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Everything posted by Dak

  1. immunology was difficult... all the different inter-connecting aspects that you can't really understand untill you understand the other bits (which you can't understand untill you savvy the other bits)... yum!
  2. Not really, no. isn't sugar-cane an extremely thirsty crop? couldn't it be the case that the buisness responsable for growing the sugar-cane over-farmed (for their personal profits), started to cause land-drought, and -- having learnt the lesson from the tennisse valley -- the US govournment is now buying the land off of the buisness with tax-payers money. iow, rather than farming responsably and cutting back production (and thus profits), the company has enjoyed unsustainably high profits, and, far from being shouted at for it, they're now getting their raped land bought off of them, whilst the tax-payer foots any repair bills. of course, that could not be the case, but this is why i don't like trusing land-managment and food-production to big bisnesses.
  3. as edtheiran said, anything that has persistant information (e.g., through hereditary), variation, and a selection mechanism will evolve. depending on how you define NS, it's entirely possible that something non-living will evolve via NS simply by having its variants culled according to some criteria (which, ultimately, would be rewordable as 'those that are best at not being culled will be most frequent', e.g. NS). an e.g.: Selfish gene theory is, essentially, NS with (non-living) genes being the individual units that NS works on, rather than individuals. again, the bananas were our fault. anyway, it's inherent in how NS works that the week and inefficient will die; that's what causes, over time, an average increase in fitness. e.g., after the Gros Michelle's all-but died out, the average fitness of bananas increased. None of this stops NS being capable of dealing with the fact that we're artificially allowing what would otherwize be bad traits to remain. Ultimately, the only way we allow them to remain is by preventing them from being so bad that NS can't cull them, so NS is still ultimately in charge of our evolution.
  4. sigh... Which one? [edit] bloody computer programmers... no one else would answre 'a or b' with 'yes' [/edit]
  5. Yes, but you have to remember that this is an artificially created situation, resulting from human selective-breeding. 'natural' bananas could adapt quick enough to survive diseases without GM. GM is only neccesary to correct problems resultant from over selectively-breeding bananas. in fact, the claim that only GM can solve the problems of new diseases -- when NS has been working out ways to counter both new diseases and new immune systems for aeons -- is kinda silly, unless you meant just in the banana population. Umm... how, exactly, would we rapidly change our environment to such an extent that we'd extinctify ourselves? espescially given that most changes that we make to our environment are benificial to us (availabililty of medicine, for example)? Also, natural selection doesn't need to be slow, and is (again, kinda tautologically) fast when it needs to be. look at the black death, and the sudden increase in delta-9 (i.e., black-death-proof) alleles in just the time it took for the BD to rip through europe and for people to then repopulate. a majour shift in allele frequencies over about 1 or 2 generations, thanks to NS. I can't help but notice that we've gone off-topic: from discussing the repercussions of allowing a few 'disadvantageous' traits to pass through NS, to somehow claiming that NS doesn't work fast enough for humans. could you tie-in to the OP with your responce please, if possible.
  6. was it just nominations staff aren't allowed to do, or can we not vote either?
  7. OK, lets try a slightly different angle: for quite some time, we've been selectively breeding bananas to be fatter and straiter. in doing so, we've -- to an extent and temporarily -- replaced NS with artificial selection. in doing so, the result is a lack of genetic diversity: one species/strain of bananas (the main one we used to eat) is now all but extinct, fallen to the panama disease. The other main species/strain of edible bananas (the one we mainly eat now -- cavendish, iirc) are: extinct in asia due to the latest strain of panama disease suffering, in africa, due to top banana-bunchy disease (i kid you not) suffering, in africa, from black rot black rot is interesting because the bananas, lacking genetic diversity, cannot adapt to become resistant to it, whereas the black rot fungus is still adapting and evolving, so, over time, is becoming more resiliant to the fungisides used to combat it. so, even tho we've temporarily lessened NS's effects on the banana, ultimately NS remains, and has killed off one species/strain, and is in the middle of doing the same to the other main strain. given that we have this example, i really, really can't see humans being stupid enough to lessen NS's effects on us in any artificial way. maybe centuries in the future, but not with our current technology and understanding. it'd just be too stupid. another example is sickle-cell anaemia: bad in one context, but -- in the presence of malaria, which it grants immunity to -- is good (possibly required: i can't recall if we can cure malaria). btw, sickle-cell anaemia, and the fact that our current technology makes it less fatal and thus stops NS from supressing it, is sort of an example of one aspect of what lucaspa said earlyer about the removal of evolutionary supression allowing for genetic diversity and the possible spread of benificial mutations (tho his actual point was completely different). so, yeah, i can't see humans actually doing what you suggest and using eugenics to any great degree. However, it would be possible to remove NS to the point where -- whilst it still applies to us -- applies to us by killing us en mass (see: bananas). So i guess we could stop NS forcing us to evolve/adapt, even if we can't stop it from applying to us, tho it'd take gross stupidity on our part to do so.
