lucaspa

I think Giorgio Martoni needs to read up on evolutionary biology and basic physics. The origin of life has been studied, as well as the origin of intelligence. Ever hear of Albert Einstein? How about the equation E (energy) = m (mass) x c^2? That shows that matter and energy are different forms of the same thing. There is no "distinction". yes, variation and natural selection. Been done. We know of several mechanisms that alter the base sequence in genes and even ADD new DNA. We also safely acquire energy from the seeds of plants. Ever eat corn? How about peanuts? Potatoes? Yet we aren't born as eggs, are we? You need to learn to test your ideas before you post. In your testing, go thru what you already know to try to find a way to show your idea to be wrong.

Look up "artificial insemination" and "ligers" to get the details. Basically, get human sperm, sedate a female chimp in estrus and inject the sperm into the chimp's vagina. If successful, the baby would have to be delivered by cesaerian section, since a human sized head would not fit thru a chimp's pelvis. Alternatively, get chimp sperm and inject it into a female human's vagina during estrus. This one could presumably be carried to term and delivered vaginally, since the head would not be larger than a human baby's. As I said, it can be done. The issue is whether it ought to be done, and that is an ethical issue. One thing that has not been done, and would cause fewer ethical issues, is to see if you could do in vitro fertilization and at least get the formation of a blastema (5-10 days post fertilization). This is the stage of embryonic stem cells and stored in vitro human embryos. Then you could kill the blastemal cells. WAIT! there is another experiment that can be done. The genes that change in reproductive isolation have been found: 1. M Nei and J Zhang, Evolution: molecular origin of species. Science 282: 1428-1429, Nov. 20, 1998. Primary article is: CT Ting, SC Tsaur, ML We, and CE Wu, A rapidly evolving homeobox at the site of a hybrid sterility gene. Science 282: 1501-1504, Nov. 20, 1998. So, since both the human and chimp genomes are now sequenced, compare the base sequences of those genes and see if they have diverged too far for viable hybrids! No ethical issue involved at all with that one.

You encapsulated the whole problem with the experiment. Scientifically, it's no different than making a "liger" or a mule, for that matter. The problem is an ethical one and the status of the organism if the experiment succeeds. Is the hybrid a human with all the rights thereto, or a chimp? It is the ethical problems that make the experiment unacceptable. As far as I can see in the article on the Russian scientist, the experiment was never performed. And the Chinese experiments remain that, a rumor. I think some hybrid mammals -- such as the liger -- represent greater genetic differences than between chimps and humans. yourdadonapogos: "When did species membership become a moral characteristic? I guess I missed the memo." The memo is the Declaration of Independence and the Constitution of the United States. The "rights" listed in there apply to H. sapiens alone. Therefore there is a moral issue making a hybrid of H. sapiens and another species: is the hybrid a human with all the legal rights enjoyed by other humans or is it an animal without those rights?

Yes, it's a common tactic. After all, ID touts that Berlinksi is an "agnostic" and I have often seen Lee Spetner described as an "atheist" or at the least "non-Christian" I see that Spetner has cited Milton on the amazon.com page. Milton was a science correspondent for an English newspaper for 20 years. So he's not a "scientist", but supposedly has the "objectivity" of the news correspondent. But, of course, if you repeat an argument long ago shown to be flawed, then you are not "objective" but pretending to be while you promote an agenda.

If heterochrony is defined as this: "A heterochronic change is, in general, a change in the rate or timing of development of some cell lines in the body relative to others. A mutation that alters the rate at which a cell line develops relative to other cell lines is a heterochronic mutation. " http://www.blackwellpublishing.com/ridley/a-z/Heterochrony.asp Then it is much more important and prevalent than just neoteny. For instance, the elongation of fingers in bats would be heterochrony. I remember a seminar looking at the wrist bones of birds. A delay in the expression of bone morphogenetic protein for just 6 hours during embryonic development caused one of the normally spheroid wrist bones to elongate to almost the length of the radius. That simply changed the timing of development. This site seems to give several examples that are not neoteny: http://hoopermuseum.earthsci.carleton.ca//heterochron/intro1.htm The following paper shows how changing the timing of embryonic development leads to the multiple "fingers" in the fins of dolphins: 1: Evol Dev. 2002 Nov-Dec;4(6):435-44. Time, pattern, and heterochrony: a study of hyperphalangy in the dolphin embryo flipper. Richardson MK, Oelschlager HH. Institute of Evolutionary and Ecological Sciences, Leiden University, Kaiserstraat 63, 2300 RA Leiden, The Netherlands. richardson@rulsfb.leidenuniv.nl The forelimb of whales and dolphins is a flipper that shows hyperphalangy (numerous finger bones). Hyperphalangy is also present in marine reptiles, including ichthyosaurs and plesiosaurs. The developmental basis of hyper-phalangy is unclear. Kukenthal suggested that phalanx anlagen split into three pieces during cetacean development, thereby multiplying the ancestral number. Alternatively, Holder suggested that apical ectodermal ridge (AER)-directed limb outgrowth might be prolonged by a timing shift (heterochrony), leading to terminal addition of extra phalanges. We prepared a series of whole mounted and serially sectioned embryonic flipper buds of the spotted dolphin Stenella attenuata. This cetacean shows marked hyperphalangy on digits II and III. We confirm previous reports that the proximodistal laying down of phalanges is prolonged in digits II and III. Histology showed that the apical ectoderm was thickened into a cap. There was a weak ridge-like structure in some embryos. The cap or ridge formed part of a bud-like mass that persisted on digits II and III at stages when it had disappeared from other digits. Thus the dolphin differs from other mammals in showing a second period of limb outgrowth during which localized hyperphalangy develops. New phalanges only formed at the tip of the digits. These findings are consistent with a model in which heterochrony leads to the terminal addition of new phalanges. Our results are more easily reconciled with the progress zone model than one in which the AER is involved in the expansion of a prepattern. We suggest that patterning mechanisms with a temporal component (i.e., the "progress zone" mechanism) are potential targets for heterochrony during limb evolution.

No, I'm trying to get my information from you and from the Amazon site. So we need your help about exactly what claims Milton is making. This is quite a common tactic of creationists. For instance, Jonathon Wells is a well known creationist, but his book Icons of Evolution only attacked evolution; it did not mention creationism. The assumption of creationists is that the only possible alternative to evolution is creationism. So, if you destroy evolution, then that means creationism is correct (in their minds). IN reality, of course, it doesn't work that way. Each theory has to stand or fall on its own. Carbon 14 dating only goes back 50,000 years. It can't be used for dating longer than that. So Milton made a strawman. Are some of his "dating methods" the amount of salt in the ocean or the human population? I find at the amazon.com site a review says Milton says "the evidence for humankind's own evolution is actually nonexistent" If you look at the sticky thread here about "evidence for common ancestry of humans and chimps", you will see a post of mine toward the end about transitional individuals linking us back thru 2 intermediate species to A. afarensis. One review says: "The evolution scenario described above is merely selective breeding, with nature doing the selecting. We know that selective breeding can never lead to a new species. Humans have been practicing artificial selective breeding on plants and animals for centuries, probably millenia, without ever having bred a new species." That isn't true. This book details how selective breeding has led to a whole new genus of plants: Muntzig, A, Triticale Results and Problems, Parey, Berlin, 1979. Describes whole new *genus* of plants, Triticosecale, of several species, formed by artificial selection. These plants are important in agriculture. Notice the date: 1979. This was long before Milton wrote his book. "As Milton points out in Chapter 14, "Of Cabbages and Kings," no one has ever observed a spontaneous inheritable genetic mutation that resulted in a changed physical characteristic, aside from a small group of well-known and usually fatal genetic defects. " Again, totally wrong. Here are just a few references: Beneficial mutations 1. http://www.cs.colorado.edu/~lindsay/creation/dup_favorable.html Accelerated evolution 2. http://www.talkorigins.org/faqs/information/apolipoprotein.html New apo-lipoprotein mutation that adds antioxidant activity. 3. Sequence of favorable mutations in E. coli http://www.pnas.org/cgi/content/full/96/7/3807 4. http://content.nejm.org/cgi/content/short/346/20/1513 Mutation giving extra dense bones

