Why is evolution so controversial?

The yield per acre and the people needed per acre has changed drastically through time, and it even differs between modern societies.You have made an unwarranted assumption that the human population has grown at the same rate throughout history.

When you consider timing, Ardi is about when the genetics says the divergence event happened, thus it is very likely that she is close to that population splitting phenotype.But also remember that this is an artistic rendition, and that Ardi was fully capable of living in trees:Ardipithecus - Wikipedia

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... Two fossil species are described in the literature: A. ramidus, which lived about 4.4 million years ago[2] during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago (late Miocene).[3] Behavioral analysis showed that Ardipithecus could be very similar to those of chimpanzees, indicating that the early human ancestors were very much like chimpanzees in behaviour.[4]

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The toe and pelvic structure of A. ramidus suggest to some researchers that the organism walked upright.[7]

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According to Scott Simpson, the Gona Project's physical anthropologist, the fossil evidence from the Middle Awash indicates that both A. kadabba and A. ramidus lived in "a mosaic of woodland and grasslands with lakes, swamps and springs nearby," but further research is needed to determine which habitat Ardipithecus at Gona preferred.[7]

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Some people put the split at 6 million years ago.Ardi is also how we know that our ancestors were pre-adapted to walking upright before the Savannah period, and thus was able to take advantage of the new habitat.Enjoy

No I don't seem to affirm any such thing. I simply discussed mathematics and your incorrect statements about that subject. If you want a definitive statement from me, you cannot model human population growth since the dawn of mankind using a continuous growth equation. It is certainly not the case that we've been able to do so for all of human history. And regardless of whether you accept that, if your purpose is to invalidate scientific consensus, you need to either demonstrate that we were never hunter/gatherers or take that part of human history into account in your prediction.And since we've been able to grow our own food and domesticate food animals, there are still limits on the food we can grow, which in turn places limits on what population an area can support. As technology has gotten better the amount of food we can grow or find in an area has gotten larger. You seem to be arguing away from your own position.But let's see your modifications. Or getting straight to the point, show me that those modifications are a simple modification of r by a factor of 2 or so. Your claim up till now does not seem to have taken those modifications into account. Also, there are multiple different resources to model as well as competition, war, disease, etc.Can you modify your continuous growth model to take those things into account? Is the resulting model still a continuous growth model? It we're allowed to change the parameters on the fly, we can model population using a linear relationship, or a quadratic one. The point is that you cannot simply pick a value of r for an environment. A stable population requires an r value of zero. Edited by NoNukes, : No reason given.

New evidence on Neanderthal mixing

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New research on a 45,000-year-old Siberian thighbone has narrowed the window of time when humans and Neanderthals interbred to between 50,000 and 60,000 years ago, and has shown that modern humans reached northern Eurasia substantially earlier than some scientists thought.

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Prior research had given scientists evidence of two possible rates, one twice as fast as the other. Because of this large range, dates obtained from genetic studies have tended to be quite uncertain. By measuring the number of mutations missing in this individual and comparing with people now, Fu was able to obtain an accurate estimate of the rate that mutations accumulated over time. Her work came down definitively on the side of a slower mutation rate, corresponding to between one to two mutations per genome per year.

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Reich said the findings on mutation rate have sweeping implications, and provide a basis for reinterpreting key dates in human prehistory. Instead of humans and Neanderthals becoming distinct offshoots sometime between 270,000 and 380,000 years ago, for example, the slower rate would put that shift much further back in time, between 550,000 and 770,000 years ago. Similarly, the slower rate pushes back estimates for the date of the separation of African and non-African populations.

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Not really. What it shows is that the rate since 50,000 to 60,000 years ago has been slow, it does not say what it was before that time. Extrapolations are highly questionable and would need further evidence to support.

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The slow mutation rates indicate that the present-day subdivisions among human populations date back to almost 200,000 years ago, well before the period around 50,000 years ago when the archaeological record documents art and new styles of toolmaking, Reich said. The implication is that the spread of modern human behavior must have been cultural, at least in part. Based on the genetic dates, it cannot be the case of a single population that developed modern human behavior spread all around the world replacing the other humans who already lived there.

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OR the assumption of a constant slower mutation rate before 60,000 years ago is false. Mutation rates are not constant and the rates at which mutations are mixed\fixed in a breeding population is related to selection pressure.

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In examining the ancient Siberian’s ancestry, Fu found about 2.3 percent of his DNA came from Neanderthals. That is a bit higher than found in modern humans living outside Africa today a level that ranges from 1.7 to 2.1 percent but too small a difference to be statistically significant, Fu said. Her findings on the date of human-Neanderthal mixing dramatically narrowed the likely range to between 50,000 and 60,000 years ago, a much tighter window than the previous range of between 37,000 and 86,000 years ago.

