Oxygen and the Cambrian: in the pre-Cambrian (Evolution)

by dhw, Thursday, October 20, 2022, 12:57 (763 days ago) @ David Turell

DAVID: That period is the time between the last Edicarans and the first Cambrians. God designed the Cambrians.

dhw: I know what the transition period is, and I know you think your God designed the Cambrians. I’m asking what you think your God did during the transition period. I shan’t reproduce the two very revealing articles, but will merely highlight the most relevant points:

QUOTE: The Ediacaran-Cambrian transition is a crucial time interval for the evolution of animal life on Earth. Throughout this interval new ecosystems formed and novel bodyplans proliferated.

dhw: The leading question is whether these novel bodyplans might provide missing links
between Ediacaran and Cambrian species.

DAVID: What novel body plans? Only in the Cambrian.

I am quoting the article. Who should I trust to know all the latest research, you or the author?

QUOTE: Though a large number of studies of the biotic and abiotic changes, and their relationship, during this interval have been conducted, questions remain and new data are continually being gathered.

dhw: It seems to me extremely important that one should not draw final conclusions so long as new data are being found. Don’t you agree?

DAVID: Yes.

Thank you.

Heading: Paleontologists Find Evolutionary Link between Ediacaran and Early Cambrian Multicellular Animals

QUOTE: They found that Namacalathus hermanastes was an early ancestor of species that appeared during the Cambrian explosion/..

QUOTE: “They help us trace the roots of the Cambrian explosion and the origin of modern animal groups.”

DAVID: Finding one link does not explain the vast array of new phyla appearing so suddenly. A small link is not a gap buster.

dhw: But an accumulation of links would gradually close the gap.

DAVID: Only if Edicaran precursors appear for 37 original phyla in the Cambrian.

Bearing in mind the extreme unlikelihood of ANY fossils surviving, I’d settle for just a few.

dhw: We must always bear in mind (a) that preservation of fossils is extremely rare for obvious reasons, and (b) that new techniques of research as well as new discoveries of fossils are already providing such links. Who knows what else might be discovered during the next hundred/thousand years? But I am emphatically NOT wishing for such discoveries or even expecting them. I am as ignorant as you and everyone else about the gap. I am merely pointing out that we should not make any assumptions – and that includes your assumption that the gap can never be filled.

DAVID: Find precursors for 37 individual complex phyla. With one so far, 36 to go. I think God just popped the first in early in late Edicaran time.

I’m in no position to find any! I rely on you to latch on to all the latest discoveries, though I suspect neither of us will be around for the next hundred/thousand years.

*****

Thank you for all the other posts. I have nothing to add.