High Speed Evolution 282
Taco Cowboy writes: Normally, the term "evolution" implicitly refers to super-long time frames. However, in the case of lizards on Florida islands, evolution seems to have shifted into a higher gear. Researchers have documented noticeable changes in a native species over a period of just 15 years, after an invading species altered their behavior (abstract). "After contact with the invasive species, the native lizards began perching higher in trees, and, generation after generation, their feet evolved to become better at gripping the thinner, smoother branches found higher up. The change occurred at an astonishing pace: Within a few months, native lizards had begun shifting to higher perches, and over the course of 15 years and 20 generations, their toe pads had become larger, with more sticky scales on their feet.
'We did predict that we'd see a change, but the degree and quickness with which they evolved was surprising,' said Yoel Stuart, a postdoctoral researcher in the Department of Integrative Biology at The University of Texas at Austin and lead author of the study... 'To put this shift in perspective, if human height were evolving as fast as these lizards' toes, the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations — an increase that would make the average U.S. male the height of an NBA shooting guard,' said Stuart."
'We did predict that we'd see a change, but the degree and quickness with which they evolved was surprising,' said Yoel Stuart, a postdoctoral researcher in the Department of Integrative Biology at The University of Texas at Austin and lead author of the study... 'To put this shift in perspective, if human height were evolving as fast as these lizards' toes, the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations — an increase that would make the average U.S. male the height of an NBA shooting guard,' said Stuart."
Is that unreasonable? (Score:4, Interesting)
the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations — an increase that would make the average U.S. male the height of an NBA shooting guard,
Is that unreasonable? If there were evolutionary pressure (ie, short people kept being killed before reproducing), and tall people got multiple mates, I could see this change happening within twenty generations. Twenty generations is enough for two people to repopulate large countries, or even the entire earth if they have large families.
Re:Is that unreasonable? (Score:4, Funny)
Yes, that degree of incest is unreasonable. You could repopulate the Earth with really tall, ugly retards with your plan for the future.
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Why on Earth would you presume all the tall people were originally closely related? No incest necessary.
Re:Is that unreasonable? (Score:4, Insightful)
That's probably why.
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Not so much. With inbreeding, there's strong selection to reduce the frequency of disadvantageous genes.
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I'm afraid that is just something your parents told you to make you feel better about them being cousins.
It's called Inbreeding Depression [wikipedia.org] and it's not psychological.
"Inbreeding (ie., breeding between closely related individuals) may on the one hand result in more recessive deleterious traits manifesting themselves, because the genomes of pair-mates are more similar: recessive traits can only occur in offspring if present in both parents' genomes, and the more genetically similar the parents are, the more o
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The analogy really sucks.
It's very hard to find a photo of Abe Lincoln where he isn't at least a head (including his beard) above everyone else. But today several countries [voxeu.org] have an average height within a 10 cm of him. The Dutch are 184 cm (about 6' 1"), but Abe was only 193 cm (just under 6' 4"). Partly that's due to nutrition, which has an incredibly complicated relationship to height (the Dutch, for example, are dragged down by the descendents of people born during a famine after WW2. Their grandchildren [wikipedia.org]
Re:Is that unreasonable? (Score:5, Informative)
Is that unreasonable? If there were evolutionary pressure (ie, short people kept being killed before reproducing), and tall people got multiple mates, I could see this change happening within twenty generations.
Interestingly, we have had a MUCH faster increase in height in the past couple centuries, probably mostly due to improvements in living conditions, food supply and nutrition, and medical advances.
According to this recent study [dailymail.co.uk], for example, European men have gained approximately 4 inches in height in 100 years, i.e., about 4 or 5 generations.
So, it probably doesn't even require significant genetic changes to produce such a shift. I once read somewhere that n the early 1800s, the average height differential between upper-class and lower-class Englishmen was something like 7 or 8 inches (i.e., rich men were something like 8 inches taller than poor men).
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Yes but if you go back to the Medieval Warm Period during The High Middle Ages in 1200 AD when food was plentiful you will find that the average height in England was quite tall and on par with today.
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Re:Is that unreasonable? (Score:4, Funny)
That's natural selection at work. If you can see further ahead in the traffic, you'll arrive home earlier and score with the women before the short men who are still stuck in traffic.
