SF, DNA, and pondering

[den]

Something level_head wrote got me thinking. Proteins. Are there other bases and base pairs besides Adenine, Guanine, Thymine and Cytocine? I expect there are but I don't know where to start looking for them.

I always wonder about this when I watch SF shows. The Heroes land on an alien planet, meet the natives, get invited to dinner and start stuffing food into their faces. Why should the carbohydrates twist the same way as their enzymes? Why should the proteins have the same bases? Why don't they get sick? The only way the Heroes wouldn't die of malnutrition is if God created all the worlds using the same basic DNA template. Assuming life on all worlds started from the same primordial soup random-act-of-bindness, the chances of two worlds having the exact same DNA would be astronomical. Even proteins with the same bases but a right-handed twist would make the stuff unusable as food for us.

In my stories each character's medical records are linked to the food services databases. How else would food synthsizers know what a character can and can't eat? Different body chemestry could mean something that is a coffee sweetener for one alien could be a narcotic for another, and instand death for a third.

If you find me shouting "WHY AREN'T YOU BEING SICK" at an SF show on the telly, it's probably dinner time for them.

Comments

[sporklord.livejournal.com]

Well, there's uracil, but that's found in RNA as a substitute for some other nucleotide, although I forget which one. It's been a while since I've studied cellular biology.

[weibchenwolf.livejournal.com]

I like the idea of the hero eating from many huge banquets and slowly dying of malnutrition.

I take it you've read "Strata" by Terry Pratchett? He was the first author I'd seen take note of this 'problem'.

"To serve man"

[ursuscal.livejournal.com]

Ack! A "Twilight Zone" episode...

Turns out that "To Serve Man" is a *cookbook* for how to prepare "man."

I do not want to hear about medical records, BTW... We have a new set of laws in the U.S. called "HIPPA," short for the "Healthcare Information Portability and Privacy Act." It was well-intentioned (as are most awful laws) to enable employees who leave one employer to get health insurance with the new one. But...

[red-frog.livejournal.com]

How else would food synthsizers know what a character can and can't eat?

Simple. No one else talks about them, but all alien planets replicate their food through use of Nutri-matics, which (paraphrased) analyze your personal physical chemistry and produce a product perfectly suited to your body.

The real question is how those people are surviving consuming nothing but a beverage that is entirely unlike tea.

Re: "To serve man"

[dewhitton.livejournal.com]

Here it's not up to the employers to provide employee health insurance. Employers must pay for "Work Cover" insurance so employees are covered if there is a work-place accident. Since every employer must pay this insurance it doesn't matter who an employee works for. They'll be automatically covered if they leave one job and start another. No transfer of records is required.

There is also Medicare. The patient visits the doctor and hands over their medicare card (like a credit card but with no personal details, just their number.) Dr. submits list of medicare numbers and waits for the Government to pay ("Bulk billing"), OR Dr. charges patient who then visits medicare office and claims a refund. Everyone pays a 1% tax to fund this.

Then there is Private Health. The Employee signs up with one of the (many) health insurance companies. (I think that's the MHO (?) system you have) You don't have to sign up, but you get better health care coverage beyond the basic services.

[hafoc.livejournal.com]

Very good. :) I run into the same thing in my writings, although I gloss over it.

Why couldn't life exist on a world with air pressure much higher than ours? Or with, say, three times the carbon dioxide? Yet such conditions would probably kill us. If such minor differences could be fatal, even on worlds where everything else was ideal, how is it possible that alien species could happily live together on the same planet? Then throw in all the other possible variations-- left-handed vs. right-handed proteins, different proteins, different genetic materials than DNA-- and the odds that we could live with alien animals, let alone eat them, seems vanishingly small.

But that would throw away all my plot ideas, so I ignore it. :)

As for SF films, I've come to believe there's a great conspiricy involved. I suspect that all those aliens are actually humans only PRETENDING to be aliens, in search of financial gain. If that's the case it's no wonder they can eat the same food we do, 'cuz they is us.

:)

[dewhitton.livejournal.com]

Yeah. Sometimes those aliens look like they have a big wad of latex on their face. I don't think they're aliens at all.

[acelightning.livejournal.com]

[level-head.livejournal.com]

Dear Batty -- you might check the spelling of that username link. ];-)

One of the webcomics dealt with the topic not too long ago. Freefall is an excellent strip, and you're probably already familiar with it, but here was that discussion:

http://freefall.purrsia.com/ff800/fv00710.htm

===|==============/ Level Head

[dewhitton.livejournal.com]

What's wrong with the user name? I deny a typo exsists.

I remember that strip and was very pleased to see the way Mark handled it. And it was funny as well. I wish I could write like that.

[ursulav.livejournal.com]

For the same reason that alien women all have compatible genitalia to Captain Kirk?

I recall some book...might've been Grass by Tepper...that included a plague caused by something converting proteins from right to left or left to right. On the planet of origin, there was plenty of both kinds of protein, so it was kept in pretty reasonable balance, but when it got off world, only the ones converting left-to-right could function in human terraformed worlds, causing widespread havoc. But I dunno, it is, indeed, a greivous oversight.

[ceruleanst.livejournal.com]

Star Trek is a special case. The telling moment was in the finale of TNG when Q talks about the origin of "the humanoid species." And I thought, well, yes, they are all one species, aren't they? Everybody can viably interbreed. And given time-travelling starships, there's not much standing in the way of the idea that there was a single origin for all life in the galaxy.