scientific theories taught as factual

Nator's analogy in effect states that one can change any nucleotide sequence into any other nucleotide sequence by just one tiny point mutation at a time. A more than sufficient set of point mutation types would be:

• Add one nucleotide.
• Subtract one nucleotide.
• Change one nucleotide to another.

The question for you is, once some number of point mutations have occurred, what prevents further point mutations? Or what prevents certain types of point mutations that might cause a species to cross the "kind" boundary?The answer is that there is nothing to prevent such changes. Your "walking to the moon" analogy has no correspondence to observed reality.Of course, Nator's analogy was intended only to make this simple point, not to serve as an analogy for all types of mutations. There are a large number of mutation types, some of them much more substantial than a single point mutation, so in reality the genome can change substantially in a single generation. Perhaps the most dramatic example is polyploidy in plants, where the entire chromosome set can become duplicated in a single generation.So not only can genomic change proceed in tiny point mutation steps analogous to walking, it can also change in larger steps perhaps analogous to crossing a river, lake or canyon. Naturally the accompanying morphological change has to be within the limits required for survival and reproduction (it does no good to evolve from animal A to animal B if there are no other animal B's to mate with, so all morphological/genetic change has to be within certain limits for sexual species, which may explain why polyploidy isn't observed in animals).--Percy

A species is not a race. A race is a subpopulation of a single species. Phylon is the wrong word. You were using the word Phyla before. Phyla is the plural of both phylon and phylum. For the context of this discussion you want the word phylum, which has this definition at Answers.com:

1. Biology. A primary division of a kingdom, as of the animal kingdom, ranking next above a class in size.

In other words, it has a very clear and specific definition, and it fits into the classification system of life like this:

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

As you can see, phylum is an extremely broad classification level, just under kingdom. The Chordates (mostly vertebrates) are an example of a phylum, and they include animals from people to sea squirts.So you were wrong to equate phyla with species (back in Message 23 you said "phyla (species, or group of animals)"). And you were also wrong to claim that phyla popped into existence in geologically short time periodsIf you want to instead claim that new species can evolve in geologically short time periods, I think this is something everyone here could agree with.--PercyEdited by Percy, : Fix grammatical ambiguity in first para.

Nice job of explaining things in your last three posts. Jrtjr1 has so many misunderstandings about evolution that one almost doesn't know where to begin, but you seem to have figured it out.--Percy

I think you've again misunderstood what Dr Adequate is saying. Transitional forms are always fully formed.So when you say, "“”fully formed’ creatures, by definition, are not transitional forms," you're dead wrong. Any argument that begins with this incorrect premise will also be wrong.You mentioned gills and lungs. The specifics of what we think we know about lung evolution is a bit involved, but lungs did not evolve from gills. Lungs evolved one tiny step at time, each creature in the chain being both fully formed in that it was properly adapted to its environment because it was capable of surviving and reproducing, and transitional between forms that came before it and forms that came after.All species are transitional because reproduction is never perfect, so offspring are always different from parents, and change is cumulative.And all species are always fully formed because they are adapted to survive and reproduce in their environment. Those that are insufficiently adapted do not survive to reproduce, and when this happens to an entire species it is an extinction event.Relevant criticism requires accurate information. It makes no sense to criticize evolution for believing that transitional forms are not fully formed, because this isn't something that evolution believes. Or has ever believed. Evolution does not believe there has ever been a species of less than fully-formed creatures. Though I can't be sure, I think the origin of the term "fully-formed" is a creationist one, as the requirement that all organisms always be fully formed is so obvious to anyone who understands evolution as to never require expression.--Percy

Hopefully all will say this. All life is transitional, no matter what situation you consider, because reproduction is almost always imperfect. If the endpoints are your maternal grandfather at one end and you at the other, then your mother is a transitional between your maternal grandfather and you. If the endpoints are Cro-Magnon man and you, then all direct ancestors between you and Cro-Magnon man are transitional. Transmutation is not a biological term. There is never any step in the process of descent where the offspring is suddenly a different species. Generally, offspring are as closely related to their parents as you are to yours. It is only the sum of many steps of descent that produces new species, and the differences are only apparent if you compare organisms that are many, many steps apart.Speciation is one of those processes that happens very, very gradually. When do the foothills become mountains? Where does the harbor become ocean? When does the boy become a man? Where does the north become the south? These are all examples of gradual transitions. At some point we realize that there has been sufficient change, and then we say, "We're in mountain country now," or "We're in the open ocean now," or "I'm a man now."--Percy

Okay, so start with chihuahuas and produce great danes. Now you've got a pair of great danes. What's to prevent their future generations from producing yet further change? Ringo's question is asking you to consider what barriers exist to change?Addressing your next message, too, Message 115: Again, transmutation is not a biological term. If you reread Ringo's message, he's just trying to accommodate your desire to use this term, but he made very clear from context that he considers the change from parent to child to be a transmutation, not because the child is no longer a human being, but because the child is not identical to the parent.And answering your next message, too, Message 118: That every generation is different from the previous generation is just a simple observation, and the generational change is always occurring. Because reproduction is imperfect there is no way to stop it from happening.--Percy

The Cambrian Explosion is a totally different subject. You requested an explanation of what was meant by transitional. Are you just yanking my chain?--Percy

