Nature Vs the Environment

[wolfeyedangel]

Bear with a moment please because this seems somewhat odd given what my Bio professor was saying back when I was taking biology. When we were in the genetics section they were still trying to figure out all the details of that because of so many occurrences of oddities, 'throw backs', recessives, partial dominants, partial recessives, and the fact that the same coloration could be the result of different genetic combinations. I personally know of at least 2 different blue eye/blond hair combinations, One is largely dominant, the other largely recessive, but only 'largely'. Now, this was somewhere around 6 years ago and I was wondering if you had any newer specifics than the general outline he gave (I didn't take his genetics course so my understanding is rather general.) He made it very clear that hair and eye color (though he didn't indicate which, if either, was 'more complicated') were the result of many alleles combining in various ways rather than a single set of alleles (like blood type). I'm definitely interested in new information since it seems that my information may be a bit dated, and as an overview it undoubtedly has holes in it that I'm hoping you can help fill.

~Wolf

[ParaLLL]

I had a bio class last semester; just a general class, but genetics were mentioned, and the professor said basically the same as yours seems to have; hair and eye (and I believe skin) colors are the result of several alleles, and multiple pairs of genes, and we can predict what a kid will end up with based on percentages and what the parents look like, and looking at genetics might get a little more specific, but not completely accurate, or anywhere close enough to be particularly useful. So we have a sort of general idea of what alleles there are, and how they tend to interact, but not really much that can be used practically (or whatever you'd call 'well this embryo will have blue eyes and this one will have light brown eyes; which would you prefer?' since I'm not sure I'd call that practical). The professor ended the mini lecture with something along the lines of 'there's more to it but I don't want to scare anyone off so I'll stop now,' so maybe there are some genes that we can recognize definite effects, but it doesn't sound like most and definitely not all.

On a semi-related note, I believe that most of the things we can figure out about embryos (gender and diseases) are chromosomal rather than technically genetic, so it's not actually specific genes that we're looking at in those cases.

[TxCat]

On a semi-related note, I believe that most of the things we can figure out about embryos (gender and diseases) are chromosomal rather than technically genetic, so it's not actually specific genes that we're looking at in those cases.

I hate to sound ignorant but...could someone explain the difference? I was under the impression that chromosomes contained genes or that they were a type of gene. Science is really not my forte and it's been over twenty years since I set foot in a classroom. I'm lucky on some days to be able to do the simple calculations in those little squares which were used to demonstrate genetics with peas (I play a pet game which requires understanding of them).

On the topic: I recall quite a few years ago seeing one of those old informational films from the 1950s which talked about the ability to choose exactly how your child would look. I found it weird because, for some reason, they illustrated the point by showing a couple going up to a vending machine-like apparatus, inputting what traits they wanted, submitting their fingers for a blood stick, and then getting that particular child. No, it wasn't a parody.

[ParaLLL]

Chromosomes contain genes; they're basically a long string of genes/DNA all wrapped up into a package. So genetic diseases are where a gene is bad, while chromosomal diseases are where something happened with the chromosome itself. I'm not sure about most of the specifics, but the ones I know of tend to be ones where a chromosome or section of one is either missing or extra. So when people (or animals, for that matter) have three sex chromosomes; generally either XXY or XYY, are chromosomal disorders. Since it basically means that a pretty significant chunk of DNA is either missing, extra, or screwed up, rather than one or two genes like in most genetic disorders, chromosomal disorders tend to be pretty severe.

[CocoaLoco]

To put in my two cents, from what I've been able to read on this subject...

Also, as far as I've been able to find, scientists have failed to control embryonic stem cells' growth and development, which usually causes tumors to form instead (in fact, as I recall, when it's been done on mice it usually killed them).

As far as forming organs or other complex things out of said stem cells? As of yet, as far as I can tell (unless I'm horribly, horribly mistaken) we haven't even been able to get them to form the simplest things (such as, say, skin), much less stimulate them so they grow into an organ, and actually stop growing when we want them too.

Not true. By using stem cells obtained from the patient, scientists have been able to grow a new trachea and implant it in her. And the best part is that her body won't reject it because it is hers. Research is currently ongoing for how to do this with other organs.

Except that I wasn't talking about adult stem cells there. I was talking about embryonic stem cells. I'm all for the study of adult stem cells.

