If they can get a mouse to grow a human ear on its back, is it feasible to have a monitor lizard grow a pair of non-functional batlike wings? Just something that looks like a pocket-drake.
How feasible is it and by what process? Would it more feasible as some sort of architecture grafted onto its back over which skin can grow, or is it within the realm of possibility that it could be achieved through genetic manipulation?
How feasible would a black market in such beasties be?
[This message has been edited by hoptoad (edited November 10, 2006).]
Scientifically? Feasible, as I understand it. To do that genetically, you'd graft (committed) somites from the developing wing of a bat (or whatever) into a lizard at the right stage of the lizard's embryologic development and control the morphagen levels and immunosupression so it retains its structure and doesn't get rejected by the host.
[This message has been edited by Jeraliey (edited November 10, 2006).]
For functional wings, you need so many physiological changes that you're really talking a whole new creature. Iguanas are pretty heavy and not the ideal shape for flight - you'd need to hollow out the bones, add a big sternum to anchor the flight muscles, change the posture to allow for the sternum, and so on and so forth.
The closest lizard I know of that would serve as a model is the basilisk - a South American lizard tha has flaps on its rear feet and runs on two legs. It's actually able to scoot across water. Arguably, it's on an evolutionary path towards flying, though it's still hardly a ong way down the road.
It was the first step towards being able to graft ears back onto people, or so I believe. While not that necessary for hearing, the outer ear (or pinna) does a lot to let us know where a sound is coming from.
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There wouldn't be any need for the second head to eat or breath, it would only need to be supplied with artieral blood from the other mouse. Assuming the brain was alive and functioning, there would be no reason it couldn't hear and see (as well as feeling pain...lots of pain), but it isn't currently possible to give the second head any kind of motor control of the body.
Anyway, back to the original question, feasibility depends on required function. If the alteration is purely cosmetic, it doesn't make sense to do it biologically, simply glueing a wing-like decoration on the lizard would accomplish pretty much the same effect. If the wing has to actually allow flight, then you're probably better off trying to engineer an organism from scratch rather than trying to modify any existing chordate. I would start from a cockroach, personally...unless the damn thing had to act like a lizard...then I'd have to go from scratch (or close enough). If you want the wings to flap and stuff, but the thing doesn't need to actually fly, then I'd go with a powered prosthetic actuated by somatic cues from the lizard.
If the customer wants to believe that the wings are "real", then I'd go with the lizard's own skin stretched over an implanted structure...you know, like a boob job.
Aren't monitor lizards reptiles? At a very basic level, I think the wings would have to come from another reptile. Maybe the wings are actually those fan/gilly things from that silly running lizard.
Also, I think the genetic quality of mice has been kind of beat-down over the generations of purebreeding, so that they are tolerant of a lot of indignities. But I could be wrong about that.
Another idea is to double-bud the arms on the embryo so it has two sets of arms, and then alter the arms so they have webbing. A final horrific surgery removes the arms and reinstalls them on opposite sides, upside down and backwards.
Oh yes... a REAL ear sticking out of its back would be FAR less disgusting!
And what's the point of an ear, particularly one that cannot hear? Now, I can think of other appendages that would be MUCH more useful. I should think a mouse could use a giant nose instead...although, sporting a giant fin-like protrusion on its back might make the act of squeezing into my silverware drawer to deposit some mouse poop more of a challenge.
The ear is produced for eventual grafting onto a human. It is a composite of cells taken from the eventual recipient and a nonallogenic "scaffold" which is attached to the mouse prosthetically. The mouse is just there to supply the human tissue with nutrients (hmmm, tasty). The human tissue grows over the scaffold and becomes a graftable piece of skin with an embedded structure that makes it resemble a natural ear.
The point of using a mouse for this is that the alternative would be to keep the human patient in a sterile environment for the several weeks it would take for the skin to cover the prosthesis completely. During that time, the patient would need to be on immunosuppressants to minimize (not eliminate) the severe itching and inflammation at the healing site (even though the scaffold is non-allogenic, the situation provokes that response, a shard of glass stuck in your foot is non-allogenic too). And a chance accident with 50+ kilos of meat lolling about could destroy the whole thing at anytime, just by accident (particularly when the patient is trying to sleep).
The ear wasn't *on* the mouse's back, but *in* it. It's implanted, and it's for growing the ear to full size so it can be put into a human whose ear was destroyed.
A functioning wing on a lizard would be different: you'd need to integrate it into the skeleton and musculature. But if you're willing to have it not be present-day, well, use your genetic engineering handwavium and you'll have little dragonlets to your heart's content. Such a world should also have a variety of other made-up creatures, too.
