(February 13, 2010 at 11:06 am)Tiberius Wrote: No, you just have a problem with inferring speciation and change on humanity, which unfortunately is how nature works. You just deny reality.

Actually, I think the only thing I have denied here is common descent. Humans clearly change...a huge variety of differences are built into our DNA just like a huge variety of differences are built into the DNA of birds, snakes, dogs, cats, etc. That kind of change is evident in the article provided my Min relative to birds and we can see the same sorts of changes in humans. I do not deny this. I think you should remember though, Adrian, relative to speciation, it is man that decides what is a new species, there is no transcendant objective standard. So just like a scientist could look at the slight differences in those birds and decide they are all different species, a scientist could look at the slight differences in humans and conclude there are different species of humans. As for me, I would just say that there are birds that differ from each other and there are humans that differ from each other.

Still none of these changes (whether or not one calls it speciation or not) necessitate a conclusion of descent of all life from a single common anscestor.

Adrian, I also have a question for you that you probably missed in another thread:

Please provide the evidence that leads you to be able to distinguish between:

1) All life has a single common descendant.

2) Some of life has one common descendant and some of life has a different common descendant.

In other words, a single common descendant compared to two common descendants.

Since you say that the evidence only supports 1) but not 2), I want to know what that evidence is.

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(February 13, 2010 at 10:04 pm)Zen Badger Wrote: I was asking how you arrived at the conclusion that logic etc does not fit into my world view.

I explained that in my post relative to your stated presuppositions (post #99). If you would like to elaborate on how your presuppositions account for logic, mathematics, and morals, I would be interest in reading.

(February 13, 2010 at 10:04 pm)Zen Badger Wrote: So again I ask you, where is your evidence for a young earth?

See post #72 in this thread. I think you just don't like my answer.

The definition of a species is one that can successfully breed with another. That is to say that if one animal can have offspring with another then they will (normally) be classified as the same species.

Now, the term species may well be a human invention but the fact that these differentiations exist in the first place is entirely natural. We simply observe them and give them names. So it is not man who decides what is or is not a new species at all. It is man who observes these clear and natural differences in the animal kingdom and gives them titles. They exist independently of our interpretation.

A conclusion of descent of all life from a single common ancestor is the most rational view as so far we have not come across a single life form that cannot in some way be shown to be biologically related to any other. If, as you seem to be suggesting, there are many groups of organisms on this world that can trace their ancestory back to completely different abiogenesis then we would see this in the biological world as it would be obvious. The simple fact that an oak tree can 'read' the dna of a shrimp must tell us something about the family history of life on Earth.

All living things on this world have their genome either in the form of DNA or RNA. That must have originated from a single common ancestor. If you can provide proof of any organism that does not use this template or suggest how, out of the billions of possible carbon/protein bonds etc. this particular solution was used by totally separate examples of abiogenesis then I'd like to hear it.

So, to summarise, we are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

This is what you said in post #72:

Quote:I will point to the Bible as the main evidence.

And you wonder why no one takes you seriously? An absurd collection of fairy tales in your mind constitutes "evidence." There is a chasm here that cannot be bridged.

(February 14, 2010 at 10:27 am)rjh4 Wrote: I think you should remember though, Adrian, relative to speciation, it is man that decides what is a new species, there is no transcendant objective standard.

Erm...we decide what a new species is based on whether it can reproduce successfully with similar organisms. For instance, donkeys and horses are separate species because although they can produce offspring (mules), those offspring are sterile. We don't have an transcendant objective standard, but that doesn't mean we don't have a very strict standard at all. Technically, no "species" exist...it's just a human way of looking at and identifying different animals. There isn't an objective way of doing this since we made up the idea in the first place.

Quote:So just like a scientist could look at the slight differences in those birds and decide they are all different species, a scientist could look at the slight differences in humans and conclude there are different species of humans.