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What 2.3 percent represents is an overall average of a variable rate for the last 45,000 years, and if later rates are closer to 1.7 to 2.1 then that would indicate that the rate of mutation 45,000 years ago was higher.Curiously this is also about the time for that bottleneck event ... when high survival pressure would have increased both mutation selection and made hybridization more likely.Enjoy.

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The yield per acre and the people needed per acre has changed drastically through time, and it even differs between modern societies.
You have made an unwarranted assumption that the human population has grown at the same rate throughout history.

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I do admit it is a stretch I did not imply it was not.But a lesser stretch than claiming a human population of ~10,000 has a effective zero growth over 50,000 years. The old long bottle neck nonsence.

Not so much "monkey-like" as becoming more adapted for tree\jungle habitat, and that is consistent with a division of apes into savannah apes and forest apes as they diverged.This also means re-emergence of knuckle-walking on the ground and shortened rear legs as they become more adapted to branch swinging (like gibbons and orangs).Knuckle-walking - Wikipedia

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There are differences between knuckle-walking in chimpanzees and gorillas: juvenile chimpanzees engage in less knuckle-walking than juvenile gorillas. Another difference is that the hand bones of gorillas lack key features that were once thought to limit the extension of the wrist during knuckle-walking in chimpanzees. ...

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It has been suggested that chimpanzee knuckle-walking and gorilla knuckle-walking are biomechanically and posturally distinct. Gorillas use a form of knuckle-walking which is "columnar". In this forelimb posture, the hand and wrist joints are aligned in a relatively straight, neutral posture. In contrast, chimpanzees use an extended wrist posture. These differences underlie the different characteristics of their hand bones.[6]

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Enjoy

Yes, a "non-constant constant." You still have not explained that particular oxymoron.Now, if you had actually learned any math, then you would know that a value which is dependent on another value is not handled by a constant, but rather by a function. A pure-birth/death model uses a constant rate, whereas a logistic model uses a rate which is a function of the conditions, primarily of the population size.As I keep telling you and you keep ignoring: You are using the wrong model! But your model requires that we choose a single value of for the entire growth of the population. As a result, your model does not accurately predict the population size.You almost stumbled upon it earlier in your search for a value for r. The rate of growth at different times in our history was different. That is why we cannot use a single constant rate, but rather need to use a rate which is a function of the conditions. Duh?But let's test your method. If you had actually studied any math or have any kind of understanding of math, you should recognize that I am about to employ "proof by contradiction", in which to prove something you assume the opposite, carry it to its mathematical conclusion, show that the opposite produces a mathematical impossibility which disqualifies it, so the original must be true. Of course I cannot apply that strictly, but at least I can demonstrate that your pure-birth model is not correct.You say, "You must calculate a new (r) for that island, ... " OK, let's do that. We are going to end up with a population holding constant at about 100 people for highly extended periods of time, such as several thousands of years. What value of r would express that? I submit that, for your model, the value of r would need to be zero.OK, using your model with a value of zero for r, as your model demands, what is the size of the population after 100 years? Two people. Is that really what we should actually find? No, that is very unreasonable. At first, the population experiences virtually unlimited resources, so it should grow exponentially as in a normal pure-birth situation. Your pure-birth model fails utterly.For the same island, the same environment, the same amount of resources, etc, there is no one single value of r that accounts for population growth and size throughout the history of that population. The value of r must change in order to even begin to model what's happening with this population. In this idealized scenario, the only thing that changes is the size of the population and it is the size of the population which causes the rate of population growth, the value of r, to change. Therefore, r cannot be a constant, but rather must be a function which varies according to an independent variable, which in this case -- and in most cases -- would be the current population size.That is simple math. Why are you incapable of understanding it? OK, so when you start counting past 10 you take off your shoes and socks, but then what do you do when you have to count past 20?I said that, because you are demonstrating that you are incapable of doing simple math. Fundamental concepts like constants and functions appear to be beyond you.Ever hear of GIGO? "Garbage in, garbage out"? Only for creationist claims it's more like "Garbage in, Gospel out." Using math to prove something only works if your mathematical model actually describes what you are trying to model. That should be a simple concept to comprehend, yet you are unable to.Your model does not describe the growth of real-life populations. It's as simple as that. Trying to apply a model that does not describe the system that you're trying to analyze will yield meaningless and useless results. Your attempts to apply your pure-birth model to the entire history of human population growth cannot yield anything other than meaningless and useless results.Creationists have known for decades (at least since the early 1980's) that their human population growth model claim is false, yet they continue to preach it. It is a ludicrous lie. Why do they believe that their religion must be served and supported with lies and deception?