Mokele, that isn't true. Read Gould's essays and he uses the word "darwinism", as does Daniel Dennett in Darwin's Dangerous Idea. No one can accuse Dennett of promoting a "magic sky god". BTW, that you use such a term shows YOU are "pushing an agenda". Science is agnostic, not atheistic. That is true. Or about the geology, either. Much of the book seems concerned with geology, not evolution.

It looks like you did a good job of it, too! So let's see if they really falsify the "mild" version of aquatic ape. Remember, we agree that the extreme version is falsified. First the bonobos: If bonobos are a speciation of chimps, it has to be less than 8 million years, since that is when we have the common ancestor of chimps and humans. So bonobos must split from chimps later than that. That's a disagreement with your source, of course. You are just quoting them. BUT, since bonobos don't spend much time in water, we would not expect much selection pressure for adaptations. So the fact that bonobos don't have adaptations does not falsify "mild" aquatic ape theory. However, you did say that, anecdotally, they are "less hairy". But since that hasn't been quantified as hair follicles/square cm (as you noted) we can't conclude anything about this in relation to mild aquatic ape. All in all, it seems bonobos neither falsify nor support mild aquatic ape. An aside here: you don't "speciate through neoteny". Rather, the adaptations that differentiate the new species from the old look like they result from neoteny. I know that this may sound like trivial quibbling, but it's not. Neoteny is not a method of speciation. Rather, the adaptations are the result of suppressing later development -- giving rise to a new phenotype. So, now onto monkeys. OK, this somewhat supports mild aquatic ape, since one claim of mild aquatic ape is that our neotenic traits are the result of selection for moving thru water. It also shows that there are adaptations to water even tho the majority of life is spent on land. It's not overwhelming support, just mild support. A failure to falsify might be a better way of putting it. You did a good job. It's not an ability to swim per se, but whether they spend enough of their time swimming in order to get resources to provide a selection pressure for adaptation. Now, the argument could be made that partially making a living from water does result in adaptations in the monkeys. But the adaptations are webbing, NOT hairlessness. OTOH, we don't have a lot of information on the amount of hair and, as I recall, don't macaques live in colder climates and the water is going to be colder? IMO, we don't have either decisive support nor decisive refutation of mild aquatic ape. Yes, there are adaptations but they are not the same ones we see in humans. Could human hairlessness be an adaptation to partial living in water? Yes. But must it be such an adaptation? No, because proboscis monkeys and talapoins still have their hair. I tend to think that our hairlessness comes from being cursorial hunters and the need to get rid of body heat. http://www.dooyoo.co.uk/discussion/evolution/370800/ There are very few cursorial hunter species, but the ones that are --dogs and wolves -- have fur! So that puts the cursorial hunter hypothesis in the same boat as mild aquatic ape in explaining the human lack of hair.

Cool. You may have found falsification of even the mild form of AAH! Let's test the falsification to see if it holds up. (yeah, everything gets tested in science.) I too find that bonobos occasionally eat small fish: http://www.sandiegozoo.org/animalbytes/t-bonobo.html "Bonobos eat leaves, stems, fruits, worms, insects, and sometimes small fish." Of course, the site also emphasizes that bonobos are a separate species than chimps, so I don't know who their evolutionary ancestor is. Do they share the same common ancestor with humans as chimps or are bonobos a speciation from chimps? That would tell us how long they have had to adapt to the diet. Also, it doesn't look like fish are an important part of the diet nor do we have information on how the bonobos get their fish. Do they go swimming or wading after them? What I'm getting at here is 1) how severe is the "selection pressure" for aquatic movement in bonobos and 2) how long, in evolutionary terms, bonobos have had to acquire adaptations. I do note the website says "bonobos are more slender and have smaller heads and smaller ears." Wouldn't those traits contribute to streamlining in swimming? Also, how hairy are bonobos compared to chimps? Now, the information about the talapoin and proboscis monkey are potentially very potent falsifiers of AAH. Have you looked at either to see if there are adaptations -- compared to other monkeys -- for moving thru water?

Apes live along streams, but no modern ape I know of fishes or dines on aquatic creatures such as clams or crayfish. Sapiens does. I'm not sure how far back evidence of this exploitation of food derived from bodies of water goes. We should do some research to find out. Look to see the oldest fish bones discovered at hominid sites. There is evidence that erectus built boats: 4. R Kunzig, Erectus afloat. Discover 20: 80, Jann. 1999. Data indicate that H. erectus used boats to get to Indonesia 800,000 years ago. Now, it is implausible that erectus would have invented boats for the sole purpose of getting to Indonesia (or any other island). Instead, it is reasonable to hypothesize that erectus began building boats so that they could get to better fishing or clam beds. And primitive people who go out on boats learn how to swim. The ones that don't are selected against by drowning when they fall off the boat. Oh, this site says evidence of fish bones goes back to H. habilis -- 2 million years ago and at least 2 species ago in hominid evolution. http://www.medicalnewstoday.com/medicalnews.php?newsid=38009

No, I didn't miss the point. The point was that there was "evidence for" AAH. What you are trying to do is introduce "evidence against. You are saying that a valid deduction of AAH Absence of these modifications is evidenmce against. I'm not sure your objection is valid under the "mild" form of AAH. Mild AAH is not even saying that hominids were "amphibious" (to use your words). They are still mainly terrestrial but are spending time swimming, diving, and wading. Therefore modifications would be limited because any adaptations to true amphibious or aquatic morphology would inhibit movement on land. After all, hippos aren't very mobile on land, are they? Velocities would presumably matter for swimming and diving. But in swimming and diving, downwards for walking is backwards for swimming and diving, isn't it? I'm not saying this disproves AA, only that the hair-direction argument is bunk. If there was enough drag for hair to be a factor, there was enough drag to make body shape a factor too, and a much bigger one at that. That does not follow. Again, mild AAH is not saying hominids are being dolphins or sharks. They are not spending nearly that amount of time in the water. AND, if what I am saying about disruptive selection is accurate, then we have other small groups of hominids in a terrestrial environment facing adaptations to that environment. That is what disruptive selection is all about: a species faces different, even opposing environments, over its range. Thus selection tries to adapt each subpopulation to the particular environments. But gene flow between the subpopulations opposes this and forces a compromise morphology that is not perfectly adapted to any particular environment. Are we sure body shape wasn't affected? After all, compared to erectus or neandertals, sapiens is "gracile". That is, sapiens is longer and leaner. Wouldn't that be less dray for swimming than short and stocky? It works for ships. Now, the alternative hypothesis is that longer and leaner is more efficient in a hot environment -- less cross section for heating by the noonday sun and more body area in shade that can sweat. After all, the Masai are the longest and leanest of all human populations, and they don't exploit resources in rivers, lakes, or the sea. Or could it be that both selection pressures worked to give sapiens their general body shape? My post was trying to look at the mild form of AAH and test it. The extreme forms of AAH don't work. You and I both agree that the evidence is against an amphibious species in hominid evolution, much less a fully aquatic species. But could SOME traits that differentiate us and modern apes be explained by selection for moving thru water? That hypothesis is fairly innocuous and does not involve totally re-writing the hominid family tree. Also, it is possible. We can argue about which traits exactly but I don't see a way to falsify the mild form of AAH. And with disruptive selection, yes, you can have traits because "they swam a lot" and traits because "they swam a little" or not at all. Different subpopulations did different things in different environments. I haven't seen any AAH proponent consider disruptive selection (I'm not even sure they know it exists). And the mild form does not give up a majority of time spent in terrestroid existence -- even for those exploiting resources under water. Even the guys today who dive for pearls do so for only 8 hours a day and spend most of their time on land. So I see no objection to keeping the basic "ape form". And, as I have said, we are more streamlined than a chimp, aren't we?

