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Xavier

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  1. Years ago, before the fall of apartheid there were persistent claims and rumours that South Africa was promoting research aimed at engineering a bioweapon that would only affect black people. In theory, this is not impossible to do but the South African paymasters were operating on presumptions based on political ideology, not science. There is no 'black' gene in the sense of their definition of black people so they didn't get anywhere (notwithstanding some conspiracy theories about AIDS and then Ebola, both of which appeared in Africa during the reign of apartheid.) They didn't really define who their enemies were and the poster of this fantasy has the same problem. Even assuming the long list of requirements for these bioweapons could be met (possible), that no-one would suspect anything until it was too late (improbable) and that the U.S.A remained free of infection (impossible)* - who, exactly, are you planning to attack/subdue? Who gets to decide the list of targets? What about the French - they're pretty troublesome - or Mexico? And what about all those illegal immigrants already in the U.S., we could target them, and the gangmembers, the environmental activists...and how about the scientists? Those smart-alecs are always making difficulties and they mostly vote democrat anyway... Draw a line between US and them and you'll never get any sort of agreement about precisely belongs with us. Even the line drawn around the human race which is pretty well defined generates some debate - should the fact that we can perceive a definable difference between humans and chimpanzees or dolphins make it ridiculous to allow that these socially and culturally active beings should have a right to life beyond our whims whilst everyone does who happens to share my body-shape, give or take half a metre and 100 kilograms (or a completely different set of genitalia, or no legs at all, or a mechanical device in place of a heart or..etc.) Don't wish on your enemies anything you wouldn't want to see headed back at yourself! *I am going to take the opportunity to recount a favourite story even though it dates back to the 1970s:- A survey of American schoolchildren (aged 12-14) asked, amongst other things, the children to point out the U.S.A. on a map of the world. Two thirds of them pointed towards Australia. The surveyors suggested that during that era U.S.A. was so isolationist that the children were taught little of the outside world so they would look for the largest island on the map and guess that it must be there. I will grant you that as British citizens, pining for the days of Empire, we know our political geography especially well (after all, we used to own it) but the insularity of Americans in their belief that they could get on just as well without the rest of the world was what made me more frightened of Americans having nuclear bombs than the soviets.
  2. Xavier

    Time?

    Don't forget that the Earth has been slowing down. It loses energy due to friction and widens its orbit, conserving angular momentum so a year took less than a year back then.
  3. One of the great problems for a sociologist who must use questionaires as a source of a large proportion of collected data is the tendency of those questioned to try to guess the intent of the question rather than simply answering it to the best of their ability. For example, when question 17 asks what you would conclude from the different results reported by two apparently identical tests many of the respondents have suggested that the question is wrong because the answer that they would give does not provide the information to the questioner that the respondent believes the questioner is looking for. If you answer the question as it is stated, most people here would answer "none of the above", though there is an argument for answer (e), combining the two results by averaging them, on pragmatic grounds (again, the respondent would not be likely to make this response as they are aware that the overall tone of the questions are towards the understanding of scientific method, not the practicalities even though averaging of results and allowing an implicit error is perfectly reasonable practice.) Thus the questioner would be able to divine something of the state of mind of the respondent in answering the other questions such as questions 2 and 7 both of which depend to an extent on the inclusiveness of the term "scientific" as used by the respondent. Any other combination of answers to question 17 also indicates that the respondent is using the term "conclusion" differently - to mean 'a plausible solution to an apparent contradiction', for example, by which definition the answer © to question 5, The word "Hypothesis" means...c) an unverified conclusion, would also be valid. On the subject of question 5, "Hypothesis" could, arguably, be said to means 'less than a thesis' so 'an unverified conclusion' is not an impossible paraphrase. Since the other answers to question 5 are clearly silly (especially since the term "hypothesis" was used in the previous question in expectation of its being understood) I suspect that the information that the questioner is hoping to derive from question 5 relates to the degree of care or hair-splitting that the respondent is indulging in. The question is well placed as the respondent is now far enough into the questionaire to be engaged but hasn't reached the more taxing or contentious questions yet. The most notable point about the questions is the use of quotation marks around key terms and I suspect that this may be contributing to the sense that there is a hidden agenda: references to "Scientific Method", capitalised and quoted, appears to suggest the questioner is implying that it is just a name, a jargon term - 'the so-called "Scientific Method" '. I think that what the questioner is trying to suggest is that the term does not have an explicit meaning and that the respondent is invited to imply a meaning based on the answers to the questions. This effect is clearer in question 12 where the question states that 'Scientists try to remain "objective" during experiments.' and then asks the respondent to affirm or deny a definition of "objective" in this context. The reference to "Field Biology" in question 16 confirms this as there is no explicit definition of that term or for "scientifically proper". The question is so broad and undefined that the answer is likely to depend on the respondents perception of the breadth of activity that can be called science. Note that in question 8 "scientific law" is not capitalised, nor is "scientifically proper" in question 16. I interpret this as a minor error in the formulation of the questions as those two phrases are not commonly bandied about (if "Law of Nature" had been substituted for "scientific law" I feel sure that it would have been capitalised.) However, I may have missed some additional trick - the 'error' may have been placed to illicit further information. Overall, I see signs of great cleverness in the construction of this questionaire. The overuse of true/false questions (typically a good questionaire asks you to 'rate' the truth of a statement of 4- or 6-point scale so you can get an index of the confidence of the respondent and get some data from 'don't know' responses) may be done to make it appear less daunting (or to look more like an examination paper?) There are enough technical questions to make the respondent feel that there should be explicitly correct answers to all the questions and several of the questions reinforce elements of other questions (so if any of us filled in a reply, our overly intellectual analysis would make a distinct response pattern) Two questions bother me, though; The 'God' question cannot offer any insight into respondents opinion of scientific validation as too many respondents will respond to their opinion of the validity of the statement itself and it isn't useful for discovering the respondents opinion with respect to faith because there is no reinforcing question (that I can spot). The other is question 19, about Organism X's friends and family. The problem with it is that, however you look at it the same answer appears. From a superficial glance, organisms A and D are closest, geometrically, from other perspectives either A or D could be justified. The chart invites the strict mendelian interpretation - but that is just A and D again (both share 50% of their genes with X, on average). Perhaps it is intended as a technical-looking question that everyone can answer, in order to put the respondent into a better frame of mind before getting on to the administrative questions. Of course the whole exercise could be aimed at question 21; a gruelling exam-style paper to remind a group of high-school pupils how difficult science can be before offering 'Wouldn't you prefer to go off to a nice four-year course at a college or university instead ?"
