ERV's: Evidence of Common Ancestory

Dr. Adequate was not referring to any a priori recognition by species of the inadequacy of the food supply, though humans certainly have more potential for making such estimates than other creatures.While you're correct to note that humans exercise a great degree of control over their own food supply, ultimately Dr. Adequate was just making a simple and straightforward reference to Malthus, who introduced the principle that populations cannot expand beyond the ability of their environment to sustain them. Correspondingly, of course, during periods of unfavorable environmental change (drought, flood, disease, etc.) populations will decline, as has been our consistent experience.--Percy

There was no claim that food was lacking. There was just a statement of the Malthusian principle stated in terms of the primary constraint, which is food, but Malthus more generally stated his principle in terms of available resources. Your point is that the population size of ancient man would not be subject to Malthusian limits in terms of food, but the limit is not an on/off type of thing. It's a continuum. The more closely limits are approached the more severely the effects are felt, so ancient man was most certainly subject to Malthusian constraints.You provided the example of ancient man being able to go wherever he liked in pursuit of food, and while this isn't a complete picture given the constraints of geography, climate and potentially hostile other groups of ancient men, it was certainly much more true in ancient times than it is today, but one of the motivating factors for ancient man to change location is due to reaching Malthusian limits in his current one.--Percy

I had the same reaction. I wonder if anyone remembers the I, Mudd episode of the original Star Trek, where they overcome the androids by presenting them logical contradictions that cause computational lock up. Attempts at rational analysis of Pcver's post might present the same dangers. He's impervious to both data and logic because he rejects one and is a stranger to the other. I haven't a clue how to respond.--Percy

Guessing you meant to say "while the *animal* is alive?" Or "while the *individual* is alive?"--Percy

It is true that evolution cannot be scientifically proven. That's because nothing in science can ever be proven, not relativity, not quantum theory, not the Big Bang, not evolution, not anything. This is because of the scientific principle of tentativity. The nature of science isn't the topic of this thread, so I'll stop there.I think when you say that evolution cannot be observed that you must have intended to qualify that. I think you must mean that significant evolutionary change requires long time periods, and that such significant change hasn't been observed, and in this you would be correct. For example, we could never observe something along the lines of the evolution of the horse because it took millions of years. But though we haven't observed mountains being eroded away to form flat plains, either, we know that they do because of geological evidence, and we can observe modern mountains being eroded away at the rate of a few inches per year. Like the erosion of mountains, evolution typically proceeds at a snail's pace, and we can observe first hand small amounts of evolution. Are you descended from your parents? And are you identical to your parents, or are there differences? The obvious answers are that you *are* descended from you parents, and that you *are* different from them. So how about that, you're a perfect example of descent with modification! Of course, the other part of evolution is selection, particularly mate selection, and good luck with that! I prefer a minimalist approach myself, but it must be sufficient for the job. You can't pour a gallon of water into a juice glass, and you can't argue against a minimalist definition of evolution that is wrong. Simplification, keeping things straightforward, they're admirable goals, but not if they make you wrong. This is a great example of simplification leading you astray. You're operating under the assumption that creatures that look almost exactly alike except for color must be the same species, but that's a very superficial approach, and it's caused you to be wrong, as Coragyps explained when he replied to the same passage.Getting onto topic, I'm not sure why some are claiming that ERVs only provide evidence of evolution, but that they aren't themselves a cause of evolution. ERV's are involved in a whole range of possibilities, from no evolutionary impact whatsoever to a dramatic evolutionary impact. One example of such a dramatic impact comes from the Wikipedia article on ERVs, which mentions immune system suppression in the fetuses of many modern mammals. Well, now you're just being silly. You may just as well deny gravity happens. Even creationists require that evolution happens, very rapid evolution in fact. They invoke rapid evolution because it is necessary to produce all the millions of modern species from the small number of kinds represented on the ark. It's contradictory to insist on common ancestry while rejecting evolution. Almost no reproductive event is without error, so descent almost always occurs along with modification. Add selection to descent with modification and voil, evolution! Evolution of new species has been observed. The problem for you is figuring out what, given the imperfect reproduction that renders change over time inevitable, could ever stop evolution? Well, I'll say this for you, you certainly don't shy away from making mistakes. You jump right in!Almost every reproductive event results in mutations. It is very rare when this is not the case. Evolution is a process of change over time, and imperfect reproduction guarantees that there must be change over time. You can only avoid change by avoiding mutations, and that's impossible.If I could make a suggestion, not just to you but to everyone, calling people liars (or any other derogatory term) is actually a barrier to communication, plus it's against the Forum Guidelines, so let's not do it anymore. Okay? I'm sure everyone on both sides of the discussion sincerely believes what they are saying. And if they don't then let the moderators handle it.--PercyEdited by Percy, : Grammar.Edited by Percy, : Grammar.

I used the example of the erosion of mountains precisely because erosion rates and mutation rates are both, to use your words, "a constant and consistent process." It's as easy to look up the mutation rates of different species as it is the erosion rates of different mountain ranges. Mutation rates are sufficiently dependable that they can be used to form rough estimates of the amount of time that has passed since the divergence of two different species, a method known as the molecular clock. You mentioned God so often in your message that I had to check to make sure this thread is actually in one of the science forums. I think you need to make certain that you're doing science where what you accept as real corresponds to the evidence from reality, as opposed to religion where what you accept corresponds to your interpretation of revelation. Your message was pretty heavy on declarations of "I believe this" and "I believe that," but pretty short on any evidence-based rationale.I thought you did a really nice job with your Goliath example. You used it to conclude that mutations could not cause change beyond a species boundary, but you never defined what would constitute sufficient change to create a new species. Is Goliath a sexual species? If so, then since sexual species are usually distinguished from one another by reproductive boundaries, you need to define the reproductive algorithm rather than the meal-time algorithm.If Goliath is not a sexual species then that's a problem, because categorizing non-sexual life into species groups is fraught with difficulties. So I hope Goliath is a sexual species, and if you're interested you might try coming up with a reproductive algorithm that we could examine.--Percy

Reproductive boundaries differentiate sexual species. So if white and black Goliaths will not breed with one another, then they are not the same species. Mate selection is one form of reproductive boundary.But for the sake of this discussion I can tell you would prefer to only consider organisms that are mutually interfertile to be the same species, whether or not they actually interbreed in reality, and that is fine, we can do it that way.So you need to define a reproductive algorithm, just like you did for meal-time. Then we can examine whether the process of mutation and selection is sufficient to cause speciation.Your reaction to the creationist passage about speciation was this: The creationist passage did not say speciation doesn't happen. It did not say, to use your words, "a new species is never created." It said the exact opposite. It stated that new species are created, that it only happens within kinds, but it happens. You've misinterpreted the passage when you conclude "I can safely claim 'speciation' never happened."You also say that speciation has not been observed, and this is also untrue, and is partly the reason creationists have been forced to concede that speciation does happen. If you look at the Wikipedia article on Speciation you'll find many examples of observed speciation.--Percy