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Timescale of Life - Printable Version

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Timescale of Life - Yazata - Jun 16, 2022

[note: I originally placed this thread in the Cosmology forum, because that's how I originally conceived it. But the way it turned out, it's more about the history of life. I was going to delete it there and repost it here, and discovered I no longer have the delete option. Well, it works both places I guess.]

Imagine that the ~13.8 billion years since the Big Bang was one year. The Big Bang happpened ot Midnight, January 1. Today is Midnight Dec 31.

That implies a scale where 1 month = 1.1 billion years. 1 day = 37.8 million years. 1 minute = 26,238 years.

So...

The Earth accretes from planetesmals in August. Life (LUCA, the Last Universal Common Ancestor and whatever led up to it) is hypothesized to have appeared in September. Modern oxygenic photosynthesis appears in early protists (cyanobacteria?) in October. Resulting in the 'Oxygen Holocaust', the greatest life-caused climate-change in all of Earth's history, when the Earth's atmosphere acquired most of its oxygen and most of the then-extant single-celled prokaryotes died from having their biochemistries disrupted by oxidation. Only a few anaerobes survive today in hidden places where they can avoid the planet's air. Eukaryotes appear in november. Their appearance of these more complicated cells might be associated with the appearance of cellular respiration that can exploit oxygen, releasing more energy, making these cells more vigorous and ready for more evolving..

The first cryptic Edicarian multicellular ancestors of plants and animals, which might not have clearly diverged yet appear on December 14. The Cambrian explosion with the first chordates, molluscs, arthropods and a bewildering variety of worms suddenly appear for as-yet unknown reasons is on December 17. Plant life leaves the sea on December 20 and evolves into forests of tree-ferns. Animals (insects) leave the sea on December 21 and are soon buzzing around the ferns, the first flying animals. Amphibians follow them by dragging themselves out of the sea on December 22. The first fully land adapted reptiles December 23. The dinosaurs (the Earth's dominant land lifeform for a long period) appear (very fittingly) around December 25. Mammals belatedly appear December 26 and live in the dinosaurs' shadow. Birds evolve from dinosaurs on December 27. Flowering plants (a surprisingly late arrival) on December 28. The dinosaurs (Earth's dominant lifeform) suddenly go extinct on December 30.

On December 31, the way has been cleared for the dominance of mammals on land. The first apes appear around 6:30 in the morning. The ancestors of humans and chimps diverge much later in the day about 9:11 PM. About 8 minutes before midnight the first anatomically modern humans appear. They live a paleolithic stone age life. Then agriculture is discovered and settled village life appears. About 11 seconds before midnight, the Egyptians build the Great Pyramids. One second before midnight, Columbus discovers America.

Our modern technological civilization is just a fraction of a second old, in that cosmic year.

(Calendar from Tampabaysolarsystem.org)


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RE: Timescale of Life - Magical Realist - Jun 16, 2022

On the schedule of the cosmos we don't even show up as blips on the radar. How fleeting and ephemeral we are. Here today and gone tomorrow!