Originally Posted by dreadgeek (Post 771505)

Thanks for the response. Can I ask you a couple of follow-up questions?

1) Since you agree that a protein is just a protein, why does it matter where it came from? I mean I could understand if the protein were, say, one that causes persons with an allergy to peanuts to have a reaction but provided its *not* one that causes an allergic reaction why does it matter?

2) What do you mean by maybe the pathways don't exist in nature for a multitude of reasons?

This is the deeper question, to me, and the reason I'm a little confused about it is this; it seems to me that the explanation I gave, just to take one for instance, why strawberries never developed anti-freeze on their own is sufficient to explain why that genetic pathway had to wait until we came along to show up in that species. For example, it would be extremely useful if humans could see down into the infrared and up into the ultraviolet. We *know* it's possible because there are other animals that can see into either one but our genome was simply never faced with the correct set of problems that would push us toward being able to do so. It's not that there's some grand design nor is it that there's something *wrong* with being able to see a little farther along the EMF spectrum than we already do, rather it's that not only Homo sapiens but primates as a whole were never in any environment where the selection pressure pushed *any* of us toward being able to see into the IR or the UV parts.

That explanation is sufficient to explain why we can't see UV or IR and there doesn't need to be any other reason. Likewise, the fact that strawberries--because they are flowering plants--never had the problem of "what do you do when your entire life-cycle is spent underneath an ice pack" is sufficient to explain why they never developed anti-freeze. Since strawberries are native to latitudes where winter is, more or less, what those of us living in the temperate zones are used to the long-standing plant solution toward the cold (e.g. produce seeds which can spend the winter underground) and that has been sufficient to preserve strawberry genes down the ages. No other explanation is really required. Why go to the trouble of evolving anti-freeze when the cold that could kill you is only 90 days long and you can just keep your genes in a seed for that period of time? No reason. Just like primates came up with a pretty decent solution for not being able to see well in the darkness--don't be active at night. Hominids came up with an even more elegant solution--fire.

I'm asking these questions of you not because I'm trying to prove some point but because most of the time when I've engaged others in this topic they haven't understood the science and so they've had some rather profound misconceptions about the nature of genes, the nature of proteins, the nature of DNA or they haven't really grasped that, for instance, while fruits *want* to be eaten vegetables, on the whole, *don't*. (I'm speaking metaphorically, of course, neither fruits nor vegetables 'want' anything.) So what is the problem with genetic engineering, in general? Not Monsanto's business practices (that's a separate issue) but with genetic engineering specifically?

Why is it unnatural to take a gene that does precisely what we want done and *only* that thing and implant it in a species unnatural when if we simply selectively bred for resistance to cold and got to, more or less, the same protein but it took us a thousand generations (plant not human) to get there it would be natural? It's the same protein, it does the same thing, the only difference is one is a one-step process and the other is a blind, multi-step process with each step along the way having a risk of picking up genes we don't want and which might have deleterious effects.

Thanks for answering. It's a rare treat to be able to ask someone who understands the biology, can do "gene's eye view" thinking, grasps the 'central dogma' of modern molecular biology (that genes code for proteins) and still is opposed to genetic engineering in the terms you've expressed above.

Cheers
Aj

Originally Posted by dreadgeek (Post 775032)

If I can ask you one other follow-up, does that same feeling (I don't know what to call it when you say your Native American side) apply to editing *out* genes? I ask that in the context of the Huntington's chorea example I gave a few days ago. Since we know that any number of repeats above 35 is where things start to go badly and there is *no* benefit to having 39+ repeats of the CAG motif on chromosome 4, editing out all repeats above 35 would prevent people from a rather horrible disease. Are you saying that just as you don't think we should be changing genes except in the long, blind process (which, in my mind, is pretty wasteful) of selection that we shouldn't edit out genes even if doing so would save lives? I'm trying to understand where the line would get drawn.

If inserting genes in is, for lack of any better term, against nature isn't editing genes out also against nature? If we apply the standard consistently (i.e. don't insert anything and don't remove anything) then aren't we condemning people who could otherwise be saved? Admittedly, it is perfectly natural to die of Huntington's. I will not argue that somehow it is unnatural. There are lots of fates that are perfectly natural but that I am glad we can overrule. I'm not ready to condemn people to a horrible disease starting at 27 just because they have 50 repeats of a gene on chromosome 4. There's no evolutionary benefit to Huntington's disease. It is simply one of those things where nothing nature says it *can't* happen so it *does* happen.

So why on Earth does the motif continue to show up in a small portion of the population? Why hasn't it been selected out? Because by the time you reach your late 20s, in the environments in which we evolved, you've already likely had children. Any gene for a disease that can, if you'll excuse the term, hold its horses until *after* you've had at least one child will tend to be able to ride along with the rest of your genome. After you've passed your genes on at least once, nature really doesn't have much use for you. Another way of putting it is that genes that cause diseases that kill you before you have a chance to reproduce are selected out. So all of the low-hanging fruit, from the gene's point of view, was selected out hundreds of thousands or millions of years ago. The genes for diseases that we see tend to strike after your early twenties which, in the EEA (Environment of Evolutionary Adaptation) was well into the average person's reproductive career. So diseases like Alzheimer's and Huntington's and heart disease and high blood pressure are all back-loaded toward the end of one's reproductive career. A bunch of fifteen year old people dying is a net-loss from the gene's point of view, particularly in the EEA. A bunch of 45 year old people dying is zero-sum from the gene's point of view. By 45 you've already reproduced a few times, your oldest surviving children are, at that point, adults. From the point of view of nature, you're now superfluous. Thanks for playing. Nice of you to leave some genes around. You're expendable, your genes are not. That's nature for you.

So unless we intervene using technology (selective breeding in humans, needless to say, is a road we should not even contemplate going down) then we're pretty much signing the death warrants of any person unlucky enough to have 39+ repeats of the CAG motif on C-4. That's the natural way. I think we should veto nature because I think it is wrong vis a vis Huntington's.

Cheers
Aj