(Image from http://en.wikipedia.org/wiki/
File:Spider_in_amber_(1).jpg)
If resin hardens, it forms amber, which is considered valuable both as a component for jewelry as well as a means by which fossils can be preserved. The photo above, for example, shows a spider that has been remarkably well-preserved by amber. It is assumed that the spider was trapped in a tree’s resin, and then the resin hardened around the spider. Because this forms a nearly airtight container, decomposition is greatly reduced, allowing for the formation of an incredibly well-preserved fossil.
Not surprisingly, different kinds of trees will produce different kinds of resin, which leads to different kinds of amber. Currently, there are five known classes of amber, based upon the specific chemical compounds that make up the amber. It has been generally thought (quite reasonably) that the chemicals in the amber are reflective of the kind of tree that originally produced the resin. However, that thinking will have to change in order to preserve the hypothesis of evolution.
In October of 2009, the journal Science published a report by P. Sargent Bray and Ken B. Anderson that discusses some amber they found. Chemical analysis puts the amber in a particular class that is supposed to have been formed by trees that make flowers. All flower-producing plants are called angiosperms, so this amber has all the characteristics of having been made by an angiosperm.2
There’s just one problem. The amber was found in Carboniferous rock that is supposed to be 320 million years old. Angiosperms supposedly evolved only about 140 million years ago. Thus, this amber is about 180 million years “too early” in the fossil record. How do the authors get around this inconvenient fact? Very easily:
Our data do not imply that angiosperms existed in the Carboniferous, because the fossil record does not record unequivocal angiosperm fossils until the Cretaceous. However, our data do suggest that the divergence of the biosynthetic mechanisms needed to produce resins based on regular and enantio-series labdanoid diterpenes predates both the emergence of true conifers and the differentiation of angiosperms and gymnosperms.
Don’t get lost in the jargon and miss what the authors are saying here. They are basically saying that because angiosperms don’t “belong” in the kind of rock this amber was found in, they are forced to ignore the clear chemical evidence that this amber was made by an angiosperm. Instead, they must assume that the complex chemical mechanisms by which resin forms evolved prior to the appearance of true conifers (cone-making trees like evergreens) and angiosperms (flower-making plants).
That’s not enough, however. They must also assume that the chemistry of amber is not reflective of the kind of tree that produced it in the first place. As a commentary that appears in the same issue of Science notes:3
The discovery by Bray and Anderson reveals that resins of extremely similar molecular composition can be produced by entirely unrelated plants. This astonishing evolutionary convergence at the molecular level presents a cautionary message to those who study amber. It is standard practice to assign the botanical origins of an amber deposit to a genus or family of plants based just on the amber chemistry. (emphasis mine)
So what does an evolutionist do when a fossil find contradicts his treasured hypothesis? He just waves the magic wand of “convergent evolution.” Remember, similarities between species are strong evidence for evolution, except when the hypothesis of evolution cannot accommodate them. When that happens, the similarities are a result of “convergent evolution,” a process by which species have similarities based on sheer coincidence alone.
So in this case, the fact that the amber has all the chemical features of being made by an angiosperm must be ignored. Instead, because the amber appears “too soon” in the fossil record for angiosperms, we must assume that it was made by something other than an angiosperm. Furthermore, we must assume that the similarities between its chemistry and the chemistry of resin made by angiosperms is the result of sheer coincidence.
That’s the kind of mental gymnastics it takes to be an evolutionist today.
REFERENCES
1. Jean H. Langenheim, Plant resins: Chemistry, Evolution, Ecology, and Ethnobotany, Timber Press, 2003, pp. 196-254
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2. P. Sargent Bray and Ken B. Anderson, “Identification of Carboniferous (320 Million Years Old) Class Ic Amber,” Science, 326:132-134, 2009 (Available online)
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3. P. David Grimaldi, “Pushing Back Amber Production,” Science, 326:51-52, 2009 (Available online)
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How well proven is the underlying theory that different types of tree produce these classes of amber, as opposed to weather, disease, or a myriad other factors?
I must confess that reading the title my first thoughts were:
Don’t tell anyone.
Burn it.
Move it to a different rock and whistle away innocently.
Burn it.
Burn it.
Reconsider your position.
Burn it.
That’s why I am glad you comment regularly, Josiah. I love your first thoughts. Actually, a version of “Move it to a different rock and whistle away innocently” is just what happened when Charles Doolittle Walcott discovered a treasure trove of fossils in the Burgess Shale. When he discovered what were clearly advanced creatures in Cambrian rock, he published a brief report in an obscure journal, and then he buried them away in his lab. They were effectively hidden until the 1980s (after Walcott’s death) when Simon Conway Morris rediscovered them and was willing to actually wrestle with their importance. Those fossils are the first ones that demonstrated the Cambrian Explosion, which is still a serious problem for evolution today. Walcott knew the problem they posed for evolution, so he hid them in his lab and whistled away innocently.
