
Dust cloud sparked explosion in primitive life on Earth, say scientists - jajag
https://www.theguardian.com/science/2019/sep/18/dust-cloud-sparked-explosion-in-primitive-life-on-earth-say-scientists
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sword_smith
I thought this would be about the Cambrian Explosion but that is 541m years
ago, and this alleged asteroid blew up 466m years ago according to the
article. Both periods, The Cambrian Explosion and the Great Ordovician
Biodiversification Event (GOBE) are periods with strong biological radiation
as can be seen on the 1st graph here: [https://www.fossilhunters.xyz/fossil-
classification/images/1...](https://www.fossilhunters.xyz/fossil-
classification/images/1273_191_314-climate-greenhouse-icehouse-devonian.jpg)

The Cambrian Explosion is replaced by the 'Cambrian Plateau' (not a canonical
name), and the GOBE comes after. The Ordovician animals were the first to
evolve jaws (in Gnathostomata/jawed vertebrates). This happened about 462m
years ago, so perhaps we can thank a 93 mile asteroid that blew up 466m years
ago for our ability to chew?

They found a pretty interesting dataset, it seems, relating various isotopes.
It's a pitty the article don't go into details on the chemical signature that
convinced the scientists that leftovers of an asteroid rained down on Earth.

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baq
the path from the beginning of time to being able to understand it is nothing
short of amazing. the amount of things that happened to allow homo sapiens to
evolve is staggering.

does anybody keep an up-to-date list of drake equation coefficients?

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jcims
I know this isn't the right way to think of it but it does attest somewhat to
the rarity.

If every atom of the universe (1e82) was a specialized computer that was able
to create a trillion universally unique combinations of a 200 base pair strand
of DNA per second (1e12/second) , and you had them all working on this task
from the beginning of known time (4.4e17 seconds), you would have discovered
approximately .0000002% of the possible combinations (4.4e111/4^200).

It's a little difficult to get a straightforward answer but the simplest
organism I'm finding right now has 160,000 base pairs in their DNA.

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java-man
The simplest molecule (dimer, actually) that has self-replication and
evolution has a complexity of about 170 nucleic acid bases [0]

It is entirely probable, in my opinion, that this is how life originated on
Earth in a shallow pool or volcanic vent - essentially primordial PCR
machines.

[0]
[https://www.pnas.org/content/99/20/12733.short](https://www.pnas.org/content/99/20/12733.short)

~~~
jcims
Nice. Also added a new term to the existential quiver, autocatalytic.

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marmadukester39
Wonder if any of that sparked biodiversity was due to panspermia