Here's the full quote: "Arguments for Aquatic Ape Hypothesis ... Humans are the only primate species in which, over most of the body, hair is so fine and sparse as to reveal the skin under it. Furthermore, human hair is broadly aligned in such a way as to match fluid flow lines while swimming. Environments known to give rise to naked mammals are tropical (in some larger-sized mammals such as elephants — which are themselves descended from aquatic ancestors — and some rhinoceros species), aquatic (whales, dolphins, walrus, dugongs, and manatees), semi-aquatic or littoral (hippopotamus, babirusas), and subterranean (naked mole rat)." http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis You don't agree with the argument. Fine. I'm not sure I buy either. I only made the point as an illustration that AAH does have "evidence for". It points out what I have been saying repeatedly: there is evidence for almost any hypothesis -- if that is what you are looking for. Therefore, what really counts is evidence against. Now, if we go back to the broad definition of AAH -- "The Aquatic Ape Hypothesis (AAH): The hypothesis that water has acted as an agent of selection in the evolution of humans more than it has in the evolution of our ape cousins. And that, as a result, many of the major physical differences between humans and the other apes may be explained, to a large extent, as adaptations to moving (wading, swimming and/or diving) better through various aquatic media and from greater feeding on resources that might be procured from such habitats." -- the hypothesis becomes very innocuous. It only says that some H. sapiens features are the result of adaptations to moving better thru water. It doesn't say humans lived exclusively in water. It looks to me that what has happened is that some proponents and adversaries have taken the AAH to extremes. You (and I at one point) think that AAH was stating that, at some point, there was a hominid ancestor that was adapted to living exclusively or almost exclusively in water -- such as dolphins or seals. But AAH isn't saying that -- or at least this formulation of AAH isn't saying that. This reminds me of the controversy over Punctuated Equilibrium. As originally stated by Eldredge and Gould, PE simply said that most speciation in the past was by allopatric speciation, and this accounts for the "sudden" appearance of most species in the fossil record -- we were unlikely to hit the exact place and time where the small population gradually transformed to a new species. This doesn't threaten neo-Darwinism at all. But it wasn't long before Gould and others took PE to extremes and made it look like PE was threatening neo-Darwinism. So the objections were not to PE per se, but to the extreme vocalizations of PE and statements that PE refuted neo-Darwinism. In the (mild) statement above about AAH, I don't find anything offensive or inherently false in it. There is a consensus that hominids lived in very small groups -- extended families. So, yes some of these groups of hominids (of successive species) would have lived along streams, lakes, or the ocean and attempted to exploit the food resources there. That would have meant considerable moving thru water and any variation that aided this would have been beneficial in that environment. Gene flow with groups not living next to water would have prevented total adaptation to water but spread some of the adaptations thru the whole species. It would be a classic case of disruptive selection with gene flow to keep the whole population as one species. So, the "mild" form of AAH fits very well within both known evolutionary theory and what we can observe of the lifestyles of "primitive" humans today. As I said, the evidence for AAH is circumstantial and does not rule out all other hypotheses. Your post, Mokele, was an attempt to offer an alternative hypothesis. One bit of falsifying evidence for AAH may be that the places where we have beds showing transition between H. habilis and H. erectus or H. erectus and H. sapiens are not (to my knowledge) adjacent to water or show extensive exploitation of resources in water.

CDarwin, this site seems an honest attempt to critique AAH: http://www.aquaticape.org/ I haven't read the entire site, so some of the criticisms may not be valid. But some are. Criticisms don't get a free ride. They are also critiqued. And the critique of the criticisms is also critiqued. And so on. At some point the ideas are valid and can't be validly criticized. But you don't know that point unless you do the testing.

I phrased my point carelessly. As far as I read AA theory, they are saying that hominids at one time were analogous to sealions, seals, or penguins. That is, they were not fully aquatic like dolphins and whales, but spent a lot of time in the water, acquiring adaptations for that lifestyle: hairlessness, the remaining hair arranged so that it is optimized for movement thru water, controlled breathing, etc. Under those conditions, the theory would not expect every adaptation to a fully aquatic environment, such as separate air passages. Instead, there would be a mosaic of features, some for swimming and some for land. Here's a broad definition of AA: "The Aquatic Ape Hypothesis (AAH): The hypothesis that water has acted as an agent of selection in the evolution of humans more than it has in the evolution of our ape cousins. And that, as a result, many of the major physical differences between humans and the other apes may be explained, to a large extent, as adaptations to moving (wading, swimming and/or diving) better through various aquatic media and from greater feeding on resources that might be procured from such habitats." Notice that this is very vague. How much time was spent wading, swimming, and/or diving? What resources? When in our ancestry? Oh, there are LOTS of problems with AA theory. I'm not an advocate. If anything, I think the available evidence is against it. I was looking at your specific objections and testing them. That's a good point. AA proponents are not good at looking at contrary evidence. Another good point. From what I have read, AA says that our precision grip came from picking up and opening shellfish. However, you don't necessarily have to swim a lot to do that. And yes, hominids would not have been good enough swimmers to catch fish just by swimming and using their hands. Seals and sealions are good enough swimmers to catch fish. But their adaptations to living in the water are more extensive than humans'. Another good question and one that I don't see AA address. That is part of the vagueness of the theory. If you look at the definition of AA above, it might be inferred that humans never totally left the water -- because they were never totally in it. That humans still live beside bodies of water (a lot) and exploit the resources in it. I get the impression that part of AA theory is a strawman of "savannah theory". They think the savannah theory prohibits any contact of hominids with water. http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis I found a paper thru PubMed in 2006: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16263222&query_hl=1&itool=pubmed_docsum This paper seems to lie within the AA hypothesis and I took the time to look at the full paper. Williams hypothesizes that hominids had 2 periods of selection by contact with water: one with the bipedal late Miocene hominoid Oreopithecus bambolii, and another at the inception of H. sapiens. I have several problems with that hypothesis and Williams' reasoning, but at least he got specific.