In answer to your serious question, if we observe resins produced by trees today, we see that their chemical nature is dependent on the type of tree that produces them. Indeed, someone who knows resin chemistry can identify the family and sometimes even the genus of tree based solely on the resin. Since amber is simply hardened resin, it stands to reason that the amber should also be indicative of the kind of tree. Weather and other factors can tinker with the final chemistry of the amber, but the base compounds come from the resin, which seems to be based on the tree. Thus, empirically, this makes sense. It also makes sense theoretically. Remember, resin is produced by the tree. Since the tree produces the resin, if a group of trees have similar biochemistry, they should produce similar resin and therefore similar amber. This is why the commentary I quoted says, “It is standard practice to assign the botanical origins of an amber deposit to a genus or family of plants based just on the amber chemistry.”
Of course, the relationship isn’t “proven,” as science really cannot prove anything. However, there is strong theoretical and empirical evidence to support it. To believe in evolution, you must ignore the strong theoretical and empirical evidence.
Dr. Wile,
It seems convenient that you take the editor’s comments on convergent evolution as the final word and at face value, while ignoring the authors comments that this amber would have been made by an ancestor (or close cousin to the ancestor) of the angiosperm that predates the divergence of the angiosperm from other tree lines. It would hardly be coincidence for the amber of an angiosperm to be similar to the amber of its ancestors.
Also, you talk about being able to trace amber to a particular genus, but this amber has only been traced to very high-level categorization that contains millions of species in several thousand genuses. if there is no closer match than that, how is this a problem for evolution?
One Brow, I was not ignoring the authors’ comments. Indeed, I quote the authors. I was just making the obvious point that their assumption was not enough. The editor’s comments fill in the rest of what is necessary to preserve the hypothesis of evolution. Yes, it would still be quite a coincidence that an ancestor of BOTH gymnosperms and angiosperms produced amber that is now associated ONLY with angiosperms. This is why the editor must assume it is an example of convergence. If it were an example of inheritance through evolution, it (or some very similar chemistry) should appear in gymnosperms as well.
I agree that class Ic amber is produced by many different trees, but they are all angiosperms, and that is the point. When you see class Ic amber, it is indicative of angiosperms. However, angiosperms are not supposed to be in Carboniferous rock, so the magic wand of convergence must be waved in order to preserve the evolutionary hypothesis.
‘I was just making the obvious point that their assumption was not enough. The editor’s comments fill in the rest of what is necessary to preserve the hypothesis of evolution.’
No – the interpretation of the data by the authors and the commenter are different. It has nothing to do with one assumption being enough or not.
The authors believe that their data is indicative of an early divergence of bisynthetic pathways for resin, the commenter believes that the data is indicative of convergent wvolution (apparently because he or she thinks such early divergence in biochemistry that is not accompanied by changes in morphology over 100 million years is unlikely).
In your article, you make it sound as if these researchers were somehow conspiring to gloss over problems the research causes for evolution, when it does nothing of the sort!
This is a case of two competing interpretations based on scant data (BOTH of which are perfectly compatible with evolution) – it happens in scientific journals all the time. I bet in teh next issue of Science you’ll have a letter from the authors responding to the commenter with their point of view.
I really wish that one of these days Creationists would stop clutching at straws while trying to poke holes in evolution and actually do some credible research.
Singring, as has been clearly explained, both the authors and the editor are correct. Clearly the resin-making processes must have existed prior to angiosperms in order to preserve the evolutionary hypothesis. Otherwise, there would be no amber in Carboniferous rock. However, at the same time, these processes could not have followed the typical inheritance model, or there would be similar processes in both gymnosperms and angiosperms.
I do hope that one day evolutionists stop clutching at straws and actually look at the evidence.
Dr. Wile,
Thank you for engaging in this discussion.
I must disagree that the editor’s comments “fill in the rest”. The editor’s comments seem to be in opposition to the author’s comments. The authors position, based on your quote, is that the amber change predates the usual date fro the split of angiosperms and gymnosperms, which would indicate either an earlier split than is currently thought, or that both types of amber were present before the split.
If the chemistryof the amber in question were identical to an extant species/genus, I completely agree that would be a case of convergent evolution. However, the mere preservation of various common characteristics, with many differences as well, between the older amber and modern resin would be the precise prediction of evolutionary theory, and so can hardly be counted as being in discord.
Since I don’t know the complete biological pathways covering the production of amber or the early evolutionary history of plants, I am only guessing here, but it seems to me that if the production of different types of amber was one factor that helped lead to the division of angiosperm vs. gymnosperm, then it would not be surprising at all to find plants before the division with amber that was characteristically angiosperm, and not find those characteristics in any modern gymnosperms. Some of the changes that caused the different amber may have even made it possible for angiosperms to develop in the first place (note I am not saying the amber itself is the source of the change, but another effect of the source of the change).
As the authors point out, we have no actual angiosperm fossils in the Carboniferous, so saying there should not be angiosperms in Carboniferous rock is merely confirming what we already know. Nothing says that angiosperm-like amber had to develop at the exact same time angiosperms did.