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Is that unreasonable?
No, it is not unreasonable, and there are plenty of examples of evolution happening that quickly, so I don't know why this particular example is news. For instance, the Atlantic cod adapted to heavy fishing by shrinking in size and spawning much younger. Moths changed their patterns to adapt to sooty cities, and back again when the soot was eliminated. Horses abandoned by Spanish explorers on the outer banks of North Carolina, have adapted to the lack of fresh water by shrinking in size and, excreting ex
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Depending on how you're using the terms, yes. "Microevolution" is synonymous with "adaptation", which is essentially what's being described in the summary and what you're describing here.
Really, these findings are only surprising if you presume that the genes to adapt in this manner were not present in the population at the time that the invasive species was introduced. I'm with you in believing that wasn't the case.
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If the people had an average of 3.1 children per generation, that makes 7 billion people in 20 generations. So, large families not required.
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Is it unreasonable for the average height of a population to grow by 7" in twenty generations? I should think so. But if you changed your initial conditions somewhat, maybe less unreasonable.
There are roughly 400 genes known to influence height. Imagine we have a small, isolated population that does not interbreed with other populations -- say on an isolated island. This population's average male height is, say 175 cm for men -- roughly the same as the average American. However the population contains a
20 generations (Score:2)
I'm not sure that's so shocking. Assume there were a predator that killed 90% of the shortest 1/3rd of all humans at age 15. Let that run for 20 generations. I don't see how the average male height going to 6' 4" would be at all out of character. Heck it might happen faster than 20 generations, possibly more like 5.
Re:20 generations (Score:5, Insightful)
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Score: +5 Funny, +5 Duh.
Re:20 generations (Score:5, Informative)
As stated in another post, if you kill off the shortest 1/3 of the population, the average height immediately goes up.
Similarly, if the small-footed lizards drop off the trees and can't find enough food, the average foot-size immediately increases in the population independent of evolution occurring. Evolution is 2-step process. The environmental advantage or disadvantage occurs during the individual lives of each member of the species. The passing of genes to the next generation is a separate process that still reshuffles the genes via sex relentlessly regardless of environment. That's what makes it hard to determine when evolution via genes is occurring vs purely environmental factors winnowing a current population. The new population of lizards still produces some amount of small-footed ones due to sexual mixing of genes--and if the environment changes to reward smaller feet, the population will again change quickly.
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In the 1950's the average Dutch man was 1m73, presently he is about 1m81, that's 3 inches more over just two generations.
The present generation of young men ~20y/o is around 1m84.
But as with all statistics you have to check the small print, in 1970 I was drafted for the military (10% of males) and the average length of conscripts was already 1m86.
Another interesting observation is the correlation between length and education, t
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Well known, (Score:4, Informative)
The "ring species" [wikipedia.org] are basically speciation events in progress. All it takes is one catastrophe, a disease or volcanic eruption or an invasive predator species introduction, that interrupts one of the breeding in one of the islands, and there will be two species. And this is what most anti-evolution folks don't get. No, a chimpanzee did not suddenly gave birth to a human. Population of the ancestor species split into two, and one evolved to become human and the other became chimpanzee. And the split need not be geographic. Changes in mate preferences, internal body temperature, food preferences, etc can lead to breeding isolation that could lead to speciation.
Still it is nice to see evidence being presented in a species much higher than mosquitoes.
No, it was not an "active" strategy. (Score:3)
The change occurred at an astonishing pace: Within a few months, native lizards had begun shifting to higher perches, and over the course of 15 years and 20 generations, their toe pads had become larger, with more sticky scales on their feet.
This language confuses most non scientists and those not used to reading about evolution. The lizards did not convene a Supreme Soviet of Lizards and pass a resolution to shift to higher perches. The did not look at the evidence, pros and cons and decide, "yeah! sticky scales on the feet are a good idea. But Lizz Ard patented it. The survival of the species depends on it. So let us use eminent domain and make it public domain". Some lizards naturally like perching higher and other prefers perching lower and most do exactly what their parents did. The ones who liked higher perches survived more than the others, and their percentage in the population rose. Eventually only those who perched higher would be left alive.