That isn't accurate. AA proponents do point to evidence. It's circumstantial. What I think you mean is "no direct fossils of hominids living i the water" I'm not sure that is a valid objection. After all, I think sea otters, sealions, and seals all breathe thru the same tube that they eat and drink from. I don't think the AA ape theory ever said that hominids were completely adapted to water. Instead, the theory states that hominids, at some point in evolution, lived predominantly in water and became partially adapted.

Go up a couple of posts and you see my response to this. I can't find any papers supporting the aquatic ape theory. Instead, I find papers that discredit it. I posted the citation and abstract of one of these. I'll ask the question again: if the aquatic ape theory is gaining support, where are the papers? It's not all that "new". It's been around since the 1960s. Punctuated equilibrium started around then, and it is accepted, not being hotly debated like aquatic ape theory. I found this description at Wikipedia: "Since the 1960s, the theory hasn't changed much nor increased its testable predictions; in most respects it has become less specific as objections have been proposed (Ellis 1993, Verhaegen et al. 2002, Morgan 1982, Hardy 1960). The theory has become less specific as to time period ranging from many thousands of years ago to millions. The theory is purported to explain bipedalism several million years ago, hairlessness many thousands of years ago [5], or the increased fat much more recently. The water source is either freshwater or seawater or some combination of the two, often depending on the objection or trait the theory is explaining. " http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis What this tells me is that the theory is not working. Instead, by becoming "less specific" the theory is trying to avoid falsification. This is a common tactic to avoid falsification. The classic example is creationism/ID. One reason Kitcher says Flood Geology fails is that it offers no specifics. It appears the aquatic ape theory is in the same position. I'm not advocating any theory. But I would note that this is false dichotomy. How well the "savannah theory" or any other alternative theories on human evolution explain things has nothing to do with aquatic ape. After all, all the currently proposed theories may be wrong. So this objection doesn't help aquatic ape theory. Aquatic ape has to stand on its own and, from the papers I see, it doesn't do very well and has been discarded. If that changes in the future, then I will change what I post. I'm simply calling them as I see them.

Both mutations and drift are NOT tied to the environment. Drift is chance. Mutations are unrelated to the needs of the individual as imposed by the environment. That is, there is no tendency to have mutations that are more fit than others. Not that we have observed, anyway. Such a skew toward beneficial mutations would require a completely different mechanism than Darwinian evolution -- such as interference by another mechanism or entity. The reason you get tiger's teeth instead of horse's teeth in tigers is selection. Those individuals lucky enough to be born with teeth that worked better on a meat diet got selected. Similarly, in horses individuals that were lucky enough to be born with teeth that were fit to eat plants got selected. But in both populations there are individuals born who are unlucky and have variations for teeth more adapted to plants in tigers and more adapted to meat in horses. Those unlucky individuals don't do well in the "struggle for existence". What "molecular mechanisms" are you referring to? Do you mean the genetics that result in traits visible to the naked eye, such as the shape and size of teeth? Or do you mean the mechanisms to cause mutations? Evolution can be much more rapid than we have seen. In the fruit fly experiment I referred to, the new species that appeared after 2,500 generations of natural selection had a genetic difference of 3%. Other experiments have shown that selection can change characteristics up to 10,000 times faster than found in the fossil record! IMO, what happens is that there is quite a bit of stabilizing selection in nature. When a species is well-adapted to its niche, then natural selection works to keep the genome unchanged, because any change will result in less fitness. This is called "stabilizing" or "purifying" selection. First, you need to be careful about teleological language. The virus did NOT "attempt to mutate". Instead, mutations happen. Because the virus population is so large -- into the trillions -- the rate of mutation is faster than what the immune system can change. If the immune system changes to one virus protein, the odds are that, out of the trillions of viruses, there will be ONE virus lucky enough to have a mutated protein that the immune system doesn't react to. And, since viruses reproduce so quickly, the lucky virus will reproduce and keep the infection going even if the immune system kills off all the other viruses. Second, traits are advantageous only with respect to a particular environment. There is no such thing as a pure benefit. Every "benefit" has its cost. In HIV treatment one way to keep the virus under control is treat with anti-virals. This kills off the non-resistant viruses. A small population of resistant viruses will then slowly build up the population again. But the cost of the resistance is decreased metabolism and ability to reproduce. Once the resistant strain is dominant, then the antiviral is withdrawn. Now the resistant strain can't compete with the normal strain of HIV and it dies off as the normal HIV strain becomes dominant. Then start the anitvirals again and start the cycle over. ALL mutations are errors in copying DNA. Every mutation is an error -- the new DNA is not what the old DNA was. The question is how that mutation affects the individual in its present environment. Is it beneficial, harmful, or neutral? Yes, there are several different types of mutations: insertions, single deletions, substitutions, duplication of various stretches of the DNA -- part of the gene, the whole gene, several genes, or even an entire chromosome. Then there are translocation, where part of a one chromosome is broken off and attaches to another chromosome. Often this happens by reversing the original base sequence. Kind of like turning a caboose end for end and hooking it up backwards to a train.

I think you have to look at the motivations for the different definitions. From what I have seen within biology, the differences come from 2 motives: trying to get their discovery classified as life (as in the case of the RNA World hypothesis) or to eliminate the discovery of the rival (as in the case of adding directed protein synthesis to exclude Fox's protocells). I stick to the 4 because 1) they work and 2) they were developed long before motivations to jigger with the criteria appeared. Also, the protocells have a sharp delineation. Start with definite non-living amino acids then add heat and then add water and voila! you have living cells. No continuum. Went from non-living proteins to living cells in one step. That may not be true for all systems, but it is for that one. Viruses I view as the ultimate in parasites. IOW, they are not moving from non-life to life, but evolved from living cells down to viruses. "elan vital" was supposed to be some inner driving force. The criteria aren't that. Instead, they are 4 objective observations on how the entity behaves. Look at them: 1. Metabolism which consists of both catabolism and anabolism. That simply describes breaking down things for energy and building up components of the living entity. No elan vital here; either chemical or some other type of reaction. 2. Growth. This can come from anabolism or accretion. Both are reactions. 3. Response to stimuli. This could be misconceived as to involve some "inner drive" but response is also chemical or physical processes. After all, look at our autonomic reflex that doctors check for when they hit your knee: chemical reactions in the nerves and then chemical reactions in the muscles. And chemical reactions between the nerves and muscles. 4. Reproduction. Oil droplets "reproduce". Any elan vital there? Basically, we can find ALL of these criteria singly or in combinations of two or three without finding life. Fire fits catabolism, grwoth, response to stimuli, and reproduction. Yet no one thinks it is "alive". It is apparent that there is no "elan vital" in fire or in the 3.5 criteria it fills. That does not follow. Look above at what I said about motivation. A person can refuse to agree because of motivation not to; motivation that has nothing to do with objectively laying out criteria for "life". Again I go back to "species". We can't all agree on what criteria to use to define "species". But species do exist. As you noted, I think we are looking at the loss of independent criteria by parasitism. IOW, it is going from life to non-life. Now that may be a continuum, because the organism is getting some of the criteria by another living organism. Criteria it once had for itself but evolved to use another organism instead. Because a non-sentient computer "life" doesn't raise the issue of "rights" like a sentience would. We can declare the non-sentient life as non-life simply because it can't reproduce it's physical self. That is, life is very tied to a physical object instead of non-physical lines of program. The programs can't make another computer. However, sentience is an idea that is not tied to a physical body. That is, it is the ability to think and reason and is sentience no matter what physical body it occurs in. So that ability could also appear as the result of non-physical lines of programs. So whether the program could make another computer is irrelevant -- we consider infertile people to be sentient. Look, you can't give me sources for other than 4 or sources for definitions that don't include one of the 4. I questioned your premise and you can't back it as fact. Yet you are still insisting it is fact. You can't keep doing that until you demonstrate it is fact. So, taking the 4 criteria that are in the dictionary, humans have already "created" life from non-living chemicals. Whether they can do so by other means -- such as the RNA first pathway or computer programs -- remains to be seen. No more so that we specifiy criteria for what is a computer, or what is a species, or what is a church or what constitutes a religion. For every entity in the universe, we set out criteria to determine, or define, that entity. Objects that meet that criteria are one of those entities. Objects that don't meet the criteria are not one of those entities. For instance, here is a definition of "mammal" "Any of various warm-blooded vertebrate animals of the class Mammalia, including humans, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young." http://www.answers.com/topic/mammal So, let's list the criteria: 1. have a backbone (vertebrate) 2. Have hair on the skin 3. be warm blooded 4. female has milk-producing mammary glands 5. be an animal So, 5 criteria. If an animal meets those criteria, it is a mammal. I don't think anyone would argue this is "conceptual elan vital". It is no more a conceptual elan vital for criteria to be alive. Sauce for the goose. Remember what I said about motivation? I think you are arguing because you want your discovery of computer "living organisms" to be considered "alive" and are thus unhappy with the criteria.