Worse. It is actually contradicted by known population levels and other evidence.A chain is as strong as it's weakest link, and a population can only grow to the limits of it's least available food\nutrient supply. Once the grass is gone the cows die.Enjoy.

Probably not a function of the population size because that would not take into account external factors that do not vary with population size. For example, if the population size ever declines, then that would mean that we have two different values for growth rate for the same population. Having two different values for the same population is not a functional mapping.Let's call it a function of time or a function of multiple variables one of which may o be the population size.If the variable were population size alone, it should be possible to use a different model in which that variable is removed. Of course the model would then not resemble an exponential at all.

First off, let's be honest and start off with proper representation of the quoted material. Should have been edited to indicate the superscript used in the article quoted by using ^and codes as follows (use peek function to see): OR by using the ^ to indicate superscript as in N = ne^rt as quoted from dwise1.Second you have to admit that you are definitely wrong here: Curiously, the curve formulas you reference are exactly the same type of curve that dwise1 was criticizing you for using -- or are you quibbling over calling it "pure-birth" vs "continuous-growth"?Let me help you with that: Are you kidding? Are you really that clueless? Don't you know what that equation is? It is the continuous-growth model. The one that doesn't work because it doesn't take the environment's carrying capacity into account.Is that better? Clear now? Capisce?Put bacteria in a petri dish on a consumable substrate and what happens?Put the same bacteria in a completely sterile petri dish and what happens?What happens to the first dish when the consumable substrate is gone\eaten\used?Do you get the same results? Do you get unlimited continuous growth? No? Then the N = ne^rt model is insufficient to account for the differences.EnjoyEdited by RAZD, : capisce not capiche

And after the first generation the numbers are different, so -- according to you and your way of approaching this -- you would need to calculate a new r for that generation ...... and the next generation ... etc etc etc :: each generation would have a different r value by your calculations.Curiously if you plot that r value against generations you will see that it declines ... in an exponential decay curve. But not exponential math apparently.Enjoy.

You can't even read, can you? Do you understand anything of what you quote? Do you even know what point you are trying to make? Are you really that clueless?You are beginning to remind me of a dumb kid who once came here to get us to join his new forum at http://creationvsevolution.freeforums.org/index.php. He had apparently recently started reading "creation science" and had gotten it into his head to use those "great new discoveries" to destroy evolution. What and others in his situation didn't know is that those "new discoveries" were just decades-old bogus creationist claims that had been soundly refuted almost immediately (hence decades before the neophyte had even been born), but the fact that they are completely false and deceptive doesn't stop creationists from lying and continuing to present them to each new generation. This kid had no clue what he was talking about, so he would plagiarize from creationist sites, simply posting their exact words as if they were his own. After he finally melted down (as admin, he started deleting messages and then lied about it -- since when did lying become a Christian virtue?; it wasn't that way half a century ago when I left Christianity) and abandoned his forum, Japanese kids have moved in and taken it over.But the funny part that resembles you was when he tried to use the bogus "leap second" claim that was created around 1979 and soundly refuted in 1982, yet is still Kent Hovind's favorite and continues to be posted all over the Web (like I said, they're lying their asses off). I kept presenting the actual facts about leap seconds and the actual rate at which the earth's rotation is slowing down, working him into a corner. I demanded that he explain part of his position and he responded by quoting a source that he thought supported his claim. Instead, he had quoted that classic 1982 article that soundly refuted the claim! The poor fool could not understand his sources! He had no idea what he was talking about!And apparently neither do you. Or at least you have offered no evidence that you do. Oh yes, I did go to high school. Even graduated. Did you?I went on to college, earning five degrees (two associates (AA Liberal Arts and AS Computer Technology) and 3 bachelors (BA German, BS Computer Science, and BA Applied Math) and did some post-graduate work, plus returned for several semesters of night classes to keep up with the ever-changing computer technology, ending up having earned more than 300 semester units. In my placement exams, I scored so high on math that I wasn't required to take any and, since I started out as a foreign language student, I didn't at first. Then at work I encountered a situation where I wanted to calculate the dimensions of a triangle based on an angle, so I taught myself trigonometry (it's really quite simple). When I started working on CS, I also took all three semesters of calculus -- actually, because I had just missed the deadline to enroll when I first arrived in the are, I took Calculus 1 as a correspondence course, meaning that I also taught myself first-semester Calculus.So, did you take any math? Or are you like Kent Hovind who would constantly brag about being such an expert on math and science, despite that fact that he had studied science for only maybe two semesters in a junior college? According to my source (which I gave in my bibliography: Michael Olnick, An Introduction to Mathematical Models in the Social and Life Sciences, 1978, Addison-Wesley Publishing Co. -- or have you never followed my link, choosing instead to keep yourself ignorant, which is the common goal of creationists?), you are dead wrong. You need to do some research yourself.Olnick's third chapter, "Ecological Models: Single Species", starts his discussion of "The Pure Birth Process" on page 54. Of course, since he uses calculus it will doubtless go right over your head, but he does end up with this equation:

