
Influenza A (H1N1) – How many bits does it take to kill a human? (2009) - gpvos
http://www.bunniestudios.com/blog/?p=353
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sndean
> There. A single base-pair change, flipping two bits, is perhaps all you need
> to turn the current less-deadly H1N1 swine flu virus into a more deadly
> variant.

Similar idea: I have a friend in a lab who recently made a synthetic version
of a virus (she said she was "resuscitating" the virus). It has a single point
mutation. It's normally BSL-4 and causes lethal infection. With the mutation
it's supposedly safe to work with and won't enter certain cells.

Apparently the polymerase screwed up and altered some part of that gene, or
maybe it wasn't mutated in the first place, or maybe the initial sequencing
was incorrect. Regardless, I got a terrified message from her saying the
synthetic version was replicating in a cell line that it wasn't supposed to.
(Fortunately, she had continued to work with it in a containment lab.)
Eventually her lab group scraped the study.

Before this, I wasn't really concerned about this kind of work.

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majkinetor
Should you be concerned ? SNP can happen in nauture easily any time, this way
the difference is that you you are aware of what is going on.

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sdegutis
Or speeding it up...

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etimberg
Viruses have a few "compression" techniques to get even more info out of a DNA
sequence [1, 2].

[1]
[https://en.wikipedia.org/wiki/Translational_frameshift](https://en.wikipedia.org/wiki/Translational_frameshift)
[2]
[https://en.wikipedia.org/wiki/Plant_virus#Readthrough](https://en.wikipedia.org/wiki/Plant_virus#Readthrough)

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matt4077
Learning about these in class must have been the most "OMG biology is so
fucking cool"-moment I've experienced. Seriously, read the links (especially
[1]) – it's evolution going full Wozniak, with a few hundred million years of
time.

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tomkinstinch
There are viruses with shorter genomes that are more hazardous, for example
Lassa is ~10.68Kb (Kilobase), or 21.236Kb (Kilobit): 2.654KB (Kilobyte).

[https://www.ncbi.nlm.nih.gov/genome/10875](https://www.ncbi.nlm.nih.gov/genome/10875)

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jwtadvice
What an incredible way to conceptualize and compare computer versus biological
viruses (with the size of them in bits looking reasonably similar).

In the virus writing scene there are a number of trends that have allowed
generic approaches to outsmart even incredibly complex "virus scanners":

1\. polymorphic code - basically you keep the Turing Machine / Program Logic
the same, but you use random widgets with random side effects to implement the
program logic. In this case each instance of the virus is different per
infected host and there are no reliable signatures based on the bits to
recognize them.

2\. Packers - basically a program that on its own is not malicious but can
carry another compressed and encrypted program that it will "unpack" in memory
and then execute - allowing a virus to ride through virus scanning.

3\. Stagers - A small and otherwise innocuous piece of code that pulls
commands in either real time or as needed from the network, keeping all
program logic in memory, and executing malicious code that is never packed
into a formal executable file (and thus never scanned by anti-virus). These
have the advantage that they are basically impossible to forensically debug
because the attacker will change or turn off the payload after the stager
succeeds the first time.

Has nature found a way to emulate any of these creative methods for bypassing
immune systems? I remember hearing that HIV can look innocuous to an immune
system, but I'm not sure that's because it uses a technique like the above.

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ghubbard
(2009)

Some discussion from the first time around:
[https://news.ycombinator.com/item?id=667801](https://news.ycombinator.com/item?id=667801)

Actual article title: On Influenza A (H1N1)

HN clickbait version: On Influenza a (H1N1): How many bits does it take to
kill a human?

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roflc0ptic
It's a little click-baity, but it's also a pretty good framing for the
article, which discusses both the number of kilobytes encoded in the virus and
the number of bits that need changing to make the virus deadlier. Much like
with naming poems, they took the first sentence of the post (minus some
preamble) and used it as the title. Idk. Seems pretty defensible to me.

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schoen
[https://en.wikipedia.org/wiki/Incipit](https://en.wikipedia.org/wiki/Incipit)

~~~
roflc0ptic
oh, neat. thanks.

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maj0rhn
Deriving a "lethal bit count" from virus genomes is not quite fair, since the
virus requires considerable metabolic support from the host genome.

I think I can kill you with 21 bits: hydrogen cyanide is a three-atom
molecule. Assume 128 chemical elements --> 7 bits per atom. And the molecule
will assemble itself from the constituent atoms, so no extra information is
needed for that.

Hydrogen fluoride might work, too: 14 bits.

And, of course, a slug of plutonium would kill you both chemically (poison)
and radioactively: 7 bits. Can't do better than that.

Oh wait, if I shot a stream of electrons at you, that could kill you, too.
There are six types of leptons (ignoring anti-matter), so that's three bits.

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jpttsn
On the other hand the surface of the planet is teeming with meat machines that
constantly execute DNA. This article is written by and for them.

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smsm42
Fascinating stuff. But for computer viruses, 22k is really a lot. Back when
computers and OSes were simpler, there were viruses fitting into a boot sector
(512 bytes). Of course, since the boot sector has also to have some useful
information (otherwise the OS won't boot and the virus can't distribute
itself) the actual size was less. It wasn't super-hard to do such viruses
either - provided you are comfortable with assembly coding and low-level OS
programming of course. I wrote one myself back when I was a student as an
exercise (didn't distribute it of course ;). It didn't anything sophisticated,
but still could replicate.

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nojvek
The read is just fascinating. I have sleepless nights sometimes thinking about
DNA cell manufacturing. If we could program DNA, understand it structure, can
we just manufactor, houses, cars, and machines from a seed that you drop into
water and it grows into a design of your choosing with the help of sunlight.

Where can I find more information about how DNA actually ends up creating a
little cell.

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ambrop7
The RNA->protein translation process is pretty awesome. Here's a very
informative video:
[https://youtu.be/TfYf_rPWUdY](https://youtu.be/TfYf_rPWUdY)

Also Wikipedia page on the ribosome has a good description if you're patient
enough to read through.

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rihegher
spoiler: 25054

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rpazyaquian
3131.75 bytes! Although I don't know if a fraction of a byte is valid.

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tim333
Looking at the numbers, Bunnie's proposed mutation may pop up in nature quite
a bit. I guess it doesn't spread as well as the other strain and so dies out
rather than growing exponentially.

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kdelok
Historically, the D->G mutation around 222 (numbering schemes vary) in 1918
Spanish flu caused a significant increase in pathogenicity. That's a single
bit-flip.

