Setting the record straight on ejaculate

[elfs]

So, apparently there's this meme going around that a single ejaculation containes something like 1.5 terabytes of data. However, after de-duplication and BWT-based compression, you'd only end up with something like 15KB of Shannon information.

See, this is what comes (ahem) of me encountering this meme while I'm in the midst of a crash course on bioinformatic visualization techniques.

Comments

[solarbird]

Which on a 1500 baud Kansas City interface cassette system would be a nice round 16 feet(!) (192 inches) of audiotape - ignoring leader and header information, of course, since that varies by cassette and system.

I'e never seen a man produce that length of ejaculate - it's always been quite a bit more compact than that - so I'd have to say that it's considerably more space-efficient than cassette.

But quite a bit messier, and even less durable.

[amindofiron.livejournal.com]

and now I have a mental image of some sort of bizarre robo-jaculate composed of a unwinding spool of magnetic tape. why do I read this stuff when I know by brain is gonna do things like *that* with it?

[drhoz.livejournal.com]

XD

[solarbird]

Be glad I didn't do the math for paper tape. There's nothing more annoying than an ejaculate cut.

[amindofiron.livejournal.com]

ow....ow ow ow OW! *shudder*, I'm going away now.

[atheorist.livejournal.com]

Note that if a sufficiently advanced entity were trying to communicate something with ejaculate, they could use protein configurations and populations, organelle positions, all kinds of extra-dna channels. Terabytes seems reasonable if you confine your attention to just DNA sequences.

I can't replicate the 15kb figure, though; even if you're compressing relative to some reference genome, the best relative compressor of genomes in wide use today gets something like 3MB (http://sun.aei.polsl.pl/gdc/).

[en-ki.livejournal.com]

...and that requires a reference genome, so it's less "compression" and more "diff".

[lucky-otter.livejournal.com]

Does that include all the various mutations?