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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by quite possibly a cat » Sat Jan 20, 2018 8:30 pm | |
quite possibly a cat
Posts: 341
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Genetics stuff:
Normally, you have two copies of a gene at a given location (technically locus) in your genome. In real the term "dominant" means the trait shows up with just one copy of a gene. In real life "recessive" means the trait only shows up if you have two copies of the gene. Both terms are referring to genes that exist in a single place on the genome. Next, you can have co-dominance where there is partial expression of a trait with just one copy of a gene. Some traits also have "penetrance" where there is a "random" factor involved. Finally, you can also have multi-factorial traits that use genes at different locus's to determine the outcome. Normally, you have an equal chance of passing either gene at a given locus to your offspring, and normally you can only pass down one. However, in real life, there are things called "gene-drives" which mess with that. This could ensure the passage of a given gene, or set of genes. In the Honorverse, "dominant" refers to this. Note it is possible to create traits that will spread in a population, while reducing evolutionary fitness, thus proving Darwin was wrong. However, which specific gene get passed down is NOT totally independent of the other genes that get passed down. To summarize: if two genes are close together on a single chromosome they are more likely to be passed down together. It is even possible to ensure that some genes are ALWAYS passed down together. In nature, this happens with genes on the Y-chromosome. With an artificial chunk of genes it would be possible (and possibly a very good idea!) to ensure that they are always passed down together. I strongly suspect this is the case for some of the larger scale modifications. Like the cat trait. Also the "switches" for genes are usually part of the DNA itself. A great many DNA traits will always be expressed in a given organism. (In the proper cells, at the proper time.) Some genes if not expressed, would result in a non-viable organism. So the "cat" trait could be one that ALL children get or only some children get. Furthermore, it may be that ALL children who carry the genes for it get said trait, in which case only "cats" would be able to have "cats". But another possibility is some non-cat children can still have cats. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by JohnRoth » Sat Jan 20, 2018 9:30 pm | |
JohnRoth
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This is what the term "locked" means. I once did a design for how a "locked" trait would work. It would have made Rube Goldberg proud. The way genetics works is complicated; unless you keep up with what's oozing out of the labs, you're probably way out of date. There are several of us that try to keep up - or at least not so far behind that we can't see the dust cloud. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by quite possibly a cat » Sat Jan 20, 2018 10:02 pm | |
quite possibly a cat
Posts: 341
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Locking a gene shouldn't be all that hard. You can probably just tack it onto the end of a chromosome. Maybe 14 or something. Nothing for it to be exchanged with. The only real worry would be accidentally adding some genetic instability. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by JohnRoth » Sat Jan 20, 2018 11:28 pm | |
JohnRoth
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A single gene isn't going to do anything useful. Most significant body parts are composed of a large number of cell types, each of which uses a cell-type-specific collection of genes and regulatory elements which are usually scattered over several chromosomes. This is what makes "locking" a modification difficult: the underlying mechanism isn't there to inherit such a scattered mess as an all-or-nothing unit. Consider a bicycle and a motorcycle. Both of them are decent transportation in some situations and for some purposes, but if you try to put something together from a random collection of parts taken from each one, the result is going to be ... unfortunate. In this discussion, remember that RFC has a general goal for the Mesa part of the series and that's an examination of the morality of certain things. He's said that he's looking at good in the service of evil and evil in the service of good. (IIRC, among other things, he's a Methodist lay minister.) The Malign is definitely evilly evil with a side helping of evil sauce, but what they've accomplished in the way of genetic uplift, as shown by the generic Mesan Alpha, is good. Examining the possibilities of genetic changes is not one of his primary goals, and exploring genetic modification technology at any realistically detailed level is also not a goal. The genetic tech shown in the Honorverse is basically an arm-wave. My interest, as someone who thinks he has a decent general overview of current genetics, is to see how much of what's there is actually possible from an early 2018 perspective, and how to accomplish it. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by aairfccha » Sun Jan 21, 2018 6:08 am | |
aairfccha
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Without special tricks, that modification still has to pass the stochastic remixing of chromosomes at play during sexual reproduction to make it into the next generation. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by saber964 » Sun Jan 21, 2018 1:54 pm | |
saber964