  4. I was working in a hospital biochemistry lab over the millenium. In the lab we had a thick Y2K action plan folder, all the necessary material for submitting handwritten reports for urgent blood test results and even a couple of torches and spare batteries! I felt that the torches should really have had a Y2K Compliance Certificate as well, but... We had TWO computer failures that night. One occurred as a result of the all the computers and chemistry analysers being shutdown whilst midnight passed - when we rebooted everything one of the collating computers hanged when it restarted and then wouldn't work until all the data from 1999 was deleted manually. I guess the Y2K compliance patch had expected the computer to be running and to deal with the glitch itself and we were undone by our own paranoia. The other glitch was even sillier; the new security system with card readers and electronic locks on all the doors crashed. Since we'ed shutdown the lab, all the staff had gone to the canteen so when we returned we were all locked out. The sillly bit was that the security system crashed at midnight on the 31st December for the next two years!!!
  5. I took a class a decade of so ago which had courses in each of the main topics of medical laboratory science; biochemistry, haematology, immunology, histology and microbiology. As the course progressed, I noticed that for each topic the subject of aging came up and was ascribed to be due to something within the topic being taught. For biochemistry - DNA breakdown (this was before telomeres became fashionable and referred to the inability of the DNA repair mechanisms to fix ever more damage - DNA repair was little understood at the time and DNA was believed to be very robust. Nowadays we believe that the DNA is under a highly sophisticated, continuous repair programme.) Immunology - the breakdown of the immune response allowing multiple low level autoimmune diseases attacking the body slowly. (Most deaths by 'natural causes' are actually precipitated by infection, particularly pneumonia) Haematology - againg was said to be due to cumulative restriction, blocking and loss of the microscopic capillaries that feed blood to every nook and cranny of the body. Individually, a loss is unimportant but cumulatively there is a reduction in perfusion over ever larger areas.More parts of the body have to try to make do with less oxygen and nutrient supply so cells die and the immune response is compromised as its transport infrastructure fails to deliver antibodies right to the beachhead of an infection. Histology - againg is caused by the accumulation of cancerous- or precancerous- particles in the body. Whilst some are voided by the immune system many are merely slowed or would never have amounted to a life-threatening condition but the cumulative effect is body degradation. By the time you are a wrinkley you are riddled with clusters of cells that are misfiring, blocking or just getting in the way of the bodies normal functions. In each case, the scientists weresaid to be making strident progress and were just beginning to get to grips with the solution to whatever they believed was the cause of aging - and they may be right. Anyway, longevity statistics for today are measuring people who lived through the Great War and the Depression! I would expect to live well beyond my grandparents average of about 80 years if I didn't lead such a determinedly unhealthy lifestyle. A child today should expect to see the twenty second century. In 'The Selfish Gene', Richard Dawkins suggested that aging and death were due to an accumulation of mutations in the human genome that cause bad consequences only when the body was beyond its usual reproductive lifespan (like Huntingdon's disease, though most of these mutations are not as horrible). There was much less evolutionary pressure to get rid of these mutations if they only did damage after the next generation was reared and again it is their cumulative effects that cause the visible degradation. He suggests that if the human race is really serious about increasing longevity, we need use only our clever brains to choose to increase the mean reproductive age by not allowing any child to survive if born of parents younger than thirty years. Evolution will favour mutations to push up the maximum reproductive age (or we can use technology to do it artificially) whereupon these negative mutations will be driven out (or their onset age increased) as they will be effecting the procreation of the next generation. In summary, I consider it a fairly much accepted scientific game to come up with a plausible connection between aging and whatever is the topic of study. Be particularly wary of explanations based of DNA damage as there has been a profound sea-change in our beliefs about DNA repair that is spilling over even into genetics of inheritance! And 'Hormones' was to the 1980's when immunoassays were first measuring that in quantity, what DNA has been to the past decade so make sure that any theories you read are up-to-date. A couple more interesting longevity factoids. Various invertebrates increase their lifespan by 50% when fed on a strict, near-starvation diet. Laboratory mice have a lifespan of 150-200% of the maximum found in the nearest equivalent in the wild (>1.5 years vs. 9 months, some lab mice live over 3 years) despite their rampant inbreeding. However, most that are killed in experiments die of cancer - typically non-malignant tumours that grow too big. People who have had a total thyroidectomy must take a synthetic thyroxine hormone in a pill twice per day to survive. When it was noticed that such people had a average lifespan as much as 10 years longer than an equivalent, non pill-popping population some people had healthy thyroid glands removed so they could take the pills instead!
  6. Consider the genes as the things that are passed from generation to generation and that the phenotypes of more successful genes act in such a way that that gene occurs in more bodies as the generations go by. Now, if the gene of interest is in the body of a parent there is a 50% chance that it is also in the body of each child. Therefore a gene that promotes the survival of a parent at the expense of a single child will be successful but a gene that promotes the survival of the parent at the expense of more than two children (or acts at the expense of a single child but does so too often) will be unsuccessful. If you add in the opportunity cost of a more resilient, longer lasting body opposed by the cost of creating new bodies from scratch and that these bodies would be competing for the same resources so you can't have both, there is a point of maximum success for the gene in the frequency with which either parent survives or child survives. A range of optimal strategies have been developed for generation time from the hour or two for bacteria up to the decades for us higher mammals. Where the optimum lies depends on other factors in the species' survival strategy - notably body size and the opportunity cost of creating new ones each generation. Mammals are close to the upper limit of generation time due to their warm blood, rapid motion and so on which are expensive to build, but makes good survivor in its niche role (from a non humanocentric viewpoint mammals could be regarded as occupying a highly specialised niche). Humans are pushing even closer into the realm of diminishing returns and it is only the enormous survival benefit of our intelligence that makes the cost of our long gestation and childhood worthwhile. As was mentioned by ed84c, evolution can only be interested in reproductive lifespan which, for females has probably hit an upper limit for our body architecture - babies are born in a woefully vulnerable state; they are popped out the moment there is a decent chance of survival despite the tremedous cost to produce them - but perhaps males could continue to increase their reproductive lifespan. But...the existence of the older males would reduce the number of children that could be raised using the available resources so this increased longevity would extend to the point where it costs more to make the older body resilient enough to survive than to make a replacement. (Of course all this is moot with respect to humans for whom inclusive fitness has little to do with survival and for whom the level of available resources are continuously growing and then crashing in the near future so an evolutionarily stable state cannot develop) I can think of a group of creatures that have taken on the strategy of making the body as resilient as possible to maximise their reproductive lifetime. They are the largest living beings on the planet; trees. If the timescale is long enough even the need to ruggedise itself against climate change or earthquake must be factored into the cost of trying to make a tree immortal - as they have already evolved the resilience to beat once per century forest fires - but even for them longevity is ultimately finite.
