Is convergent evolution evidence against common descent?

randman responds to me:

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So we should never expect DNA sequencing patterns to be convergent, since convergency ONLY applies to "surface" traits?

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Is that what you are claiming?

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No.

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Intelligence implies will. Natural implies no will. Therefore, an act can be either natural or intelligent, but not both. Intelligent actions are artificial in nature.

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So by definition then, you are saying breeding dogs, plants, and the use of genetic engineering by people is not "natural", eh?

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No, it is not natural. It is artificial. That is why it is called "artificial selection." That is why it is called genetic "engineering." The actions are not natural but are aritificial. You will note that I am not claiming they are supernatural or violate physics. I am saying that the actions are not natural.This makes at least twice I have told you this directly. When will you remember it?Or are you about to equivocate the dichotomy of natural/artificial with the dichotomy of natural/supernatural? For someone who claims he doesn't want to argue semantics, you do a hell of a job of making semantic arguments.

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Just want to get your definition of what constitutes "natural."

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Again, this makes at least twice I have given this direct definition to you. When will you remember it?

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If so, then why would this "intelligent force" use a method that looks exactly like an evolutionary process?

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Why do we use processes to create new dog breeds that "look exactly like an evolutionary process"?

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But it doesn't. No natural evolutionary process would produce a Chihuahua. An artificial selection process would, however. There are plenty of breeds out there which, because of the unnatural, artifical selection process, have crippling defects within their genomes such that they could never survive without the artificial supports put in place. Giant breeds such as Great Danes are prone to hip displasia. More than one breed is prone to deafness.There's a reason why wild dogs don't look anything like purebreds.Wild dogs are the product of natural selection. Purebreds are the result of artificial selection.

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Natural processes don't allow for willful adjustment of the results. Therefore, an "intelligent force" that produces natural results must also be incapable of allowing willful adjustment of the results...which does away with the "intelligent force" and thus the process is natural.

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But dog breeds are natural, right?

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Wrong.They are artificial.

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Dog breeds are the result of a "willful adjustment of a natural process by an intelligent force", the human dog breeder, and yet you are claiming by definition that somehow, since dogs appear to be natural, that this does away with the intelligent force.

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Incorect. Dog breeds do not look at all natural. They look artificial. Therefore, since they contain no signs of natural processes, they cannot be the result of natural processes.And, indeed, they aren't. They are the result of artificial processes.

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But if the trait is similar all the way down to the genes that express it, then the trait cannot be convergent. It must necessarily be descent. Common environments can give similar SURFACE traits, but they cannot give similar FOUNDATIONAL traits.

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So if someone can show you where a convergent trait is similar all the way down to the genes that express it, are you willing to accept this as evidence against common descent? Is this something that falsifies universal common descent?

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Unless and until you give a more specific example, I cannot answer your question. I will not play gotcha.So be careful. Remember that in order for this to happen, you have to start with completely distinct genes and have them converge to the same ultimate product. You cannot start with identical genes and have them mutate in the same way.This is the point you keep missing: Convergence works from the outside. You start with completely distinct and different foundations and by applying pressure on the outside, make them adapt to the same external morphology. Because they have different internal structures, it will be extremely unlikely that they would adapt toward a common internal structure. Evolution does not have a guiding force telling it how to achieve a solution. It simply makes do with what it has, putting out variations and seeing which one manages to make it through the selection process.If you have a structure that is large and needs to be reduced, the solution will most likely be quite different from a structure that is small and needs to be enlarged. In the former, you might simply take the current structure and make each component smaller. In the latter, there are other options...rather than simply make things bigger, you can duplicate the internals so that you have a bunch of little things rather than a single big thing.

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In layman's terms, if we can see something besides surface traits evolve convergently, would you be willing to go on record that this would disprove common descent, or not?

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Until you give me a more specific example of what you're talking about, I shall withhold any comment. You've already been equivocating on this thread multiple times. I will not allow you to equivocate so easily again.

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Also, define SURFACE traits and FOUNDATION traits so we can see if your assertion is true.

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I already have. I have even given you examples. Please go back and read the thread. Remember the distinction between sharks and dolphins?

