3.4 billion year old fossils recently discovered

Martin Brasier of Oxford and his team have just described some very ancient fossils discovered in rocks dated to 3.4 billion years of age. The article is unfortunately behind a paywall, so I am unable to review it, but Jerry Coyne lays out the evidence neatly:

As the authors note, “determining the biogenicity [biological origin] of putative Archaean microfossils is notoriously difficult.” How do we know that these things are real remnants of bacteria and not just inclusions or artifacts? There are several independent lines of evidence, none conclusive but together building a very solid case:

  • They look like cells, being cell-shaped, cell-sized, and forming chains of spheroids that look like chains of both well-established fossil bacteria and modern bacteria. Some can even be seen “dividing” or expelling their contents after cell damage (see figure above).
  • The variation in size of the bodies is small—smaller than you’d expect if they were abiological inclusions. A uniformity of size, however, is expected if they’re all members of one living species.
  • The cell “walls” of the microfossils, too, are of uniform thickness, unlike that of artifacts like silica grains coated with carbon.
  • The geochemistry of the bacteria and surrounding rock supports the idea that these are true organisms. This involves not only the isotopic nature of the carbon, but the presence of nitrogen, a crucial biomarker, within the cell walls.

This reminds me very much of Margulis’ endosymbiotic theory and its multiple lines of evidence. Of course, that idea was a cornerstone achievement of 20th century biology whereas this recent discovery pushes the known origins of life back about 200 million years, but that does not mean it isn’t important. Braiser’s find goes to demonstrate the nature of early bacteria. Many of the features in these fossils show that ancient bacteria operated in ways similar to certain bacteria today – if you find something that works, keep it up. The find also demonstrates that life can come to be quite quickly. Earth is only 4.54 billion years old and probably was not hospitably cool enough for life for its first half billion years. Given this 3.4 billion year date plus the fact that these fossils are fairly complex, it is not a stretch to say life dates back even further, probably quite soon after it was possible for it to do so on Earth.

Finally, I have to reflect Coyne’s curiosity that this was not published in Nature or Science, but rather Nature Geoscience. It’s still in a prestigious enough journal, but the paper is important enough where it deserves publication that comes with a higher profile. I’m sure the authors attempted to reach the best level possible, so who knows what the deal is.

Abusing science

Conservapedia is back to abusing science. This is from their “news” section.

The study, which was published on July 14, 2009 in the peer-reviewed journal Nature Geoscience, found CO2 was not to blame for a major ancient global warming period and instead found “unknown processes accounted for much of warming in the ancient hot spell.” The press release for the study was headlined: “Global warming: Our best guess is likely wrong.”

“In a nutshell, theoretical models cannot explain what we observe in the geological record,” said oceanographer Gerald Dickens, a co-author of the study and professor of Earth science at Rice University. “There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models.”

The mistake Conservapedia made is so readily linking to the abstract.

We conclude that in addition to direct CO2 forcing, other processes and/or feedbacks that are hitherto unknown must have caused a substantial portion of the warming during the Palaeocene–Eocene Thermal Maximum. Once these processes have been identified, their potential effect on future climate change needs to be taken into account.

While the idiots over at Dumbopedia (good one, right?) are claiming that this study PROVES!!! that global warming is not man-made (thus implying that any polluting business practice is a-okay), the study is saying no such thing. This is referencing a period of warming where CO2 alone does not account for all the warming. That isn’t to say that the rise in CO2 can be dismissed during that time – nor is it saying anything about our time. It’d be like saying natural selection doesn’t account for all the change in evolution, therefore evolution is false. CO2 still was a huge factor by which warming was initiated (upwards of 38 degrees F). Today it remains a huge factor.

Let’s just say it. Conservatives are not concerned about science. They care about allowing businesses to practice as they please. That’s it.