The inuit are able to eat fried whale meat fried in blubber nonchalantly because those who could not handle that much cholesterol died out ages ago. Lactose intolerant toddlers died out en mass some 8000 years ago in western europe. That is why humans should try to stick their "ethnic ancestor" foods. [begin personal rant] Indian Indians (not American Indians) went through so many cycles of feast and famine. Only those who had the ability store fat in the times of plenty survived the lean times. When they get F-1 visa, then green card then citizenship and melt into the melting pot guzzling beer, eating pizza, their genomes are still gearing up for the next famine that could be just round the corner. Heart disease and diabetes is rampant among the immigrants from historically impoverished ethnic groups are very very susceptible to diseases of the plenty. Your body evolved to eat what your grandpa and his grandpa ate. If they eschewed bacon, stay clear of bacon. If they ate rice and lentils and ate samosa and jamoons only on festival feasts, you would do well to do the same. Stop ordering dessert in every meal and pigging out in the 9$ lunch buffet with unlimited mango lassi at India Palace. [end rant]
It is fascinating to see it from evolutionary perspective. But evolution has been used by every one with a perverse agenda to justify their ulterior motives most scientists steer well clear of explaining it in simple terms. They hide it in obscurantist journal papers with very dry commentary.
How is this surprising? (Score:5, Insightful)
Mod parent up. (Score:2)
The important part is that we are NOT seeing such rapid changes amongst the PREDATOR population. So this is not unusual at all.
The lizards that are not sticky enough to climb out of reach of the predators are the lizards that get eaten by the predators.
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I don't either - the speed of evolution is directly proportional to generation time and pressure. The former is one of the reasons why fruit flies are so popular for genetics research - from egg to ready to lay more eggs is about three weeks.
Farm (Score:4, Informative)
We see this on the farm. Nature guides the hand of evolution in the wild through selective adaptive pressures. On the farm it is the hand of man, sometimes, but the same thing. We use selective pressure to improve our livestock. In just the past slightly more than a decade we have made significant evolutionary changes to our pigs. They're a particularly nice animal to work with for genetic selection because they reproduce fast (up to 3 litters a year) with very large litters (8 to 21 piglets per litter) with rapid growth (6 months to market, 9 months to breed) so we can turn over generations quickly.
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We see this on the farm. Nature guides the hand of evolution in the wild through selective adaptive pressures. On the farm it is the hand of man, sometimes, but the same thing. We use selective pressure to improve our livestock. In just the past slightly more than a decade we have made significant evolutionary changes to our pigs. They're a particularly nice animal to work with for genetic selection because they reproduce fast (up to 3 litters a year) with very large litters (8 to 21 piglets per litter) with rapid growth (6 months to market, 9 months to breed) so we can turn over generations quickly.
Bacon! Even nature sees the evolutionary benefits of Bacon.
Glorious, delicious Bacon!
Bacon is the universal meat. Loved by all who eat it, so so versatile, and the only known word that all by itself is the most effective counter to the Vegan Argument.
Teh Vegans try to convince me to not eat meat?
"BACON!"
Teh Vegans walk away thoroughly and intellectually beaten....
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Good point. How long does it take to produce a new animal breed?
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Probably about two decades, which is very fast in genetic terms. That's to weed the genetics to the point of breeding true on a bit over two dozen major traits we need. Things like extra nipples, more hair (think winter), shorter thicker upright ears, longer legs, improved grazing, marbling, etc.
Selective breeding, an extreme form of evolution? (Score:2)
Consider dogs (all breeds derived from wolves several thousand years ago) and foxes http://cbsu.tc.cornell.edu/ccgr/behaviour/Index.htm the genetic basis has been studied and similar studies have been done on other domestic animals. The chicken http://en.wikipedia.org/wiki/Junglefowl This type of "evolution" is really just exploitation of existing genetic variation within a species.
Wolves and coyotes in Yellowstone (Score:2)
Nothing really new here.
Wolves, then seen as unreservedly undesirable, were eradicated from the Yellowstone region by the early 20th century. Between then and the end of the century, coyotes got larger and started hunting in packs, taking the ecological niche that wolves had filled and pursuing larger prey.
Then (1994) we reintroduced wolves to Yellowstone.
Even in the short time since, observed coyotes have gotten smaller and started acting less like apex predators and more like the sneak and scavengers tha
Re:Falsifiability (Score:5, Insightful)
Discussion?
