SkepticLance

ultma I find it quite difficult to sort out exactly what you are saying. Can you try to make your points a bit clearer? Just a quick comment. You mention dioxins. According to USEPA, the minimum dose likely to be lethal, by means of cancer, is 20 parts per billion based on body weight. The maximum dose actually found in humans is about 50 parts per trillion. This is well outside the 1% rule. Apart from that, I find your statements a bit hard to nail down. You seem to be concerned about phytoestrogens. There is nothing new about them apart from our increased understanding. Phytoestrogens have been part of the human diet since Adam wore short pants. They seem to have done very little to harm us. Soy beans contain phytoestrogens, sure. But so do lots of other traditional foods.

ultma It appears you have started this thread with a firm conviction that these beliefs are correct. However, many go against what good science has demonstrated. For example : While it is absolutely correct that modern youth pass through puberty at an earlier age than, say, 100 years ago, there is no evidence that this is a bad thing. According to Dr. Peter Gluckman (University of Auckland, Liggens Institute for Medical Research) earlier puberty is simply a response to better nutrition, and particularly more fat in the diet. He believes that our ancestors who lived a more primitive life, eating more meat and less grain, probably went through puberty earlier also. If he is correct, then we have simply returned to a more 'natural' pattern. There is little doubt that excess saturated fat in the diet is harmful. You also seem to have fallen into the trap of believing 'more is better' in relation to nutrients. It has been well demonstrated that those people who consume vitamin pills simply excrete the excess - they make very expensive urine! Vitamins in animal liver are treated the same way. Simply excreted. In fact, too many vitamins, and especially vitamin A, can be positively toxic. You said : its amazing to see the teeth of these non "westernised cultures) all striaght broad with little to no cavities I have personally visited a number of non western cultures living by the old ways and with the old foods, and especially Pacific Islands, and Papua New Guinea. Almost without exception, they have dreadful teeth. Most have big gaping holes in their mouths where the teeth were by the time they reach 30 years of age. Archaeologists who study the dead bodies of primitive hunter-gatherers nearly always comment on the damage to teeth at an early age. The main cause here is abrasion. If your food is often contaminated with dirt and sand, when you chew it, you are grinding your teeth over very potent abrasives. You need to be very careful about what you believe from non scientifically recognised sources. There is so much garbage written. Toxins are an example. Small amounts of all sorts of synthetic chemicals are very well tolerated by the human body. It is only larger doses that matter. In fact, the biggest doses of toxins are all natural materials. Did you know that cabbage contains more than 40 different toxic chemicals, and more than half of them are carcinogenic in high doses? And cabbage is one of the most healthy foods you will ever eat. Those toxins are simply at a low enough dose to be harmless. You should treat all claims of toxins in food with care. As a rough rule of thumb, find out what the quantity of toxin present is. Then find out how toxic it is. Usually you can work out how much toxin it would take to be fatal. If the dose is 1% or less of the minimum fatal dose, then the amount is probably not of concern. The best example is ethanol - a well known toxin. If you drink one standard glass of whiskey, you are consuming 1% of the minimum lethal dose. If you consume that amount each day, and no more, you actually improve your health.

ultma Eastern societies have been consuming soy products for thousands of years without early puberty. However, when those societies start consuming western diets (meaning lots of fat) early puberty becomes the norm.

My vote goes with the crazy nutters. Your comments contain some statements from them that, if true, show them to be more than nutters - becoming dangerous nutters. For example : unpasteurised milk was historically one of the causes of transmission of tuberculosis. One estimate I read suggested that in Britain alone, pasteurisation of milk saved 65,000 people per year from becoming infected. While I am sure the situation is much better today, due to vets checks of cows, it is definitely a retrograde step to recommend we stop pasteurising milk. Soy beans contain a protein that is an allergen for some people. Perhaps one person in a hundred is affected. For the other 99, soy bean is a wonderful food. If what you say about their take on fats is correct, then their followers are set for early death through heart disease. Saturated fats need to be consumed in small amounts only. Unsaturated fats are much healthier. Trans fats are bad - found in margarine and in over-used cooking oils, such as in fast food joints. Fresh olive oil, canola oil, sunflower seed oil etc are all excellent foods. They are very calorific and contribute to obesity, so should not be consumed in massive amounts. But in reasonable quantity they are excellent.