  8. Yes, but now we understand artificial insemination -- and the (lack of) ramifications therein -- better. I don't see this as ethical concerns eroding; rather, justified caution in the face of the unknown giving way to the knowledge that it's harmless. hmm... that's still quite a jump, and i still can't see us making it (unless we're talking waaaaaaaay in the future). espescially compared with safer alternatives, such as in vitro selection of zygotes -- effectively early abortion for any zygotes that would be phenotypically Lou Gehrig, for example. Still 'eugenicky', but at least letting recessive alleles remain in the population, and not replacing NS per se (rather, adding a small artificial layer on top of it). to significantly displace NS by the means you suggest would require that most people stop reproducing via sex, and/or that most people submit their foetus to peri-natal genetic screening. Not going to happen imo, both because most people won't do it, and because most geneticists/doctors will understand why eugenics-level genetic 'tinkering' is stupid. maybe waaaay in the future, when we have a better understanding of the exact effects, we will utilise eugenics and completely replace NS with artificial selection, but even then we'll still be subject to NS (i.e., if we screw it up, we'll die); faced with this, i can't imagine the knowlegable geneticists who'd have to do it agreeing to do it in such a way that'd reduce our diversity, or at such a speed that NS would 'catch up' by killing us all As i said, we litterally cannot remove ourselves from the effects of NS. if we are not fit enough to survive, we will not.
  9. Maybe they did. I don't think the US wants Iran to have nukes. And, as you said, they are american defence dollars.
  10. ah, i see. Yes, if we manually choose the alleles to propagate/not propagate, then we'd be replacing NS with artificial selection. I'd be very surprised if we'd ever do this, at least in the near future, simply because it's a dumb idea. Most geneticists know -- and understand why -- eugenics is a bad idea. maybe fixing the odd unquestionably bad trait here and there (which we're allready doing), but not a whole-sale displacement of NS. iirc, the proposed EU charter on human rights has something in it against eugenics, for example.
  11. This one country, btw, being the single biggest reciever of US aid in the world.
  12. I'm sorry, but you've missed the point that i made earlyer. NS is a tautology: if a trait does not prevent it's possessors from passing it on, then that trait is not too bad. It's not possible for us to technologically accidentally push 'bad' traits through NS; it's only possible for us to 'neutralise' bad traits and stop them being bad, at which point they are no longer suppressed by NS, but also they're no longer bad so this doesn't matter.
  13. tbh, i was thinking something along the lines of what phi said -- either a sub-forum or just a sticky on sfn. otoh, swansont's link kinda covers it allready...
  14. hmm... i don't recall the last time i got a picture advert...
  15. the talkorigins of global warming Basically, i've seen the same (crappy) arguments come up time and time again against GW, and have to be refuted, at great length, ad nausium. It's allready been observed that GW deniers have more than a passing similarity to creationists. So, i suggest a talkorigins-esque database of the more common crap and a canned refutation for each argument, that we can link to during discussions, thus saving ourselves time and hopefully allowing for some saner (and less longwinded) threads about GW. thoughts?
