Wednesday, 22 June 2016

Protein Compounds in Exceptionally Well Preserved “1.88-Billion-Year-Old” Microfossils

Modern cyanobacteria are anything but simple. Image courtesy of Kelvin Song, Creative Commons (CC BY-SA 3.0).

Joel Kontinen

‘Exceptionally’ is the key word in a paper recently published in Nature Communications on microfossils discovered the Gunflint Chert in Canada. They are assumed to be 1.88 billion years old, but they don’t appear to be that ancient:

The significant degradation that fossilized biomolecules may experience during burial makes it challenging to assess the biogenicity of organic microstructures in ancient rocks. Here we investigate the molecular signatures of 1.88 Ga Gunflint organic microfossils as a function of their diagenetic history. Synchrotron-based XANES data collected in situ on individual microfossils, at the submicrometre scale, are compared with data collected on modern microorganisms. Despite diagenetic temperatures of ~150–170 °C deduced from Raman data, the molecular signatures of some Gunflint organic microfossils have been exceptionally well preserved. Remarkably, amide groups derived from protein compounds can still be detected.

The researchers suggest that the microfossils resemble modern cyanobacteria. They are also known as blue-green algae and they are featured in several evolutionary stories.

They are the earliest living fossils.

We would not expect to find remains of proteins in “1.88 billion- year-old” fossils.

The present study shows that, in addition to the fine-scale morphologies, the molecular biosignatures of some Gunflint organic microfossils have been exceptionally preserved. In fact, despite the 1.88-Gyr-long geological history that they experienced, Kakabeka Falls and Schreiber Beach organic microfossils exhibit C- and N-XANES spectra sharing strong similarities to those of modern cyanobacteria and modern micro-algae. Despite a higher content of aromatic compounds compared to modern microorganisms, these microfossils exhibit a quite high content of oxygen-based functional groups (carbonyl, phenolic, carboxylic and hydroxyl groups). In addition, these microfossils still contain amide functional groups (absorption feature at 288.2 eV), which were likely to be involved in the proteinaceous compounds synthetized by the once living organisms.”

Once again, the facts do not support the evolution story. If practically no change occurs in “1.88 billion years”, evolution is in big trouble.


Alleon, Julien et al. 2016. Molecular preservation of 1.88 Ga Gunflint organic microfossils as a function of temperature and mineralogy. Nature Communications 7: 11977 (17 June).