Unfortunately, until we can mix and match genetics like kids mix and match sweets, not every cell may be created from bone marrow (the ones generally used) stem cells. Embryonic cells are completely able to become any body cell. Blastcyst (early stage embyro) cells can be stimuated to form solely new organs or tissues, whereas adult stem cells can be stimulated mostly to produce things such as red blood cells (which, yes is a break through), but other paths can be taken using embryos, hence the emphasis on embryonic stem cell research.

Yes, they are completely able to turn into any body cell... Or a tumor, which they're more likely to do at the point we're at in such research. As of yet, scientists have made no breakthroughs in it, while adult stem cell research has already proved to have merit, hence why some people think that we should stop giving embryonic stem cell research billions of dollars, and put more of that money towards adult stem cell research.

Adult stem cells are quite likely to cause tumors too, especially if you want them to be able to turn into more types of cells than just the ones they usually do, because to do so you need to treat them with cancer-inducing factors.

Except that that's IF we want them to do something which they would need the aforementioned treatment for. Unlike adult stem cells, the embryonic stem cells do it without such conditioning.

Like you shouldn't inject stem cells into someone's face just because you felt like seeing what would happen--all that would happen is you get a lump of abnormal growth (not quite cancer, can't remember what it's called, though) that will kill you.

Would tumor be the word?

Nope. Different. Otherwise I would have just written "tumor." It's similar to a tumor, I guess, but not the same thing.

Ah, well, just wondering. I've known people who space out on things that are really obvious sometimes. (including me, when I'm tired...)

And as I stated in my first post, I don't believe that a blob of rapidly dividing cells counts as life. Especially because it hasn't differentiated yet.

Well, I disagree with this (since cells are technically the smallest living things we know of), but I'll not argue the point on this.

I think that's a purposeful misinterpretation of what I meant. Sure, they're living just like bacteria are living. I don't have any qualms about killing bacteria, though, so I don't have any qualms about killing them. Especially because we're not actually killing them. They're still alive; they just won't become a fetus.

No, because I understood what you were saying, and I wasn't trying to twist it. I just disagree with you on that point, since I view a human in pretty much any stage (with very few exceptions) as being a life.

[Knuckerbearer]

Except that that's IF we want them to do something which they would need the aforementioned treatment for. Unlike adult stem cells, the embryonic stem cells do it without such conditioning.

Of course, the embryonic stem cells can also become cancerous tumors without the aforementioned conditioning. Has there ever been a documented case where adult stem cells actually did turn cancerous?

[Destrauxe]

I think this can be really sick. I mean alot of times the children have 2 moms and 1 dad making 1 designer baby. The surprise of eye color and hair color is part of the secret. It's just like when a couple chooses not to know the baby's gender.

[nightclaw]

This is an idea I've had for a while from a series by Marion Zimmer Bradley that I've read. It's about selective breeding and the enhancement of certain favorable traits in humans.

I think that since we have tried to breed more.... well, breeds of other animals to improve the breed, why not do the same with ourselves?? I know that there are ethical reasons against this, but why improve other races when we do nothing to improve ours?? We could have a society in which specialized people do different things. For example, you could put the gene that allows salmon to be deep underwater and is like a coolant so that thier blood doesn't freeze, and if people had that gene, they could explore underwater ecosystems, and strong people could do manual labor and stuff like that.

Well, I hope this topic isn't locked, since I look forward to hearing other answers.

[DoomedDaphnia]

I feel the "Salmon gene" would fall under the category of genetic modification, not selective breeding since it's not naturally found in humans.

This may seem cliche, but why should we selectively breed ourselves when we have machines to do manual labor and such for us? With submarines, we're able to explore the deep ocean and discover ecosystems we previously thought couldn't possibly exist at such cold, crushing depths. We have specialized machines that can harvest trees. We even have machines that can work on microscopic levels. Unless there's some sort of way to genetically enhance intelligence or cleverness, I don't really think there's a point, and so far I haven't found an article that conclusively states that intelligence is hereditary (if you have an article that says different, feel free to link me to it )

[nightclaw]

Yeah, but would you really want machines t do everything?? I agree about manual labor and stuff like that, but we still can't use them to do everything. And if we did use them to do everything, we would grow too complacent and.... well, soft.

And yes, that's what I meant.