One Brow, the comments in the commentary certainly do fill in the rest. Once again, if the resin-making processes that had to exist prior to the split between angiosperms and gymnosperms were passed down to the modern angiosperms today from the common ancestor, then the chemistry of amber among gymnosperms and angiosperms should be very similar. That’s the prediction made by evolution. That prediction fails miserably, however. The amber-making processes are fundamentally different. Thus, you must use convergent evolution to explain why SOME modern angiosperms JUST HAPPEN to make resin that would form the kind of amber the common ancestor made. Your idea that angiosperms “held on” to the common ancestor’s resin-making processes while the gymnosperms went in a different direction doesn’t work, because there are many different resins made by angiosperms today. If this was something that aided (or was affected by) the split between angiosperms and gymnosperms, at least the angiosperms should all have similar resin. They do not.
As the author of the commentary makes clear, “The discovery by Bray and Anderson reveals that resins of extremely similar molecular composition can be produced by entirely unrelated plants. ” This is the classic definition of convergent evolution – similarities that exist in unrelated species.
I agree that there are no actual angiosperm fossils yet found in Carboniferous rock. However, this amber has all the characteristics of coming from an angiosperm. However, to hold on to the hypothesis that the angiosperms didn’t evolve for about 180 million years after the era that is supposedly represented by Carboniferous rock, we must wave the magic wand of convergent evolution to explain away the most reasonable conclusion: that the amber was made by an angiosperm.
Isn’t it possible that modern angiosperms produce exactly the same amber because that gene has not, in general, mutated again since the split, whereas it was the ancestral gymnosperm that had the divergance to produce that form of amber (as well as all the other divergances).
The only reason that this would not work would be if angiosperms were themselves considered the descendants of gymnosperms, with the flowering process considered an advancement in tree evolution.
Josiah, that’s essentially what One Brow is saying. Somehow, the angiosperms “held on” to the biosynthetic pathways of the common ancestor, while the gymnosperms took a different path after the split between gymnosperms and angiosperms. There are several problems with this view, the biggest of which being that the common ancestor between gymnosperms and angiosperms was supposed to be very gymnosperm-like. Archaeopteris, for example, is considered the first true tree found in the fossil record, and its wood is incredibly conifer-like. It is not considered a direct descendant of modern trees, but more of a cousin. The direct descendant of modern trees is thought to have come from the group know as “Progymnosperms,” which are very gymnosperm-like. Thus, if any group of trees should retain the resin of the common ancestor, it should be the gymnosperms.
This is the whole reason convergent evolution must be assumed in order to square this find with the evolutionary interpretation of the fossil record. The trees most closely-related to the common ancestor don’t make the resin that the common ancestor supposedly made. Instead, trees that are more distantly related to the common ancestor make that kind of resin. This is precisely the opposite prediction of evolution, so convergent evolution must be offered as a way out of the problem.
‘However, at the same time, these processes could not have followed the typical inheritance model, or there would be similar processes in both gymnosperms and angiosperms.’
Not at all true. If the bisynthetic pathway for resin production in gymnosperms and angiosperms had already diverged in the Carobinferous, then they would be expected to be even MORE different today, not less.
Once again, you are either misunderstanding or misrepresenting the basic disagreement between the authors of the papaer and the commenter: the former argue that the biosynthetic pathways for resin found today in gymnos and angios had already diverged in gymnosperms in the Carboniferous, while the commenter is quite certain that this is not the case, but that convergent evolution between todays angios and an ancestral population of gymnos explains the data best.
Both have some sound arguments on their side.
Since this research is based on a single group of samples and is not supported by fossil evidence or genetic evidence, it is hard to say who is right at the moment.
Singring, I am not misunderstanding or misrepresenting the basic disagreement, because there is none. Convergent evolution is required to explain this find, specifically because the trees that supposedly existed in the Carboniferous period are gymnosperm-like. Thus, the fact that angiosperms today produce resin that is more similar to the trees that existed in the Carboniferous means that the more distantly-related trees produce the more similar amber. As the author of the comment says, this can only be understood in terms of convergent evolution.
I do agree that it is hard to say what the complete story is, since this is just one find. However, I will say this – to believe in the evolutionary view that angiosperms were not around when Carboniferous rock was supposedly formed, you must “explain around” the evidence of the amber find.
Dr. Wile,
I read some other posts on your blog. While you probably don’t need it, I want to thank you for your principled, scinece-based stance on vaccinations.
The progymnosperms seem to date from about 380 million years ago, while this fossil is 320 million years old. Archaeopteris seems to have gone extinct circa 340 million years ago. So, this common ancestral population could have come well after true trees devloped, yet developed different amber chemistries well before the development of true angiosperms. For exmaple, the first diagram in the link below, drawn in 2007, indicates a ancestral split that goes back to the early Carbiniferous.
http://www.seedbiology.de/evolution.asp#fossils
It seems to be true we don’t have known sources of this amber chemistry between 320 million years ago and 140 million years ago. We may later find some, or we may never find some. I don’t think we’ll find proof such sources never existed. I still don’t see why we need to rely on convergent evolution to explain this.
