
Scientists discover chemistry that may help explain the origins of cellular life - dnetesn
https://phys.org/news/2019-07-scientists-chemistry-cellular-life.html
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apo
A fascinating study that tries to solve the most difficult problem in the
origin of life: bootstrapping. Nobody has been able to explain how the
multitude of complex organic molecules needed to support life got there in the
first place.

It's a little like we're trying to reconstruct modern industrial civilization
by assuming Dow Chemical exists whenever necessary. Dow and the entire
chemical industry arose from a bootstrapping process in which simple
feedstocks become ever more complex inputs to ever more specialized
industries. The Industrial Revolution would have been impossible without it.

This study looks at the ability of alpha-hydroxy acids to spontaneously
assemble semi-permeable compartments ("microdroplets") that could have played
an early role, concentrating reactive species and enabling reactions that
couldn't take place otherwise. As such, they'd serve as a kind of scaffolding.
Useful for a time, and then discarded with the appearance of better
structures.

Four out of 5 of these candidates (which are all hydroxy analogs of amino
acids), are chiral. The rate of formation, permeability, and durability of the
compartments formed might expected to depend on the enantiomeric purity of the
starting hydroxy acids.

Surprisingly, the study apparently says nothing about enantioenrichment of the
alpha-hydroxy acids. Then again, the study only begins to scratch the surface
of what this new chemical system might be capable of.

AFAICT, this is a brand new, highly hackable chemical system with vast
potential not just in the origin of life, but across chemistry and biology.

So far, the study only demonstrates inclusion of dyes. The real test will be
to get these things to facilitate reactions that would not occur in the
surrounding medium.

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ggggtez
I really like the idea of this as a scaffold for collecting lipids for the
first cell membranes. It seems likely to me that there would need to be some
relatively simple compound responsible. The fact this is present in meteorites
gives me some confidence that it must be a compound that forms fairly easily.
Once again, the "improbability of life" just got a little more probable.

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agumonkey
What ecosystem would provide lipids in those times btw ?

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fergalish
Since reading it somewhere in the distant past, I have become convinced that
the moon played a vital part in the origin of life, by creating the tides.
Picture a coastline in early Earth. Tide washes up a bunch of chemicals that
get baked in a warm sun, while simultaneously getting exposed to a harsh
atmosphere with plenty of energy surges (volcanic/atmospheric). Tide washes in
a bunch of fresh chemicals to reiterate the process. Rinse & repeat a few
hundred billion times.

Given the rarity (AFAIR) of moons as large as ours orbiting planets as small
as ours, that might also explain the apparent rarity of life in the cosmos.

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tasty_freeze
One thing arguing against this is that there was little free atmospheric
oxygen, and thus little ozone. According to Nick Lane in his book, "Oxygen",
UV light at the surface of the earth was 30 times greater then than now.

Life has had a lot of time to build up mechanisms to protect against UV light
[1], including sophisticated dna repair mechanisms and creating sophisticated
antioxidants and regulation mechanisms.

But at the dawn of life, whatever self-catalyzing reaction which constituted
the first replicators would have been extremely fragile and unlikely to
tolerate baking as you suggest.

[1] In David Goodsell's book "The Machinery of Life", p.112, he mentions that
when you stand in the midday sun without sunblock, UV light can cause adjacent
cytosine and thymine rungs on the dna to cross link to each other. A repair
mechanism sweeps the dna looking for this exact bond to unlink it before it
gums up normal dna transcription activity. How often does it happen? 50 to 100
times per second ... per exposed cell.

~~~
photojosh
Thanks for the book recommendations— right up my alley as I very much enjoyed
Lane's "Vital Question" too.

~~~
tasty_freeze
The full title of the first book is "Oxygen, The molecule that made the
world", and was published in 2002. I'm not sure how much things have changed
in the past 17 years, but presumably it is mostly still up to date.

The first half of the book is about the history of oxygen on the planet and
interesting details on how we can know it. The second half of the book is
about oxygen processes on life mostly at the cellular level but also some at
the whole-organism level.

The book is pretty dense but it is fill with enough interesting ideas, such as
why it is believed that cells had developed the ability to produce
antioxidants before there was much free atmospheric oxygen. There is a
discussion of how can it be that at every cellular division there is a certain
fraction of transcription errors, yet the germ line still can pass on for
billions of generations and still produce a healthy population.

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yehosef
The problem is that once you start to appreciate the immense complexity in a
single, most basic cell, you realize how far away we are from understanding
how life got started.

This article would be comparable to some future generation trying to figure
out how our computers were made and then stumbling upon factory that could
make the cases. The case is important, but relatively trivial part of the
machinery. Similarly, the cell membrane is critical (not just important), but
very simple compared the molecular machines (and more) involved in all cells.

Personally, I think if someone researches the physics/chemistry/biology deeply
enough, he'll get to the conclusion that abiogenesis not possible naturally
with the physical laws we have now. I believe this is an opening for a proof
that this world is really a simulation.

Anyone else feel like that?

~~~
ibraa
I find it funny that people would rather believe in the matrix/simulation
rather than God

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yters
I'm not sure how the simulation theory even solves anything. It just pushes
the problem to the simulator. I guess the assumption is maybe the simulator is
much less complex, so makes the problem disappeared through our ignorance
about the simulator, which is just the 'god of the gaps' fallacy in techno
speak.

~~~
ibraa
The simulator is not less complex, the difference is that the simulator is not
subjected to the same limitations/rules/laws of our universe.

You either choose the universe itself to be infinite (always have and always
will exist) which contradicts all our observations about it, or you assume a
higher entity (outside the universe) that is infinite (always have and always
will exist).

The third option (nothing infinite) means we wouldn't exist at all, because if
there's no "start" then you go into an infinite loop trying to find a start
and nothing happens. But since we are actually here, then third option is out,
and only the second option (higher entity) makes logical sense.

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mgamache
We'll probably never know for certain, but we are getting closer to models
that can account for abiogenesis. It might not have a tangible impact on daily
life, but most people would like to know how the whole life thing got started.
Is there any practical use for this research? Maybe terraforming?

~~~
lithos
It's a start to "nanites" as seen in sci-fi.

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icanhackit
As an aside, when reading this I considered a fun alternative theory (I'm not
actually proposing it as any kind of truth) that if it's ultimately discovered
that the processes behind the creation of life are just too complex to be
duplicated in our universe...

...Rather than invoking a god which comes with its own problems (i.e. who/what
created the creator) one could infer that life came from a universe where the
physics/conditions for creating life are possible, and life somehow crossed
branes moving from one universe to the next.

Consider a reverse/inverted universe where instead of space being a void,
space is solid containing voids/cavities/pathways between voids, allowing
complex chemical processes to occur naturally and at great scale.

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drallison
Stuart Kauffman
([https://en.wikipedia.org/wiki/Stuart_Kauffman](https://en.wikipedia.org/wiki/Stuart_Kauffman))
has long maintained that the complexity of biological systems and organisms
results from self-organization, far-from-equilibrium dynamics, and the
inherent fundamental properties of chemistry, particularly carbon chemistry.
In his view, the origins of cellular life are baked into the fabric of the
universe.