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P = P₀e^at

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If you do not understand how I was able to display the equation like that, then use Peek Mode to see the HTML tags that I used. Like trig and calculus, it's really quite simple.You will also notice that that is your continuous-growth equation. The Pure Birth Process (AKA "Pure Birth Model") uses a continuous-growth equation. And your linked-to source says nothing to contradict that -- actually, it doesn't say anything about it, so why did you link to it?That's right! You don't know anything about math, do you? So you had to Google for information on exponential functions. Then what? You projected your own ignorance about basic math onto me? Really, not everybody is as ignorant as you are about math.I will also refer you to a Wikipedia source that should be easier for you to access than Olnick's book, which I would assume is no longer in print. Of course, that doesn't mean that you would be able to understand what the Wikipedia article says, considering your demonstrated inability to understand your own sources: Biological exponential growth. It gives the formula as a derivative:

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If, in a hypothetical population of size N, the birth rates (per capita) are represented as b and death rates (per capita) as d, then the increase or decrease in N during a time period t will be:

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dN/dt=(b−d)N

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(b-d) is called the 'intrinsic rate of natural increase' and is a very important parameter chosen for assessing the impacts of any biotic or abiotic factor on population growth.

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Despite different variable names, that is the same equation that Olnick develops. When you integrate it and clean it up a bit, then it becomes the familiar:p(t) Ne^(b-d)twhere p(t) is the function of population size with respect to time,
and your r = (b-d)But what you should note about that article is where it states several times (my emphasis added):

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When the resources availability is unlimited in the habitat, the population of an organism living in the habitat grows in an exponential or geometric fashion.

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Resource availability is obviously essential for the unimpeded growth of a population. Ideally, when resources in the habitat are unlimited, each species has the ability to realise fully its innate potential to grow in number, as Charles Darwin observed while developing his theory of natural selection.

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Any species growing exponentially under unlimited resource conditions can reach enormous population densities in a short time. Darwin showed how even a slow growing animal like the elephant could reach an enormous population if there were unlimited resources for its growth in its habitat.

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So the point, which you keep ignoring, is that your pure-birth formula is only of any use when the resources available to the population are unlimited. When that situation does not exist, as during virtually all of human pre-history, then your formula simply does not apply.

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Now, if you had actually learned any math, then you would know that a value which is dependent on another value is not handled by a constant, but rather by a function. A pure-birth/death model uses a constant rate, whereas a logistic model uses a rate which is a function of the conditions, primarily of the population size.

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Actually the function for (N resulting population) is the constant-growth eqation. I used (r) as a local constant. Again you only persist in obscuration.Referring back to the paper you cited, the deterministic and stochastic models for population growth do not further your arguments.Since I am not being either precise or exhaustive about human growth rates, but only outline a general truth, your objections are only a side show.Look at my illustration:Effective zero population growth in humans from a initial population of 10,000 over 50,000 years is a fairytale. It is a whole cloth fabrication and defies logic.Your illustration the bunny concerning human population since a flood, although creative, fails to supersede the bottleneck as being the more ridiculous.You construct a straw-man argument and battle me over minutia.

The first thing I did when I created my first web site was to post my old entries to the Science & Religion Library on CompuServe circa 1990. Rather then go through and re-edit all of them, I posted them as-is. We had no access to fancy formatting tools at that time on CompuServe, so everything had to be in ASCII.Even though the ^ is a popular way to indicate an exponent, it causes confusion on a C Programming Forum I contribute to, since C has no exponentiation operator and ^ is actually the exclusive-OR operator. We've actually had beginners post about the unexpected results they got when they tried to raise a value to a power by using ^ . Sorry, but since I've been learning Italian ..."ch" represents the hard "k" sound, just as "gh" represents the hard "g" sound. When followed by a front vowel (ie, an "i" or an "e"), the "c" takes on the sound like the English "ch" as in "church". Similarly, "sci" represents something like the English word "she", whereas "sco" as in "scola" would be like the "sch" in "school", which is what "scola" means. We have the same thing in English, only we lack the special spellings to help us spot the exceptions (eg, "gent" v. "get"; no hint, you just gotta know).So, the 2nd person singular familiar form of "capire" is "capisci" and the polite form is "capisce", which is the same as the 3rd person singular.Just FYI.

P.S. Try to shorten your novel like responses so I do not have to spend all day parsing the Bull