Evolution is easy to falsify. Apply pressure and see if the species DOES NOT adapt to the pressure.
If you believe that genes exist, then you believe in evolution, it's that simple. And if you don't believe that genes exist, then you might as well not believe in medicine either, or believe that cell phones exist, because it's all the same science.
Re:Falsifiability (Score:5, Insightful)
It's not quite that simple, but you could probably simplify it to a few basic steps, like:
Is there a coding mechanism for heredity? - Yes, the genetic code.
Is there a way to generate new code? - Yes, mutation.
Does that code allow unlimited blending? - No, if it did the two sexes would completely blur together, among many other lesser examples.
Is there selection for fitness? - Yes, not everything gets to reproduce as much as it attempts to, and at least some of that is attributable to being "unfit".
Basically, people can point to examples where limited blurring may occur, or being taken out of the gene pool may have nothing to do with fitness (all dinosaurs are equally unfit to survive a 5 mile wide asteroid strike), or many other such factors, but they aren't really offering any effective criticism of evolution unless they want to claim things like selection or mutation never happen.
This is also why what Darwin did was science. His publication made several testable predictions - that there would be a genetic code, that the code could be altered on occasion, and that it would not allow unlimited blending of traits.
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Evolution does not require "genes". Any biological or physical or even behavioral feature that allows information to be transferred to other members of the species, especially to new members of the species, can support evolutionary pressures. We can see it in social and cultural evolution as well as biological evolution, and they also in co-dependent ways. A great deal of child-rearing is learned behavior in more neurologically complex species.
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Cell phones aren't made of actual cells, buddy.
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Apply pressure and see if the species DOES NOT adapt to the pressure.
That does not prove evolution by natural selection. Lamarkism [wikipedia.org] would be an alternative explanation. Darwinian evolution not only predicts that species will evolve, put predicts a specific mechanism: The better adapted individuals reproduce more than the less adapted.
Most evolution is believed to be Darwinian, but there are Lamarckian adaptions such as epigenetic inheritance [wikipedia.org]. Life is complicated.
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Sometimes organisms adapt to selection pressure, sometimes they do not. Sometimes they go extinct.
Some going extinct is adaptation. The remaining life forms on the planet are more adapted to the situation. That's how evolution works.
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Some going extinct is adaptation
No. Let me recommend this book: http://en.wikipedia.org/wiki/T... [wikipedia.org]
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No, again, not unfalsifiable. If you apply pressure and they don't adapt, then you falsified evolution. It just happens to be really hard to falsify, because it's actually happening, and we can observe it.
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You are claiming that all organisms will adapt under selection pressure, under testable timeframes?
This is absolutely false.
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But it is certainly true. If a species have a long generation cycle, then you must just wait long enough. You can make an experiment that spans 200 years or more.
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No, again, not unfalsifiable. If you apply pressure and they don't adapt, then you falsified evolution.
No, that's absolutely incorrect. Evolution, as commonly understood, is the result of a RANDOM genetic process. Whether an appropriate adaptation will arise given selection pressure is always a matter of chance, and any given instance of a species NOT adapting isn't much evidence of anything really. By that logic, we could argue that all of the species currently going extinct due to manmade changes in environment etc. have somehow disproved evolution... which is obviously not true.
The only way to falsif
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Maybe you don't understand the word: Evolution. Let me scope it out here for you.
You said that you believe in genes. Let's assume that you believe in the reproductive process too. When the genes of two parents combine you get all sorts of possible outcomes for the genetic result, or child. This child is then a combination of parental traits and yet not the mother nor the father. The child is new. We have also witnessed random mutation. You with me so far?
Now let's read the biological definition of the word
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Back to school you go.
You got part of it - genetic (or epigentic, it really doesn't make a difference to the theory) variation.
And.
Selection. You need that part. Otherwise you just have a whole bunch of very slightly different critters wandering around the petri dish. Don't forget selection.
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Join me in class, won't you?
You don't need that part. Luckily you don't have to satisfy every definition of a word at the same time. English would be impossible if that were true.
Selection is outside of the scope I gave you and for good reason.
I am speaking of biological evolution with no respect to behavioral science.
