Land Mammal to Whale transition: fossils Part II

Hi Randman,I see your Message 56 is being responded to in this thread already and I don't have to do anything. I'm sorry you don't like the spectrum analogy, but you were the one who introduced it in Message 51: This isn't an analogy that would have occurred to me, but it seemed an okay analogy, so I just stayed with the analogy you seemed to like. If you think it's a dumb analogy I suggest you complain to the originator. I haven't read past this message yet, I hope this isn't indicative. Let's keep this thread on topic and not start arguing about analogies.--Percy

As far as the Coelacanth goes, I think I have to agree with Ned, though it might hinge on how you define "closely related". Modern species of Coelacanth are not the same species, not the same genus, not even the same family, as those we've found in the fossil record. They're the same order, which is a very broad classification category. See Message 73 for more detail.I think Ned's point is that the modern Coelacanth, being only in the same order as extinct Coelacanth's, is not what we normally refer to as "closely related," and that he suspects the same is true about the others you mentioned.--Percy

I'm not sure drawing a distinction between bush and tree is helpful. I've heard this analogy many times, but look at the characterization you quoted: If there's something about a bush that is analogous to "starts and stops and major jumps", I'm at a loss. I trim both trees and bushes around my yard all the time, and this description doesn't ring any bells for me at all. I doubt it does for anyone else, either, except perhaps the author of this description.In my view, the distinction between tree and bush is tiny. You shrink a 100 foot elm down to 3 feet high and it would look like a bush. If some people find the bush analogy more helpful than the tree analogy then I think that's fine. What they're actually trying to do is emphasize the fine graduated changes that happen in evolution, which is what we've been telling you all along. I think what you're trying to say here is that if the modern horse evolved from an evolutionary tree that included 28 ancestral relatives (not all living at the same time, of course) that the whale should have some similar number. This is not an unreasonable assumption, but you have to recognize that there are many other factors to take into account:

• There is no way to know if horse evolution is typical. Only by examining the evolution of many different species could we arrive at some kind of relationship or general rule for the number of species expected to be represented over time.
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• We can't know how complete our record of horse evolution is. It may be very complete. On the other hand, 57 additional varieties of horse may have evolved and left fossils in a region of the American west that has since eroded away and no longer exists. Or they may be buried in geological strata that are still buried a mile underground. We can't know what's in the missing or unreachable strata. This is part of why the fossil record is so serendipitous, so unpredictable in what gets preserved or discovered.
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• Speciation rates are a function of the stability of ecological niches. A stable ecological niche should not produce much, if any, speciation. Rapidly changing niches should cause a great deal of speciation. In making comparisons between horse and whale you have to factor in the relative rates of change of their ecological environments.

That we do not know these things is why the rest of us belive you cannot estimate how many fossils of extinct whale-related species we should find. So I think we all pretty much disagree with you when you say this: Why do you think we should find more whale transitionals than we do? You can much more reasonably argue that more whale transitionals existed than have been found (a pretty safe bet, I'd say, given the rarity of fossilization), but it makes no sense to insist that they must be found, or even further, to insist that since they haven't been found that they therefore never existed.--Percy

Hmmm. Okay, we must be thinking about different types of bushes. Almost all my bushes have "main stems", exactly analogous to a tree.I think the bush analogy is fine if it works for you, but for me in terms of branching structure I see no significant difference. The fact that a tree is big and a bush is small doesn't seem relevant, it's the branching that's significant.I have no objection to the bush analogy. What I objected to was its characterization as representing "starts, stops and jumps." I don't see how a bush is any better at representing these than a tree, which is to say, not at all.--Percy

I have bushes with an even heavier emphasis on the trunk than a tree, relative to height. Maybe it would help if someone mentioned the type of bush and tree they have in mind for this analogy, because the supposed distinction between bush and tree isn't apparent to me. When I look around my yard, which has plenty of each, the greater bushiness of bushes is not apparent.I understand the distinction people are trying to make with the analogy. Anyone who finds the analogy helpful is welcome to it. But in the end I think there is no guarantee that people will all draw the same distinction between bushes and trees, and once you have to start explaining the analogy it has lost its effectiveness.I wonder if part of the problem is that the tree people are thinking of is the one used to represent the evolutionary tree in old text books. That tree definitely is not as bushy as the ones I have in mind. When I think of a tree I'm already thinking of something pretty bushy. Before people introduced the bush analogy I already thought of evolution as very finely graduated with many offshoots, and so I didn't see the need for it.But we're drifting way off my main objection to the analogy, which was that the characterization of a bush as better representing "starts, stops and jumps" than a tree. Does anyone see this?--Percy

Don't forget that next word was "but". It could possibly have been a reasonable assumption if it weren't for the points that followed.

• You haven't established that horse and whale evolution are comparable.
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• You don't know how complete the fossil record is for either horses or whales.
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• The rate of evolution varies according to the stability of the ecological niche.

I think you're confusing two different things:

• The number of transitionals that existed.
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• The number of transitional fossils actually discovered.