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Rrhain

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Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

Ned, oops, I misread you sorry. You are correct. I am suggesting that we could assume common descent when convergency is how something occurred.Sorry about that.

randman responds to me:

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So now, genetic engineering is not even science because "science is about things that happen all on their own."

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Well, no. Engineering isn't science. It's based upon science, certainly, and you can't possibly do engineering without understanding a fair amount of the underlying science, but it isn't science in and of itself. Engineering is the application of scientific principles in artifical ways.Mathematics is on the other end of the scale. Mathematics isn't science. Science is based upon mathematics, certainly, and you can't possibly do science without understanding a fair amount of the underlying mathematics, but it isn't science in and of itself. Science is the application of mathematical principles in specific rather than abstract ways.As the old cliche goes, engineering is applied physics and physics is applied math.

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Science is not just about "things that happen all on their own."

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Yes, it is. Science relies upon repeatable, testable phenomena. If you cannot repeat it because there is a capricious, willful variable in the process, then there is no way to get a repeatable, testable result. You will note that this is different from a random variable.

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Furthermore, and this is a typical problem in your camp, you are confusing 2 different uses of the word "natural".

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(*chuckle*)How interesting that you are trying to palm off your equivocation onto others.

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When people speak of a non-natural arena outside of the purview of science, they are speaking of "natural" in the sense of real.

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And this is is a perfect example of the equivocation you are making that I am talking about.When evolution talks about "natural selection," it is not referring to the sense of "real." It is a logical error to behave as if it is.

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But your contention that science cannot address or be involved with anything artificial is just insanity.

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Right. So if I take a beaker of water, put it on my lab table, and leave the room, I should think that it is just a natural occurrence to return and find that it has been transformed into petri dish filled with agar. If it happens every time I leave the room, then it's just a "natural" occurrence and it should never cross my mind that perhaps my lab assistant is doing something when my back is turned? And when he decides to replace it not with an agar-filled petri dish but with a pile of salt, well, that's just another example of the "natural" process.The actions of my lab assistant are capricious and arbitrary and are beyond the scope of scientific inquiry.

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Moreover, intelligence and intelligent action is part of evolution

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Not quite. There is a difference between artificial and natural selection.

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Rrhain

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Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

You are not defining your terms.Surface versus foundational seems highly suspect, and it's not clear.Are bones surface or foundational, for example?I'd say a wombat and a woodchuck share a whole lot of similar traits that are not just "surface" traits, and moreover, the area of great difference is in reproduction, pouch versus placental, right?So in reality, that is a pretty good example disproving your surface versus foundational way to determining which is which.Also, is the molecular level surface or foundational?I sort of get your point in thinking of foundational as pertaining to the foundations, or prior existing form, that a species had prior to evolving a trait, but non-surface traits evolve through convergence, and you don't seem to be aware of that. I don't think the term "surface" is very helpful anyway, and even the foundational concept is suspect.Take DNA convergence. Here we see right from the DNA to the morphological trait, DNA from different species can be predisposed to evolve into a certain pattern. I fail to see the relevancy. Certainly mutations and traits via natural selection, whether common ancestry or convergence, involve selection via environmental pressures.But you seem to be ignoring some things. If similar traits can be produced from different foundations, then that is evidence that similar traits do not indicate a common ancestor, right?Moreover, if DNA is predisposed to mutate a certain way, and do so convergently, then there is pressure with or without evironmental pressures pushing a species and many different species, in fact, towards certain forms. Certainly the outside pressure helps, but the fact is the DNA is programmed to tend towards a certain direction and pattern, to a degree.In other words, the DNA is predisposed to mutate a certain way not because of factors outside the species, but internally and foundationally. That does not discount natural selection, but it does show another factor pushing for similar traits.

randman responds to me:

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Convergent evolution involves the sharing of a small number of traits that are similar only in final effect and not in fundamental structure.

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Could you explain to me how marsupials and placental mammals only share a small number of traits with their seeming counterparts?

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Because you are still looking at the surface. You do not understand what "small number of traits" means.Question: Just how many traits does an organism such as a wolf or Tasmanian wolf have?