It is my opinion that behavioral science is bullshit and sexual selection is arbitrary. You didn't specify what kind of selection, either. There are countless different types of selection and
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The organism will ALWAYS adapt, it is simple logic. If pressure is placed on an organism, then less of the ones that carry genes susceptible to that trait will reproduce, because they will die. Ones that carry genes that help with that trait, will reproduce more. This WILL cause adaptation over time. And random mutation will be constantly introducing new genes into the mix.
There is absolutely no question on if pressure will cause a species to adapt. The only question is if the adaptation will happen at a pa
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Well, I'm glad you find it to be "simple logic", particularly since your claim is simply verifiably false.
If there is no genetic pathway to characteristics that will allow it to survive in the environment creating selection pressure, the organisms will simply all die. Maybe "not adapting = adapting" to you, but the question at hand is what set of characteristics we are considering "evolution" and a test for that.
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I don't think the modern synthesis makes the claim that this process needs to be successful on a species basis, or needs to "save" or preserve certain populations or not in order to be true, which sounds like what you're proposing. Really all evolution claims is that (1) organisms change through generations, (2) these changes are subject to challenges from the environment and competition, and (3) changes that
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Well, to clarify a few points...
I am in absolute agreement than "evolution happens". I am in disagreement with the untestable assertion of "only evolution happens", which is the only form of the assertion most people of a certain worldview, particularly, say, fans of Dawkins, care about. They'll happily destroy valid science and the understanding of it as long as they can hope they are damaging religion in some way by doing so.
Falsifiability, when possible, is a very valuable attribute of any scientifi
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Who has made this assertion? Sure not TFA or really anyone else here. Or is this just your thing?
A lot of people including myself [slashdot.org] have given you examples of how it could be falsified, and you can only really get to the idea that it can't be by making categorically false assertions, such as "evolution demands that all change is evolu
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No. Physics is real and math is abstract. It often provides close approximations of physical reality but it is not reality itself except in the sense that it is neurons firing in brains.
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At this point, evolution isn't really falsifiable. But not because of it not being a valid theory (the theory is that if you have things breeding, and their genetic makeup changing as they breed, then any selection at all will cause changes over time), instead, it's simply because of the huge body of evidence - we have watched many species evolve at this point, and hence know without a shadow of a doubt that it does happen.
This is why it's so ridiculous for religious nuts to argue against evolution.
What's
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Your assumption is that "the evidence" is only open to one interpretation. Like the Interpretations of QM, that is not the case here.
If you could give me a generalized description of how you would methodologically know that an organism we -know- is designed, because we did it ourselves, if you had not read the news saying we did it and found rather partial remains, then you'd have a strong argument. Rather, though, you are assuming your conclusion by fiat. You have no actual differentiating evidence betw
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If you could give me a generalized description of how you would methodologically know that an organism we -know- is designed
That's the point though, we know it's not designed. We can sit there and observe how a new organism is produced from the parents. We can sit there and observe how this produces new things for natural selection to test, and we can set there and observe that the less successful ones don't get to breed. Finally we can sit there and observe that in not breeding their genes become less likely to be present in the following generations, and that the following generations develop general traits based on the abo
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No, you absolutely don't know it's not designed, and you have given no reason even to think so, other than there's reproduction and survival involved, which you somehow take as definitive on the matter.
Again, I can give you two animals, one which absolutely does have design as an explanation of its characteristics (say, fluorescent cats or spider-silk producing cows), unarguably, and one which may or may not, say a common farm animal. How, outside of the fact you happened to read about genetic engineers de
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Did something, at some point in those billions of unobservable years, modify genes by means much like we do today? You have no idea
Please describe a test that would falsify such a designer.
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Interesting. So evolution says it is an optimal solution given the constraints of the environment and the timeframe required, but you'll discard the conclusions of evolution in favor of your personal subjective context-dropping opinion, if it allows you to disparage the designer.
Do note, though, that to address one particular notion of that designer (the issues and value of the question remaining even if we consider it, say, some extraterrestrial intelligence), it is in no way stated Earthly physical "perf
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However, none of that is evidence that it is
Re:Falsifiability (Score:5, Funny)
However, none of that is evidence that it is not designed.
Indeed. All we can say is that the theory doesn't need a designer. It doesn't need a painter or hair stylist either. Would you prefer if we rewrote the theory of evolution so that there was a hair stylist fixing the hair of the woolly mammoths ?