  7. Assumption: 1) The world is grossly overpopulated with humans 2) Many people are struggling to get enough food Perfectly logical conclusion: Humans should eat humans - In practice: 51% of the population can get together and decide that, for the good of the majority they should butcher the other 49%. At the end of the exercise, 100% of the population are better off. So, if the assumptions are correct, why doesn't this happen? Because risk to each individual of being in the 49% outweighs the reward of being in the 51% - if the sides are randomly selected. But shift the selection procedure and it suddenly becomes very attractive to those who are fairly sure of being on the side of the reward. For example, suppose the basis of deciding who gets to be eaten (or isn't allowed to reproduce) is made on the basis of (lack of) intelligence then it becomes less surprising that people who contribute to a science forum see some merit in the argument... In order to support this sort of 'for the good of the majority' solution as a general principle you really want a clear, visible signal to distinguish 'us' from 'them' which is why skin colour is such a boon to those morally-challenged few millions of of people who want a quick fix for societys' ills. (In fact there are some uncomfortable echoes of the standard in western foreign policy towards those who are clearly separated from 'us' by geography rather than a physical difference; the only difference is that we don't butcher the third worlders with the 'humaneness' we reserve for cattle and we let the resulting food supply go to waste. Oh!, and we are far less than 51%)
  8. A lot is going on to make functional changes to a population of creatures through natural selection. For a start, within any population there may be several different sequences of DNA(genes) at each particular place on each chromosome which exist in different combinations in different individuals of the live population(the gene pool). In a stable environment several combinations can exist that give the same overall inclusive fitness by slightly different means. When the environment changes, different combination may become more beneficial. Situations can arise where too extreme or prolonged environmental change makes the gene pool sparse as there are no more combinations of genes that can increase survivability and this is one of the reasons supposed for species extinctions occurring (i.e. pressure from a new predator makes grazing animals need to run faster. The sheep-like creature and the pig-like creature are both undergoing natural selection for longer legs and bigger leg muscles but, whilst the sheep can just need a lengthened femur and built-up rump, the pig would need a reshaping of its hip which has been a part of its body architecture for so long that there are not sufficient options in its population of genes - there are too many other genes that only work with a standard pig-shape that bearers of any other gene wouldn't survive - so the pig-like creature dies out) Mutations creep into the genepool with time if it doesn't have a negative effect on inclusive fitness and whilst the enivronment is stable the diversity of genes that combine to do roughly the same job of making a surviving creature increases. This is an aspect of the widely, though not universally accepted theory of punctuated equilibrium in evolution. Amongst animals that use sexual reproduction there is a mixing of genes where pairs of chromosomes come, one from each parent and before that each chromosome is also spliced and rejoined so that the chromosomes received from your mother will derive from parts of those she got from each of her parents. Each gene therefore gets mixed up with a different set of fellow genes in each new generation. However, genes that are close to one another on the same chromosome will stay together unless the splice happens to fall between them so they are likely to be together for several generations. This allows genes to evolve in groups that are mutually dependent. Various activities can cause genes to change their place on a chromosome and when two genes that happen to complement each other (ie. increase inclusive fitness of their body) happen to move close together and thus be more likely to be together again in the next generation will tend to remain together. They could become so necessary to each other that it makes more sense to describe them as a single gene. Amongst humans (in this case the choice of humans as an example is due to that species being studied far more intensively than any other - one presumes the same to apply in other species) there are many areas of the DNA code that are apparently unused. There are many ideas for why it is there and just one of them is that it is left over genes that are no longer used. This idea is bolstered by other bits of our genome that appear to be genes but which never get swithched on and still others that do get switched on but then either get immediately interrupted or the code is read and then the mRNA which transports the code is disposed of, rather than sent off to be processed. There may well also be some proteins amongst the thousands that remain unidentified within our cells that are made by genes but which no longer have any effect at all. These all appear to be different stages in the removal of DNA code that is presently surplus to requirements. There are legion examples of proteins (eg. melatonin, a byproduct of hormone building that is now used as a sun screen) processes (sneezes and coughs have been developed into audible communications in some animals) and whole body parts (our lungs may have begun as buoyancy bladders in fish?) that have apparently found new uses presumably because something that hadn't been removed from the genepool during the random shuffling of DNA just happened to slightly improve inclusive fitness in a new environment or in combination with a new gene. I haven't even mentioned the newer ideas about evolution in the gene expression control mechanisms. The take-home message is that the mutations that give a beginning to the whole diversity of life may be random and beneficial mutations may appear extremely unlikely (in fact computer simulations and 'creation in a bottle' experiments have shown that there is time to spare. Punctuated equilibrium came, in part, from the question of how come evolution took so long to get to us) but they is a lot of complex meachinery working to make the best possible use of it. As far as the genes are concerned, if they had concerns at all, mutation would be death.
