Joe M, a question

[grumbler]

I lurk on the usenet site and have been following with interest your discussion of just what the triluninaries detected with Sinclair and the other pilots. I don't want to discuss it there as discussion threads there are too easily broken.

I find your logic compelling, but also find it confusing based on your assertions re: Delenn's transformation.

In several threads here you have (logically) held that Delenn must have been transformed almost completely into human DNA in order to be impregnated by Sheridan, and assert that David was "human in all respects."

Given that this was the case, then it was ALSO true that Valen (and maybe Catherine Sakai) was/were transformed "in all [respects] but a few cosmetic ones" and that his/their children were Minbari "in all respects."

Therefore, there WAS no human DNA for the trluninaries to detect in Delenn pre-chrysalis (or any of the other "Children of Valen), correct? And therefore the triluminaries could NOT have been reacting to human DNA, but must have been reacting to something else, if I understand the whole logic chain you present re: Delenn's conversion.

OTOH, we have the claim in "Atonement" that human DNA still exists among the Children of Valen, in which case it logically works out that there is still Minbari DNA in David Sheridan.

This isn't a challenge of any sort, it is a request for clarification. You clearly have thought about this more than I.

 

[Joseph DeMartino]

That does seem like a major problem, but consider two things:

1) There may be (and probably are) matching Human and Minbari chromosomes that have different content in each species, but similar functions. In that case the original DNA (different content) might remain unchanged in both Sinclair and Delenn as they pass from one species to the other because functionally it makes no difference. It can then be passed on to their children without anybody even knowing about it, if it does not produce a visible difference or health problem.

Here's what I hope is an interesting bit of speculation: proto-Minbari didn't have headbones. A mutation introduced the headbone, and both natural and artificial selection favored it. Minbar is a world filled with natural crystals and the Minbari often dwelt in crystal caves. Hypothesis: The floors of crystal caves are slippery, and sharp crystal outcroppings common. People who slip while moving forward, especially while running, tend to fall over backwards as their feet fly out from under them. So Minbari with headbones survived and reproduced at a greater rate than their non-bonehead bretheren. The Minbari also came to associate headbones with strength, health and beauty, and therefore also tended to chose bonehead mates over non-boneheads, further reducing the chance for non-boneheads to reproduce. Boneheadedness became a dominant trait, so that the children of a non-bonehead and a bonehead would likely be boneheads. Only the rare pairing of latent non-bonehead genes would produce a non-bonehead child. Differential mating patterns would also favor those with larger headbones, thus setting up large bones as a trait in many families.

If the shared section of DNA involves the skull, then it becomes plausible that in going from Human to Minbari Valen acquires the dominant Minbari trait of a headbone, while Delenn, moving in the other direction, has only a vestigial headbone remaining as a partial expression of her Minbari skull gene in an otherwise Human genome, because the match is not 100%. This vestigial trait is not expressed in her son David, whose skull growth and shape is dominated by Sheridan's DNA.

2) A certain amount of all our genetic material is "junk DNA", non-functional stuff that never gets used for anything and seems to be some kind of genetic padding. (It is a very odd concept and a comparatively recent one, and I've probably expressed it badly but if you look up the term you'll see what I'm talking about.) If the unchanged bits of both Delenn and Valen are "junk" DNA then it gets passed down without doing anything at all other than being picked out by the triluminaries.

Sound plausible?

Regards,

Joe

[Edited to correct a couple of "boneheaded" spelling errors. 16 Feb 2004]

 

[Adrian]

Certainly it was made clear that all the "internal parts" of Delenn transformed to human.
I always remember the episode just after Delenns transformation when Ivanova had sorted out Delenns hair and she then asked (to Ivanova's obvious horror) what these strange stomach cramps were!!

 

[Jade Jaguar]

2) A certain amount of all our genetic material is "junk DNA", non-functional stuff that never gets used for anything and seems to be some kind of genetic padding. (It is a very odd concept and a comparatively recent one, and I've probably expressed it badly but if you look up the term you'll see what I'm talking about.) If the unchanged bits of both Delenn and Valen are "junk" DNA then it gets passed down without doing anything at all other than being picked out by the triluminaries.

This concept was developed long after I studied such things in college, so I can only clarify this a bit. Rather than "junk DNA," I believe the best term is 'unexpressed DNA,' and it is believed that much of this DNA has accumulated throughout evolution, but is no longer used, thus unexpressed. They are searching for the mechanisms which cause DNA to be expressed, or suppressed. I find it interesting that this concept lends creedence to time-honored scifi concepts expressed in such things as the movie Altered States, Dr. Jekyll and Mr. Hyde, and a certain infamous EP of Voyager.

My own personal admonition to scientists who say that as much as 90% of our DNA may no longer be necessary is that just because we can't see exactly HOW it is used doesn't mean that it ISN'T used. We have learned a lot, but we still have a lot to learn.

But, for the purposes of explaining how Minbari could have human DNA, and vice versa, it seems as plausible an explanation as our current science will allow.