Possibly. But there is also the evolution of means to settle differences within the group by non-violent means. After all, if deadly force were used within the group, then that weakens and eliminates the group. So IMO we have contrary selection pressures. When group cohesiveness evolved, weapons technology was very primitive -- stone clubs and spears. Display often won the day, like we see with many other species where members confront each other. And indeed, human groups still spend a lot of time posturing before they resort to violence. We can see this is gangs confronting one another where they shout insults, shove each other, and finally reach for the guns and knives. Nations do the same thing: there is always a period of "diplomatic" maneuvering and posturing with the military before someone attacks. The weapons now are more widespread, so that once violence starts, it can get pretty general. BUT, notice the use of precision weapons now -- hit only the target you want and limit the collateral damage. Even the new IEDs employed by the Iraqi resistance -- the forged warheads -- are more precise. They are limited to hitting only the vehicle they are aimed at and are not omni-directional. This limits the destructiveness. Also, there is a trend to view the entire human race as the "group". The United Nations is part of that idea and it is a foundational belief of many religons: Christianity, Buddhism, and Sunni Islam. Therefore any violence is viewed as violence within the group and the mechanisms to stop that come into play. We'll just have to wait and see.

Not what I say, but what the data says. Now, if you can post the abstract from the Leong paper to show that they have measured pelvic dimensions of women and show a difference in the last 200 years, then that is different data. Perhaps you could even post some data from tables in the paper. However, since the paper is not available on any database I have access to, I can't check to see if the paper really has that data. WAIT! I found the paper! It's at http://www.medicine.mcgill.ca/mjm/issues/v09n01/crossroads/Pelvis%20sexual%20dimorphism2.pdf OK, so now let's look at it. As I suspected, the article is talking about how pelvic dimorphism (difference between men and women) arose. Leong thinks sexual selection had a lot to do with that, along with natural selection. Leong says BOTH seem to have worked for WIDER pelvi. Leong catalogs the problems that can result in childbirth when there is a baby size/birth canal ("pelvic-fetal anatomy") incompatibility. He then says: "In light of the plethora of injuries associated with childbirth, it is easy for one to postulate that in the absence of healthcare, incompatible pelvic-fetal anatomy could result in significant infant and maternal mortality and morbidity. Although concrete scientific evidence does not exist, one has to wonder if medical practice is indirectly and insidiously introducing variability to the human anatomy." Leong is making the same speculation you are: modern health care, combined with a tendency to view thin females as desirable, is adding "variability" to human anatomy. Leong won't even go so far as to say that there is directional change, but rather that narrow-hipped women, so far being selected against, are now being kept in the population. Look what I bolded. Even with the much weaker claim Leong is making, he says there is no data. Which is exactly what I was skeptical about. Glider, if you want to present the idea as a speculation/hypothesis, that is fine. In fact, it was fine. I expressed my skepticism towards it, and gave my reasons. Where you got into trouble was 1) trying to say there was supporting data and, therefore, the speculation was fact and 2) trying to use the number of caesarian sections as data. 1) doesn't work because there is no direct supporting data. Leong says that outright. 2) the number of caesarian sections doesn't work because of the data and reasons I gave: there are too many alternative hypotheses to explain the rise in the number of c-sections. Even in England (did you notice I limited the papers I used to England?). So we can't say the rise in the number of c-sections is due to an overall decrease in female pelvic size. Some other interesting quotes from Leong's paper: "Natural Adaptive Forces in Shaping Sexual Dimorphism of the Pelvis: Bipedalism versus Parturition An evolutionary pattern towards bipedalism, taking into account selective pressures of reproduction, has been demonstrated by the increase of critical dimensions of the pelvis as the maternal skeleton becomes larger. ... These adaptations to ease parturition as reflected in the sexual dimorphism in the human pelvis and femur are disadvantageous to women in terms of mechanics of locomotion." "Superficial to the skeleton and musculature of the pelvis, sexual dimorphism in pelvic morphology is most apparent in body fat distribution as measured by waist hip ratio (WHR). The WHR has been shown to be independent of overall body weight and an accurate predictor of risk for various diseases, premature mortality, degree of estrogenicity and fecundity of women (4). Undoubtedly, healthy women have a greater propensity to possess rounder hips and a lower WHR compared to most men (4). ... Finally, cross-cultural and historical data have suggested that the relationship between WHR and female attractiveness is not culture-specific and not inculcated by what modern Western fashion dictates or media (15)." Now, Leong quotes some surveys: "It has been shown that both males and females assigned higher ranking for attractiveness, youthfulness, healthiness, reproductive capability and intelligence to normal weight figures with low WHRs. ... Female and male subjects, judged heavier female target figures with low WHRs as more attractive and healthier than thinner figures with higher WHRs. Female subjects perceived heavier female target figures with low WHR to represent ideal female figures. It is proposed that female attractiveness and ideal female shape may be more influenced by WHR than overall body size (4)." Basically, this says that everyone -- male and female -- regard rounder hips as more desirable. Low weight, rounder hips are what give a low WHR. So the daat presented by Leong says there is NOT sexual selection for narrow hips! Sorry, Glider.

