Thanks Bex,
Evolution, (the word) can be used easily to describe an observable fact - variation, which we all acknowledge. Or "micro evolution" as is sometimes used. It's observable and always has been observable. But to use this term, and then extend it out of the realms of what has been observed now or anytime in history is, once again, to my mind very deceptive and that is the key here. As though time itself, environmental conditions, mixing of genetics, has the magic to allow small changes to become significant, over time, so much so, that one animal could in fact, become something else. According to evolution.
Of course. That is where the theory comes in - the tentative application of known process to past events to see if they can be explained by those processes.
This is one of the problems I have with the term "evolution" -- it means too many things. In biology it means a process, a theory and a whole scientific field. Outside biology it has several additional meanings that further confuse the issue. That is why I like to distinguish them:
Evolution (the process) is the change in hereditary traits in populations from generation to generation (you can also call this descent with modification, to use Darwin's 'naturalist' formulation, or the change in the frequency of alleles in populations over time, to use the 'genetic' formulation).
Evolution (the theory) is that the process of evolution is sufficient to explain the diversity of life as we know it, from the world around us, from history, from the natural history of fossils and geology, and from the genetic record of heredity carried by DNA. This is testable: we can observe rates of evolution that occur today, and apply those to any set of fossils or skeletal remains to see how much change would be required to get from {A} to {B} with those rates, and we can compare the geological times to see if this means it was possible. For instance we can take current examples of life, a fish and an bird, and test if one could have evolved into the other in say a 5 thousand years. If we do this with known rates of evolution the answer is likely to be no. We can compare a wolf and a dog and ask the same question and the answer is likely to be yes.
Evolution (the science) is the process of applying the theory to the evidence and testing it to see if it is valid. Lab experiments, field experiments, surveys to uncover more information, data, on the current diversity of life, are all parts of the science of evolution. Developing theories for various mechanism by which the process of evolution occur, and basing theories on those mechanisms, such as punctuated equilibrium, is also part of the science of evolution.
There seems to be a barrier, no matter how much variety you get within a kind, no matter how much interventive breeding, we do not seem to be able to break that barrier. You cannot breed an animal out of its own kind. Nobody disputes the incredible potential for such variety contained within all creatures genetics, but when it gets out of the realm of observation and into the realm of imaginationary scenarios is where I find it becomes deceptive.
Ask yourself this: do you think it is possible to breed offspring that are not descended from their parents? I honestly do not know of any evolutionists that think so, and what this means to me is that this concept of descendents being able to "break that barrier" is a bad concept, and the real question is whether there is any barrier between existing species and what they may otherwise become in the future. I would also say that so far, the genetic evidence is that there is no section of DNA that is immune to mutation, and that this is the only way I can conceive of such a barrier existing. This may be my own limitation of imagination, however, and I am willing to be shown wrong on it.
See, here we have an example of indoctrination once again. Assuming evolution took place is what you are doing. Then asking whether the changes were dramatic, as though it took place and it's a fact. Not allowing for anybody to consider anything else. You would need to prove this took place. Then provide pictures to the contrary showing it has. Proof of the fossils and fossil record? Start producing it on here. I've already been through the dinosaur to bird theory and you guys still cannot get past the fact you haven't been able to prove skin/scales turn into feathers, let alone a dinosaur itself could become a bird. Wow, it seems that one can repeat themselves and given pictures on here incessantly and then they bring it up again as though it never happened.
Not at all, what I am doing is suggesting that we can look at the fossil record and see the degree of variation, adaptation and hereditary changes that occurs over time in the fossil/geological/physics time frame, and compare that to the evidence we have of evolution today.
And no, I do not need to "prove" that this actually happened, all that I need to do is show that it is possible, given known rates of evolution and known periods of time for the evolution as we know it (whether you call it microevolution or not) to explain the evidence in the fossil record, as what this proves is that the claim that evolution cannot account for it is false.