No they can't. This isn't how scientists do it these days. Classification has moved on since the days of Darwin! Yes, Darwin looked at the finches and thought they were all different species because they looked different, but when he got back from his voyage, a bird expert corrected him and told them that they were all the same type of bird. This was the idea that got him thinking about evolution in the first place. I'm afraid you are very much mistaken if you think that "slight differences" make scientists conclude "different species".

Quote:As for me, I would just say that there are birds that differ from each other and there are humans that differ from each other.

Yes, and yet there are some birds that cannot mate successfully with other birds, and we call these different species. You are making a bad comparison because birds are a single class (Aves) that contain numerous species, whilst humans are a single species (homo sapiens). If you want to compare the two, you'd have to point to a specific species of bird (i.e. Finch) rather than use the entire class.

Quote:Still none of these changes (whether or not one calls it speciation or not) necessitate a conclusion of descent of all life from a single common anscestor.

Of course they don't...nobody is arguing that. How did you get from methods of classification to "common descent"? The two are not directly related at all...

Quote:Please provide the evidence that leads you to be able to distinguish between:

1) All life has a single common descendant.

2) Some of life has one common descendant and some of life has a different common descendant.

In other words, a single common descendant compared to two common descendants.

Since you say that the evidence only supports 1) but not 2), I want to know what that evidence is.

To put it simply, gene sequencing. Our DNA has similarities (i.e. sections that are identical) with all other life on the planet. The theory of common descent would predict that animals that are anatomically similar would have similar DNA, and this prediction holds true across every sequenced genome. We share 95-99% of our DNA with chimpanzees / orangutans, confirming the theory that we have a common ancestor in "recent" history. With other primates, we share less DNA, showing that chimpanzees are (as far as we know) our closest relative. I read somewhere (and I'll try to find the article) that we are more closely related to chimps / orangutans than chimps / orangutans are related to gorillas.

Going back further, we have less in common with rodents, even less in common with retiles, even less with fish, but we do share similar DNA with all life. It is through this methods of comparing DNA that we can draw up the tree of life, comparing every animal with every other animal. If one animal didn't fit, or had differences in its DNA that didn't correspond with its anatomy and where you would predict it to go on the tree, then common descent would be ruined.

This isn't to say that there weren't multiple "first" organisms, but if there were, then from the evidence we have, one of two things must have happened. Either:

1) The other "first" organisms died out, leaving no trace of their existence (and if they were bacteria as is likely, this would be very possible).
2) At some early stage, two or more of these first strains converged and formed one strain, which then became the common ancestor of all life.

The first scenario is more likely, since the second would have to rely on the two or more first strains having genetically similar RNA in order to reproduce, and the odds of that happening when these are two different life sources are astronomical. This would also mean that reproduction by a means other than self-replication would have been in the world long before it currently appears to have been.

So going on what the evidence shows, what we can rationally say based on that evidence (and not mere speculation), there appears to have only been one common ancestor. If there were many, they would all have to be in bacterial form, and they either all died out or merged (which seems unlikely given their ways of reproduction).

(February 14, 2010 at 10:27 am)rjh4 Wrote:

(February 13, 2010 at 10:04 pm)Zen Badger Wrote: [quote='Zen Badger' pid='55853' dateline='1266113096']So again I ask you, where is your evidence for a young earth?

See post #72 in this thread. I think you just don't like my answer.

And the Physical evidence that supports the bible?

(February 14, 2010 at 11:06 am)Darwinian Wrote: The definition of a species is one that can successfully breed with another. That is to say that if one animal can have offspring with another then they will (normally) be classified as the same species.

Not necessarily. For example, even the article provided by Min said: "No exact rule exists for deciding when a group of animals constitutes a separate species." I would be quite surprised if the new species in the articles was incapable of breeding with the other tanagers even though they might not breed with them and yet the scientists in the article called the birds a new species. There was no indication in the article that the new species couldn't interbreed with other tanagers, just that they didn't possibly because of their songs. See also Species and some of the difficulties with that sort of definition, particularly "ring species".