To lucaspa It appears you are correct on one point anyway. I lost the google reference I used for EQ, but there are heaps of others. One stated that Homo habilis had an EQ of 4.2, so I suspect my original source made an error and got Homo habilis and Australopithecus mixed up. On the others, though, it simply seems that EQ measures are not consistent. You said The first one you listed is doi.wiley.com/10.1002/0471663573.ch1 This goes to the Wiley Interscience site where you need a subscription to access the paper there. So there are no EQ values there. Are you telling us you have a subscription? The other source -- http://www.physicsforums.com/archive...p/t-16355.html -- is a post from a forum on physics. It talks about an unsubstantiated e-mail with a professor. Couldn't you have looked at an .edu site? It appears that you don't check the reliability of the sources you use. My point here was simply to point out that different sources appear to quote different EQ's. You have taken this beyond what I was saying. And yes, different sources DO quote different EQ's. Anyway, it appears that chimps and australopithecines have similar EQ's. Since chimps use tools, including short spears, I see no discrepancy here with my statement that australopithecines may have used crude spears for defense. It is still possible that they may even have chipped crude stone tools. The usual explanation for why such tools are found with australopithecine fossils is that the tools were made later and just happened to get mixed up with the earlier fossils. That may well be correct, but we don't know.

lucaspa said : No, it's not. We are back to Toumai and Orrorin. Here the brain size (by your index) is much smaller than chimps. So, by your index, the brain is too small for the cognition of chimps but are equal to primates that do not use tools. As I said before, brain size, per se, does not necessarily mean anything. Only two species today actually manufacture tools, as opposed to picking up something convenient and using it. That is : humans and the New Caledonian crow. The crow has a tiny brain by comparison with any primate, but is clearly smart. The African grey parrot is the only organism apart from humans that can be trained to use any human language meaningfully. And it also has a brain that is tiny compared to any primate. There was an article in New Scientist a few weeks back (Australian printed edition) which included a graph showing the EQs of a range of organisms. The smarter members of the crow and parrot family has EQ's similar to chimps on this graph. My information of Australopithecus body structure came from a Scientific American article a few years back. It did not give quantitative measures, but did say that in terms of upright stance, leg length and strength, and arm length and strength, the australopithecines were intermediate between chimp and human. Thus, the stance is more upright than chimps, legs longer and stronger, and arms shorter and weaker. lucaspa said So, the numbers don't match the ones you gave us. Big surprise. Not the first time you've given us bad data. You had EQ of chimp = 2.4 and A. afarensis = 4.2. So, did you deliberately tamper with the data or did you just get bad data? If the latter, where exactly did you get your data? The above statement is a rather nasty insinuation that I might not stick to the truth. I always stick to the truth as I know it. Does not always mean that the data is accurate, since my sources can be wrong, but I do not knowingly tell lies. I conducted a google search to locate my data. Sadly, I have discovered that estimates of EQ are very variable. Here is a piece of the google search page. Quote [PDF] Brain Evolution and Endocasts: IntroductionFile Format: PDF/Adobe Acrobat man EQ is 5.46, the chimpanzee 2.25, and the gorilla ... our early hominids to overlap with chimpanzee EQ. values. In our quest to better understand the ... doi.wiley.com/10.1002/0471663573.ch1 - Similar pages Encephalization Text - Physics Forums LibrarySpecies EQ Man 7.44 Dolphin 5.31 Chimpanzee 2.49 Rhesus Monkey 2.09 Elephant 1.87 Whale 1.76 Dog 1.17 Cat 1.00 Horse 0.86 Sheep 0.81 Mouse 0.50 Rat 0.40 ... http://www.physicsforums.com/archive/index.php/t-16355.html - 13k - Cached - Similar pages As you can see, the estimates vary drastically. My first source did not agree with yours. No surprises there! It seems from my later search that no two sources seem to agree with each other. My first source showed Australopithecus EQ a lot higher than chimps (4.2 compered to 2.4). However, you can see in the two sources above, the chimp EQ is shown as 2.25 and 2.49, while human is shown as 5.46 and 7.44. It appears that the result may differ depending on the method used to calculate.

