New Cambrian Research

A very interesting article (the link to the paper is in the article) on linking the Ediacaran and Cambrian biota

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Haven’t looked at the paper super closely yet but if it’s findings are accurate it suggests the fossil record is telling us what the molecular data has been telling us for a while now. That there was a deep divergence of animals. Sometime in the Precambrian.

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The link is broken.

Fixed

Thanks. In light of this, was there really an “explosion” of body types in the Cambrian or was it gradual over tens of millions of years from the Ediacaran through the Cambrian eras?

Yes a large expansion of different animal forms but its seems to have happened over a longer time period to be calling it “explosive”.

@T.j_Runyon what people make of the data from the paper is one thing, but all the data from the paper is actually saying is that a member of the Ecidarian Fauna lived into the early part of the Cambrian, and is now classified as an animal. Does this push back the “origin of animals”? It might though I thought sponges were around well before the Cambrian too. It doesn’t change anything about the scale and swiftness of change where 70 phyla of life spring up within a very short geological time. It just says this one pre-Cambrian creature survived a bit into the Cambrian, instead of going very rapidly extinct like the rest of the Ecidarian fauna when all this new stuff showed up. It is not even claiming this creature evolved into anything else.

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Out playing baseball with my buds. I’ll give you my thoughts later

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@T.j_Runyon, that’s one long baseball game. :wink:

Actually, only around 20 phyla, maybe 30 if you stretch, are known from the Cambrian at all. And “a very short geological time” would seem to be around 25-30 million years. The majority of animal phyla have no known fossil record.

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So…in the months since the publication of that article, did many anti-evolution proponents claim victory because “Evolution scientists were proven wrong yet again and have to rethink their timeframes!”?

Do you mean there is no fossil record of any species within those phyla? If so, that’s very interesting. I would have guessed at that level that the majority would have something.

Yes. You must remember that the majority of animal phyla are small worms, most of which you’ve never heard of, with no hard parts. But of course their status may change with new discoveries. I think, if I recall, that the first known putative gastrotrich was just found recently in a Cambrian deposit.

Here’s a related news article from Ed Yong at The Atlantic.

Most of the article describes some of the research from Rachel Wood that is published here:
https://www.nature.com/articles/s41559-019-0821-6. Unfortunately, my library has a 6-month waiting period on Nature articles.

I really like this one quote, though :stuck_out_tongue:

“I think it’s a valuable reframing of the story,” says Phoebe Cohen, a paleontologist at Williams College. “The more we look at the Cambrian explosion, the less explosion-y it looks.”

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We are in the bottom of 153rd inning. Real pitcher’s dual here

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