However, the interpretation of the structures has always been controversial, and it is still hotly debated among scientists searching for Earth’s earliest evidence for life. Specimens from the site apparently displayed branching structures that some researchers said were inconsistent with life, while others dismissed such branching as artifacts from photo software.Analysis of the structures themselves suggested they were carbon-based, and therefore associated with the organic chemistry of life, but some contended they were a type of carbon known as graphite, while others said they were kerogen, a mixture of organic compounds.
Now University of Kansas geospectroscopist Craig Marshall and his colleagues have taken another look at the Apex Chert structures and determined they might not be carbon-based after all. Instead, they seem to just be a series of fractures filled with crystals.
“It’s one of those funny moments in science when you go out to do one thing and it completely flips 180 on you,” Marshall said.
– – Charles Q. Choi (Study of ancient fossils asks, ‘Is it really life?’: Many structures aren’t microbes, but mineral formations, researchers claim, 3/25/2011)
Happens in every field, actually.
The obvious result is that eliminating some of the very oldest proposed life forms narrows the window for the Holy Grail, a purely accidental origin of life, to appear.
Eventually, numbers catch up with people.
You didn’t read that in the story, so I didn’t quote it.