I pointed out a little earlier the main fallacy in the idea of terroforming Venus. It relies on micro-organisms converting CO2 and other materials to oxygen and water. On Earth, when cyanobacteria evolved, it took 1000 million years. Even if we manage to genetically modify very efficient micro-organisms for the job, it will take many tens of thousands of years. I doubt too many people will be prepared to engage in a project of that time span.

lucaspa said : SkepticLance, I see one major problem with that: dinosaurs were among the most mobile! One question. Do you know what marine dinosaurs survived to the end of the Cretaceous? Since fish survived, it would seem that totally marine animals would have an advantage. The New Zealand case, though, has some clear commonalities with the KT event. It may be worth thinking about.

"Successful politician", able to win office, and good leader, an asset to the nation, are two quite different things. There are three qualities needed for a good leader. 1. Charisma. Without being able to look good on television, the person simply fails to get elected. 2. Competence. Once in a position of leadership, the job is essentially becoming a decision making machine. Data in and decisins out. A competent leader produces good decisions. 3. Benevolence. Adolf Hitler had qualities 1 and 2, but no benevolence, and was a disaster. Benevolence means using the other talents to the benefit of the people, and I mean all people - not just Americans. The sad reality, though, is that only quality 1 is needed for getting elected. Competence is quite lacking with the current American President, and benevolence is a rarity.

Lockheed said : The list of skeptics who were scientists numbered less than 100, from what I found. I would be incredibly startled if you could find a list of every global warming sceptic. However, maybe you are indeed a worker of total miracles. I am aware of six climate scientists here in New Zealand who are sceptics. If this is a fair sample (and I know the number is too small), then the number of similar sceptics in the USA alone is more like 500. Even if the rather simplistic calculation I just used is out by a massive error factor, the number of climate scientists who retain significant scepticism would be in the hundreds. Remember, I am talking of sceptics - not deniers. To be a sceptic, you just need to withhold belief of some aspects of the current paradigm, not all. That describes my own view. As I have said before, I accept that the world is warming, and that human activity is a prime causal factor. It is just some of the more extreme interpretations that I query. Such as the way some of you guys stick to your belief that greenhouse gases were the prime driver of warming/cooling even before they had risen to a level where they could have much impact. That is an extreme belief. Other factors have been more potent drivers, as shown by the data. Your statement on the accuracy of climate models is just that - a statement. It seems that every month I read about some new discovery that causes modellers to go back to their computers to factor in something else that had not been there earlier. If the models are so bloody accurate, why are they constantly changing them?

My country, New Zealand, is actually a more recent and very similar though local case. The fossil record shows that NZ had a broad population of dinosaurs. However, before humans arrived 800 years ago, there were no large terrestrial land reptiles or mammals. There was, instead, a massive population of birds that had evolved to exploit the normal range of niches that mammals and reptiles enjoy. The reason for this appears to be that, during the Miocene, the entire country went underwater for a period. This would have wiped out all land animals. After surfacing again, a wave of invaders took over. This included birds that could fly there, and small reptiles that could survive months without food or water, and drift on small clumps of debris. The birds became king, evolving into flightless forms up to 3 metres high, and into a wide range of tiny forms also. The major predator was the giant NZ eagle - at the time the largest eagle on Earth. 11 species of flightless moa became the grazers, ranging from 3 metres tall to turkey size. The only mammals were two tiny species of bat, and pinnipeds and cetaceans. Bearing in mind what happened in NZ, is it possible that much of the Earth above water was essentially sterilised by the KT event, similar to NZ going underwater, leaving pockets in isolated areas? Only the most mobile were able to migrate to repopulate the once sterile planet, leaving the dinosaurs to die.