  9. This comment and the web site that spawned it needs answering fully. I hope others will wiegh in as well, but here are my thoughts:- Firstly, the OneHumanRace website. The content of the site preaches anti-racism from a biblical context - so far so good - but its sideswipes at evolution seem scattered and selective, using quotations and partial notions without any understanding of the underlying concepts. Deep into the web sites comes the question "How does evolution influence racist attitudes?" and the answers give a piecemeal history of the social attitudes to race through history including the way darwinian evolutionary theory was used as an anology for the human condition. It is worth clearly pointing out that during the age of european colonisation of the rest of the world - before anyone had heard of evolution - 'racism' was accepted as right; after all the Victorian Englishman could clearly observe that the natives of the lands that he conquered did not worship the christian god, wear clothes or have good table manners so they were 'clearly inferior' and they were, of course easily conquered which proved it. The chinese, on the other hand, were much more difficult to conquer than the Africans so were considered less inferior, though they were still considered alien and dangerous. From this context, other races fitted the analogy of animals better than humans - after all everyone knew what a human looked like whereas animals came in all shapes and sizes and they existed to be controlled and used by men. (The chinese fitted the analogy of demons or other supernatural entities quite well as they were not controllable and the inscrutable oriental became a stock villian for the Victorian horror story) Then along comes Darwin and evolutionary theory and the religious Victorian society are up in arms about the idea that they are related to monkeys. Monkeys are chosen as the point of shock perhaps as it is very well known by then that blacks and whites can and do interbreed and that it is far from impossible that any Victorian actually did have a mixed race ancestry. A species is defined as a group that are able to interbreed in a natural environment, a definition that grew in importance from a mere taxanomic device with evolutionary theory and humans were clearly of a single species. Social evolution was dreamed up at the end of the Victorian era as a last gasp of the notion of a clear divide between the the races within the human species and without the benefit of a genetic mechanism for evolutionary progression, it must have seemed reasonable that evolution of a society was analogous to evolution within a species. Eugenics, the dabbling in the system was way of directing human interbreeding was intended for the betterment of the human species, just like breeding programs for domestic animals. The problem throughout is with the judgement of what constitutes 'Better': the europeans presumed they were better because their religion told them so and it was backed up by their superior technology. The social evolutionists argued that the betterment of the species was, by definition better for all the individuals - at heart, this was a misconception of the nature of evolution as having a purpose and a goal that all individuals aspired to in some subconscious metaphysical sense. Currently there is a dogma that it is impossible of any human to be 'better' than any other where 'better' might be loosely defined as 'more worthy to use up his or her share of the available resouces'. This is not really our true opinion of the matter is evidenced by that fact that court cases to this day crop up where a seriously congenitally disabled persons right to have sex is being championed or challenged (which one depends on the prevailing opinions of the legal guardians), not to mention the lack of any moral concensus on the issue of genetically engineered 'designer' babies. Those are cases where the spectre of eugenics still causes debate because there are valid arguments on the side of human intervention in natural procreation (for example preimplantation genetic diagnosis of IVF embryos to select for a baby lacking some particular defective genes). Each person may argue differently in these very special cases but they show that the principle of absolute equality is not clear cut. In fact, practically the principle of absolute equality barely gets a lok in to real life. But the most important criterion of discrimination is not anything as abstract as race; it is geography. The closer someone is to you, the more you care about them. Closeness, here can mean physical proximity, or social proximity or even just imagined closeness, such as peoples relationship with celebrities. Race, particularly where there is an obvious viual disticntion between your race and that of another person, is just another marker in the index of closeness to another person. This practice IS evolutionary in origin. It is a part of kin selection, the determination of which other individuals who are more likely to share your genes. If you aid those with whom you share genes in survival and reproduction then there will be more of your genes in succeeding generations, including the genes that promoted the behaviour of helping your gene-mates. The most obvious example of this is with families; if you know your relationship with your parent/child/sibling then you know that they carry half of the genes that you do (the other half coming from the other parent) so genes that promote helping them have a better chance of being in the next generation of bodies than genes that do not. A mother can be fairly certain about her relationship with a child and a father a little less so (a lot of animal behaviour can be explained by the male's desire to be certain that he is indeed the father of the brood he helps to nurture - though not necessarily human male behaviour) but for a sibling, they must generally assume that any individual sharing their nest is more likely than not to be a brother or sister. In species with extended family groups (packs, tribes) the degree of relationship is not known but there is sufficient advantage to be gained (for the spreading of the genes that promote it) from spotting those who share your genes that recognition of individuals whom are often seen and even family resemblances have evolved. Humans are uniquely gregarious in the number of different individuals they interactions with. Furthermore, part of their success as a species has been in large scale cooperation. The closer you are to others the more likely they are to share at least some of your genes, whether this is on the scale of your household, your village or even your nation. The communications and travel revolution over the last couple of centuries have made a mockery or this but as little as 100 years ago most inhabitants of a rural village would be related. The Green Beard effect is an ethnographic thought experiment that postulates the existence of a gene that simultaneously gives a clear visible indication of its existence in a body, like having blue eyes or a green beard and also promotes giving help to any other body whose beard is green. Because you know for certain that that body has the green beard gene then, as far as your own 'green beard' gene is concerned if you risk your life to save the other fellow the payoff is the same - the green beard gene still survives. Such individuals would be closer than even siblings as you don't know for sure which genes are in your brother or sisters body - for a gene promoting any sort of sibling-helping behaviour there is a 50% chance that it is wasting its time. Skin colour is a sort of reverse gren beard effect. It doesn't have the certainty of the green beard gene but it indicates the the different-coloured person is from a different sub-population (ie race) with a somewhat different genepool. Helping them is therefore less likely to get the helping-behaviour gene into the next generation than helping a same-coloured. This is exactly the equivalent of helping someone who bears a family resemblance with you over some one who doesn't getting that behaviour-gene into the next generation; only the reason for presuming a greater genetic closeness is different. And this is precisely the same, qualitatively, as favouring your child over a stranger! Any person who claims that racial discrimination is always completely wrong must accept also that familial discrimination is also wrong. The practice of inheritance will have to be closely examined for evidence of discrimination against non-family members! I need to qualify this statement by reminding you that there is a great difference in degree between race and family, just as there is the difference in the percentage of your genes being also in your brother compared to someone who merely has the same skin colour. However, I described the racial discrimination as 'always' and 'completely' wrong. If any sort of discrimination is entirely wrong then how can 'family values' be any less wrong? Racism is an evolved trait. It increased the chance of the genes in a body that practiced racism to be more poplace in suceeding generations I shall, for the sake of propriety restate the obvious, that ethnographt does not translate to humans as we have free will, we have societies that make the behavioural traits of our genes irrelevant, wildly out of date and in this case actually counterproductive. In the global village of the past century or so there would have been a strong evolutionary pressure against racism as worldwide cooperation becomes increasingly important, except that social pressures vastly outweigh evolutionary pressures and act on a hugely faster timeframe. EVOLUTION is a fact. It is a logical sequence of events that must occur given the starting premises - there exists an entity that can replicate itself, different forms of the entity can have a differential effect on the rate of replication of one entity over another and the replication is highly, but not perfectly, accurate - or Facility, Fecundity and Fidelity. HOWEVER, whether evolution acted upon life on Earth to create the world we see around us is unproven, in fact the only evidence is circumstantial - it seems to fit well as a theory (of course the ame can be said of the Theory of Gravity) BUT, given that we know that there is an entity that posesses facility, fecundity and fidelity, any competing theory must not only explain life on Earth but must also explain how it came about that no evolution took place. Racism is a small part of a long, complicated logical sequence of events that was inevitable from the moment the first replicating entity appreared on the planet. To try to ignore the evolution of life on Earth because it had this inevitable consequence is foolish. To understand that there is the potential for racism inside everyone (of every race) and that it does not make them evil or wrong is preferable as it will make people more aware of the need to recast about their instinctive reactions as concsious social beings.