(February 14, 2010 at 11:06 am)Darwinian Wrote: Now, the term species may well be a human invention but the fact that these differentiations exist in the first place is entirely natural. We simply observe them and give them names. So it is not man who decides what is or is not a new species at all. It is man who observes these clear and natural differences in the animal kingdom and gives them titles. They exist independently of our interpretation.

As seen in the wiki article above, it is not quite so easy as you make it out to be as scientists cannot always tell when two groups can potentially mate. So it is still scientists that make a decision.

(February 14, 2010 at 11:06 am)Darwinian Wrote: A conclusion of descent of all life from a single common ancestor is the most rational view as so far we have not come across a single life form that cannot in some way be shown to be biologically related to any other. If, as you seem to be suggesting, there are many groups of organisms on this world that can trace their ancestory back to completely different abiogenesis then we would see this in the biological world as it would be obvious. The simple fact that an oak tree can 'read' the dna of a shrimp must tell us something about the family history of life on Earth.

All living things on this world have their genome either in the form of DNA or RNA. That must have originated from a single common ancestor. If you can provide proof of any organism that does not use this template or suggest how, out of the billions of possible carbon/protein bonds etc. this particular solution was used by totally separate examples of abiogenesis then I'd like to hear it.

So, to summarise, we are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

I have no idea why you brought up abiogenesis as that was never part of the discussion. Furthermore, why do you assume in my question that at least one of the two original life forms had to use something other than DNA or RNA? I want to know what evidence would distinguish between all life descending from a single anscestor and part of life descending from one anscestor and the other part of life descending from a second anscestor, where the two anscestors both use the same template (as you put it). None of your comments addresses this issue. And if there is no such evidence that necessarily distinguishes between the two, then it would seem that common descent merely assumes only one anscestor (the use of a common template does not necessitate a conclusion of common descent from a single anscestor).

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(February 14, 2010 at 2:52 pm)Tiberius Wrote:

(February 14, 2010 at 10:27 am)rjh4 Wrote: I think you should remember though, Adrian, relative to speciation, it is man that decides what is a new species, there is no transcendant objective standard.

Erm...we decide what a new species is based on whether it can reproduce successfully with similar organisms. For instance, donkeys and horses are separate species because although they can produce offspring (mules), those offspring are sterile. We don't have an transcendant objective standard, but that doesn't mean we don't have a very strict standard at all. Technically, no "species" exist...it's just a human way of looking at and identifying different animals. There isn't an objective way of doing this since we made up the idea in the first place.

Quote:So just like a scientist could look at the slight differences in those birds and decide they are all different species, a scientist could look at the slight differences in humans and conclude there are different species of humans.

No they can't. This isn't how scientists do it these days. Classification has moved on since the days of Darwin! Yes, Darwin looked at the finches and thought they were all different species because they looked different, but when he got back from his voyage, a bird expert corrected him and told them that they were all the same type of bird. This was the idea that got him thinking about evolution in the first place. I'm afraid you are very much mistaken if you think that "slight differences" make scientists conclude "different species".

Quote:As for me, I would just say that there are birds that differ from each other and there are humans that differ from each other.

Yes, and yet there are some birds that cannot mate successfully with other birds, and we call these different species. You are making a bad comparison because birds are a single class (Aves) that contain numerous species, whilst humans are a single species (homo sapiens). If you want to compare the two, you'd have to point to a specific species of bird (i.e. Finch) rather than use the entire class.

Quote:Still none of these changes (whether or not one calls it speciation or not) necessitate a conclusion of descent of all life from a single common anscestor.

Of course they don't...nobody is arguing that. How did you get from methods of classification to "common descent"? The two are not directly related at all...

See my comments to Dar regarding species. And I agree that classification has nothing to do with common descent. I only brought this up as the only thing I have been denying, contrary to your implication in your previous post.