I am afraid that lucaspa's post was not so excellent. Several errors, and some inconvenient points ignored. lucaspa said the point at which the hominid line split did not include simple tool use. Instead, it was bipedality Actually, that is pure speculation. The problem is that using tools and weapons is a quality that is not preserved in the fossil record until stone tools are chipped, or favourite tools are grooved. We know Australopithecus used tools for gatherig termits, since the tools used have survived and carry the characteristic grooves. However, any use of sticks etc will not preserve. Bipedality is preserved in fossils, but not tool use. So we cannot say which comes first. your progression doesn't work because chimps and bonobos are equally related to humans In making this statement, you are suggesting things I was not implying. I said that a progression existed. I did not say it was correlated to genetic relationship with humans. We do not even have equal tool use among different cultures of humans. The progression exists over time. How do you conclude that Australopithecus was weaker? The fossil record shows stronger legs and weaker arms. Muscle mass can be deduced from bone structure. Arms are used as weapons. Unless Australopithecus was into karate, legs are not. In this sense, they were weaker than chimps. Chimps are much more able to fend off leopards, due to their very strong arms. Australopithecus was supposed to be the first plains ape, as opposed to forest ape, because of the increased leg strength and reduced arm strength. An adaptation for walking, not climbing. This means that they are less able to escape up a tree, and more likely to be away from the trees. They also had upright stance, which means they are adapted to carrying things. But what would they carry, apart from females carrying the young? The logical answer is some kind of tool or weapon. Instead, it is the manufacture of stone tools that is used to demarcate Homo. The authorities I have read on this subject did not limit it to stone. If someone makes a weapon from iron, does that mean they are not human? By this standard, virtually no-one in the 21st Century is human. Yet if you do the logical alternative, and say that it is tool manufacture that designates human, you have to call the New Caledonian crow human. It manufactures tools. Your statement is not correct. You also said BTW, what really matters is absolute brain size in cc, not compared to body mass If that is correct, then most of the world's top authorities on this subject are wrong. It also means that quite a few animals are smarter than humans, since they have larger brains. For example : The bottlenose dolpin has a brain of 1700 cc, compared to the human male of 1400. Neanderthal man had a larger brain than modern man, but an EQ very similar. I believe that many whales have even larger brains. I have not looked it up, but I suspect that the elephant has a larger brain also. However, if you look at the EQ, you get a much closer correlation to intelligence and tool use. The New Caledonian crow, for example, has an EQ very close to the chimpanzee, though its actual brain is much smaller.

Just a comment on the use of micro-organisms to generate an oxygen atmosphere. The fossil record shows that, on Earth, the time from when the first cyanobacteria appeared to when Earth had an atmosphere with substantial, rather than trace, amounts of oxygen, was nearly a thousand million years. You better have some potent bacteria!

Actually, as I said before, the best place to "terraform" is space itself. In due course, our technology will develop to the point where we can build very large habitats in space, rotating for gravity. They will contain nuclear reactors, which I hope will be fusion powered, to provide essentially unlimited energy. The outside of these habitats will contain a shell of water-ice about 10 metres thick to screen out radiation, and provide a store for all the essential water based processes. These habitats will be mobile. Advanced ion drive motors will be able to move them anywhere inside the solar system to collect raw materials - ice and minerals. The biggest advantage of these compared to settling a planet is that they can be set up in Earth orbit, close to an unlimited source of raw materials, and easily accessible after the first space elevator is built, within 100 years. They will never land, so need not fight gravity. They will be pretty much independent of any planet, and so can take any amount of time in their travels. Longer term, they will build their own new habitats, using raw materials gleaned from moons and asteroids. Eventually, it will be these space habitats that leave our solar system to colonise the galaxy. The long term destiny of human-kind may be to leave planetary surfaces entirely.