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Also, can you show that how they are "similar only in final effect and not in fundamental structure"?

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The article you referenced already did. Do you not know the differences between marsupial and placental mammals?[ad hominem commentary deleted for space]

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Rrhain

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Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

randman responds to me:

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Is the molecular level SURFACE or FOUNDATIONAL?

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Depends. Are we talking about the function of the molecule or the structure? If it's the function, that's surface. If it's the structure, that's foundational.Do you not understand the implication arrows involved? Two items that are structurally the same will have functional equivalency. But just because two items have the same function doesn't mean they are structurally the same. All squares are rectangles. Not all rectangles are squares.The examples you give are surface examples: They have similar effect but different internal structure. Your example even says so, directly.What do you think "has an entirely different primary structure" means? What do you think "its three-dimensional structure (tertiary) structure is different" means? Even though the effect of the two molecules is the same, they look nothing alike an arose from completely different genetic origins.

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Rrhain

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Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

randman responds to me:

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You are not defining your terms.

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What part of English don't you understand, then?

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Surface versus foundational seems highly suspect, and it's not clear.

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Excuse me? Your own source understands the distinction: There is the function of a molecule and then there is the structure. While molecules with the same structure will have the same function, molecules that have the same function will not necessarily have the same structure.As I previously said, surface is simply how it looks and behaves, not the internal structure. Foundational is the internal structure.

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Are bones surface or foundational, for example?

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Are you talking about how they are made or what they are used for?

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I'd say a wombat and a woodchuck share a whole lot of similar traits

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Like what? Be specific.

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the area of great difference is in reproduction, pouch versus placental, right?

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That's one. What else? They're both mammals so there's going to be an awful lot they have in common, but I'm asking you to be specific.

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If similar traits can be produced from different foundations, then that is evidence that similar traits do not indicate a common ancestor, right?

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Wrong.You have to look beyond the surface for it won't tell you anything. You need to get past the superficiality of the function and look at the structure underneath.A house with wooden siding is not the same as a house with vinyl siding, even though they may look the same and the siding is performing the same function. And neither are the same as a house with aluminum siding.

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Moreover, if DNA is predisposed to mutate a certain way, and do so convergently

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You are assuming that the same DNA sequence exists in both organisms.I have no problem with selective pressures being so strong that only specific types of mutations can survive the selection. We've seen it happen.But that only works when you're starting with the same gene.

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In other words, the DNA is predisposed to mutate a certain way not because of factors outside the species, but internally and foundationally.

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Of course. Biology is a chemical reaction and certain chemical reactions are favored over others given the chemical environment.Your attempt to insert consciousness into it is unfounded.

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Rrhain

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Thank you for your submission to Science. Your paper was reviewed by a jury of seventh graders so that they could look for balance and to allow them to make up their own minds. We are sorry to say that they found your paper "bogus," specifically describing the section on the laboratory work "boring." We regret that we will be unable to publish your work at this time.

It depends how far you want to characterise a trait. I can't see any way in which a specific protein coding sequence could be predisposed to develop almost de novo but within an alrady established gene there may well be hotspots which frequently mutate leading to specific traits, such as the many human developmental genetic syndromes which have been well characterised. Some of these developmental syndromes may be said to be physical forms which are predisposed to develop due either to chromosomal or sequence level mutational hotspots.So within a given sequence there may be a predisposition towards a certain mutation but this does not neccessarily correlate with a phenotypic trait, although it may in some cases.The microsatellite and repeat sequences studied ar very different in character to protein coding and gene regulatory sequences of DNA. These are perhaps the second simplest form of DNA one could find, i.e. repeats of a 2bp (ACACAC) sequence as opposed to a stretch all of one nucletiode type (AAAAA), and the amount of effect they might have on anything relating to phenotype is probably minimal. That is correct, although more general environmental factors may also be involved. Particular metabolic processes within the cell or particular proteins produced in the cells might also have predisposing effects on certain mutations.TTFN,WK

In this case I would think that both structure and function should be seen as 'surface' elements since they are so inextricably linked. For a foundational element one would need to look at the DNA coding for the particular protein as there are a number of viable sequences capable of coding for a specific primary sequence of amino acids or of a particular class of amino acids allowing a specific structure, such as a helix-loop-helix, to form.TTFN,WK

Please elucidate the shared characteristics. This should be informative! You do realise that marsupials and placentals are the two very distinct subgroups of mammal, don't you? (Of course I'm not discounting the monotremes, just nto specifically addressing them because it would make your position even more ridiculous.)Are we going to go through a comparison of the thylacine (marsupial tiger or is it wolf?) with its supposed placental counterpart? Please provide your assessment of the importance of considering similarities of reproductive mechanisms in the taxonomy of organisms.