  10. 1. Polystyrenes = 20% 2. Disposable Diapers = 10 % 3. Fast Food Waste = 10% The only permanent solution is 100% recycling or living in an infinite universe. It may not be so bad as we might run out of resourses to make the stuff before we run out of places to put it once we're bored with it. Even the 100% recycling isn't possible yet but not making the stuff in the first place is the best solution. Disposable diapers are the classic example - 2,000,000 babies in the UK use 3 diapers each at, say, 0.5KG each = 100,000 tons of waste per year that just didn't exist when tery nappies were washed and reused for years. The Grune Punkt law in Germany said that for every product displaying the green point symbol (and there were tax penalties if it didn't) the manufacturer was resposible for the entire cost of disposal of the item. Designing in recycling potential then became a way of mitigating these costs, excessive packaging was removed from products and environmentally toxic - therefore expensive to dispose of - materials like heavy metals and CFCs were used more sparingly or replaced. Connecting the disposal with the production and profit stopped a lot of waste-material-to-be from ever being made. The german scheme helped but not enough and, of course the companies were more interested in finding loopholes, cutting deals with the regulators and using the law as a stick to beat their competitors with than with the spirit of the exercise. The teeth of the, initially quite draconian laws were pulled when it was found that the big companies were driving smaller competitors out of business and a sort of 'cartel' had formed around the deals between big business and the waste disposal business. Best thing to do is ignore the problem and give the nanotechnology research business even more billions in the vain hope that it really isn't a bunch of pie-in-the-sky hooey. No, everything will be fine just as soon as we run up a couple of nanobots! That'll be One Squillion Bucks, thank you.
  11. I think that what you are referring to is the island of Las Palmas, the third largest of the Canary Islands a few hundred miles off the north west coast of Africa in the Atlantic Ocean. The island is made up of two volcanoes with a high ridge of land running north to south between the peaks. I is believed that around a trillion tons of rock, essentially the half of the western side of the ridge could slide into the sea displacing enough water to create a tidal wave that would inundate the eastern seaboard of the USA up to 100 miles inland! Apparently, a Hawaiian volcano collapse did something similar to Australia on a much smaller scale. See this Newsmedianews report
  12. Gross cultural stereotyping of sexual mores is unlikely to explain any evolutionary consequences as they are too short term in evolutionary timescales and often just plain wrong. Consider elephant seals, for an example where a bull has a harem of up to 100 cows from whom he keeps away all other males. The females have no choice and are entirely submissive - but the 1-2% of bulls that manage to acquire a harem are aggressively selected for prowess. The females (or their genes) have chosen to accept this system. In the case of submissiveness the removal of sexual selection behaviour would be unlikely to occur because that would cause a big loss in inclusive fitness (which includes the sum of the ability to survive, mate, reproduce, rear the young and anything else that increases the chance of your genes being numerous in succeeding generations) (This presumes that the capacity for sexual selection ie. brainpower, senses and something upon which to judge the other gender are available to the organism) It is very easy to become Adaptationist and conclude that if there is an observed difference in populations of a species there must be different evolutionary pressures the populations due to their different environments. An alternative is hybrid vigour; or the "make me taller" genetic variant may have fallen into disuse in the past and by chance been lost completely from one population and not the other so when the environment changes for both populations making tallness desirable, in one group the pre-existing gene increases in number whilst the other group must wait for a novel mutation to turn up by chance. But there is plenty of variation in height between individuals suggesting that varients are available and that there are many contributary causes for the effect of adult body length (ie. size of your mothers womb, your fathers ability to procure good proteinaceous food) so I prefer the idea that there is some environmental difference between the oriental and occidental hemispheres. The effect could be nurture, not nature - as Coquina said nutrition is usually credited with the national growth spurts of recent history. The average heights of victorian schoolchildren from wealthy public schools were as much as six inches greater than their peers in the first schools for the poor (and there is still a measurable difference today) and the increase in average height appears to take a generation or two to become established after the diet is improved (not due to genetic changes, of course, but perhaps a mother who is undernourished as a child when the body's insulin tolerance and body fat (leptin) levels are 'calibrated' will still produce a small child even if she is well nourished as her body is still 'programmed' to expect lean times and not to lavish more than minimal nutrients on the baby) so perhaps asia is still 'catching up' with our level of excess and engorgement. Surface area to volume ratio decreases as size increases, making a large body easier to keep warm in a cold climate. This suggests why europeans are taller than asians. Alternatively, they may have been the prey of different styles of predator; the burst-speed predator such as a tiger in asia could be evaded with stealth, speed or agility requiring a small stature whilst the european top predator, the wolf was an endurance hunter and the only way to evade was to out-endurance or out-fight (ie. outnumber) it which demanded bulk. Perhaps the food supply in asia was so consistently good that lean times were rare but elsewhere the food supply was intermittent and it was necessary to gorge in times of plenty and a large mass helped pile on the fat and eke out the reserves in time of famine. This behaviour is consistent with the greater tendency towards obesity from east to west.