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What about Dr Masserelli of HMS Charles Ward? IIRC she had triangular ears, extremely long finger nails and eyes last seen on a German shepherd. Also there was a talking head on Into the Fire who had blue hair because a grandparent who was liberated. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by aairfccha » Sun Jan 21, 2018 4:12 pm | |
aairfccha
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A mixed bag. Amber eyes are rare but occur in humans and the fingernails probably need little tweaking to return to something claw-like. Pointy ears and slitted pupils are likely a bigger challenge unless you could do straight copy and paste. The biggest problem of the bunch might actually be the blue hair since blue is a very rare colour in animals and at least birds and butterflies cheat: They don't have blue pigments but create it through interferometry. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by ldwechsler » Sun Jan 21, 2018 10:35 pm | |
ldwechsler
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We tend to forget that this story takes place thousands of years in the future. Genetics is not much more than a hundred years old. The thing with the doctor is that it is only dealing with appearance. That might be a lot easier than changing intelligence or other things. But consider where we were fifty years ago, even thirty years ago. There will be many changes. We know that Alison could do a lot of changes. We don't know how since RFC does't know how and in some cases, humanity at this time does not know how. But we will. |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by Brigade XO » Mon Jan 22, 2018 12:35 am | |
Brigade XO
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Locking the modifications in, such as described for the Meyerdal mods implies that EVERYTHING in the gene mix for the indivudal traits is going to be both passed down to the suceeding generations AND will be dominant (requiring only one of the gene pair grouping for that specific mod) reguardless of what each suceeding generationg gets for genes from indivicuals who do not have the Meyerdal mods.
We have no clue how to do that yet. We also have only a good view of what is needed for some specific traits and those are not particularly complicated. Eye color and hair color fall in there. The largest impediment to understanding is because, based on present knowledge, there can be many different genes which affect what is expressed and that also depends on wether specific genes are "on" or "off"- which also seems to be tied to what other genes are doing in on/off dependent on other factors. That doesn't start to cover such fiddling complex things as WHEN different things turn on/off (dependent on things such as age or other stuff we haven't figured out yet). Of course, if enough stuff (or only one thing) doesn't go right, the organism /person can just die (or not make it to birth) because one or more system in the body just goes TILT and either the body dies or there is a cascade failure amoung other systems that has the same effect only it takes longer. Adding (well, sustituting plus adding) genes for the cat characteristics mentioned in the description of the Dr. means making a LOT of changes in genes and you have to make sure that none of them either directly or indirectly kill the individual or signifcantly cripple them. While there are some very general grouping of what effects the development and expression of some traits and physical characteristics. we have no clue what grouping would need to be modified (and imported) to give people cats eyes (at least in shape) nor cat fur (vs "normal" human body fair range of coverage, textures, lengths, colors). You get the idea. Heck, someting required to end up with a person with so many cat characteristics could also make them susceptible to Catnip (or just common mint) a semi-narcotic drug. Or you could find that some decedents had retractable nails if not outright claws. Im surprized that Manpower didn't play with the larynx and throat arrangement so that they could Purr. (big smile) |
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Re: Detweiler Vision vs Beowulf Code: "Right" and "Wrong" | |
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by JohnRoth » Mon Jan 22, 2018 2:02 am | |
JohnRoth
Posts: 2438
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This isn't quite right. The real issue is to make sure the modification gets inherited in an all-or-nothing fashion when mated to a baseline. Making it dominant in that situation is an additional, optional follow-on. If the mating is between two people with the same modification, there is no issue: the normal mix and match can occur without a problem. As I said up-thread, I did a back-of-the-envelope design for what would be needed to make it happen. It was rather complicated, but the essential core was a "platform" of changes that would be needed to allow any all-or-nothing mods. That platform has to get into the guts of the processes that create sperm and egg, and the process that puts the two genomes back together after sperm meets egg. That platform only needs to be created once. Here's a clue: there's currently a major international effort to redesign the genome of one of the standard organisms that's used for a lot of experimental and production genetic work, to make it easier to modify. I think it's baker's yeast. The last I heard, they had completely redesigned over half of the yeast chromosomes and also moved most of the problem spots to a new chromosome where they wouldn't cause problems. So, making it work requires redesigning the genome. The people who lead up to Earth's Final War clearly thought it was something they needed to do, so they did it. |
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