  16. to add to this (and expand on what Edtherian said): 'natural selection' is a tautology, and it's not possible to circumvent it as such. In as much as NS is a filter, it's possible to pass through it, or not pass through it -- how and why you managed to pass through it is, strictly speaking, irrelevent. in other words, extreme short-sightedness used to be a problem, and would probably have prevented large numbers of short-sighted people from passing the NS test (e.g., they'd either not survive to reproduce, or they'd not be sexually selected, at least in as high a frequency as normally-sighted people). it's important to realise that the very reason that NS worked to suppress short-sightedness was because it was a huge disadvantage. If we're in the situation now where NS can't 'see' short-sightedness (hehe), it's because short-sightedness is no longer a problem, as it's trivially fixable with technology. in which case, it's completely unneccesary for NS to supress this non-disadvantage. so it doesn't. iow, if NS isn't 'working' to supress certain traits, it is tautologically unneccesary to suppress these traits. may as well accept simpler eyes that are boosted by technology in order to unburdon our genome and eyes. if our eyes ever degenerate to the point where they're problematic, then NS will, tautologically, start exerting force upon eyes again, to stop them becoming any worse (i.e., it'll start working to supress disadvantageous traits if/when these traits genuinely become disadvantageous). sorry if that was a bit waffly
  17. yuppers. made so much difficulter by the fact they used standard notation for dominance/recessivity (Aa, Bb) why not the other way round? actually, i'm not sure what exactly this means tbh... yup well, for the first gene, the parents are Dd * Dd; that gives, in equal likelyhood, DD, Dd, dD, dd. two of them are hetrozygous, so the chance is 2 * (1/4) = 0.5 for the first gene. no, miles off. a gamete will have one allele for each gene. so, a parent that is Aa can make 'A' and 'a' gametes. a parent that's AaBbCC can make ABC, AbC, aBC, abC = 4 different types of gamete. no. incomplete dominance is across one gene. so, if R = red and w = white, then: RR will be enough red pigment to make the phenotype red ww will be no pigment, == white Rw will either make enough pigment to make the phenotype red (dominance), or enough to make it pink (incomplete dominance). if it was on one gene and, say, RR == red, YY == yellow, but RY == orange, then it'd be co-dominance. But, this involves more than one gene... give up on this one till you know the answre to the last question.
  18. So tempting to ban you for threadomancy there...
  19. yup. when DNA is copied, mistakes are made: in theory, these should be spotted and fixed by the cell's post-DNA-replication error-checking machinery; if they can't be fixed, the cell should be killed. however, mistakes quite often slip through, and these mistakes are sometimes in the genetic information that codes for the cell's error-checking and DNA repair mechanisms. so, you'll eventually get cells loosing the ability to check for and repair DNA damage. after that, replication errors will start to accumulate. Also, DNA shortens with every replication. to overcome this, chromosomes are capped with telomeres, which are replicated slightly differently than the main body of DNA. the end result is that the telomeres shrink and enlarge with every replication. eventually, they'll become so short that they stop doing their job, and after that the chromosome will shrink with each replication, eating into the genes and causing numerouse other problems (another thing telomers do is stop chromosomes' ends being 'sticky'; so, after they're gone, the chromosomes can fuse together, which has a lot of wierd 'degradory' effects). etc.
  20. +1 ------ what exactly is this whole 'friends' malarkay about?
  21. expecting someone to behave reasonably is a two-way street: no doubt he does it with you because he's learnt that you'll reciprocate and behave reasonably to him. if his teachers aint prepaired to reciprocate, then maybe he's not willing to behave reasonable to them. Not saying it's all the teachers' fault, or your son isn't to blame at all, i just remember how annoying it was for me as a kid, being expected to 'behave' (read: just do as told by the person who i didn't choose to place in charge of me, in a place that i didn't choose to go) wilst being treated arbritrarily and unfairly. fwiw, i allways behaved reasonably towards the teachers who treated me reasonably.
  22. iirc, ms didn't 'barge in'; rather, hardly anyone was buying the laptops due to their lack of support for ms. linux isn't so much better than ms that anyone really wants to pay the cost of conversion yet -- they'd be happy if everyone used linux, but not being the first minority to use linux in an ms-dominated world/market -- and that seems to include africans.
  23. hmm... your kid is in a place where he does not wish to be, and no-one's paying him. He's no doubt being expected to act like an adult, whilst not being treated like one. Would you act any differently to him? I know i didn't, you didn't, I doubt i would now, and i suspect you wouldn't now. Maybe, rather than teaching him respect for authority (which i suspect you yourself only have in small, claused amounts), teach him respect for others -- if others are trying to learn, it's rude to disrupt them -- and try to get across to him the value of an education. hitting him with a cane is unlikely to improve anything (personally, id've just laxatived their coffy in retaliation, or maybe burnt their car down, and resorting to violence would certainly not have made me 'respect' authority).
  24. also, cooking does the first stage of breaking down molecules, which would otherwize require that we spend our own energy doing it, thus increasing the overall energy yield of cooked food vs. raw food. as to how people figured this out..?
  25. not to mention that you'll probably either have to do a dissertation (100% self-study) or a recerch project (where your supervisor is extremely unlikely to teach you everything). You have to learn to research stuff yourself. iirc, number 8 should be pretty easy for anyone who's studied them at all.
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