What about these articles do you think supports your argument? From the first site: "What is the typical rate of spontaneous mutations? Rates of spontaneous mutation seem to be determined by evolutionary balances between the deleterious consequences of many mutations and the additional energy and time required to further reduce mutation rates. Bacteria, Archae, and Eukaryotic microbes produce about one mutation per 300 chromosome replications. For E. coli this works out to be between 10-6 and 10-7 mutations per gene per generation, however it is important to note that there are certain "hot spots" or "cold spots" for spontaneous mutations. (A "hot spot" is a site that has a higher rate of mutations than predicted from a normal distribution, and a "cold spot" is a site with a lower rate of mutations than predicted from a normal distribution.) Higher eukaryotes have the same rate of spontaneous mutation, so that rates per sexual generation are about one mutation per gamete (close to the maximum compatible with life). RNA viruses have much higher mutation rates -- about one mutation per genome per chromosome replication -- and even small increases in their mutation rates are lethal." So, bacteria, eukaryotes, and RNA viruses have different mutation rates. But within each category, the mutation rates are constant. Which is what I said all along. Notice the sentence I put in italics. It is what I said to begin with. But both the articles you quoted were looking from a population perspective. IOW, both took the mutations in a POPULATION and then went from there to the average rate per individual. From the article: "These viruses circulate within infected hosts as vast populations of closely related, but genetically diverse, molecules known as "quasispecies". " Did you see that? "Vast populations" Now, somehow you have gone from my simple statement that evolution happens to populations to "Understanding the biology from a total view, such as molecular and cellular is just as important to me as from a population perspective ". No one ever said that the individual was not important, but simply that evolution doesn't happen to the individual. Evolution happens to populations. Again, did you read the paper? From the Abstract in the Methods section: "Methods F1, F2 and F3 generations were obtained through reciprocal crosses between stf and normal plants." Did you see that? "generations", "plants". Both plural. They are studying the population. First, again, evolution happens to populations, not individuals. This is not disputable because the data is overwhelming. And of course the reality is very complex because we are trying to simplify things so that you can understand. We are not presenting the totality of complexity to you because are missing the simple points. Second, when you say "questions posed about evolution in total", what do you mean? Do you mean questions about whether evolution happned? About how evolution happens? Or about whether evolution can explain the diversity of life on the planet? We have a "tree of life". It represents that ancestor-descendent relationships among species. Yes, that has been, and is continuing to be done. By 2D gel electrophoresis, proteins between species have been compared. In fact, amino acid sequences between species have been compared. 1a. Cytochrome c differences in amino acids: http://members.aol.com/SHinrichs9/descent/denton.jpg This compares the protein cytochrome c across species to species. Look at the title of the paper below: 7. SA Chervitzet al. Comparison of the complete protein sets of worm and yeast:orthology and divergence. Science 282: 2022-2027, 11 Dec. 1998 Also been done: 13. JF Banfield and CR Marshall, Genomics and geosciences. Science287: 605-606, Jan 28, 2000. Discusses cladistics to help map evolution of microorganisms and relate this to changes in geochemistry. You don't have to "press", you simply have to join. The interdisciplinary approach is already being used. Look at the one above: genomics and geology. Here's one looking at ecology, medicine, and evolution: 6. Ecology and evolution of infection. Science 292: 1089-1122, May 11, 2001. Here, these are good evolution sites: http://www.aaas.org/spp/dser/evolution/ http://evolution.berkeley.edu/ http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookEVOLII.html http://www.swarthmore.edu/NatSci/cpurrin1/evolk12/evoops.htm On a side note my use of the word expression was to simply mean that genetics express in the organism, such as hair color.

I was hoping you could give me some citations rather than the generic "I think I have heard". Let me suggest that adding criteria beyond the 4 is to avoid having to admit that someone else has made life from non-life. This is where the "must have DNA" or "must contain carbon" comes from. Those rule out your virtual critters as "alive", don't they? Let's face it, the guy who does create life from non-life has a Nobel waiting for him. Scientists are human like anyone else and can sometimes let jealousy interfere with acknowledging what is going on. As a biochemist, I'm hardly likely to disagree. However, actually a package of chemical reactions. Life is not one single chemical reaction, but consists of many chemical reactions happening within a defined volume/area. Prions and viruses, no. They don't, by themselves, have metabolism. They have to hijack the metabolism of living cells. The computer programs suffer from the same problems as the viruses: they can't make the computers that hold them. In a sense, the programs are viral parasites without the ability to make their own "bodies". However, we may have to modify the definition if a computer program becomes sentient. After all, our behavior is the sum of algorithms run in our brains. I can't see that algorithms run by a computer program are all that different. That argument is flawed. There probably isn't an elan vital. But our inability to make a definition doesn't tell us anything one way or another. Look at "species". No one can make a precise definition of species, either, but no one denies that species exist. Or that one species can evolve into another species. If we take the basic 4 criteria -- metabolism, growth, response to stimuli, and reprodution -- then I submit that people have already made life from non-living chemicals. The protocells made by thermal polymerization of amino acids meet all 4 criteria.

First, there is no such thing as a "fitness bonus". It's simply "fitness". Second, fitness is not diluted as you are saying. Yes, in a complex organism with lots of traits, there is going to be selection on each of the traits -- separately. Why? Because each of the traits is either beneficial or not to the organism and there are so many individuals. So let's go to the trait level and have traits A1B1C1D1. What you seem to be trying to say is that having trait D2 would lower fitness and therefore trait A1 would be lowered in the individual with A1B1C1D2. A1 would not be lowered, but the fitness of the individual would be, so we would get individual A1B1C1D1 that would survive and reproduce, thus still propagating allele a1 which is responsible for trait A1. That's not "base chance". That's determinism based on natural selection. And yes, you can do that calculation. You can calculate the frequency (proportion of individuals) that have allele A in the next generation. The equation is: delta p = (1/2)spq/(1-q) where delta p = change in frequency of allele a1. q = frequency of allele a2. s = selection coefficient which is 1- fitness. So, you can calculate the x copies of a. yes, that is genetic drift. BUT, such a significant change can only happen in very small populations as long as p > 0.1. That is, if p is in 10% of the population and you have a population of 1,000, changing 1 individual by accidental death isn't going to make a significant change; it will be a change of 1 individual out of 100. Supposedly you are arguing <50, but use an example of 2,000? You never calculated the probability of your shift. And, in fact, it is quite high. You are talking a considerable selective mortality/breeding here. Hardy-Weinberg says that, by chance, the next generation should also have 500 with the allele. That is the outcome of Mendelian genetics: unless acted upon by an outside force, frequency remains constant. To go from 500 to 450 in one generation -- a 10% change in frequency from 0.25 to 0.225 in that population, you are going to have to have gene flow, selective mating, or natural selection. Chance isn't going to be that large. But fixation is necessary for evolutionary change to occur. In order to make a new population A1 really different from the original population A, then some alleles must be fixed and other alleles lost, so that the genetic makeup of A1 is irreversibly different from A. Otherwise you have vacillation of frequencies like you see in the peppered moth and no permanent change. If all else is equal, frequencies of alleles don't change at all. That's Hardy-Weinberg Law. The end result of "effect", for evolutionary change, is fixation. In a large population, an allele with a low frequency can be eliminated by drift. Remember, the frequency of a new mutation is 1/2N. In any population of 1,000 or more, that is very low. Thus, an allele can be eliminated by accident if the sole possessor of that allele dies. Mokele made that point earlier. The effect of genetic drift on populations > 50 is negligible. The effect is so small compared to the effects of non-random mating, gene flow, and natural selection that it effectively does not exist. And yes, in populations < 50, all alleles are susceptible to drift. All you have to do is take my example of a population of 10 and plug in whatever frequency you want. However, the magnitude of the shift becomes less if you are close to fixation. we have 10 breeding pairs (20 individuals) with 10 of a1 and 10 of a2. One of the a1 dies in the next generation. Now we have 9 a1 out of population of 19 = 0.474. The frequency has shifted quite a bit by chance. I used p = 0.5. But lets use p = 0.9 (almost fixed) and have 18 of a1 and 2 of a2. Now one of a1 accidentally dies so we have 17 of a1 and 2 of a2. The frequency has shifted from 0.9 to 0.89. Not nearly as big a change as when we were at p = 0.5. Not from the equations I see. Normally, the less fit homozygote a2a2 is eliminated. Instead, in this case it has just as much fitness as a1a1 and is, therefore, kept. Therefore the number of a2a2 and a1a2 heterozygotes increase until p = 0.5. If a2 is the dominant allele, then it happens faster than if it is the recessive allele.