At any rate, this find seems to be consistent with how one person interpreted the angiosper-gymnosperm knowledge some three years ago, so I don’t believe it contradicts evolutionary theory.
One Brow, thank you for your kind words. I appreciate your willingness to read more of my blog to see that I do take a scientific stance on issues. That is certainly more than I can say for some of the people who comment. You and I might disagree on the scientific interpretation here, but that is to be expected. Scientific disagreements are very common, and if discussed properly, they often lead to greater insight.
I agree that the diagram you show indicates an ancestral split that goes back to the early Carboniferous, but once again, look at what this diagram says the closest relatives are to the Lyginopteridopsida, which form the group that supposedly gave rise to the angiosperms: the Cycadopsida and Pentoxylales, which are both gymnosperms. Once again, then, in order to make sense of this amber find within the bounds of evolution, you must assume that the more distant relatives produce the more similar resins. This is opposite the predictions of evolution, and thus convergent evolution must be used to explain around the find.
I hope this settles the issue. I contacted David Grimaldi, the author of the commentary. He says:
Thus, as I originally said to both One Brow and Singring, there is no disagreement between the study and the commentary. There are two components: the resin-making processes that formed the amber in the study must have existed earlier than expected (obviously), AND the similarity between it and the amber produced by “younger” angiosperms must be the result of convergent evolution.
First, I want to thank you for contacting Dr. Grimaldi, and emphasize that I have no doubt your transmission of his statement is accurate. That said, this would still be third-hand knowledge.
The abstract for the paper is here:
http://www.sciencemag.org/cgi/content/abstract/326/5949/132
In particular, “… the types of polylabdanoid resins that are now typically found in conifers and those now typically found in angiosperms had already diverged by the Carboniferous.”
Now, maybe I’m reading too much into the choice of words. However, had the abstract said “had previously diverged” (indicative of a prior instance), instead of “had already diverged” (indicative of a prior timeframe). Having never submitted a scientific paper, I’m not sure how much attention is paid to these word choices.
Thanks for the followup, One Brow. While this is not directly from Dr. Anderson’s mouth, remember that Dr. Grimaldi and Dr. Anderson are colleagues. Thus, they are more than passingly acquainted with one another’s views. On a technical note, this is second-hand knowledge, not third-hand knowledge.
There is no need to have linked the abstract, as I link the full paper in my references. I have published several scientific papers over the course of my career in many different peer-reviewed journals. The word choices are quite important to the author, of course, but the reviewers can interpret them differently. However, given the fact that Dr. Grimaldi and Dr. Anderson are colleagues and that they discussed it and they both agree that convergence is the only possible explanation, it is now quite clear what the authors meant. They meant the PROCESSES existed, but they could not have been passed on to angiosperms by evolutionary inheritance, because there was no ancestor for angiosperms yet.
In other words, the progymnosperms (or early gymnosperms) that existed at that time had already developed several modes of resin production. That’s what “had already diverged” means. However, given the fact that the ancestor of angiosperms had to exist much later and would be quite different from the progymnosperms (or early gymnosperms) that existed in the Carboniferous (assuming the standard evolutionary view), there is no way angiosperms inherited this mode of resin production. Instead, some angiosperms developed it later independently.
Perhaps this what you and Singring are missing: The idea here is that organisms develop diversity over time, but much of that diversity is lost due to extinction. Thus, the authors are saying that the trees of the Carboniferous had already diversified a lot more than expected. However, most of that diversity was lost due to extinction, etc. When angiosperms came along 180 million years later, they just happened to evolve a resin that was very similar to one of the resins that was lost after the trees of the Carboniferous diversified and then mostly went extinct.
Hello Dr. Wile,
First let me say that, despite my flippant comments, I really am trying to get my hands on more scientific journals/publications, and I would like to offer a more sincere thanks for correcting me, so thanks. 🙂
I have been reading the comments and I had a quick question. If its not an example of convergent evolution, are there any other possible reasons?
Thanks again,
Pyrodin
Thanks, Pyrodin. I hope you find some good resources!
If you are asking what I think the explanation for this amber find is, I think it is angiosperm amber. That is certainly the most straightforward interpretation of the evidence. Now let me make it very clear that the straightforward interpretation is not always the best one. However, I tend to choose it until I find good reasons to choose otherwise. Of course, I have no problem with this being angiosperm amber, because I think angiosperms existed when Carboniferous rocks were laid down.
I think Carboniferous rocks, like most of the fossil-bearing rocks in the geological record, were laid down by a global Flood. Thus, unlike most scientists, I don’t see the various layers of sedimentary rock as representing time periods. Instead, I see them as representing different ecosystems that were preserved in different stages of the Flood. In my mind, this amber was simply transported from an area that had angiosperms and ended up landing and being preserved in an area that didn’t have any angiosperms in it. This, in my mind, explains both the absence of angiosperms in the rock formation and the presence of amber that (by all indications) came from an angiosperm.
