What I'd like to know is this: The only thing in this universe that is constant is change. Since we are made of the same things as the rest of the universe (atoms/molecules), how can one make the outrageous claim that everything changes but life? DNA is just molecules, we know it changes (mutations) all the time. If DNA is what controls our growth and development and even some behavior, and our DNA can change...doesn't it follow that life changes (evolves)? Given enought time this is obviously what will happen, especially considering that as the environment changes (not just climate, but also what species you comepte or cooperate with, new food sources, diseases, whatever), survival becomes a selction process where only those fit enough to survive will. So, as conditions continue to change, and since DNA changes all the time...doesn't it follow that only the DNA that allows for the forms and functions that can survive in the new and ever changing environment will be the DNA to survive? This is all evolution is. Of course, it is pointless to debate this with a young-earth creationist like campbell. They'll just say there wasn't enough time anyways so it doesn't matter. But not only have they already decided, they also discard so much evidence of an old earth that to debate it with them is an exercise in futility. They have a right to their belief, but that doesn't mean it makes sense to debate it with them, because they're not open to the suggestions and ideas we entertain. But I don't see how anyone who accepts the old age of our earth can not accept evolution. It's totally illogical and inconsistent.
Yes and no. No one, I think, would argue that adaptation does not occur. However, to assume that mere adaptation allows for new genetic information simply is currently unsubstantiated. One of the problems for evolution is the proposal of common ancestry. Just because adaptation happens doesn't imply that new genetic information can be created. Shoot, adaptation decreases the ability of a species to adapt in the future. Let's say that species X is in environment Y and can adapt to environment A,B,and C. If species X is moved or separated and placed in A, B, and/or C, it can adapt. However, by adapting, it, through natural selection, becomes less able to adapt to it's original environment Y, or to the other environments. Change becomes harder and harder. The big issue for me is the mechanisms. There are two major mechanisms behind evolution: 1) Random mutation: Most mutations are neither beneficial nor harmful. Both beneficial and neutral mutations do not tend to perpetuate. The idea that mutuation can be one of the driving elements of change seems nice over a grandiose scale, but on a daily basis mutations are added and removed from any given populace. The odds of a mutation surviving in a population over time (especially in a species that reproduces sexually) is low. In order for a mutation to have a real chance, it would have to be extremely dominant genetically, and/or both parents must develop the mutation (or one very similar) simultaneously. In real life, it just doesn't happen that way. Random mutation might be a part of evolution, but I doubt it is the driving force that many people think that it is. 2) Natural selection: A tautology is an empty or vacuous statement composed of simpler statements in a fashion that makes it logically true whether the simpler statements are factually true or false; for example, the statement Either it will rain tomorrow or it will not rain tomorrow. The idea of natural selection is a tautology. Here is a pretty generic description of natural selection that I have found: An organism may possess some inheritable trait or character which, in a given environment, gives that organism a greater chance of passing on all of its genes to the next generation (compared with those of its fellows which don’t have it). The problem is that, when you boil it down all the way to the core, what you have is this: those who are most likely to survive tend to survive and reproduce. Who survives? Those who are most likely. What is a survivor? One who is likely to survive. In short, survivors tend to survive. What a concept, huh? There are many books written about these two areas and both are recognized as issues that evolution must deal with. One more thing to consider, common ancestry requires that new genetic information be created over time. So far, this has not been documented in the real world. Adaptation uses and expresses genetic traits that were already present in the organism or its parents. Simply because an organism adapts doesn't mean that evolution has occured. There is an intellectual division that must be drawn between the two concepts as they are distinct in form, function, and observability. Not really. I can believe that God took millions of years to form the planet simply because He wanted to. He then populated it with completely formed creatures in a short period. My beliefs are non-contradictory (therefore, they might be non-logical or logical, but not illogical). Nor is it inconsistent as a belief structure. It is completely consistent with itself. Now I am not saying that I believe this, but I wanted to point out that such a belief is *not* totally illogical and inconsistent.
This seems to me to be a point in favor of the creation of new genetic information. If creatures only had a limited amount of adaptability, they would rapidly become extinct. Now, you may argue that we have long lists of extinct creatures - but if evolution does not occur, and species die out because they've used up their adaptability...then where did today's vast variety of life come from?
Not true. Even when species X changes to adapt to it's new environment (we'll keep it simple and say one trait changes, say, long fur), the new trait will follow a bell curve shifted towards the more adapted end, that is, towards having long fur. But it won't be completely all long furred animals in the population, there will always be some with shorter fur. If the climate warms, those on the edge of the bell curve tend to survive better and the bell shifts back. There is always genetic variability in a population, and the variability is fluid. Once it changes, it isn't necessarily stuck there. Well, evolution tends to work faster in small populations (which is what you'll have in a population under stress: a faster dieoff ratio, ending with a smaller population). The fewer the organisms, the better chance for genetic drift, that is, for genes that would normally be wiped out to remain and even take over. And also, some mutations that are neutral are retained (again, in small populations, whether under stress or not), and if an environmental change occurs, they may end up being useful. Or perhaps a prequisite for another mutation to the same gene that will be useful. Keep in mind we don't yet know what all that "junk DNA" is for, it may not be junk at all. Yes, but it's not as stupid a comment as you make it seem. Of course those more likely to survive probably will. It's not like we're just saying "that's just how it is" with no explanation: there is a REASON the survivors tend to survive. They are better adapted to the environment, better fit to survive, and statistically, over time, they will come out on top. To suggest otherwise would be the idiotic statement, that the losers will win...right? Adaptation is microevolution, speciation is macroevolution. They work the same way, via inherited genetic variability. To suggest microevolution occurs but macro doesn't is like saying I can walk to the end of the block but not across the city. It's saying DNA can change, but the change cannot be passed down. We know for a fact DNA can change, look at resistant bacteria, viruses, and insects. And obviously they're passing this genetic information on to offspring. Given the complex nature of evolution (EVERY gene is acted upon all at once in every individual in the population, not just one like my example), I'd say that it's nearly impossible that a species, under a constantly changing environment, would be perfectly equipped with the same DNA for millions, billions, of years. We've had asteroid impacts, ice ages, climates from polar ice to tropical desert to open ocean to rocks 2 miles deep in the crust. Not to mention all the inter-species intereactions: predator/prey, parasites, disease, competitors, cooperation, etc. And all that's going on all at once. Whether god controls evolution or not, I think it's amazing that anyone can claim life is stable in a completely unstable universe. Change is the rule here, and what doesn't change perishes.
