Posted on 07/24/2003 1:55:39 PM PDT by Mr.Atos
We most certainly observe gene duplications followed by separate evolution of the duplicated genes. That is clearly an example of evolution of greater complexity.
Dark_Lord asked what would refute common descent, and I replied with several examples - one of which was that the genetic code would differ between organisms. Agree?
but the archea have some codes which do not read the same as with the rest of living things.
THese guys are interesting, and there are others that use "weird" amino acids. But they still for the most part use the same code.
Not correct. While we do observe mutations, we do not observe mutations which are either favorable
I suggest you start with reading about how antibodies work.
For the most part does not quite cut it though. To read the genome incorrectly would mean death of the species. This is the problem for evolutionists - any change which would result in death has to occur instantanoeusly. That would be a miracle. Also it is against gradual evolution.
Not correct. While we do observe mutations, we do not observe mutations which are either favorable-me-
I suggest you start with reading about how antibodies work.
I am quite aware of how antibodies work. They were specifically designed to be different. The system is specifically different than other human systems. This is not mutation, but a specific system to achieve different antibodies to fight disease. The proof is that the successful one, is multiplied many times to fight the current disease and the 'model' for it remains in the system for future use. That is why vaccination works. There is nothing stochastic or random about it.
No, I meant they use the same code as all other life with the exception of one or two codons.
I am quite aware of how antibodies work.....There is nothing stochastic or random about it.
Ahh but there is. Mutations have been observed to occur in the antibody genes after an infection. Some mutations lead to better antibodies.
No, I meant they use the same code as all other life with the exception of one or two codons.
I completely understood your statement and I am aware that it is not too many codons. However that is enough to make some proteins totally unusable which are made with that code if they are read differently. So that is why it would be impossible to do a "chage over". You would have to rewrite the whole genetic code of the organism to accomplish it and of course that could not be done by mere chance. It would have to be done by design.
Ahh but there is. Mutations have been observed to occur in the antibody genes after an infection. Some mutations lead to better antibodies.
That is what I was addressing. Here is more of an explanation:
3. Antibody Production. The stimulated B cell undergoes repeated cell divisions, enlargement and differentiation to form a clone of antibody secreting plasma cells. Hence. through specific antigen recognition of the invader, clonal expansion and B cell differentiation you acquire an effective number of plasma cells all secreting the same needed antibody. That antibody then binds to the bacteria making them easier to ingest by white cells. Antibody combined with a plasma component called "complement" may also kill the bacteria directly.
Can a chihuahua mate with a wolf? Isn't the disparity in size simply too great?
Forget artificial insemination; if they can't do it without help, they're different species.
To prove it or disprove it, would require complete DNA sequences, or at least lengthy sequences, of both living descendent species as well as the DNA sequences from assumed common ancestor species.
No, all it would require would be finding something that, eg., uses a different genetic code. Or has bones made of cast iron.
Or was an intermediate form between lineages that are not related in that way. For example, something with feathers *identical* (in biochemical detail) to bird feathers, but with the skeletal features of a mammal or amphibian.
Granted, some bizarre finds like these would *probably not* be considered evidence against standard biology, but would probably be taken as evidence that the one creature that seems to violate it is not native to the Earth.
However, if a large percentage of Earth's life were to be like this, it would disprove evolution theory.
Another possible disproof would be if the phylogeny derived from anatomy, biogeography, behavior, etc, (pre-1950s biology) were to differ greatly from that inferred from molecular studies of proteins and dna, or if the biochemical data didn't conform to any sort of tree structure. Of course, in the real world, the biochem data complements and provides supporting detail to the already-known taxonomy.
Now here's one for you: State the atomic theory of matter in a succint, disprovable form.
I won't try that. The "atomic theory" of matter was effectively disproved once they started busting out subatomic particles in the original "atom smashers". And I sure don't remember the original atomic theory since I don't think they have been teaching that since...heck, I don't know. The '40s?
The problem is, the DNA evidence just shows that all life on earth is related. It doesn't require descent from common ancestors. Clearly the concept of intelligent design also fits that bill. And intelligent design doesn't necessarily mean God with a big G. Could be aliens. Or devas. Or angels. Or Chuthulu. Or whatever.
The fundamental issue is that evolutionary theory, as stated (and vigorously challenged in various posts by me), seems to merely hold up in two cases that can be experimentally demonstrated, which are: (a) plants, and (b) within a species, that is, breeds. The evidence for species differentiation appears to be inferred. Having a CS background, I know the jokes and understand the dangers that occur when you attempt to prove your theory and end up saying "now, by induction therefore...".