  13. Xavier, male, age 38, absent
  14. When parts per million (ppm) is used as a unit, there should be an indication as to what phase the solute and solvent are in e.g. w/v - 1 unit of weight of solute in 1,000,000 volume units of solvent but where that is not mentioned there is an implication that the solute and solvent should be in the same phase. As this is the case in your example, you can just dilute the hypochlorite by 10,000 in 1,000,000 in water, or 1%. If the hypochlorite were in powder form and you were instructed to make a solution of 10,000ppm w/v then you'd compare the basic S.I. unit for the different phases; for volume, litres and for mass(a.k.a. weight) this is kilograms (that is is not grams is a special brand of madness brought to us by the French). Therefore the dilution is of 10,000 KG of hypochlorite per 1,000,000L of water, or 10G/L. However 1p.p.m. could be interpreted as 1 molecule of solute per million molecules of solvent (1 particle per million), rather than in bulk units. Then you would have to take the molecular masses into account: 1 p.p.m. = (mol.mass of solvent)/(mol.mass of solute) mG/L Which interpretation is meant is not stated. It seems that you must guess from context. In the example presented, the former is intended whilst in air pollution figures the latter is clearly meant.
  15. The essence of a hydrogen fuel cell that acts as an electrical generator in that a positive charge is passed from one half-cell to another electrically isolated half-cell using chemical energy. This creates a build-up of potential difference between the half-cells that can be tapped by a wire completing the circuit between them. The simplest (in terms of the chemistry) type of fuel cell makes use of a membrane that is electricaly insulating (electrons cannot pass through) but allows hydrogen ions (protons) through. The oxygen dissolved in a dilute acid will use up some of the abundant protons to spontaneously form water in the presence of platinum or a similar catalyst; not much but enough to slightly reduce the acidity and cause a few more of the molecules of the acid to dissociate than is energetically optimal for the species. Gaining further protons to replace those removed by the oxygen would put this half-cell in a more energetically favourable state. Meanwhile, more platinum breaks up a few dissolved hydrogen gas in the other half-cell liberating protons which are drawn through the membrane along the chemical potential. In a normal solution the electrons would jump along with the protons and the hydrogen and oxygen would combine slowly (depending on the catalyst, temperature etc) until they are depleted but in a fuel cell the electrons are specifically excluded from moving, except via an external wire. A saltbridge as used in a galvanic cell is not what is needed between the half-cells but replace it with a bridge which conducts protons, not electrons and the rest is easy. There are a variety of designs of fuel cell that package the positive charge as different ions with suitable ion selective membranes for different combinations of efficiency, throughput and operating temperature and pressure and the actual chemistry is quite odd looking as it requires some rare, energetically very unfavourable species to accumulate, which they will because the energetic 'payoff' of the H2+½O2->H2O reaction is so big. NB the usual membranes are reasonably high-tech polymers but I have heard discussions of the use of kidney cell membranes, which have massively efficient active proton pumps in them. This is an example of Molecular Manufacturing (The pores consist of 2-3 protein molecules that would be individually placed in a self assembled lipid bilayer membrane) that is on the cusp of appearing. More prosaically, I once read that, at c.1°C the surface layers of ordinary water ice crystals can conduct protons, not electrons! Now, if that could be used in a fuel cell... A topical website:How to make a fuelcell at home! http://www.guerrilla.net/reference/power_systems/fuelcell/fuelcell.pdf
  16. If I may... Johnny5 has indeed constructed a specific scenario in which certainty is binary. And he has, I believe, demonstrated by example that any scenario can be broken down into a position where there is a single choice to which a probabilty and confidence level might be assigned but which can only have a certainty of 1 (certain) or of <1 (uncertain) - a binary state. However, in so doing the scenarios have moved too far from the real world. It is ironic that Johnny5 stresses "human certainty" for it is precisely our human abilities (or possibly our logical disability) that renders us all but capable of refining a real situation to its logical series of single choices. By way of illustration, I ask you to consider your thoughts as Johnny5 first described the 'swans in a bag' scenario. First, we know that swans are, in general, white and presume that Johnny5 also knows this but we are also aware that this is a thought experiment in statistics so we are half expecting an improbable event to occur. Therefore, we are less surprised than we 'should' be when the statistically unlikely black swan makes its appearance. On the other hand (and this is want I was thinking) as we all know that swans are white and his style appears to be edging us towards wondering whether he is going to throw in a black swan I was quite sure that the last swan was white and I'd call his bluff. So he double-bluffed and I got caught out. The infamous question is now become a very complex one to answer - more complex than I could process in a conscious, logical way in the time available so I used instinct, a hunch, experience, guesstimation - call it what you will and then washed it through that famously inaccurate human ability to analyse risk and felt quite certain that I 'knew' the (wrong) answer. If I was closely questioned in a rigorous debate about whether I was really, reallly certain I would have to admit that I was not BUT I might wel have acted on the information as if I was certain. The doomsday scenario echos this clearly; the world could end tomorrow but we don't act on that information because..well, what could you do about it? (in fact, we do act on it in small ways, taking out insurance and making wills and so on and these things are just part of 'normal life', that is a set of simplified rules to follow that stop us from the need to consider thousands of tiny risks that we can't or don't want to rationally consider. The religious ban on pig-meat due, it is suggested, an increased incidence of disease passed on through this means long ago is an example of a rule that stopped those people from having to worry about a small threat, so much so that the original reason for the rule is long forgotten. So I think this discussion boils down to semantics. Humans feel different levels of 'certainty' based on the risk and reward, social factors associated with the presentation of the event, attention span, our inbuilt difficulty in negative statements and overeager pattern recognition. The strict definition of certainty can only be used logically as in the experiential world Nothing is Absolutely Certain and the word is meaningless. To use the word 'certainty' in alliance with 'human' implies the meaining "certain enough that I don't think that I will lose out by acting as if this is certain."
