tlb wrote:George J. Smith wrote:Assuming all the Meyerdahl immigrants to Sphinx had the locked Meyerdhal mods, how many generations would it take to spread the those mods throughout the general population of Sphinx?Galactic Sapper wrote:IIRC they're pretty well spread on Sphinx. Something like a third to half the population has one of the Meyerdahl mods. It appeared in one of the early books but I don't have machine readable copies.ldwechsler wrote:And that was just in a few hundred years. Note also that people with the mod almost certainly married those from outside Sphinx. There were undoubtedly a real lot of people on Manticore and Gryphon who had the mod. If it is actually locked in, there would be a lot of genies. Since there aren't, it is likely that it is not.
I have included the quote from chapter 3 of In Enemy Hands. The quote makes it clear that the Meyerdahl mods are dominant, but not locked."Don't worry, My Lord. Mike Henke teases me about it all the time, and the explanation's simple enough. I'm a genie."
The earl blinked briefly, his expression totally blank, then nodded in sudden understanding. It was considered extremely impolite to use the term "genie" to describe someone, but given Harrington's neurosurgeon father and—especially—geneticist mother, she was probably more comfortable with the label than many. For that matter, the prejudice against genetically engineered humans was slowly dying out as the last memories of Old Earth's Final War faded from the racial forebrain. But there had been no such prejudice in the early days of the Diaspora, and quite a few colonies had been established by genies specifically designed for their new environments.
"I wasn't aware of that, Milady," he said after a moment.
"We don't talk about it much, but I'd guess the majority of Sphinxians are genies by now," she replied. He raised a polite eyebrow, and she shrugged. "Think about it," she suggested. "Heavy-grav planets are one of the most common 'hostile' environments. You know that even today most heavy-worlders have shorter than average life expectancies?" She looked at White Haven again, and he nodded. "That's because even with modern medicine you can't put a body designed for a single gravity onto a one-point-three or one-point-five-gravity planet and expect it to function properly. I, on the other hand—"
She made a graceful gesture with one hand, and he nodded slowly. "I knew about the modifications for Quelhollow, but those are much more readily apparent than what you seem to be talking about," he observed.
"Well, Quelhollow had some other environmental concerns, whereas my ancestors were more of a . . . generic design, I suppose. Basically, my muscle tissue is about twenty-five percent more efficient than a 'pure human's,' and there are a few changes to my respiratory and circulatory systems, plus some skeletal reinforcement. The idea was to fit us for heavy-grav planets generally, not one in particular, and the geneticists made the changes dominant, so that every parent would pass them on to every child."
...
"That's only an estimate, and it's not one modification. The Harringtons are descended from the Meyerdahl First Wave, which was one of the first—in fact, I think it was the first—heavy-grav modification, and folks like us probably make up about twenty or twenty-five percent of the population. But there are several variations on the same theme, and worlds tend to attract colonists who can live there comfortably. When you add the free passages the government offered to recruit fresh colonists after the Plague of Twenty-Two AL, Sphinx wound up attracting an even bigger chunk of us than most, including a lot from the core worlds who wouldn't even have considered emigration otherwise. In many respects, the Meyerdahl genies are the most successful, in my modest opinion, though. Our musculature enhancement is certainly the most efficient, at any rate. But we do have one problem most of the others don't."
"Which is?"
"Most of us don't regenerate," she told him, touching the left side of her face. "Over eighty percent of us have a built-in genetic conflict with the regen therapies, and not even Beowulf has been able to figure out how to get around it yet. I'm pretty sure they will eventually, but for now—"
Sigh. A little knowledge is a dangerous thing.
To use the high school textbook example, let's say you've got a single gene that has a dominant and recessive version. Let's call it A, with the dominant version being a capital A and the recessive version being a small letter a.
Now, assume that one parent has the recessive version, meaning aa, and the other has a dominant-recessive pair, meaning Aa.
The children are going to be half Aa and half aa.
This is bog-standard Mendelian inheritance, which has been well understood since Mendel's work was rediscovered in the early 20th century.
The fact that a variation is dominant does not mean that it will be inherited. Dominance does NOT mean "it will be inherited."
If a parent is guaranteed to pass it to ALL of cis children, then it's locked. That's one of the two things that locked means.
