Ediacarans, Cambrian Explosions and the dangers of falling for one set of data

Fans of Paleontology, and non-fans of Paleontology, there’s something for everyone here, so don’t click away. But fans will instantly remember the marvellous Burgess Shale formations of British Columbia. They’re about as good as it gets: Old (Cambrian, 520million years BCE); incredibly well preserved (you can see the compound eyes in trilobites); and above all the first good examples of just about every major group of animals is suddenly here, fully formed and ready to go. Here are all the answers to what the first arthropods. the first molluscs and the first vertebrates looked like, and its dazzling. And some people were dazzled . Over the years enormous theories were erected about this sudden Cambrian Explosion. Why so sudden? Why nothing like this earlier? There seemed to be nothing but a few old funny shapes, which may not even have been animals, in the poor old Precambrian. And bacteria-but as they are not exactly photogenic, who cared about them?

But some people always had doubts. Firstly, the molecular evidence pointed to a much earlier divergence of animal groups-maybe by two or three hundred million years. And there were all those pesky little burrows and strange shapes in places like Ediacara in Australia and Charnwood Forest in England. And some multicellular things like red algae have been around unchanged for fourteen hundred million years and are still washing up on beaches today. Now Traci Wilson of Nature tells how discoveries in the Precambrian are completely upending the Cambrian explosion and showing how the really important stuff was happening long. long before. There’s loads of good stuff here, and links, and great pictures. For us the highlight was some scientists who recovered 550 million years old cholesterol to prove some of the strange blobs were real animals, but there is loads more.

However, the real point is: don’t get carried away by one discovery, however good it looks. No one book holds all the answers. No scientist thinks that Darwin wrote the last word on biology, or Newton on physics. What people think about the Cambrian is no real danger to the world. But there are plenty of other people with fixed ideas who are. And who kill for them, even in churches.

Animal, vegetable or something else entirely? For decades, researchers were baffled by fossils of bizarre living things that dated back to the Ediacaran period — around half a billion years ago. But recent evidence suggests that some of these alien-like species were in fact animals — including ones that had guts, segmented bodies and other sophisticated features. Researchers are using these finds to re-examine a pivotal event in evolutionary history: the Cambrian explosion. “I would just love to be swimming over these communities and see, finally, how are they really growing? What on Earth are they?” says palaeobiologist Rachel Wood. “So much would become obvious.”Nature | 12 min read

https://www.theguardian.com/world/2020/oct/29/knife-attacker-in-nice-kills-three-people

#niceattacks #cambrian #precambrian #yilingiaspiciformis #ediacara #charnwoodforest

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