Of course, that’s the young-earth interpretation, and I am well aware that most scientists disagree with it.
Dr. Wile,
I did some additional checking into the biology involved with a source I trust, but would prefer not to reveal without explicit permission. It seems the chemical composition of the two resins are identical, and function is also identical. The primary difference is shape of the molecule. Since there is no functional change and therefore no evolutionary pressure, the use of the term “convergent evolution” may not be appropriate.
It also seems as thought this difference may be due to as little as one mutation. Last I checked, by chance every human is born with something like 9 mutations, most of which are neutral. So, I don’t think saying that similar mutations, even if two or three were involved, occured in the same lineage separated by some 100 million years requires a “magic wand”, nor is it “sheer coicidence”. When compared to 100 million years, it’s not even unlikely.
Thank you for hosting this discussion.
One Brow, your source is quite wrong. In brief, Class Ia ambers are made from regular polylabdanoids that have succinic acid. Class Ib ambers are made from regular polylabdanoids that do not have succinic acid. Class Ic ambers are made from enantio-series labdanoids without succinic acid. Your source doesn’t seem to appreciate the huge difference. While it is true that these chemicals have the same CHEMICAL FORMULA, their chemical function is ANYTHING but identical. Consider aspartame, the active ingredient in Nutrasweet. It has two enantiomers. They have the same exact chemical formula, but one tastes bitter, while the other tastes sweet. This is the same situation here. Enantiomers are quite different from non-enantiomers, even when the chemical formula is the same. Their chemistry, function, and production are quite different. To say otherwise is to demonstrate a huge ignorance of stereochemistry.
Also, the idea that only one mutation could make the difference between producing regular labdanoids and enantio-series labdanoids is completely wrong. Producing enantiomeric versions of a chemical is much more difficult than producing non-enantiomeric versions of the chemical. Thus, the resin-making machinery that produces class Ic amber is quite a bit more sophisticated than the machinery that would produce class Ia or Ib amber. This, of course, is why angiosperms are the only known producers of this kind of resin. In addition, this is also why such amber is NOT classified with class Ib amber. If your source was right, there would be no reason to put this amber in a different class. It has its own class because the chemistry is quite different and because the processes needed to produce it are quite different.
Finally, if you think “convergent evolution” may not be applicable here, you need to take that up with Drs. Anderson and Grimaldi. They are the most closely-associated with the data, and they both agree that the ONLY way to explain it is through convergent evolution. Since they have strong arguments in their favor, you will need some strong arguments of your own to try to argue against them. So far, you have given none.
So once again, the data tell us that this amber comes from angiosperms. However, according to the hypothesis of evolution, angiosperms did not exist in the Carboniferous period. Thus, evolutionists must “explain around” the data by waving the magic wand of convergent evolution.
Dr. Wile,
Since I have assured my source of their privacy, I will only say that they are at least as as close to the research as is Dr. Grimaldi. Of course, as an eponymous poster quoting an anonymous source, I expect you will discount what I am saying. That does not affect its accuracy.
As to your assertion that only one mutation could not make the change between the different versions of the amber, that is actually refuted in the public record. For example, “The findings, though, may not surprise chemists, says David Gang of the Institute of Biological Chemistry at Washington State University in Pullman. Plants have a huge diversity of terpenoids, which are crucial for making important hormones. Since Carboniferous plants already made terpenoids, they wouldn’t have had to do much to make the compounds found in the Illinois amber, Gang says. A new version of one enzyme could do the trick. ‘This is interesting and neat, but not startling,’ Gang says. ”
http://www.thefreelibrary.com/Flowerless+plants+also+made+form+of+fancy+amber%3a+fossilized+resin+may+…-a0210724555
No, Dr. Gang is not my source.
As I pointed out, the current understanding many people close to the situation is that since 1) the Carboniferous trees are thought to be of the same lineage as angiosperms, and 2) there is no selective pressure because the different ambers work approximately identically, “convergent evolution” may be the wrong term. Convergent evolution is what a marsupial and a placental mammal both wind up looking a lot like a wolf due to the demans of the environments.
Thanks you for considering my comment and responding to them. I’v learned a lot.
One Brow, thanks for continuing the conversation. However, the link you gave does not support your view, and it clearly indicates that the authors also believe that this is the result of convergent evolution. Let’s begin with the convergent evolution part. The link you gave starts out with this quote:
Obviously, the “everything comes back in style” part of the quote is referring to convergent evolution. The “style” of amber was lost, and then it “came back” later when angiosperms happened to evolve it by sheer coincidence. Also, note that the link tells us the researchers say the tree which made this amber “could have been a predecessor of ancient conifers or some strange extinct fern.” Once again, then, it could not have passed the amber-making process on to angiosperms, as it was not an predecessor of angiosperms. This is what Drs. Grimaldi and Anderson both say.
