A2: Microbes in the News

Article and Link: 3.77-billion-year-old fossils stake new claim to oldest evidence of life.  Science the magazine. March 1, 2017. Link: https://www.sciencemag.org/news/2017/03/377-billion-year-old-fossils-stake-new-claim-oldest-evidence-life

Summary: New fossils may provide evidence that life on Earth existed 300 million years prior than what we can prove today.  Structural and chemical signatures show that iron-oxidizing bacteria may have formed features caught in the 3.77-billion-year-old fossils.  Other scientists, aren’t so optimistic about the findings.

Connections: We’ve went over in class the two ideas that life formed at the surface or below the surface.  In this article, these fossils show that deep-sea microbes may have existed before the current 3.4-billion-year-old stromatolites, which were near or on the surface.  Also, it connects to energy-procuring strategies of microbes such as chemolithotrophy found in this article.

Critical Analysis:  I found it interesting that the evidence that  the article is based on are fossilized structures that are easy to miss with the human eye, and how it has caused such a debate due to the implications of accepting that life conclusively existed 300 million years prior to what we can prove at the moment.  I think the article was scientifically accurate because it provided both sides of the story.  The backers of the evidence claim that not only are the structures very similar to what occurs at modern hydrothermal vents by microbes, but that the chemical signatures also point toward life.  The naysayers argue that such characteristics found in such ancient rock are hard to use as certain evidence due to the amount of changes the rock has undergone through time that may lead to inaccurate findings; they also argue that it isn’t impossible for abiological processes to create similar structures.  I believe it was written well.  Clear, concise sentences and not very long in length to lose the reader’s interest in the minutia.  For that reason, I also thought it did a good job of communicating science to the public.  It gave information on a contested issue relevant to most people as a whole in a snack-size chunk that wouldn’t turn people away from reading the information.

Question: A stromatolite formation found in Australia is currently given the nod as the oldest proof of life currently.  At the time it was discovered, how long did it take the gain this level of acceptance?

 

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