Another way of looking at this question, is to try to estimate how smart the various contenders were. The best method for doing this is the "encephalisation quotient (EQ), which is the ratio between brain mass and body mass. Calculated figures are as below (taken from wikipedia). 1. Homo sapiens 8.5 2. Tursiops truncatus (bottlenose dolphin) 6 3. Australopithecus afarensis 4.2 4. Chimpanzee 2.4 5. Dog 1 This makes it pretty clear that our Australopithecine ancestors were considerably smarter than chimps. If chimps can use tools, why not Australopithecus? Add to that piece of logic the known facts that Australopithecus, as compared to chimps, had a marked upright stance, larger legs for its body size, and smaller arms (less used in climbing trees), and considerably less formidable dentition, combined with much weaker arms. It is, thus, less well equipped for escape into trees, and less well equipped with natural weapons. With its better intelligence, it would seem logical to deduce that it made more use of tools and weapons, instead.

lucaspa said : True, but that doesn't mean we have a "gradual" progression of making weapons from sticks and then making stone tools. We have a kind of progression already known, in that chimps make a lot of use of tools, while bonobos do it a bit less. Gorillas almost not at all, and Orang Utan rarely. If our current modern cousins can use simple tools, it is rather probable that our ancestors did also. I would rather suspect that the point at which the human line split off from the chimp line included very simple tool use. The human line thereafter would increasingly use tools and weapons. Perhaps not as a simple linear development, but the increase would probably be there. No, the point is not made, because groups of primates about the same size fend off large predators today. And, as CDarwin pointed out, Smilodon was not in Africa. You cannot compare a modern chimp with Australopithecus. The chimp is very strong, and can literally tear a human arm from its socket. The chimp also has quite aggressive dentition. I also have to say I have seen little proper evidence of any primate group fending off large predators. The standard response is to get the hell out of there! Smilodon in Africa. Whoops. I made a boo boo. However, it does not change my point. There are, and have always been over the past few million years, lots of large feline predators in Africa.

Glider said : However, your point implies that men are really, really dumb and would be working under the assumption that their unsterilization only works with their wives Not at all. Just that males love sex, and preferably with lots of women. If it is available, they aint gonna say no! Males have been cavalier with pregancy risks since when Adam wore short pants. It's not likely to change any time soon.

Sayonara said : Why can't we just do that on Earth? It would sure be cheaper. And easier. And safer. And much more convenient. That is correct. However, we will not be setting up colonies on Mars with the purpose of sending our surplus population there. I suspect the first, very small colonies will be research bases. They will need to be as independent of the Earth as possible, which means growing their own food and generating their own oxygen. This will require energy input as both heat and light. After time, there will be people who are born on Mars, and they will want to make a home. Hence a larger Mars colony. Lockheed said : It would be more convenient but it goes back to the practicality issue. It would be much better to build a bio-dome. True, but your inhabitants would be dead from cancer within a few years. As said earlier in this thread, radiation will be a major problem. The people going to Mars will receive an substantial fraction of the lethal dose while travelling through space, and some will die of cancer from that. Radiation on Mars is lower than in space, but still much higher than on Earth. To survive, people will need to have something like 10 metres of rock overhead to shield them for most of their time. Time outside that protection will be rationed. Even growing plants in a biodome will be difficult. Solar radiation reaching Mars is way lower than what reaches Earth, and would have to be supplemented with artificial light. The dome would need to be heavily thermally insulated, which would probably stop light getting in anyway, and would require substantial energy input as heat to keep the environment warm enough for plant growth. And agricultural workers would have to ration their time in the dome to avoid lethal radiation. I suspect a cavern would prove simpler.

CDarwin said : Male Australopithecus are also considerably larger than the females. This could easily be seen as an adaptation to a social structure where big males are expected to fight off predators, at least long enough to let the reproductively more valuable females escape. Good point. Could I not, though, take this a wee bit further? If large males are the fighters and defenders of the tribe, would it not make sense to suggest some sort of basic weaponry? Perhaps equivalent to the sharp hunting sticks of female chimps, only longer. They did not have the big canine teeth of baboons, or other natural weapons. After all, we know their descendents shaped stones.