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" It is, scientifically, not understood better than "magic""
Considering that magic uses a lot of science to make its tricks work, that's pretty funny.
So are you talking about abiogenesis or evolution?
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Well, yeah, my kind of "magic" would use a lot of science as well, specifically only requiring that on a quantum level, "random" (which is a non-explanation causally anyway) isn't entirely "random".
Consider it a potential universal back-door to all of reality, as a good engineer would naturally install up-front.
As for what I'm talking about, I'm talking about what you are referring to when you refer to it. Redirection doesn't seem to accomplish much here.
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Thanks for the silly characterization. Hopefully you'll learn the difference between that and science and actual arguments someday.
Okay, explain how "random" is not "booga-booga", then.
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No a random side does not come up. The outcome is totally determined by the initial conditions and the physics involved in he coin toss.
That's pseudo-random, which is the reality of most cases of apparent "randomness" we observe.
If you're going to use it as a core component of a causal -explanation-, though, much more detail is warranted.
What are the causal factors that determine a particular result of the "random" mutations, or is it in fact not random?
"Random" is not an explanation. "Random" is a placeh
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Darwin himself was careful to specify what he was arguing for - His first book was, after all "On the Origin of Species", not "On the Origin of Life". His theory is about how existing life divides into distinct groups, and (in a modern version of his phrasings), why species are 'distinguishabe sets with fuzzy boundries', and doesn't really touch on where the first life forms came from, one way or another. We could start from some assumed single primative life form, or imagine a world where there was somehow
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This is why it's so ridiculous for religious nuts to argue against evolution.
Perhaps because people like you refer to them as "nuts" and dismiss their views as "ridiculous", when you clearly don't even understand what their views are. Christian (and Muslim) fundamentalists do not deny that evolution occurs. There is clear and obvious evidence that it does, and they accept that. What they do NOT accept is that evolution can lead to the emergence of new species, and (more importantly) is the sole explanation for the existence of humans. There is strong evidence that they are wrong
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This statement does not reflect the broad diversity of doctrine on this issue, beliefs run the gamut from theistic evolution thought intelligent design to young-Eartherism.
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However... Not all dogs are still wolves. That is, there are actually now sufficiently large differences between dog breeds that they can't interbreed, and hence could reasonably be classified as different species.
Similarly, these lizards are likely to become a new species too, because by living high up in the trees, they'll not come into contact with their less grippy cousins, and hence are likely to evolve in entirely incompatible ways.
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If it falls to the ground quickly, it's gravity.
If it drifts to the ground slowly, it's gravity.
If it falls because someone pushes it off a cliff, it's gravity.
If it just slowly slides down a slope without anyone touching it, it's gravity.
So, basically, if downward motion occurs in there somewhere, it's gravity.
I'd really like to see a falsifiable rendering of "gravity". It would make discussion so much easier.
Until the, TEACH THE CONTROVERSY!
Sigh... (Score:2)
Fine, bring on the "redundant" mods.
jeffb (2.718), typing more slowly than Anonymous Cowards since 2008 or so...
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And if we find a case where it doesn't behave that way, the current model is falsified. That's why theories of what gravity is and how it works is falsifiable, and therefore science.
What is the case in which you would -not- call a biological change "evolution", and how is that different from the mere criteria for "reproduction"?
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"And if we find a case where it doesn't behave that way,"
And if my aunt had balls, she'd be my uncle. We haven't found any, so we moved on. Why can't you?
"What is the case in which you would -not- call a biological change "evolution""
Biological change in what? An entire species, an individual, before he reproduces, after? What? Describe your experiment a bit better.
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Because I'm in favor of actual science, rather than "no clear counterexamples found yet, therefore forever proven".
Biological change in what? An entire species, an individual, before he reproduces, after? What? Describe your experiment a bit better.
You are just restating my question. Give me the criteria for what you consider "evolution", and your test/experiment for that, by which it could in theory be falsified.
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"no clear counterexamples found yet, therefore forever proven".
I don't think anyone really claims that.
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In Biology, there's the concept of Stochastic Mutation. It's most commonly attributed to viruses, for example HIV is a known stochastic mutator. In these cases, some (not all, just some), types of cell mutations occur, where there's no selection pressure - the virus changes its protein coat in one of several ways (4 for HIV), and type B is just as likely to mutate back to type A or into Type C or D, as to stick where its at. In equilibrium, none of the protein coats is preferred by natural selection, and th
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I don't think "falsifiable" means that *will* find any contrary evidence, just that you have to be able to *look* for it!