You are also quite wrong when you say there is no possibility of selective pressure, because “the ambers work approximately identically.” The function of the AMBER is irrelevant to the tree. The function of the RESIN is what is important to the tree. A stereoactive resin has completely different chemistry from a non-stereoactive resin. Remember, the difference in stereochemistry of the isomers of aspartame causes one to taste bitter and the other to taste sweet. Thus, the chemistry of the resin that makes class 1c amber is quite different from the chemistry of the resins that make class 1a and 1b ambers, and that could very well be the result of selective pressures.
And yes, “convergent evolution” is the correct term. As Wikipedia defines it, “Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.” The amber is the same biological trait, but the lineages are unrelated, as your own source admits. So even your source agrees that if you don’t want to believe that this amber came from angiosperms, you must wave the magic wand of convergent evolution.
Now to the idea that one mutation could be responsible for making such a different kind of amber. The source says, “A new version of one enzyme could do the trick.” This is very true. To produce an enantiomer of something that it already produces, an organism would just have to come up with a new version of one enzyme – the one that catalyzes the production of the molecule. However, that new version could not be formed by one mutation! To come up with a process that is selective to stereochemistry, the entire active site of the enzyme would have to change. It would have to go from distinguishing no isomers to distinguishing just one. This higher selectivity could only occur as a result of multiple changes in both the shape and chemical properties of the active site, which would require multiple mutations.
Given your previous post detailing that even bacteria (let alone trees!) do not undergo and preserve two mutations which combine to completely resolve a problem while preferring a number of gradual changes to mitigate it, surely such an instance of convergent evolution shouldn’t even be on the radar. This requires a number of distinct mutations to return to a previous form of Amber at a survival benefit that is at best dubious.
Josiah, you are completely right. However, this kind of convergent evolution has to occur all the time in order to preserve the evolutionary hypothesis against the data. It is one of several reasons why many who follow the data and understand how the evolutionary hypothesis works have a hard time believing in it.
Dr. Wile,
I understand that, for you, there is no common lineage for gymnosperms and angiosperms, and I have no expectation of changing that position. However, if we are discussing an apparent difficulty within evolutionary theory, we need to stay within what evolutionary theory says. Currentnly, the oldest estimates for the branching between angiosperms and gymnosperms are less than 250 million years. The branching of all seed-bearing plants is stil under 300 million years. So, within evolutionary theory, the plants that produced this amber, living 320 million years ago, would be common ancestors to both gymnosperms and angiosperms, and therefore of the same lineage as modern angiosperms. There is no unrelated lineage in this instance, they are the same lineage, or very nearly so.
You are correct that the key is the resin, and not the amber, and I apologize for the apparent confusion there. However, while it is possible for two different isomers of resin to behave differently in the presence of air, my source was quite explicit that, in this particular instance, no such difference exists. For these resins, the drying properties are basically identical. Thus, there would be no selective evolutionary pressure to prefer one resin over the other.
You said the active site would have to go from distinguishing no active isomers to just one, but since the enzyme is actually being produced by the plant, would it not be more appropriate to say that active site would have to go from producing one enzyme to a different enzyme.
Here is an exact quote from my source:
“Both forms of labdanoids are biosynthesized by an enzyme and the difference between the enzymes that produce the labdanoids associated in modern resin with angiosperms and the variant that synthesizes the labdanoids associated with modern gymnosperms may differ by as little as a single mutation. Such a mutation could have randomly occurred several times and since the function of the resin is not affected, there is no evolutionary pressure selecting for either variant.”
I believe this will be my last comment on this post. I want to thank you again for your willingness to dialog and your firm commitment to science.
One Brow, I appreciate your thoughts. However, you still seem to be missing the obvious fact that you have been missing from the beginning. There is simply no way this trait could have been passed on by inheritance. This is why Drs. Grimaldi and Anderson are so emphatic that convergent evolution is the only possible explanation.
Perhaps your confusion lies in the concept of what a “related lineage” really means. This is a common source of confusion for those who don’t study evolutionary theory in depth. In a sense, evolution says that ALL species are related by a common ancestor – the organism that was first spontaneously generated from nonliving chemicals. However, in detailed evolutionary theory, the concept of relatedness depends on biological traits. Two lineages are related in terms of a given trait if they both share it due to inheritance. Thus, for this tree to be related to modern angiosperms in the context of this trait, it must have passed the trait on to the modern angiosperms. This is, of course, impossible, as Drs. Grimaldi and Anderson both agree. The reason is simple: the trees that are supposed to have lived in this era gave rise to gymnosperm-like trees first, and THEN that line gave rise to the ancestor of angiosperms. Since the gymnosperm-like trees do not produce this kind of amber, it is clear that this kind of amber-production died out BEFORE the angiosperm line. This is why the article you linked to me also relies on convergent evolution. It is the only possible answer in the evolutionary paradigm. It is hard to understand how you can read three articles (the two in Science and the one you linked to me) that all agree on this point and yet not accept it.