Joke:
The CS prof says: 1 is prime, and 3 is prime, and 5 is prime, and 7 is prime, therefore by induction all odd integers are prime.
(And the physics prof says: 1 is prime, and 3 is prime, and 5 is prime, and 7 is prime, and 9 is, uh, experimental error, and 11 is prime, and 13 is prime -- therefore all odd integers are prime within the bounds of experimental error.)
So whenever I see the bio types in their experiments say: well, it would take too many generations, and too long, and too much money to actually prove this, so therefore we infer that species differentiation would eventually result, therefore evolutionary theory has been proved, QED...I am not willing to accept their inference as evidence.
Let me give a counter example. Suppose that at some point, some big old alien space ark showed up and dumped a complete ecosystem into Earth's oceans. We have no evidence that such a thing has happened, of course, other than strangenesses like the sudden appearance of shelly invertebrates: trilobites, brachiopods, mollusks, and so on being rather bizarre. But the point is this -- the current evidence of genetic similarity just means that everthing alive today is related. It doesn't mean that it all derived from common ancestors. All life today could have derived from different ancestors that were also related.
To clarify, if you say that since there is a lack of unrelated genetic code, therefore common ancestry - seems a non sequiter to me. I don't think you can prove common ancestry by the absence of a negative.
If your point is merely that the presence of unrelated genetic codes would refute common descent I would agree. But the absence of unrelated genetic codes does nothing to prove common descent.
Sez you. But a chihuahua can mate with a beagle, and their offspring can mate with a cocker spaniel, and their offspring can mate with a german shepard, and that offspring can mate with the wolf. So, no, they aren't different species.
But the dna mutations can be arranged into a tree structure. And when you do so, it's the same tree that was earlier found by biologists.
Clearly the concept of intelligent design also fits that bill
What is not compatible with intelligent design (but is compatible with stupid design) is the existence of shared errors in the dna of related species.
There's no reason to postulate a designer that mimics natural processes.
The evidence for species differentiation appears to be inferred
Inferred from evidence. Like I've argued on other (?) crevo threads, the presence of shared defects in dna can be explained in several ways: it was designed that way, the mutations occured independently in different lineages, or the mutation ocured once and has been inherited in the different lines.
It might (or might not) make sense for a designer to make use of common parts - it doesn't make much sense to me that both chimps and apes (to use my favorite example) should have been 'designed' to be susceptable to scurvy, by using the exact same scurvy mutation.
The notion that the same mutation occured independently is very unlikely, assuming that mutations are more-or-less random. So far, that's what the evidence shows.
So we're left with inheritence. No hypothetical designer, no special mutations. Just plain old heredity. Seems like the most likely inference to me (and almost all biologists and biochemists). Not to mention the fact that it matches an inference made by other, independent, observations. When distinct lines of inquiry lead to the same conclusion, most people consider this evidence that the conclusion is valid.
Yes. Remember this was one of the examples I gave in response to your post#1729:
Regarding the claim that "all life on earth is descended from one (or very few) common ancestor(s)" -- how is that falsifiable?
If life on Earth did not show identical characteristics at the molecular level, it would falsify common descent and therefore fulfill your request.
I was just pointing out how in fact all remarkably similar the DNA is of all life is from bacteria to humans. I never set out to prove common descent, just to show the prodigious amount of evidence for it.
A fine example of a ring species, where the species boundaries are somewhat arbitrary.
If you had a dog-free island with lots of game, and introduced some male wolves and female chihuahuas (or vice versa), 100 years later there would be no dogs.
If instead you introduced both sexes of both animals, 100 years later there would be two true-breeding populations. (unless the wolves managed to hunt to chihuahuas to extinction)
Now imagine the same experiment with horses and donkeys, or quaggas and zebras, or any other combination of equids. In this case it is possible for the different species to mate, (I don't know if they do it in the wild or not), but the offspring are almost always infertile. Again, 100 years later, no equids. Again, if you had both sexes of both species, 100 years later you have distinct true-breeding populations.
Why are the equidae different species, but the chihuahua and wolf aren't? Isn't my experimant a good test of specieshood?
Well the way I see it the two major possibilities are:
1. Common descent from a single ancestor, or
2. The intelligent designer went to quite a bit of trouble to make it look like it.
The relatedness between species extends to arbitrary codon usage for specific amino acids (Is there something special about 'UGG' that is should encode for tryptophan in every organism?), shared errors and other oddities.
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