 

[Vonbloodbath]

Here's an interesting bit of speculation: proto-Minbari didn't have headbones. A mutation introduced the headbone, and both natural and artificial selection favored it. Minbar is a world filled with natural crystals and the Minbari often dwelt in crystal caves. Hypothesis: The floors of crystal caves are slippery, and sharp crystal outcroppings common. Peopl who slip while moving forward, especially while running, tend to fall over backwards as they're feet fly out from under them. So Minbari with headbones survived and reproduced at a greater rate than their non-bonehead bretheren.

I like it! I like it a lot!

VB.

 

[KoshFan]

As I understand it, "junk DNA" appears to be inert and not expressed, but I seriously doubt that any scientist would recommend clearing away the "junk." We don't know what it does.

 

[A_M_Swallow]

Possible uses for junk DNA.
1. It is the test tube, allowing new sequences to be developed/modified without damaging the ones in use. Similar chemicals can be used for different purposes.
2. Banned sequences, possibly held in an encoded form. This DNA kills its host so any new sequences can be checked against it.
3. Earlier versions so if DNA containing a bug is produced a working version can be substituted.
4. A combination of the above.

 

[grumbler]

Re: Joe DeM, a question

Thanks, Joe, that all makes sense. What you are arguing is that DNA-wise the offspring of D&S are for all practical purposes fully human (rather than an unqualified fully human), and that makes sense.

It does leave open the question of when Joe will introduce the "quadriluminary" to detect Minbari DNA in the human "Children of Delenn" in the far-distant future!

BTW, sorry about leaving out the "De" in your name in the title - the spirit was willing but the flesh is a bonehead!

 

[Joseph DeMartino]

Re: Joe DeM, a question

BTW, sorry about leaving out the "De" in your name in the title

Would that "Joe M" were the worst thing I'd ever been called, on this site or elsewhere.

As we used to say in my old neighborhood, "No autopsy; no foul."

Regards,

Joe

 

[sleepy_shadow]

My impressions (and my mistakes too, corrections welcome):


Unexpressed DNA:
----------------

DNA which has never been observed to receive use in protein sythesis. It may still be relevant for structural purposes. Provided activation, it may still be capable of creating proteins which do something (aside from looking pretty). It still gets copied. But probability of such DNA ever producing a protein (thus accomplishing any notable change in metabolism) is very low.

Is it junk?
-----------

Partly. What is junk? Is my old typewriter junk? Is my kindergarten-time lunchbox junk? Is my 1998 floppy junk? By some definitions they are, by some definitions not. I am not using them currently. But provided a change in circumstances, I might find them useful for something.

Unexpressed DNA is certainly doesn't get translated into proteins... and thus passes on mostly unmeasured by evolution... for which reason it generally sits there degrading. If we could and wanted... large portions of it *might* be safely removable. (However, such a venture might produce more hassle than benefit.)

Over time, it becomes noise. Unless a mutation again produces an active gene, or removes the unused sequence without compromising important information.

Does it contain possibly functional genes?
------------

Yes it does. Old genes are rarely removed. More often they "fall asleep". Despite being unused, and thus not maintained by evolution, genome degrades slowly. Some small portion of sleeping genes might go unchanged for a hundred million years.

With high probability, we have inactive genetic sequences of complete or notable similarity to genes actively used in other species... for example to facilitate the formation of scales, gills or air bladders.

It is merely that such formations are incompatible with our bodies -- for which reason the activation of such genes would generally cause us harm. Not necessarily, but with high probability. There are almost certainly some old genes we can safely express.

As example, I would mention that humans can safely grow a tail. Happens rarely, but happens. Not good for self-perception, though -- and thus usually removed. I cannot tell whether it is caused by a sleeping gene waking.. or an active gene changing. But the scenario qualifies as example.

Does it contain something we might want to remove?
----------------

Yes. Some viruses embed themselves in host DNA. Sometimes they malfunction, "fall asleep" and never awaken. Sometimes, a mutation awakens one. By then, it is possibly outdated, damaged and unable to live... but sometimes, it lives and infects, or lives and triggers cancer.

--------

If Minbari would indeed use DNA with the same four bases which Earth life uses... a limited amount of inactive "junk" from Human genome getting into Minbari genome... might not do anything, but still allow recognition.

However, should it get translated into active components of Minbari cellular metabolism (either proteins or something equivalent to proteins) serious harm would be only a few genes away.

 

[Jade Jaguar]

sleepy, your mention of viral DNA pricked my memory a bit. I do remember reading that besides DNA that has been bypassed/made obsolete by evolution, the other major source of our unexpressed DNA seems to be viruses, which have managed to insert parts of their DNA into out own. I also recall reading that if we can learn how to switch on obsolete DNA, we could create humans with things like the more acute sense of smell, or hearing, that our primitive ancestors had, but that other, modern faculties would be inhibited. Sounds like a good premis for a scifi story to me.