For instance we can take a known amount of variation within species as a measure of what is possible for variation within a speces. The variation in dogs from wolves is a good example of the amount of variation that can occur within a species. We can envisage this as a "cloud" around the basal form of the wolf, and say that anyting within that "cloud" is a possible variation based on known evolution of dogs from wolves. We can apply that "cloud" to other fossils, say of eohippus, to test horse evolution, and see if the different fossils fall within than cloud around eohippus. We can eliminate many contemporary (time and location) fossils, such as bears and sloths, but we can also see that mesohippus falls inside that cloud. With this approach we can (tentatively) conclude (but not prove) that it is possible that eohippus and mesohippus are related. More importantly, we
cannot eliminate the possibility that they are related. Science works by eliminating false concepts, not by proving theories.
Now it is perfectly possible that you may want to suggest an alternative theory that we can test at the same time. For instance we can hypothesis that all animals stay in strict kinds, that they are all descended from "original kinds" by microevolution, and that there is some kind of barrier between different kinds that prevents one evolving into a another kind, and we can test that against the evidence. Such testing of this theory of common descent from "original kinds" would then allow us to see if we can determine what those actual original kinds were. Do you see any problem with this application of these theories to the evidence?
If this theory of (micro)evolution and this theory of common descent (in kinds) are both true then they can be tested by the objective reality of evidence.
Please RAZD, produce proof that this process took place. Show me where in the fossils and the fossil record it shows dinosaurs becoming birds. Scaled skin turning into feathers. Front legs becoming wings.
Science does not prove theory, it eliminates invalid concepts. Thus if we could show that dinosaurs
could not possibly evolve into birds, then we would have to conclude that this did not happen. The problem is that there is a clear pattern of possible evolution in the fossil record, and it grows more complete every year. We have dinosaurs with bird bones (hollow) and bird lungs (using hollow bones as part of their breathing process), that exist before acheopterix and other feathered fossils. We have fossils of dinsaurs with non-flight feathers that are between those dinosaurs and archy in time and space, we have early feathered dinosaurs that may have glided or flown, with feathers on all four limbs, and with feathers that are symetrical (have not developed into flight feathers of today with narrow leading edges). We have archy with mixed dinosaur and bird traits.
More importantly, we
cannot eliminate the possibility that they are related and one has descended (with modification) from the other.
You compare a mature oak tree with it's beginning as an acorn, to a dinosaur becoming a bird......do you know RAZD that the only changes to an acorn is growth? Are you aware of the differences between a dinosaur and a bird? We're not talking about an egg becoming a bird (growing) we are talking here about another animal becoming a totally different kind of animal. Please, please stop insulting our intelligence. It's as ridiculous as comparing grass seed becoming grass and thinking gosh this proves evolution. See what I mean by the evolutionist trying to match growth from its early stages and then claiming that as proof that one kind of animal can become another?
The only difference is growth. Both start from single cells, with DNA that is formed of exactly the same amino acids, with cellular structure that is identical, the only difference is the arrangement of those amino acids, and we know that mutations rearrange the structures of DNA in every organism in every generation today, and you claim that this is greater than the difference between an acorn and a full grown oak tree? Do you know - precisely and in detail - what the difference is between a bird zygote and a dinosaur zygote? Can you tell one from the other? If you looked at the cells from different animals could you tell which ones were which?
Think about the genetic impossibility of dinosaur to bird, as though this can be compared with "growth". Wow, I'd imagine that the oak tree, given enough time, could probably become an arm chair too, given no outside creative intelligence. That's actually more feasible than dinosaur to bird! At least it's made of the same stuff! If you want a more accurate comparison, try something more outrageous. Though given enough time and the right environment, throw in some imagination and you could come up with anything. Oh and an oak tree and acorn don't require a missing link Just plant the acorn and water the soil and wait for it to grow. There's plenty of existing examples too and hey you can re-produce this experiment yourself! No real mystery RAZD.
And yet the argument from incredulity has had an absolutely abysmal record of restricting what can and cannot occur in nature. Nor has a straw man ever proven a logical argument to be true (the armchair is not a living organism).
Can you demonstrate that there is a "genetic impossibility"? or is this just wishful thinking.
Enjoy.
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Note: my time is limited, so I only choose threads of particular interest to me and I cannot guarantee a reply to all responses (particularly if they do not discuss the issue/s),
and I expect other people to do the same. Thank you for your consideration.[/color]
