
The energy expansions of evolution (2017) - havella
https://www.nature.com/articles/s41559-017-0138
======
hoorayimhelping
Maybe this is obvious, but I always enjoy thinking of it: except for a
comparatively little bit of radioactively decaying material inside the earth,
and some tidal forces, all energy on this planet, every single joule of energy
ever expended is just stored sunlight.

Sunlight hits photosynthesizing bacteria which create biological fuel
molecules called sugars. Plants store these sugars and convert the energy in
them into leaves and roots and organic material. Animals eat the plants and
convert the stored energy into useful work. Plants and animals die, and the
stored energy in their bodies is consumed by other life which turns them into
work. Sometimes it gets captured by the earth before it can decompose and over
very long timespans, it gets compressed and turned into super energy dense
organic material called coal or petroleum.

All the gasoline we're expending, all the coal and natural gas we're burning
is just stored sunlight in very efficient organic batteries. Even the wind
energy we're capturing is created by the external energy of the sun injecting
heat into our earth system and creating work.

~~~
jolmg
> except for a comparatively little bit of radioactively decaying material
> inside the earth, and some tidal forces

There's also geothermal energy.

EDIT: I erased what I said about tidal forces. I thought it referred to all
currents in the ocean, but it specifically refers to the periodic pull the
moon has on the Earth, to greater effect, on its water.

~~~
trenchgun
Geothermal comes from radioactively decaying material. Geothermal is powered
by naturally occuring fission.
[https://blogs.scientificamerican.com/observations/nuclear-
fi...](https://blogs.scientificamerican.com/observations/nuclear-fission-
confirmed-as-source-of-more-than-half-of-earths-heat/)

~~~
jolmg
I didn't know that most geothermal energy was from fission, but as the article
says, not all geothermal energy comes from fission. There's also the release
of heat as the outer core solidifies into the inner core. That's what I
previously thought that most geothermal energy was.

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jbattle
This made me realize that there are no lifeforms getting energy by mechanical
means (harness wind, waves, tides). That seems like an oversight on
evolution's part!

~~~
dcolkitt
Biological evolution does a pretty poor job of mechanical adaptations in
general. For example in the entire history of life on Earth there's no
instance of a true wheel being developed.

I'd say evolution is really good at chemical engineering, decent at aerospace
engineering, okay-isn at electrical/computer engineering, and incompetent at
mechanical engineering.

~~~
quasimodem
If you believe that humans are too just products of evolution, then I'd say
evolution gets credit for aerospace engineering too.

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ripa890
> geochemical energy, sunlight, oxygen, flesh and fire

Hey, we’ve got nuclear reactions now too!

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designium
Interesting enough, oxygen (O2) came after cyanobacteria evolved on Earth -
there was no free Oxygen until then:
[https://en.wikipedia.org/wiki/Great_Oxidation_Event](https://en.wikipedia.org/wiki/Great_Oxidation_Event)

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ericjang
PDF to non-paywalled article:
[https://www.researchgate.net/profile/Olivia_Judson/publicati...](https://www.researchgate.net/profile/Olivia_Judson/publication/316561085_The_energy_expansions_of_evolution/links/5b9ced28a6fdccd3cb581926/The-
energy-expansions-of-evolution.pdf)

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dang
Discussed (a bit) at the time:
[https://news.ycombinator.com/item?id=14386273](https://news.ycombinator.com/item?id=14386273)

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yters
We can harness the equivalent timeframes of evolution with simple GAs over
quick runs (<1m), but we get nowhere near the results. What is the secret
sauce?

~~~
MaximumYComb
The building blocks of life are far more complicated and are being run with
enormous populations. 1m generations are less than 100 years for a lot of
bacteria and the population they are working with is stupidly large.

I just tested one of my GA's and it's solving a logic problem with 3k pop, 30
children per gen, in 1-2k generations. If I make it 300 children per gen it
solves in 150-300 generations. 1500 children is solving in 30-50 generatikons.
Now imagine 5 x 10^30 pop with 10^30 children per generation, over millions of
generations.

~~~
yters
Where do you get those population sizes from? My research shows on the order
of 10^18 organisms on earth. And the shortest generation time is on the order
of minutes for bacteria. As we go up the complexity scale to higher animals
reproduction time drops drastically. If its just a matter of reproduction
cycles, bacteria should be more advanced than humans. How does this efficiency
jump happen where suddenly we only need a few offspring over the course of
decades to outpaced the evolution of much more fecund populations?
Additionally, humans should be evolving at a blinding rate with each new
generation compared to bacteria. The whole thing doesn't make a lot of sense
to me.

~~~
MaximumYComb
I googled "number of bacteria in the world" and the number is around 5 *
10^30. I mean, there are 7 * 10^9 humans and each human has trillions (10^12)
bacteria, so the human population + bacteria in the body totals over 20^22
living organisms alone.

~~~
yters
Even so my point remains. Why do bacteria seem significantly less complex than
humans, yet have an extremely greater rate of evolution?