Apparently this is not indexed in PubMed. Can you find some other articles that are indexed in PubMed? The title of this one suggests that it is looking at the differences between male and female pelvi -- the "sexual dimorphism" and that mate selection has given us the general dimorphism, not anything within the last 200 years. So, please, post some other articles. Next time, let me suggest you read my entire post before you start to reply. If you had read the next paragraph,you would have seen that I was NOT questioning sexual selection in general, ONLY the specific comment that the mean width of female pelvi had changed within the last 200 years. First, I agree that sexual selection can be a powerful selective tools. Second, the examples you gave is artificial selectio, not sexual selection. That the changes you do to "random selection" are not that. Selection itself is not random. It's just that the humans are making a very severe environment. Artficial and natural selection are the same thing: artificial selection is natural selection where humans dictate the environment. And yes, in nature the environment rarely imposes selection pressures that are so severe but, when they are, evolution is just as fast. See this paper: Evaluation of the rate of evolution in natural populations of guppies (Poecilia reticulata). Reznick, DN, Shaw, FH, Rodd, FH, and Shaw, RG. Science 275:1934-1937, 1997. The lay article is Predatory-free guppies take an evolutionary leap forward, pg 1880. Again, this is natural selection, not sexual selection. From your examples, I think you are confusing the terms. I agree that humans are under natural selection. I'm questioning whether there has been enough time for natural and/or sexual selection to change human female pelvi in 200 years. Remember that we are talking number of generations. Evolution is change in populations from generation to generation. Both lizards and the finches have generation times that are 1 year or less. Thus, you can get 20 or more generations in 20 years. And the populations are relatively small -- in the few thousands. In contrast, humans have a generation time of 20 years and the population in the last 200 years has been in the tens to thousands of millions. It's diffficult for new changes to spread so fast thru such a large population. The problem is that NONE of your examples of mate selection was really mate selection. OK, let's look at mate selection. In mate selection only particular members of the opposite sex are chosen to mate with. What you have to have is just a small proportion of one gender producing all the offspring. Now, how many women in the UK are unmarried? Of the married women, what proportion are having babies? For your hypothesis to work, especially in 10 generations, you need ONLY the narrow hipped females to find mates and have kids. Just as an observation here in the US, which has the same culture for beauty as the UK, I don't see this. Yes, men may chase slim hipped women, but the fact is that men who don't get the "ideal" mate do not go mateless. Remember, the gender ration is close to 50:50. Since slim-hipped women would make up a small percentage of the women, say even 50%, that means you should see 50% of men be bachelors because they would not get the mates they want. I don't see this. Instead, the men who do not "get" the slim-hipped women marry and have kids with women who have wider hips. Ethically, no. In practice, yes. In order to survive, the hospital/doctor in the US has to bring in money to survive. If there is some justification for a procedure that can be billed, that becomes an indication to do the procedure. Reimbursement is higher in the US for C-sections than normal delivery. Now, you said "Further, labour wards in the UK do not charge the patient" That implies that patients ARE charged for C-sections. Is that true? Or are they not charged no matter what happens to the patient? C-sections is a gray area. What constitutes "necessary"? How much risk to the baby is deemed "necessary" in order to decide to do a C-section? Any risk at all? Something greater than that? If it is the first, then all delivery is a risk to the baby and C-sections are "necessary". In this case, it is trivial. The overwhelming source of malpractice suits in obstetrics is harm to the baby: cord wrapped around the throat, narrowing of the head as it passes thru the birth canal -- with possible neural problems, use of forceps and possible neural problesm, etc. So, cesearian sections remove all that and make it much safer for the baby. And, since the cesearian is done to protect the baby, it is necessary. 1. Analgesics make the birth process easier, but it doesn't remove the uncertainty of which day labor is going to start, does it? From the 9th month onward, women could go into labor anytime. 2. Again, can you give me some data on that "rarely demand"? Actually, no. It seems to depend on "progress". Here is a study -- conducted in England. First, women who had a cesaerean were just as satisfied with their delivery experience as women who had normal birth. See the first bolded section in the abstract. Also note that cesaerian is pretty low in England: <10%. This argues AGAINST your contention of high cesaerian birth rate due to narrow pelvi. Instead, the decision to have a cesaerian depends on whether labor is "progressing" in a timely matter, not fetal distress or concerns about width of the birth canal. Effect of different partogram action lines on birth outcomes: a randomized controlled trial.Lavender T, Alfirevic Z, Walkinshaw S. University of Central Lancashire, Preston, United Kingdom. Tinalav@yahoo.co.uk OBJECTIVE: The World Health Organization recommends partograms with a 4-hour action line, denoting the timing of intervention for prolonged labor; others recommend earlier intervention. We assessed the effect of different action line positioning on birth outcomes. METHODS: A randomized trial of primigravid women with uncomplicated pregnancies, in spontaneous labor at term, was conducted in the northwest of England. Women were assigned to have their labors recorded on a partogram with an action line 2 or 4 hours to the right of the alert line. If progress crossed the action line, diagnosis of prolonged labor was made and managed according to standard protocol. Primary outcomes were rate of cesarean delivery and maternal satisfaction. RESULTS: A total of 3,000 women were randomly assigned to groups; 2,975 (99.2%) were available for analysis. Questionnaires were completed by 1,929 (65%) women. There were no differences in cesarean delivery rate (136/1,490 compared with 135/1,485; relative risk [RR] 1, 95% confidence interval [CI] 0.80-1.26) or women dissatisfied with labor experience (72/962 compared with 81/967; RR 0.89, 95% CI 0.66-1.21). More women assigned to the 2-hour arm had labors that crossed the action line (854/1,490 compared with 673/1,485; RR 1.27, 95% CI 1.18-1.37); received more intervention (772/1,490 compared with 624/1,485; RR 1.23, 95% CI 1.14-1.33); and, if admitted to the midwife-led unit, were transferred for consultant-led care (366/674 compared with 285/666; RR 1.26, 95% CI 1.13-1.42). CONCLUSION: In this birth setting, for primigravid women selecting low intervention care, the 2-hour partogram increases the need for intervention without improving maternal or neonatal outcomes, compared with the 4-hour partogram, advocated by the World Health Organization. CLINICAL TRIAL REGISTRATION: Current Controlled Trials, http://www.controlled-trials.com/isrctn/trial/|/0/78346801.html, ISRCTN78346801. What happened to your ethics? The "natural consequences" are traumatized or dead babies! How ethical is it to refrain from a surgical procedure if such restraint is going to harm the baby! That cause is not listed in the obstetrics literature. According to this article, what matters is the experience of the obstetrician, not the pelvic size. New obstetrician, more cesearians. J Obstet Gynaecol. 