Yes, the figures weren't the best. I know the bird wing still has digits - they are just not important structural support members of the wing as in the bat (an even worse figure, actually).

randman, What loaded semantics? False, homologies aren't necessarily due to descent, convergent traits, for example. Cite please.And what is "convergent DNA sequencing". Convergency must be driven by environmental pressures, it's not convergent otherwise. I am assuming you know what is meant by convergent evolution, rather than have your own specific definition of it that is peculiar to you? You are dodging the point.Birds are thought to be related to therapods because of the raft of homologies that have no business existing unless common descent occurred. Your argument is that convergent evolution "spoils" the homology argument. But for convergent evolution to occur, similar selective pressures must be in evidence to shape the characters that are converging. This means similar environments. Given birds & therapods do not particularly occupy similar environments or niches, the homologies in existence have no right existing, yet they do. Common descent explains this.The reptilian ancestry is supported my molecular systematics, again from organisms that occupy vastly different niches, & so the homologies again cannot be considered convergent. No, not necessarily. There's no reason an Allosaur couldn't get away with a more mammalian clavicle, for example. In most cases any one of a number of solutions are possible. There is no reason for a pattern of common descent to be in evidence if it is not indicative of reality. Depends on what it is, I suppose. We are not talking about single homologies. Systematics takes an overall view from as many characters as possible. No, I am not assuming this. Systematics takes an overall "average" view of the homologies. When two taxa share a shed-load of homologies that occupy different niches, yet another taxa that shares a niche possesses none when they should, then you have a problem. Your argument becomes one of massive coincidences in every instance. What is "convergent DNA"? It's the only testable answer that is consistent with the facts.Your original argument that convergency presents a serious problem for systematics is false for the reasons given. The point has been well made. If you wish to argue for ID, or any other reason for homologies then by all means do so. You will need to present a logically valid evidence based argument, "what if" is insufficient.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Good point about the topic. There are eduction threads you could take it to. You repeat this a lot but this form of mysticism isn't very convincing to me. As it is concerned with the cosomology and not biological evolution we can leave it to other threads. Absolutely agree. The question is how do these laws etc produce the patterns. Well, this is exactly one part of the laws producing the pattern and we agree on it. Agreed again. So far you seem to be backing current biological thinking in the same way any Christian biologists might. At the lowest level there are, of course, chemical "tendancies" that cause some of the behavior and patterns in genes. You may believe the nature of physics and chemistry is "pre programmed" if you wish. There is no evidence for an specific preprogamming beyond that.What are these tendancies and how do they cause the patterns we see? You have yet to even begin to answer the question. You are a good theist. I have no problem with you believing that if you so wish.Can you get around to answering Rrhains common question as to whether anything even the role of a dice, happens without God's intervention then?So far you have not offered a different explanation for the pattern of fossils and life that is the topic of discussion that is different from the accepted biological explanation with a God in the background somewhere.Again, what is your explanation for the pattern? This you may take to the convergence thread.

the difference is a branch where the common descent features are strong and consistent: humans and chimpanzees share 98% of the DNA sequences, down to and including minor variations in sequences that seem to have no purpose, but have accumulated over time (excess repeats).there is no reason for such consistent matching errors in uneccessary sections to be shared by two species except by common descent from a single ancestor.on the other hand we share apparent bareness with the chijuajua, pigs and a cat, but the common descent branches that connect us to those species do not involve this bareness feature: it has occured by a convergent pattern, and not by a common descent pattern.the whole pattern of convergent evolution is superficial appearance of similarities rather than real subsurface similarities. the skin of humans chijuajuas, pigs and cats is different, even though they may appear similar.your argument is similar to noting that there is a painted like coloration of red and black on the back of a Chrysemys picta and that this is also true for a Myioborus pictus (note the similarity in the names), so therefor the Chrysemys picta cannot have evolved from turtles, in spite of the wealth of information on the evolution of turtles.see the difference?