(February 14, 2010 at 2:52 pm)Tiberius Wrote: To put it simply, gene sequencing. Our DNA has similarities (i.e. sections that are identical) with all other life on the planet. The theory of common descent would predict that animals that are anatomically similar would have similar DNA, and this prediction holds true across every sequenced genome. We share 95-99% of our DNA with chimpanzees / orangutans, confirming the theory that we have a common ancestor in "recent" history. With other primates, we share less DNA, showing that chimpanzees are (as far as we know) our closest relative. I read somewhere (and I'll try to find the article) that we are more closely related to chimps / orangutans than chimps / orangutans are related to gorillas.

Going back further, we have less in common with rodents, even less in common with retiles, even less with fish, but we do share similar DNA with all life. It is through this methods of comparing DNA that we can draw up the tree of life, comparing every animal with every other animal. If one animal didn't fit, or had differences in its DNA that didn't correspond with its anatomy and where you would predict it to go on the tree, then common descent would be ruined.

This isn't to say that there weren't multiple "first" organisms, but if there were, then from the evidence we have, one of two things must have happened. Either:

1) The other "first" organisms died out, leaving no trace of their existence (and if they were bacteria as is likely, this would be very possible).
2) At some early stage, two or more of these first strains converged and formed one strain, which then became the common ancestor of all life.

The first scenario is more likely, since the second would have to rely on the two or more first strains having genetically similar RNA in order to reproduce, and the odds of that happening when these are two different life sources are astronomical. This would also mean that reproduction by a means other than self-replication would have been in the world long before it currently appears to have been.

So going on what the evidence shows, what we can rationally say based on that evidence (and not mere speculation), there appears to have only been one common ancestor. If there were many, they would all have to be in bacterial form, and they either all died out or merged (which seems unlikely given their ways of reproduction).

So it seems your argument assumes a naturalistic explanation of the first anscestor(s) and because the odds would be astronomical for more than one anscestor having genetically similar RNA you assume there must have been only one. So the abiogenesis argument does come into play here but I think you previously indicated that it was an entirely separate issue. So while common descent may not require the assumption of a single original life form, it is assumptions that lead you there nonetheless and not necessarily the evidence alone.

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(February 15, 2010 at 6:44 am)Zen Badger Wrote: And the Physical evidence that supports the bible?

I am not quite sure what you mean by the question. Can you clarify please?

(February 11, 2010 at 1:03 pm)rjh4 Wrote: If you cannot know anything for certain, I guess you wouldn't even know how good your probability assessments are.

I wouldn't for certain no... but I'm not talking about for absolutely certain am I? I'm talking about probabilistically.

Quote: So while you might think that one thing is more probable than another, you really don't know.

Not for certain no... but very very close to certain indeed I reckon. Probability is measurable - and there's also a such thing as estimated probability.

Quote: So while you may think that it is more probable that God does not exist, you cannot even say this with any certainty[...]

Not for any certainty? No I can know for some certainty, just as I said - not for absolute certainty.

Quote: as it might really be more probable that God exists (speaking from within your own worldview).

No because I have reasoning in my world view that makes be believe that God is indeed, highly improbable. I don't need to know for absolute certain to make probabilistic judgements...... - if I had to know for absolute certain then it wouldn't be probabilistic judgement.

EvF

(February 15, 2010 at 9:45 am)rjh4 Wrote: So it seems your argument assumes a naturalistic explanation of the first anscestor(s) and because the odds would be astronomical for more than one anscestor having genetically similar RNA you assume there must have been only one. So the abiogenesis argument does come into play here but I think you previously indicated that it was an entirely separate issue. So while common descent may not require the assumption of a single original life form, it is assumptions that lead you there nonetheless and not necessarily the evidence alone.

My argument had nothing to do with an explanation of the first ancestors. I never mentioned abiogenesis...

Just to clarify, mentioning first ancestors doesn't at all mean I am talking about where they came from. I am required to talk about first ancestors because your question involved them, and your question was about common descent. Common descent is related to the first ancestors, in that all life has to be related in some way to a first ancestor. This has nothing to do with where that ancestor came from.