Your source is quite wrong, and there is just no way around that. He or she clearly doesn’t understand the immense chemical differences between stereoisomers. The fact is that a steroactive resin will behave chemically quite different from a non-stereoactive resin. Once again, take the case of aspartame, where each stereoisomer tastes completely different. Why? Because they are chemically quite different and thus interact with our taste buds in quite different ways. In the same way, a stereoactive resin will behave chemically quite different from a non-stereoactive resin, and thus selection pressure certainly can play an important role.
Let me clear up your confusion related to enzymes as well. The active site of an enzyme is, essentially, the part that does the work. It is where the substrate binds so that the substrate can be changed. As the article you linked said, a change in one enzyme could cause the change between class 1b and class 1c amber. However, in order for that to happen, the active site of that enzyme (the part to which the substrate binds) must change from not being sensitive to stereochemistry to being sensitive to stereochemistry. Once again, this can only happen if many details of the shape of the active site and the chemistry of the active site of the enzyme changes. In order for that to happen, the gene that produces the enzyme must mutate so that the shape and chemistry of the enzyme changes in the specific way necessary to produce stereoactivity.
This will not happen as a result of one mutation, regardless of what your source says. Indeed, we know your source is wrong, because his or her quote claims that the function of the resin would not be affected, and that is demonstrably false. Stereochemistry causes isomers to behave totally differently. This is well known and can be demonstrated by many examples, including the one I have been repeating over and over. Even Wikipedia understands this basic point: “As a result, different enantiomers of a compound may have substantially different biological effects.”
Dr. Wile,
I just wanted to offer a couple of minor clarificaitons.
When I typed up my last few comments, it was with the understanding that the trait could not have been passed on, but arose independently. That is, I understand the plant that produced the amber in the Carboniferous did not directly pass this trait on to angiosperms, and that this trait arose separately a several million years later. Nonetheless, for the reasons I mentioned, it does not qualify as “convergent evolution”.
You quote, “As a result, different enantiomers of a compound may have substantially different biological effects”. Note this is “may have”, not “must have”. According ot my source, this is one case where they do not have different drying properties. Many stereochemicals can only be distinguished by the use of polarized light, from what I have read. Do you have a reason for saying it is different in this particular case? You refer to one resin as stereoactive and another as nonstereoactive. It has been explained to me that each resin contains a different isomer. That is, we don’t see both isomers present in one resin, so neither resin is nonsteroactive (at least, that’s what I think you mean by the term). So, that would make them both stereoactive, with different isomers, would it not?
You wrote, “However, in detailed evolutionary theory, the concept of relatedness depends on biological traits”. That would be backwards. Biological traits are used to infer relatedness, but it is the relatedness that causes the similarity in bological traits, not the other way around. I would agree that in detailed evolutionary theory, the determination of relatedness depends on biological traits.
Also, based on what I have learned from my source, you should not insist that you know what Dr. Anderson says when you only have Dr. Grimaldi’s version. You are claiming an authority you have not verified.
This comment is probably more argumentative than I wished to be, but I did feel the need to say these things. Thank you for your patience.
One Brow, I am glad you see that the trait had to arise independently in order to preserve the evolutionary hypothesis. However, you don’t seem to understand convergent evolution, because that is the definition of convergent evolution. Once again, “Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.” Since you agree that the trait had to arise independently, then in terms of that trait, the groups are unrelated. Thus, this is, indeed, convergent evolution, just as Drs. Grimaldi and Anderson stress.
Your source still seems quite confused when it comes to stereochemistry. Entantiomers are isomers that are mirror images of one another but not superimposable. Class 1b ambers are made with labanoids that do NOT have this property. Thus, their components are NOT stereoactive at all. Class 1c ambers are made with labanoids that DO have this trait. Thus, they ARE stereoactive. So Class 1b ambers are made of nonstereoactive chemicals, while Class 1c ambers are made of stereoactive chemicals. This is, of course, why the resin that makes Class 1c ambers will be chemically quite different from the resin that makes Class 1b ambers.
Your statement “Many stereochemicals can only be distinguished by the use of polarized light” is quite incorrect. One of the properties of a stereoisomer is that it polarizes light in a certain direction. However, when it comes to biology, EVERY stereoisomer can be distinguished by its biochemical interactions. This is because all proteins are stereospecific. 19 of the 20 amino acids that make the proteins of life are stereoactive, and only ONE stereoisomer (the “L” form) is used. Thus, the very constituents of proteins are stereospecific. If a stereoactive molecule interacts with proteins, then, the enantiomers will react in different ways. Since the resin that forms 1c ambers is made from stereoactive molecules, it will react with other biochemical systems in a different way from the resin that makes 1b ambers, which is not at all stereoactive. When the Wikipedia quote says that a stereoisomer MAY have substantially different biological effects, the “may” refers to “substantial.” ALL stereoisomers will have a biological effect. Most effects are substantial, others are not substantial, but still quite measureable.