To Lockheed Growing crops on Mars will require an artificial environment, including artificial light. A large cavern underground, thoroughly insulated to retain heat, with daylight bulbs everywhere, liquid water, and crops in soil or hydroponics. The whole thing driven by a reactor - nuclear fission or fusion. Wth enough resources (remember, this is the future, with advanced technology) it might be possible to build underground parks, for recreation.

I can see a problem in concentrating on men, as opposed to women. I know a guy who is married. Some years ago he had a vasectomy. He told me that, afterwards, his success with extramarital sex increased dramatically. Men are often quite keen on having lots of sex with lots of women. The women involved are more likely to cooperate if they think the guy is sterile. Imagine that all males were rendered infertile at puberty. They would then probably enjoy more sex than such guys enjoy today, since the gals would not have so much to fear. Now imagine that these guys get married, and decide (with their wives) to become unsterile, so they can have kids. The 'other women' who share sex with them might rather embarassingly find themselves pregnant. If those women are married, that means lots of sudden divorces from husbands who know themselves to be sterile.

To immortal Radiation from rocks is well within tolerable limits, as shown by the very large number of people over human history who have chosen to live in rocky caves. To tell you the truth, I have felt for a long time that the best new area to colonise is space itself. To colonise Mars, or Venus, we will have to build elaborate habitats with seriously complex life support systems. Why not build those habitats and life support systems in space? A suitable set of expeditions to an asteroid or satellite can use the raw materials on said asteroid or statellite to build the space habitat. By building them in the form of a spinning cylinder, we have gravity. Our habitat can move freely in space with an ion drive and a little reaction mass. It can move between asteroids, and satellites, and pick up the ice and minerals needed by its inhabitants. It is much easier to travel from Earth to a space habitat and back, than to and from a colony on Mars, since you do not have to fight a second planet's gravity well. The space habitat can move to any part of the solar system as required for gaining new materials, or even set off to the next stellar system when ready. I could envisage a time, perhaps 50,000 years in the future, when most of humanity was on a few billion space habitats that freely travel between star systems, and slowly move outwards to colonise our galaxy.

Pat. There are serious logistical problems with a floating habitat on Venus. Almost every last gram of substance in a colony must come from the planet, since transport from Earth is prohibitively expensive. On Mars, it could be done, with everything from soil to metals mined from the surface. On Venus, even getting to the surface and remaining alive would be pretty much impossible, much less mining enough minerals to build a floating habitat.

To CDarwin The reason other primates do not need weapons is that they habitually retreat when attacked, mainly into trees, but sometimes up onto rocks. It appears unlikely that Australopithecus could do this, since it was somewhat de-adapted for tree climbing, and more adapted to plains walking. A minor correction. You said that all tool use by chimps is in preparing plant food. Not so. Some tools are used to extract termites, and female chimps in the wild have been observed using short sticks with sharp points as a kind of spear to hunt monkeys. http://news.bbc.co.uk/2/hi/science/nature/6387611.stm Quote : Chimpanzees in Senegal have been observed making and using wooden spears to hunt other primates, according to a study in the journal Current Biology. Researchers documented 22 cases of chimps fashioning tools to jab at smaller primates sheltering in cavities of hollow branches or tree trunks.

bombus Venus would take an awful lot more modifying than Mars. The surface temperature would melt lead, which means there is no way people could set up any kind of habitat there. Such habitats on Mars are at least possible in theory. I agree with agentchange that there is little incentive to try to terraform Mars. There is no reason in theory why we cannot have even cities on Mars, all enclosed as artifical habitats screened off from the nasty Martian cold and toxic atmosphere. I could envisage, some time in the next 100 years, special robots being designed and built to excavate on Mars to create massive habitat spaces. With a nuclear reactor to provide unlimited electricity for the new colony, there is no reason why they cannot live quite comfortably without terraforming.