  17. As Albert was asking earlier about fuel cells and the quotation from the site he indicated includes the term 'primary cell' I think that the source of the confusion is that the quoted website is talking about a potential developing cell that develops potential whilst everyone else is thinking only of the potential resisting circuit/electrolyte etc. You will all doubtless recollect that technically, the definition of anode and cathode refers to the direction in which the current is flowing rather than the charge that is developed at the electrode when there is a capacitative gap. The terms, of course predate much of the theoretical understanding of electricity but the fact of the flow and circuit was clear from the beginning. Consider a silver electrode in a solution of potassium chloride, for example. When a positive potential is created in the silver electrode with respect to an inert reference electrode placed elsewhere in the electrolyte KCl solution, electrons move along the wire away from the electrode. A small capacitance is generated between the electrode surface and the bulk of the electrolyte solution as a thin boundary layer around the electrode becomes relatively electron depleted and becomes a bit of an insulator. Chloride ions will be drawn to the positive charge in the vicinity of the electrode and cross the depletion layer, there to grab a silver atom which ionises to give up an electron to the need for current The electrode is positively charged with respect to the solution and the electron flow is attempting to move from the surface of the the electrode into the wire. This is an anode. At the electrode surface the reaction is: Ag(s) + CL-(aq) -> AgCl(aq) + e- Now think of the situation in a cell (meaning a battery, not biologic etc.) where a chemical potential is driving the chloride ions to the silver electrode and where the the price of completing the overall exothermic (energy releasing) reaction of Cl- ion with Ag atom is to expend some of that energy pushing an electron away from the Ag atom into the electrode thus generating a negative potential difference with repect to the reference electrode which will cause a current to flow from the silver electrode towards the reference electrode. At the electrode surface the reaction is Ag(s) + CL-(aq) -> AgCl(aq) + e- exactly the same as the previous example (ignoring the other chemical events elsewhere in the solution that contribute to the overall exothermy of the chemistry) and the electrons are still flowing away from the electrode surface up the wire so this is still an anode. However, at the electrode surface there is a net negative charge with respect to the solution!
  18. The technical ability to shift atoms around has gone from awe-inspiring to trivial in record time - though whether you can get them to react together in just the right places is arguable, and argued vociferously by the biggest names in nanotechnology (or molecular manufacture as Eric Drexler terms it) Read all about it at The Foresight Institute website. The problem is not the ability to manipulate atoms but with where to put them. DNA strands can be built up from industrially synthesised nucleotides with ease - if you know what sequence to use and how to 'bootstrap' it into 'life'. In fact, this has been done. A polio virus (one of the smallest and simplest) has been created from scratch from its known RNA sequence. Injected into mice, it gave them polio!! See this report in the BMJ. And amazing as that sounds I think the most shocking of all is that instead of splashing 'LIFE CREATED' or 'MAN BECOMES GOD' across the world media, all we got was 'Loony scientists could make new bioterror weapons'
  19. I realise belatedly that the diagrams in the various 'fuel cell basics' websites were trying to describe the original Francis Bacon type fuel cells of which alkaline fuel cells are the most prominent type. I apologise for some misleading here as I had essentially forgotten about their existence in following up my own interest in PEMFCs. The AFCs do indeed have an alkaline electrolyte between the two gases in their solutions. The electrodes do not have to be in contact with the electrolyte as ions made can meander across from the catalyst/electrolyte region through the gas solution which must be pure and hence a good insulator. I imagine that designing the components such that there is not a substantial leak of electrons between the halves of the cell by way of the electrolyte is the great challenge in making the things. The different types of fuel cell all have particular sequences of ion formations. From your first question, I believe the solid oxide fuel cells allow ions of oxygen to pass across the cell but in the PEMFCs (which I was previously, possibly misleadingly, considering as the 'standard' fuel cell type) it is the proton that crosses whilst in the AFC it is hydroxide ions. The constituents of the gap between the sides of the fuel cell are specifically designed to conduct a particular ion. Proton exchange membranes are often made of very clever polymers that are electrical insulators but which allow protons to cascade along their backbone forming temporary bonds with each monomer unit in turn and tending towards travel right across the membrane due to the concentration gradient (ie. more protons pushing them from behind than from in front). As an aside there is a suggestion that if a phospholipid bilayer - like a biological cell membrane - were put in this place and studded with as many hydrogen ion channels as are found in certain cells in the kidney, a tiny but hugely efficient fuel cell could be created (if you could only keep the temperature low enough). Regarding the second question, in the PEMFC case the O2 molecule is first attacked by newly arrived protons to make an H2O in a sufficiently energetically favourable reaction that the exotic O2+ ion is formed - carrying in itself most of the energy made by the that reaction. Thus when the O2+ ion reaches an electrode it pulls eletrons from the electrode 'with force', converting the chemical energy to electrical potential. In the other cases the oxygen molecules are prepared by catalytic action (which requires some energy so only occurs in a small fraction of the oxygen atoms but the energy budget is swiftly balanced). In AFCs the oxygen molecules oxidise water to OH- and OOH- ions fairly readily in the strongly alkaline conditions, which contributes to their efficiency. There is a good paper from ChemPhysChem 1(4) pp162-93 Dec 2000 (http://www3.interscience.wiley.com/cgi-bin/abstract/76504449/ABSTRACT) though you'll need an Athens Login, a friendly librarian or $25
  20. A newborn has a newly minted immune system but lacks templates of the epitopes of potential invaders. Its mother donates an immunogenic profile of templates in the form of a collection of B-lymphocytes that she has received from her mother and added to during her lifetime. Should that baby be afflicted during its first weeks its survival is materially affected by the whether the immune profile that was passed to it includes a suitable template that can be used to manufacture a targetted immune response in days instead of weeks. Evolution is a process, an algorithm that logically must proceed if three conditions are met, regardless of the medium (be it genes, memes, fragments of code in a computer, patterns of crystal formation in a snowflake etc.) These three conditions are, roughly: 1) There is an entity that can replicate itself more than once.(Facility) 2) Some property of the replicator can differentially affect the frequency with which it can replicate. (Fecundity) 3) The entity replicates itself with great, though not perfect precision (Fidelity) Applying these conditions to the previous narrative, condition (1) represents the immune profile as the replicator, since the profile existing in the mother is reproduced in each of her offspring. Condition (2) is clearly met but condition (3) is arguably problematical. The question is: Does the B-lymphocyte library that the baby acquires remain in a recognisable form into adulthood? Certainly, some immunities stay with a person for life (eg. chickenpox, mumps) whilst some vaccinations require regular booster shots (eg tetanus) and whilst very large, the immune profile must lose some candidates as others are gained or it would become impossibly large. Is the replication too imprecise to have an appreciable evolutionary effect without being overwhelmed by the more orderly instructions of the genes? I would suggest that genetic evolution would select against anything that would disrupt this Lamarckian trait as the generation frequency of mammals compares unfavourably with the speciation frequency of bacteria. Thus babies would be in acute danger during their first weeks from bacteria that its genes had never heard of, making for a very strong genetic evolutionary pressure in favour of not buggering with the system. It seems possible that the mouse immunogens mentioned earlier are a result of just such a process. The whole process may be difficult to detect precisely because it is so effective; whole phalanxes of hostile micro-organisms are perhaps kept down so effectively by this mechanism that we have never found them and hence we don't know even that there may be something out there to look for.