You claim my view on biological traits and relatedness is backwards. It most certainly is not. Indeed, the whole point of convergent evolution is to get around the fact that in MANY cases, similar traits cannot be the result of relatedness. Thus, SOMETIMES similar traits are the result of relatedness, and SOMETIMES they are the result of convergent evolution. As Drs. Grimaldi and Anderson make clear, this trait is one that comes from convergent evolution. And yes, it is also clear that Dr. Anderson believes this is the result of convergent evolution. First, his paper is clearly consistent with the idea, and second, for more than a year now, he has not objected to Dr. Grimaldi’s analysis of his paper, which appeared in the very same issue of Science. Indeed, as far as I can tell, there has been no objection to Dr. Grimaldi’s analysis by any evolutionary biologist. Thus, you are staking out not only an untenable position, but one that is rather isolated!
I didn’t find your comment argumentative – just inconsistent with the facts. I endeavored to explain the facts to you so that you will understand while your view is simply incorrect. Please do not take offense. I am an educator, and I am simply trying to educate.
If evolution theory survives contradictions, it’s because it has strong fundamentals.
I find it so funny when Creationists imply that Evolutionists have an agenda: to not accept screaming evidence of God. Really? Science don’t give a damn if God exists or not. It just wants to explain how things have come to be.
Take for example quantum physics. There’s a multiple of theories and no satisfying explanation yet (unlike evolution, which is a well established theory).
IF quantum physics were as important to christian faith as man creation, I bet we would be hearing: “these arrogant scientists are trying to explain the sub-atomic world with their natural theories but it’s proven physics can’t explain it. They just don’t admit there’s evidence pointing that God have direct control over sub-atomic particles”.
PAPA, the hypothesis of evolution survives contradictions because it is so plastic, it can be adapted to fit any data.
I agree that “Science don’t give a damn if God exists or not.” However, many scientists do, and there’s the crucial difference. Nowhere in my writings do I imply that evolutionists have an “agenda.” I just make the obvious point that their preconceived notions affect how they look at the data.
I think you need to do some reading about quantum theory, as you obviously don’t know that there are a lot of Christians who do not like quantum theory at all. However, those Christians who are interested in understanding God’s creation realize its importance, since it does so well at predicting the data. This, of course, is why evolution is certainly not a well-established theory, as most of its predictions have been falsified by the data.
I find it so funny when Creationists imply that Evolutionists have an agenda: to not accept screaming evidence of God.
Personally I find it funny when Evolutionists imply exactly the same. A few weeks ago I was reading Richard Dawkin’s famous book “The God Delusion”. I have not read any of the “response to Dawkins” type books. However even I as a 16 year old student can see that the book is full of cultural misunderstandings, ignorance of the opposition, straw man fallacies, Circular reasoning falacies, and more. It is a desperate attempt by a man who should know better.
It is an attempt to convert people to atheism by an Oxford Professor of Biology. The same man who is deputy to the British Humanist Association and tries to block the Papal visit to Britain & even have the pope arrested. Yet you say that scientists don’t care whether or not God exists?
Josiah, you are so right when you say Dawkins’s The God Delusion “is a desperate attempt by a man who should know better.” I heartily recommend his books on evolution – even his latest one – as they are well-written and represent reasonable thoughts from the other side. However, The God Delusion is simply awful.
Now that is interesting. I had kind of been put off by finding his most famous work so poor, but I suspect it might be more a question of his most infamous work. I’ll put his other works back onto my potential reading list then.
I won’t go into all that I didn’t like about it (unless I actually had an opponent), but I will ask for your thoughts about the little titbit on Anselm and Proslogion. A COMPLETELY random selection, of course. 😉
Wow! You are so lucky, Josiah. How did you randomly choose to ask me about one of my favorite philosophers?
Unfortunately, Dawkins tried to address Anselm by poking fun at him. As has been shown by several commenters on this blog, people who resort to poking fun rather than addressing arguments show that they really can’t defend their position. To call the Ontological Argument, for example, “logomachist trickery” shows how little Dawkins understands philosophy. Certainly the Ontological Argument is a weak one, but it has fascinated philosophers for centuries. Attempting to dismiss it by calling it names is just nonsense. Also, resorting to Euler’s quote [(a+bn)/n=x therefore God exists] indicates that Dawkins thinks Anselm is just pulling things out of the air. Of course, nothing could be further from the truth. The Ontological Argument is logically valid – it just relies on a very odd premise (actual existence is greater than existence only in the mind). Atheists in my undergraduate philosophy course at the University of Rochester at least understood enough philosophy to attack that premise. Dawkins couldn’t even do as well as freshman philosophy students!
I actually think Dawkins’s best work is The Blind Watchmaker; however, that book is getting a bit old. The Greatest Show on Earth is not quite the masterpiece that Watchmaker is, but it is certainly more relevant today.