Even if God had created the first ancestor, or ancestors, what happened from then on is documented in the genetic makeup of life. My points about what could have happened still hold. These points are based on evidence, not assumptions. I made no assumptions about the origins of the first ancestors, nor did I have to. You gave me two scenarios (one first ancestor, many first ancestors) and I worked to interpret the evidence for each position. I pointed out to you that the chances of their being many first ancestors were almost impossible, and this is why the accepted view of science is that there was only one.

I thought I explained myself clearly, it is sad you had to twist my words to try and make it seem like I am working on assumptions here. Please don't do it again.

(February 15, 2010 at 9:45 am)rjh4 Wrote:

(February 15, 2010 at 6:44 am)Zen Badger Wrote: And the Physical evidence that supports the bible?

I am not quite sure what you mean by the question. Can you clarify please?

What in the real world is convincing support for the version of events portrayed in the Bible?

I.e evidence that the universe is only 6000 years old.

Incontrovertible evidence of the "Great Flood".

A Dinosaur fossil with a saddle, stuff like that.

Or do you consider the bible to be sufficent in itself.

(February 15, 2010 at 5:02 pm)Tiberius Wrote: I pointed out to you that the chances of their being many first ancestors were almost impossible, and this is why the accepted view of science is that there was only one.

I thought I explained myself clearly, it is sad you had to twist my words to try and make it seem like I am working on assumptions here. Please don't do it again.

Adrian, I am really not trying to twist your words. Apologies.

Please explain why you think that the chances of their being many first ancestors is almost impossible.

It was my interpretation of this statement of yours that may have resulted in my inadvertent twisting of your words. Let me explain. As a creationist, I believe that God created plants, animals, and humans in the beginning with all of them based on the used of DNA/RNA. All changes that have occurred since then have been a result of variations built into the systems and mutations to the DNA/RNA caused by other things (e.g., radiation)(to this degree I have no problem with evolution). So while I believe all humans have first anscestors, I also believe that all cats had first anscestors, and all dogs had first anscestors, etc. but I do not believe that all the first anscestors are the same. Any evidence you have presented so far is not inconsistent with this. The only thing that you have said that would address this in any negative way is that "the chances of their being many first ancestors were almost impossible", and from this you appear to conclude that there was a single anscestor. This statement of yours must be either based on some evidence, or based on some assumptions you are making, or both. I took it as you saying it was impossible because of the odds of more than one anscestor of the same type (RNA/DNA) coming to be naturalistically is too much. Since this would at least appear to be refering to abiogenesis (as there does not appear to be any reason to say it would be impossible when God is considered the source of all the initial life), that is why I said what I did.

Given all of this, I am interested in your explanation as to what you meant by your statement.

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(February 16, 2010 at 7:29 am)Zen Badger Wrote: What in the real world is convincing support for the version of events portrayed in the Bible?

I.e evidence that the universe is only 6000 years old.

Incontrovertible evidence of the "Great Flood".

A Dinosaur fossil with a saddle, stuff like that.

Or do you consider the bible to be sufficent in itself.

I do not think there is incontrovertible evidence for any of it (from my side or yours). Anything I could throw at you, evidence wise, you would merely reinterpret based on your own worldview and likewise with you throwing evidence my way. (Maybe I would be wrong on this if we did find a dinosaur fossil with a saddle , but no such thing has been found as far as I know.) Anyway, take your reference to the flood, I think that the great majority of the geologic column is evidence of the Biblical flood whereas I would guess that you would interpret the geologic column as evidence of millions of years of uniformitarian processing. So while I look at the geologic column as confirming what the Bible said about the flood, I am guessing that you look at it as evidence that the Bible is wrong. It is because we are looking at the same thing but with different starting points.

While I do consider the Bible to be sufficient in itself, I am not left with that as I think there are things that confirm what the Bible says (note my comments about the flood). But that doesn't mean that someone who does not believe in the Bible cannot come up with some other explanation for anything I take as confirming the Bible either.

I hope this explains my position better for you.

Are you ever going to address my question as to how your first principles accounts for logic, mathematics, and morals?