  21. This may be a geographical difference in taxonomy, but in the UK its called Molecular Biology (a name coined before actual genetic manipulation was anything more than a pipe dream) . My (jaundiced?) impression is that molecular biology came along as a super specialisation and pinched some of the fun bits from boring old biochemistry and then, when genetic engineering took off it expanded massively, leaving Biochemistry as a poor relation. There must be many more courses in the UK using the phrase Molecular Biology than Biochemistry (in the early 1990s I heard it said that around 90% of UK medical research grant applications claimed to be in the field of Molecular Biology) In the UK, at least, 'Biomedical' is a sort of non-word; a prefix to sex up a dull course title by implying that it is something more than general biology but which doesn't have the content to go for 'Clinical' which would imply that the graduate would be legelly capable of giving a clinical opinion. (For years I was Medical Laboratory Scientific Officer in the National Health Service (formerly called Meical Lab Technicians). Then TPTB decided we should be called Biomedical Scientists - whilst cutting out our pay rise and various contractual benefits! But it made us feel really special...) On a more pragmatic note, if you are sufficiently dedicated you should try to acquire expertise in cell culture. It is tedious but exacting and requires some 'green fingers' but it will surely make you more employable or a highly valued intern lab assistant. Ask whether courses will give hands on training in cell culture. Top marks for actually approaching labs yourselfto find a postion. However, lab-dwellers are shy, retiring types who probably got a fright at your keenness. Letters or telephone calls the the 'Lab Manager' or 'Lab Director' will avoid putting them on the spot (or chat with the secretary who'll probably know the most effective person for you to talk to). A good official-looking letter from a course tutor or careers advisor on headed notepaper will aid your veracity. And you could consider leaving the USA for a country with a more rational, modern science policy or by the time you graduate there may no longer be any such thing as genetics.
  22. I have had a look at that website you mentioned. The bit that they call an Electrolyte clearly cannot be. If it were conductive the electron would cross directly from electrode to electrode, bypassing the wire. The applet shows protons crossing the 'electrolyte' (though in the text these are mislabelled as electrons at one point) carrying their positive charge from one side of the cell to the other along a concentration gradient that is actively maintained by the reaction that generates the water scouring the protons from the oxygen side of the cell whilst the O2+ ions actively 'pulling' electron from the hydrogen side through the wire increases the rate of creation of protons there. The key element to a hydrogen fuel cell is the barrier between the two gases that conducts protons but not electrons. Actually, a quick primer through the internet reminds me that there are other designs than the proton exchange membrane fuel cells I have been describing (which are the only choice for miniaturised systems). The main rivals are solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC). Their main differences are in what is used in place of the membrane and their advantages are in their higher operating temperatures giving better efficiency on the large scale. For further research, may I recommend Google Scholar (http://scholar.google.com/) as it focuses on research papers and (claims to) sort by research impact.
  23. I'll have a go at explaining hydrogen fuel cells. The molecular hydrogen and oxygen molecules are separated a non conducting membrane that is permeable to protons. A platinum catalyst encourages the molecular hydrogen to separate into H- ions and H+ (protons). A few of the protons slip through the membrane as a rare diffusive event before reintegrating with their negatively charged pair. Now it gets interesting. On the other side of the membrane, the protons will speedily latch onto an oxygen molecule (I admit I am hazy on the exact chemistry which, I gather, involves some weird and wonderful transitional states as this is a highly exothermic reaction that drives all the rest) but the end products are water molecules and O2+ (that is doubly positively charged oxygen ions) which aggressively try to get electrons. The source of additional electrons is the other side of the non-conducting membrane but a wire conducting them from the platinum catalyst to the O2+(aq) will draw a current. The energy of the electron acquisition by O2+ aids the platinum in producing more protons in a positive feedback loop til the membrane transport process is saturated or the fuels run out. An electrolyte solution is not strictly necessary at all in the fuel cell. On the hydrogen side the gas will be dissociated by platinum on the membrane surface, reduced to a proton and zip through the membrane. On the oxygen side the O2+ ions would find their way to a large eletrode nearby by diffusion, though removing the waste steam and resupplying the O2 makes this a little tricky. This is the design of most interest in making microscale - and in future possibly nanoscale fuel cells to power nanobots.
  24. A cells nucleus, or the DNA within, 'controls' the rest of the cell by creating the building blocks from which it is made along with the construction tools and the tools that will ultimately be used for its demolition. The control seems rather weak but lifetimes of molecules and structures on the cellular level can be very short indeed (milliseconds) and still be effective. The control exerted simply through the supply of the fixtures and fittings can be very precise but it would be enormously hard to consciously design as it is hugely chaotic with vast numbers of variables in play at once (There are thousands of different proteins that float around in cells that we have no idea of the function of, if any, not to mention the dozens of different ions that are actively or passively manipulated around a cell - Calcium ions are currently thought to be the most important of the 'second messengers' that take information that is passed through the cell membrane (in the form of a particular chemical) and passes through the nuclear membrane to signal the arrival.)) This could only be brought into existence by a massive sequence of trials and error. Fortunately we have one called evolution! The way the system has evolved for earthbound life uses chemistry more the way we use electricity; almost instant and highly manipulable (is you have the appropriate setup) to exert effortless control over almost any aspect of the world. The scale makes it work as bulk transport/diffusion are far less limiting and there is none of this waiting for a reaction to reach equilibrium. The insides of cells are landscaped with chemical gradients as reactions proceed at a rate of the same order as the time taken to diffuse across a portion of the cell so the ratio of product to reactant at any point tells how far it is from the site of release of that substrate. Thats the trouble with 'How does it work' questions in biology; the answer is invariably either a) Its complicated; b) It simple...except for these several exceptions..or c) We don't know (but if you give us a million dollars we might be able to find out)
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