2.1 Billion Years ago, Something in Gabon, Africa Left a Trackway...1.5 billion years before complex life evolved. Or so we thoughtsteemCreated with Sketch.

in science •  6 years ago  (edited)

Caption: Microtomographical reconstruction with a transparent view of internal structures, and a sequence of virtual cross-sections of the sample. Credit: A. El Albani & A. Mazurier / IC2MP / CNRS - Université de Poitiers

I have written about how Sky father, the anthropomorphic concept of the universe at large, likes to mess with our expectations for how the universe works. Every time we seem to think we have something figured out, WHAM, a new surprise. Often times, its such a big one, we have to completely rethink what we think we know. Sky Father had a counterpart from the old mythologies known as Mother Earth. She survives today as the Gaia concept or in other forms. It seems that Earth Mother was getting sick of Sky Father getting all the fun in surprising us.

She just said, "Hold my beer."

And decided to surprise us all.

I have written specifically before the world we know and the life in it is not the first to have graced this world. It was my second ever article written on Steemit entitled "We Were not the First." In that article, I talked about the Francevillian Biota of Gabon, Africa. Let me do a quick recap.

During the Archean Eon, cyanobacteria began to photosynthesis and produce oxygen. There had been photosynthetic life before, but it was anaerobic: it didn't produce oxygen from the process, unlike modern plants. This produced the first free oxygen in the atmosphere like we had today, but it was in far, far smaller quantities. Even after the evolution of aerobic photosynthesis, build of oxygen in the atmosphere took a long time. Minerals and chemicals in the waters needed to be oxidized before the oxygen could build up in the atmosphere and then in the oceans of the world. You might just say that the world needed to rust first. This even and its build up was called the Great Oxygenation Event.

There was a record of a huge event near the end of the Great Oxygenation Event. This is called the Lomagundi Excursion Event. (yes, yes, event again. I don't make the names, folks). In only a few cases geologists can measure the exact composition of the atmosphere from the past. Frex, from air bubbles trapped in ice, especially glacial ice from the most recent ice age is the single case I know of where scientists who study the past can do that. Instead, they use what we call 'proxies.' These are the ratios of isotopes of oxygen, carbon, strontium or other elements. If there is a sudden shift in the isotopes of carbon, they can tell if there was a huge spike in carbon dioxide. Or a sudden drop. These often happen when life suddenly becomes very successful or gets wiped out in Mother Earth's temper tantrums we call mass extinctions.

During the Lomagundi Excursion Event, there was massive change in the ratios between the different isotopes of carbon. It has been described as the single biggest excursion or change in carbon ratios in the Earth's history. This, in turn, meant a lot of carbon was getting locked away and oxygen was becoming more common in the . In fact, papers have found that oxygen levels rose during the Lomagundi to such high levels the oceans became, well, not highly oxygenated, but far, far more so than they had been before. Likewise, the shallow water oxygen levels were high enough they were much, much closer to modern levels than they would be for over a billion years.

10.1371_journal.pone.0099438.g003.png

Figure 3. Pyritized macrofossil assemblage from the FB2 black shales of the Francevillian Series, Gabon. Credit: Abderrazak El Albani Stefan Bengtson ... Andrey Bekker

In the midst of the Lomagundi, researchers found in 2014 evidence of life that was different from our modern forms, but quite complex. Indeed, their forms were so large, there would be nothing that size for 1.5 billion years. The fossils were weird, to be sure, looking like snot dribbles and fried eggs. Dr. Abderrazak El Albani and his team from France's Université de Poitiers (and elsewhere) found a huge and varied number of macroorganism (large critter) fossils. This was met with skepticism. However, over time, Dr El Albani has defended his extraordinary claim and has returned to Gabon to excavate more. There, he and his collaborators, found something stunning.

That something was a trackway. That is, like fossil footprints. However, it was far, far smaller. They were on the order of millimeters in diameter. However, at the time, as far as we knew until Dr El Albani and his team started looking, nothing should have been able to leave a trackway. To be sure, there were no little marks from feet. Even Dr. El Albani states it was probable it was a colonial organism like a slime mold that made the trackway. However, again it cannot be repeated enough, something was big enough to leave a trackway 2.1 billion years ago in the fossil record.

Assuming no one can come up with another explanation, one that fits better than what Dr El Albani has, this trackway would clinch the case complex life arose 2.1 billion years ago. And died out. No fossils of this sort were found from the deposits from then until the Ediacaran. Then, our ancestors arose, between 600 and 700 million years ago.

What happened to it? Did the Vredefort and Sudbury Impacts - two asteroid impacts so large they dwarf the dinosaur killing Chicxulub crater - kill off the Francevillian Biota? Did they run out of resources because they didn't form a Gaia network? Was there some other explanation?

Time and research will tell.

Organism motility in an oxygenated shallow-marine environment 2.1 billion years ago
https://www.pnas.org/content/early/2019/02/05/1815721116

Ancient fossilized tracks suggest multicellular life far older than previously thought
https://www.eurekalert.org/pub_releases/2019-02/uoa-aft021319.php

Discovery of the oldest evidence of mobility on Earth
https://www.eurekalert.org/pub_releases/2019-02/c-dot020719.php

Scientists discover oldest evidence of mobility on Earth
https://www.eurekalert.org/pub_releases/2019-02/cu-sdo021119.php

Francevillian Biota
https://en.wikipedia.org/wiki/Francevillian_biota

The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099438

Archean Eon:
https://en.wikipedia.org/wiki/Archean

Great Oxygenation Event:
https://en.wikipedia.org/wiki/Great_Oxygenation_Event

The rise of oxygen and siderite oxidation during the Lomagundi Event.
https://www.ncbi.nlm.nih.gov/pubmed/25964326

Paleoproterozoic positive δ13Ccarb excursion in the northeastern Sino-Korean craton: Evidence of the Lomagundi Event
https://www.sciencedirect.com/science/article/pii/S1342937X10001395

Rock samples suggest oxygen levels during 'Lomagundi Event' were high enough to support life development progress
https://phys.org/news/2017-01-samples-oxygen-lomagundi-event-high.html

Selenium isotopes record extensive marine suboxia during the Great Oxidation Event
https://www.pnas.org/content/114/5/875

Slime Mold
https://en.wikipedia.org/wiki/Slime_mold

Vredefort Crater
https://en.wikipedia.org/wiki/Vredefort_crater

Subdury Basin
https://en.wikipedia.org/wiki/Sudbury_Basin

Chicxulub Crater
https://en.wikipedia.org/wiki/Chicxulub_crater

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