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

Hi randman, this might appear to be slightly off-topic, but Ned thought this might be the best place for it. I'm not entirely sure of that, but I trust his judgement so I'm going with it.The reason why its not entirely on topic is due to the fact that it doesn't really discuss convergent evolution. I would like to discuss with you (and heh - the last time we discussed it it was fairly off topic anyway )Analogy timeLet's imagine we need to convey a secret message to Mr Bush. The message is "Lookout! The terrorists are coming". To do this we use a code book that Mr Bush has a copy of. The number '6' would refer Mr Bush to the message "Lookout! The terrorists are coming". In order to arrive at this number we use a collection of three digits and find the sum of them. For example:
213: 2+1+3 = 6
222: 2+2+2 = 6
312: 3+1+2 = 6
114: 6And so on. We can see clearly here that there are many ways of arriving at the same message.Why is the analogy applicableOK, replace 'message' with protien. So instead of saying "Lookout! The terrorists are coming", we are now saying "Cytochrome c". Instead of using digits, we use A,G,C or T (or rather the chemicals they represent), in three-long 'codons'. Instead of only needing one codon we need 104.Each of the 104 codons refers to an amino acid. Different codons can code for the same amino acid (1+1+4 gives the same result as 2+2+2), and so there are many many different ways of coding for any given protien.Some figuresThere are twenty amino acids that go towards making protiens. There are 4³, 64, different combinations for the codons. The upshot of all this is between one through six different ways of making any given amino acid...which means there are an awful lot of different ways of making a 104 amino acid long protien.A picture is worth a thousand wordsLook at this diagram. It shows the entire DNA string for cytochrome c in humans, and cytochrome c in mice. There are 78 codons which are identical. Is this a strange occurance?How many different ways can these 78 codons have been? Look at the diagram there - 1.3 x 10³³.MorphologyThe way that Cytochrome C is made has no bearing on morphology. Indeed - human cytochrome c can be genetically engineered into yeast cells and they will function identically. Indeed, how the amino acids are put together to form the protien is made is irrelevant to the morphology of the creature. I can say this because it has no relevance to the morphology of the protien.The pointThere is no reason a Creator would code Cytochrome C in Chimpanzees in an identical manner to humans, and code it slightly differently in Rhesus monkeys (one amino acid difference). The fossil record shows us that the general order that life evolved through was fish->amphibian->reptile->mammal (a simplification of course). There is no reason whatsoever for a Creator to code Cytochrome C in similar ways for mammals, less similar for reptiles, less similar again for amphibians and less similar again to fish.In conclusion
The cytochrome c protien could be coded the same way in humans as it is in herring, and dramatically different in Chimpanzees. For some reason, this is not the case. Whilst a Creator might have set this up (for no known reason), it seems more parsomonius to assume this is the result of heriditary and divergance from common ancestry.And this is just considering one protien. We haven't considered this study which looks at over 500 genes, and arrives at the same conclusions. We haven't considered broken genes such as the broken vitamin C gene in primates.Creationists like to use statistics to prove that evolution is so unlikely as to be impossible. The chances of mice and men having the same 78 codons for one protien are approaching astronomical levels. The chances that almost all creatures have the appropriate (for evolutionary predictions) codons is approaching incredulity unless common ancestory is the cause. And this is just ONE protien...this relationship can be found in hundreds of these things.Convergence
I'll add this bit in just to make it a bit more relevant. A diagram is useful here More cytochrome goodnessLook at the bottom two. Lamprey and tunafish. According to evolutionary models, the tunafish is closer related to us than the lamprey, yet the picture shows a different story right? Since we are dealing with random mutations, we have convergence here. When we start to examine other genes, this appearance vanishes.This message has been edited by Modulous, Sun, 05-June-2005 09:05 PM

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