis of the ortholog gene content on its own places the comb jellies as the sister group of Placozoa, Cnidaria and Bilateria (this last group accounts for 95% of extant animal species). Including homologous gene family content data, however, identifies ctenophores as the sister group of the Cnidaria. This result agrees with a proposal drawn from morphological studies — the Coelenterata hypothesis — that dates back to the mid-19th century, a view which had gone out of favor in recent years.

“We conclude from our results that the anomalous placement of some highly divergent lineages, such as the comb jellies, reflects a fundamental limitation in the ability of conventional sequence-based methods — which rely on data for orthologs alone — to resolve the branching patterns of very ancient lineages,” says Wörheide. Paper. (paywall) – Walker Pett, Marcin Adamski, Maja Adamska, Warren R Francis, Michael Eitel, Davide Pisani, Gert Wörheide. The role of homology and orthology in the phylogenomic analysis of metazoan gene content. Molecular Biology and Evolution, 2019; DOI: 10.1093/molbev/msz013 More.

For various views, see

Researchers: Sponges Definitely Oldest Animals, Not “Anatomically Complex” Comb Jellies

Our physics color commentator Rob Sheldon offers an analysis:

Problem. Square peg. Round hole.

Solution. Bigger hammer.

Who says evolution has unsolved problems?

So let’s wait and see what the other side says. Chances are we haven’t heard the last of it.

Sponges vs. jellies: Comb jellies still the “oldest” complex life form, researchers say

Sponges back in the ring with comb jellies for “oldest” title fight

Comb jelly files: Complex features do not each emerge once

Comb jelly DNA sequence offers “unintuitive facts” about evolution…

and

Researchers: The sponge is the oldest animal phylum after all (2015)

and

2 Replies to “Sponges really are older than comb jellies, researchers say

  1. 1
    Ed George says:

    Comb jellies are far more complex than sponges. However, sponges can perform a neat little trick. If you put one in a blender and then pour the slurry back in a tank, it can reassemble itself.

  2. 2
    AaronS1978 says:

    “Oldest Animal Turns Out To Be 40 Million Years Older Than 558 Mya”

    Pun intended
    This is starting to get old!

    But seriously this annoying, One minute it’s the sponge the next minute it’s the comb jelly I’m pretty sure if the two are directly related to one another they would have nearly identical genetic codes you know nearly like them humans and them chimps. But I swear every single time something that comes out ,such as fossil evidence that supports one, research like this will come out immediately there after challenging it. It’s kind of annoying and old

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