Okay, so I get the picture. Nearer today probably stick with non-functional wings that is the result of some sort of surgically implanted scaffold. A little further down the line a genetic version with either functioning or non-functioning wings achieved through genetic tinkering may be okay ie handwavium. I imagine that if you could get these critters only through some blackmarket then they would also be engineered to be sterile to protect the market a bit.
[This message has been edited by hoptoad (edited November 12, 2006).]
Not necessary if the alteration is surgical, not sufficient if it is genetic.
A genetic alteration would be present in every living cell of the creature, and if biotechnology were advanced enough to produce such a beasty, then cloning one from any living cell of an existing specimen would be a snap. Heck, we could do that much with today's technology if you're talking about lizards, mammals are far more difficult to clone and that's yesterdays news.
So you could get 'cheap' knock-offs and imitations with dubious production values leading to unexpected results in subsequent generations.
I suspect the variations would probably trend toward the ancestral norm ie, wings eventually breed out and the drake reverts to basic lizard. How likely would more interesting, stable, speciating effects be?
[This message has been edited by hoptoad (edited November 12, 2006).]
I'm not sure I understand...you're talking about animals that cannot reproduce naturally anyway, so technically there isn't any meaning in talking about their species.
Of course the 'knock-offs' would have some failures, but a first generation lizard has billions of cells. Even if we assume that the success rate for cloning them is miniscule, a thousandth of a percent chance of a high quality duplicate, you can still get thousands of basically perfect copies from any first generation sample. A single first generation lizard would keep a bootlegger in work for life, if the alteration were genetic.
The tendancy for the quality to "breed out" would be entirely negated by simply not cloning anything that wasn't a prime specimen. Heck, successive generations of clones might end up being "better" than the originals, even though you forfeit the effects of meiosis and sexual reproduction. But the natural selection pressure against having a non-functional organ wouldn't be in effect. For one thing, the wings are the only thing that makes these things 'fit' to be pets, and for another, the 'breeding' is 100% artificial.
I think that you're better off going with articulated surgical implants if you want to control the supply. The implants could be genuine bones grown around a biodegradable scaffold, and you could even do some musculature using the same technique (in the future, current technology is not quite that far). If you incorperated autonomic nerve tissue, the wings would even react to the lizard's moods (lizards aren't as moody as mammals, but they do have moods...of a sort) and movements.
Such a surgical technique would be much easier to perfect than a macrogenetic alteraction of that scale, and there would be little danger of anyone being able to make copies without reduplicating the entire initial investment.
now, continuing the question, if we can graft the ear onto the mouse, and maybe in the future make a mini-dragon, then whats next? Superman? then maybe Spiderman, flash, and all those other people you wished you could be when you were a kid.
do I think it could be done? maybe... (evil lab with mutant lizards pops into thought bubble)... YOU SEE NOTHING!
There is a different mechanism, the one where fruit flies grow legs out of their eyes. You can get a chick with four wings by putting wing cells on the embryonic leg buds. It has to do with stem cells and cell differentiation. There seem to be mechanisms that control for left, right, fore and aft on an animal, and different controls for distal, proximal and so forth. That's why in my model you would have to have a similar type of animal. If you could get wing stem cells from another reptile, suck out the relevant DNA, put the komodo DNA in, it would in theory grow wings. But while these things sound simple, there are a whole bunch of things we don't really understand that try to keep them from happening It seems to me too much mutation all at once reduces the chances for gene transmission since, let's face it, no one wants to mate with a mutant. Unless you're Wolverine, but Wolverine kills all his lady friends, so there you go.
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The interesting thing is that you don't even necessarily have to use the same species. The gene that allowed flies to grow all kinds of eyes in all kinds of different places is a master regulator called "eyeless". And when they tried switching in the "eyeless" master regulator from the mouse genome, it resulted in the same phenomenon: the fly grew eyes (fly eyes!) wherever the experimenters wanted it to.
The reason you'd have to use differentiated somites is that if they're undifferentiated and uncommitted, hox genes and developmental morphagens will control what structures will grow from which cells. Regardless of where the cells actually come from. If they're differentiated, though, they'll develop into whatever structure they're committed to, no matter where you put them (if the morphagen gradient doesn't affect it too much at that point).
Hmm...that's an interesting observation about Wolverine. It brings up an interesting question or two, which I will not pursue.
Anyway, that just gets you a lizard with an extra set of forelegs, which then have to be altered somehow to make wings. The problem is that if you make those alterations genetically, then it will tend to turn all your forelegs into wings. Making the extra set of forelegs into wings while leaving the proper set as legs is really difficult. And it seems kind of pointless since the wings wouldn't be functional without radical changes in the overall phenotype, including a lot of central nervous system meddling.