Wednesday, December 12, 2012

Astonishing Claim About Pre-Cambrian Fossils

From December 13, 2012 news.com.au, a rather astonishing claim:

EVIDENCE that the world's first animals formed in the Flinders Ranges 550 million years ago has been called into question by new research published today in the journal Nature.
Professor Gregory Retallack ,from the University of Oregon, says "most of the better known and iconic Ediacaran fossils of South Australia" were not animals.
"These large fossils were organisms that lived on land, not in the sea," he said.
"They were probably neither plants nor animals, but fungi, a separate kingdom."
Okay, somewhat interesting, but not terribly so.  Until we get this later in the article:
Yesterday Professor Retallack said the tubular shells of Cloudina and organic tubes of Sinosabellidites may have been animals - but added that "other evidence for Ediacaran animals had been falsified".
He said the first animals emerged much later in the Ediacaran period and didn't "appear in force" until the Cambrian period. 
Falsified?  You mean, like Piltdown Man?  That's an astonishing claim, and I would love to hear more.

Here is a more clear explanation of the dispute from December 12, 2012 Science Now which explains that the argument is about whether these are marine or land fossils:

The fossils of various frondlike and sacklike organisms that supposedly lived at the bottom of ancient oceans may actually represent some of the earliest organisms to dwell on land. That's the controversial interpretation of a new study, which suggests that rocks long thought to have been formed from sediments deposited on ancient seafloors may actually be the remnants of early soils. If true, the finding would push back life's transition from sea to land by tens of millions of years—and possibly by 100 million years or more.
Fossils reveal that life on Earth diversified rapidly during the Cambrian period, which began about 542 million years ago and lasted until about 485 million years ago. The so-called Cambrian explosion yielded most of the major groups of animals known today, but fossils of a host of organisms bearing little resemblance to modern life forms are embedded in Precambrian rocks—including those of the Ediacaran period, which began about 635 million years ago and lasted until the onset of the Cambrian. Most researchers have considered these unusual organisms—some resemble segmented worms or fronds, and others look like nothing more than bags of tissue—to have lived in the sea, because the types of rocks that entombed them typically accumulate as sediments in marine environments.
I still want to know why Retallack says that other evidence was "falsified."  That's quite a claim to make, unless he meant in the sense of "proven wrong."  (One of the tests of scientific theory is whether you can "falsify" it: prove it wrong or right.)

1 comment:

hga said...

I'd blame the press. Either he was speaking off the cuff and didn't really mean what his plain words say, but your interpretation, and they didn't catch the goof, or they just got the quote wrong and again didn't catch what they have him saying.

It's a very big thing, potentially career ending and legally actionable, to claim another scientist is a fraud. I doubt he'd start the process in that sort of forum.