2005 Oct;25(7):666-8. Links A prospective observational study of emergency caesarean section rates and the effect of the labour ward experience.Griffiths AN, Avasarala S, Wiener JJ. Department of Obstetrics and Gynaecology, Royal Gwent Hospital, Gwent, UK. Dr@anthony36.freeserve.co.uk The National Sentinel Audit found that one in five births in England and Wales was by caesarean section. The reasons for the increase in caesarean section rates are multi-factorial. Anecdotally, it is suggested that obstetric intervention rates and caesarean section rates vary among obstetricians without a difference in fetal and maternal outcomes. The aim of this prospective observational study of 817 deliveries was to assess the effect of experience on the caesarean section rates for different obstetricians. Obstetricians with greater than 3 years of 2nd on-call labour ward experience had a statistically significant lower caesarean rate than less experienced obstetricians 10.25% vs 25.49%, respectively (p < 0.05). Differences in instrument deliveries was also studied. Here's another article from England. It documents an increase in caesarian births by request. Obstetricians say yes to maternal request for elective caesarean section: a survey of current opinion.Cotzias CS, Paterson-Brown S, Fisk NM. Institute of Obstetrics and Gynaecology, Imperial College School of Medicine, Queen Charlotte's and Chelsea Hospital, Goldhawk Road, London W6 0XG, UK. AIM: To determine what proportion of obstetricians would agree to elective pre-labour CS for 'maternal request'. METHODS: Every fifth consultant on an alphabetical list of obstetricians in England and Wales obtained from the RCOG (243) was surveyed by post and asked (a) "Would you agree to perform an elective CS on a woman with an uncomplicated singleton cephalic pregnancy at term for 'maternal request?"' and (b) if yes, in relation to this 'Has your practice changed over recent years?" RESULTS: 155 questionnaires were returned (63% response rate -- four unanswered, leaving 151 for analysis). One hundred and four (69%) consultants said they would agree to 'maternal request' for CS. Of the 'yes' respondents, 62 (60%) claimed their practice had changed recently. CONCLUSION: This survey demonstrates that a majority of obstetricians are now prepared to agree to maternal request for CS in the absence of obstetric indications. Here's one showing that affluent women opt for caesarian section birth: Investigating the relationship between affluence and elective caesarean sections.Alves B, Sheikh A. SpT in Public Health, Brighton and Hove City PCT, Brighton, East Sussex, UK. The proportion of women delivering by caesarean section has increased dramatically in England and many westernised countries. It has been suggested that one important reason for this increase is the growing proportion of women opting for elective caesareans for lifestyle reasons, a trend that is, it is argued, most common among the affluent. We investigated the hypothesis that affluent women are more likely to deliver by elective caesarean section. Logistic regression modelling was used to analyse data from half a million women who delivered in English NHS hospitals between 1996 and 2000. We found that women living in the most affluent areas of England were significantly more likely to have an elective caesarean section than their deprived counterparts. All in all, I can't find any support in the obstetrics and gynecology literature for your hypothesis that an increase in caesarian births is due to pelvic size. Wait, here's a study looking at ALL risk factors for caesarian births. Breech presentation is a high risk factor, which has nothing to do with the width of the pelvis, of course. Elective caesarian is high on the list. We do see "Extremes of neonatal birthweight" and "increasing neonatal head circumferences". Both of these don't really indicate smaller pelvi, but rather the baby on the extreme of size. That would be a problem from the baby's side, not the woman's pelvis; it would have been competent to handle a normal sized baby. So, yes, I did look in the obstetrics literature. But I didn't find what you said I would find. Instead, I found support of my hypotheses and refutation of yours. But thanks for the opportunity to do some research and increase my knowledge. 1: Int J Epidemiol. 2005 Apr;34(2):353-67. Epub 2005 Jan 19. Links Prenatal risk factors for Caesarean section. Analyses of the ALSPAC cohort of 12,944 women in England.Patel RR, Peters TJ, Murphy DJ; ALSPAC Study Team. Division of Obstetrics and Gynaecology, University of Bristol, St Michael's Hospital, Southwell Street, Bristol BS2 8EG, UK. roshni.patel@bristol.ac.uk BACKGROUND: There has been an escalation in Caesarean section rates globally. Numerous prenatal factors have been associated with elective and emergency Caesarean section, some of which may be amenable to change. METHODS: A population-based cohort of 12,944 singleton, liveborn, term pregnancies were used to investigate risk factors for Caesarean section using multivariable logistic regression modelling. Numerous prenatal factors were investigated for their associations with the following outcomes: first, with Caesarean section (both elective and emergency) compared with vaginal delivery (spontaneous and assisted); second, for their associations with elective Caesarean section compared with attempted vaginal delivery; and finally emergency Caesarean section compared with spontaneous vaginal delivery. RESULTS: 11,791 women had vaginal delivery and 1153 had Caesarean section (685 emergency, 468 elective). Non-cephalic (breech) presentation (all Caesareans odds ratio (OR) 36.6, 95% confidence interval (CI) 26.8-50.0; elective Caesarean OR 86.4, 95% CI 58.5-127.8; emergency Caesarean OR 9.58, 95% CI 6.06-15.1) and previous Caesarean section (all Caesareans OR 27.8, 95% CI 20.9-37.0, elective Caesarean OR 54.4, 95% CI 38.4-77.5; emergency Caesarean OR 13.0, 95% CI 7.76-21.7) were associated in all analyses with an increased risk of Caesarean section. Extremes of neonatal birthweight were associated with an increased risk of Caesarean section (all Caesareans and emergency section) compared with vaginal delivery as was increasing neonatal head circumferences. In all analyses increasing maternal age (OR 1.07 per year, 95 % CI 1.04-1.09; OR 1.04 per year, 95 % CI 1.01-1.08; OR 1.11 per year, 95% CI 1.08-1.15) was independently associated with increased odds of Caesarean section. Increasing parity was associated with a decrease in risk for all Caesareans and emergency section (OR 0.63, 95% CI 0.53-0.75 and OR 0.46, 95% CI 0.33-0.63, respectively), as was the outcome of the last pregnancy being a live child. Increasing gestation was independently associated with a decreased risk of both all Caesareans and elective Caesarean (OR 0.86, 95% CI 0.80-0.93 and OR 0.52, 95% CI 0.46-0.58 respectively), whereas diabetes mellitus was associated with increased risk. These variables were not associated with emergency section. However, epidural use was associated with an increased risk of emergency Caesarean (OR 6.49, 95% CI 4.78-8.82) while being in a preferred labour position decreased the risk (OR 0.59, 95% CI 0.49-0.73). CONCLUSIONS: A careful exploration of risk factors may allow us to identify reasons for the increasing rates of Caesarean section and the marked variation between institutions.

Can you please cite those with 7? I've only ever seen the 4. I think the key there is "virtual environment". When the definition of "life" was made, computers didn't exist so everyone was looking at physical entities. Maybe an additional criteria should be that "life" has its own independent physical existence. Even when Star Trek Voyager explored the similarities of a collection of computer programs to living humans, they still had a physical entity by a physical "hologram". OTOH, if your critters evolve to the point of sentience, does that sentience matter if it is a computer program rather than a physical entity. I've seen at least one science fiction book exploring that. Gotta look up the name, tho. You and lots of other people. Yeah, but I like the protocells better. When stimulated, they produce a depolarization exactly like that found in nerve cells! Now, that's a response to stimuli!