Inheritance of eye color is unrelated to imperfect reproduction, i.e., mutations. Like a copy machine set to the task of making copies of copies, the copies are never perfect, and you eventually get unintelligible copies. The imperfections accumulate. That's why genetic change in all species is inevitable, and why all species are in a state of transition.The difference between evolution and a copy machine is that evolution includes selection so that the lucky "imperfections" spread throughout the population. No, variation is not a transition. Variation is just the variety of different traits possessed by a population. Selection operates upon variation, making it more likely that those with favorable traits will reproduce.--Percy

This is easier to explain if we have the full exchange between you and Ned: So you thought that Chen believes the new body plans of the Cambrian appeared suddenly, and Ned was trying to tell you you're wrong. And you are wrong. Chen is not advocating a sudden appearance of new body plans, and your article clearly says he isn't further on: Two or three million years is not sudden, though it is certainly a much shorter period than the more widely accepted view of around 20 million years.Your Globe article appeared in May of 2000, and it doesn't appear that Chen's ideas have found much acceptance in the time since then.--Percy

Let me make it even simpler: If you have a son, he's transitional. More accurately, assuming he eventually has children of his own, he's transitional between you and your grandchildren.Given perfect reproduction, then your son would only possess exact copies of gene alleles from you and your wife. But reproduction is not perfect, and so some of those gene alleles will contain copying errors and hence no longer exactly match any gene allele that you or your wife possess.These copying errors, mutations, accumulate over time, and that is why it is impossible for any species to remain static, no matter how stable their environment. This is called genetic drift.Interestingly, recently discovered genetic evidence indicates that the human race is evolving more rapidly during the past few thousand years than at any time previous. This is an unexpected finding, since there is thought to be an inverse relationship between population size and the rate of evolutionary change. Given the huge size of the world's population, the expectation would be that the recent rate of evolutionary change would be extremely slow.The speculation is that this is because we originally evolved as hunter/gatherers, and that the more sedentary contemporary lifestyles exert tremendous selection pressures.--Percy

It *was* sudden. The Cambrian Explosion is actually thought to have taken at least 20 million years, and evolutionists consider even that to be sudden. The suddenness is what caused the coining of the term "Cambrian Explosion".But what you said back in Message 138 was this: It can be seen that you were arguing against the possibility of gradual transition through tiny evolutionary steps, instead asserting that it happened suddenly. We agree about the word "suddenly", but because "suddenly" in this context means at least two to three million years, and more likely at least 20 million years, there was plenty of time for huge, tremendous numbers of tiny transitional steps.--Percy

To those who know who they are,We don't really need the content-free posts, there's plenty of substance that's been posted to respond to.--Percy

There are two primary possibilities for why life was single-celled for most of the history of life on this planet:

1. For a long time conditions were not favorable for multicellular life, so single-celled life outcompeted any incipient evolutionary forays into multi-cellular life.
   ​
2. Evolution of traits favorable to the teaming up of individual cells was the long and difficult part of the evolutionary history of life. Once multicellular life finally emerged it exploded into a wide variety of life forms and body plans because of their ability take advantage of huge numbers of previously unexploited ecological niches.

Moving on: As someone already explained, the percentages aren't additive. If someone told you about a South Pacific island where 50% of the population was wiped out by an epidemic once every century, you wouldn't then conclude that over the past 10 centuries 500% of the population had been lost, right? That's just not the way percentages work in this context, plus you seem to be forgetting or ignoring that families and genera, just like populations, are constantly replenished with the passage of time.You claimed to be approaching this with an open mind, and maybe you even believe that, but your inherent resistance to the idea of evolution is causing your mind to make ridiculous logical and math errors in order to avoid the conclusions you feel uncomfortable with.--Percy

This is irrelevant to the major point, but I'll correct this anyway. Being anywhere on the food chain except at the very top provides no advantage. To say a creature is at the top of the food chain means that it is not prey for any predator. Carnivores are typically at the top of most food chains. Being anywhere other than at the top of the food chain means being prey for something. Speculation about the passenger pigeon seems to be that it was prey for human beings (in which case what happened to all the pigeon recipes, but that's a different matter). There was unlikely to have ever been a time in the passenger pigeon's evolutionary history when their population was reduced to a single pair. Species are not produced suddenly but gradually in small transitional steps, so there was never any "first passenger pigeon pair," no Adam and Eve of passenger pigeons. Populations of evolutionary ancestors of passenger pigeons experienced slow and gradual evolutionary change until they finally evolved into the modern but unfortunately now extinct form. For the umpteenth gazillionth time, what you think evolution is isn't being taught, except by creationists at their websites and in their books and lectures. New species do not begin with a single pair. Species evolve as populations. For sexual species, the genetic diversity of a single pair is likely far too low for the species to be viable, inbreeding being only one of the problems.Evolutionary theory has been scientifically developed and elaborated based upon ever increasing mountains of evidence, but it isn't complete or perfect, and we're not trying to claim that it is. But the criticism's you're making are not about anything that evolution actually says. Where we could be having a discussion about evolutionary theory, we're instead engaged in a series of corrections to your misconceptions.--Percy

You're not thinking this through, not even a little. Once again your resistance to evolution is leading your thinking down irrational pathways. You haven't bothered acknowledging any of the explanations of your many errors in this thread, so I'm not even going to bother explaining the problems with yet another one.When evolution is shown wrong it will be by people who understand what it actually says, and most certainly by people who can say things that are actually true and draw conclusions that actually make sense. Criticizing evolution for things it doesn't say with logic that makes no sense and evidence that isn't true is a pointless exercise.--Percy