What about evolution prevents you from *looking* for any contrary evidence? I'm sure plenty of people have. Guess they didn't find any.
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No, falsifiability means you could at least envision a test by which the theory would fail.
Given the scope of what is defined as "evolution", as I said every apparently-possible scenario involving reproduction, what would you propose that test to be?
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"No, falsifiability means you could at least envision a test by which the theory would fail."
Yeah, how is that different from " that you have to be able to *look* for it!"
Look and envision is pretty much the same thing.
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Dogs giving birth to reptiles would be a start. The modern synthesis of genetics predicts that the phenotype of a child will be a combination of the parents, and many aspects of evolutionary theory and particularly sexual selection rely on this observation.
Something evolution implies is that it's path-dependent, so you might expect that traits emerge and are retained in some kind of chronological order, there's the old joke about Haldane looking for "bunny rabbits in the Cambrian epoch" that illustrates th
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I'd really like to see a falsifiable rendering of "evolution". It would make discussion so much easier.
That must be the basic problem with physics too. The universe we live in is NOT falsifiable; therefore physics can never come up with a valid scientific theory that us internally consistent and also completely covers everything.
;-)
Is that the philosophy of science in a nutshell? Enquiring minds want to know
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Evolution happens faster than we expected....specifically in 20 generations, toe pads can become X times larger
That is completely falsifiable.
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And that being falsifiable has nothing to do with evolution being falsifiable.
Evolution is the theory that such selection mechanisms explain -all- variation, over -all- biological history.
"Often, therefore always"?
Your "test" is akin to saying all animals have two legs, looking at the guy next to you, and considering your theory unfalsified.
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Nice try.
A weird attempt at dodging and/or censorship, but I'm sure that you've been on Slashdot long enough to know that posting only within the narrow set of responses you imagine are framed by the story, is almost never the case here.
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That is, the hypothesis is that the lizards legs grow longer under pressure. If God himself decided to help the lizards out by giving them longer legs, then it is still irrelevant to the hypothesis.
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The thing about falsifiability in scientific theories is that it doesn't appear until somebody comes up with an alternate theory. And there just aren't a lot of good alternative theories to Evolution.
As far as I can tell there've been three theories as to why species exist/change/etc.
1) God made them that way. This was proven inadequate by the demise of the Dodo bird (after all, if God specifically made Dodo birds because he liked Dodo birds, why would he let us kill them all?), and was really on it's last
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....Now about those Moon landings, would you need some falsifiable evidence there too?
Does a link to a Faux News web site count? ;-)
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Glad you're taking it.
Then you are saying all change is evolution, and all reproduction entails genetic change, so "evolution" as you've rendered it is functionally equivalent to "reproduction".
Nothing could falsify evolution that doesn't equivalently falsify simple reproduction. Not quite what I'm looking for.
Let me be clear, I am not against evolutionary processes being a very significant factor in genetic change, I am after a falsifiable definition of it. And the typical usage of "evolution can be anyt
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Arms race .... heh heh.
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The problem with your statement is that the existence of "species" is more controversial than the theory of evolution. I would say that the word species is not well defined.
Species used to be defined by what animals are sexually compatible enough to create offspring. A more recent definition, using genetic science, could relate to the number of chromosomes. The mule is an example that shows the problem well:
Mule:
"A mule is the offspring of a male donkey (jack) and a female horse (mare).[1] Horses and donkey
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Normally, the term "evolution" implicitly refers to super-long time frames.
Ummm, no it doesn't. Fruit flies, bateria, viruses and a host of other living things evlove on timescales that are observable by humans in near real-time. Taco Cowboy better stick to something other than commenting on biological processes that he knows little about.
It's not a well crafted sentence but yes, most discussion of evolution concern themselves of long spans of time. It actually has only relatively recently when we were able to clearly see evolutionary changes in macroscopic organisms that occurred over a period of just a couple of years. Of course, rapidly dividing little things have been the forefront of molecular basis of evolution for some time but some people have found it difficult to grasp that growing longer toes and creating antibiotic resistance a
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