Accepting just for the sake of discussion your estimate of hundreds of horse transitionals, because of the rarity of fossilization you cannot conclude anything from discovering only 30.This is why I am encouraging you to seek some consensus about the likelihood of fossilization. It makes no sense for you to keep announcing your conclusions about how unsupportive the whale fossil record is of evolution if they're based upon an erroneous assumption of frequent fossilization.What I am saying is, you don't have to keep claiming the whale fossil record doesn't support evolution in every other post. We already know you believe this. What is under dispute is your underlying assumptions that allowed you to reach this conclusion: you assume a relatively complete fossil record and that evolution is non-continuous.In other words, until you convince people that the fossil record is relatively complete and that evolution is non-continuous, there's no point in jumping ahead to your conclusions.--Percy

You're mistaking an argument for data. You're assuming that horse and whale had similar fossilization histories because they're both mammals. This is an argument, not data.That they are both mammals is slim support. Many, many creatures are mammals, yet few, if any, have as complete a fossil record as the horse. That the horse fossil record is cited so often is because of its unusual completeness relative to other creatures.Additionally, whales evolved in different geographic regions, different environments and different geological periods, and they were, of course, prey to different species and microbes. As I said, you don't have any data for your point of view, unless you consider the fact that "they're both mammals" is data. And I don't have any data, either, but unlike your argument that "they're both mammals", the fact that few fossil histories are as complete as the horse and the fact that all the conditions under which they evolved were different argues strongly against the simplistic "they're both mammals, so they should have similar fossil representation." How are you going to conclude anything numerically useful with a range from 50:1 to 1000:1? If I asked if you could drive over to my house tomorrow and you asked me how far it was, and I told you between 50 and 1000 miles, that wouldn't help much, would it? Numerical answers that span orders of magnitude usually aren't very useful. I wouldn't even venture a guess. You can venture a guess if you like, but it would just be a guess and not very useful. You continue to keep restating this conclusion in contradiction to the facts. By your own guestimate (not one I necessarily accept, by the way, I'm just sticking with figures you accept for now) the ratio of total species to fossilized species ranges across a couple orders of magnitude. You can get some outer bounds on the problem, perhaps, but nothing approaching a solid answer. It is the fallacies you accept that lead you to believe asking this question makes any sense. Evolutionists would not make any estimates of the number of fossils that should be found across so broad a range of geography and time. It would be a fools errand. Fossilization is too serendipitous a process.You are once again drawing false conclusions based upon your erroneous assumption that fossilization is common. You can't keep jumping ahead to your conclusions until you settle the discussion of how rare or common fossilization is. You cannot generalize like this. The good representation in the fossil record of one group cannot be used to extrapolate that all groups should be well represented, even of similar creatures. For example, many creatures are known by only one or a few fossils, and in some cases by only a tooth or toebone. As I mentioned in the Where are all the missing links? thread, one possible reason is that evolutionary change is more rapid in small populations, which because of their small numbers are much less likely to be fossilized and discovered. And there are other factors I mentioned in that thread, which I won't repeat again. Neither point is relevant. Evolutionary change is continuous. Our modern classification categories are imposed upon the current evolutionary state of living species, a mere snapshot in time. But this is the classification system upon which we view fossil history, though the categorization of fossil species into modern categories can often be problematic.--Percy

I already described this in some detail in Message 123. You haven't responded yet. Why don't you give it a read and let me know if you have any questions. It cannot be anything but. Each offspring is only very slightly different from its parents. Evolutionary change cannot proceed in steps any larger than the difference between parents and child.It becomes obvious that evolutionary change cannot proceed in species-sized steps when you ask who an offspring that was a new species would breed with. Obviously there would be no available mates, and the new species would die out at the end of the life of its first member. So we know just by this simple logic alone that evolution must proceed in steps that are smaller than the size of a species.But genetic information tells us that the change is very tiny, and I described this a little in the other thread. This is why DNA testing can determine parentage, because the genetic distance between parent and child is so small. It proceeds at a varied rate, but I certainly wouldnn't call it "strange".If micro-evolution is possible then macro-evolution is inevitable. Let's say you're going to take a trip, and you're going to do it on foot. You're going to string together many micro-trips of one step each. After enough micro-trips you discover you're in another city and that you've accomplished a macro-trip. At what point did you complete sufficient micro-trips to be considered a macro-trip. For the purposes of this analogy, we could call it a macro-trip when you reach the next city.So we could consider macro-evolution as occurring when a species reaches the next species, meaning that it can no longer interbreed with the original species. And it achieved this macro-evolution with many small micro-evolutionary steps, each one accomplished through a single reproductive event. Yes, we know we don't find large populations leaving a record of gradual change. We've explained many times now why large populations tend to be stable, and I'm running out of analogies for you. We've explained that small changes are swamped by large populations but can have a significant impact in a small population. I myself have used a couple analogies. I've used the analogy of shouting in a small quiet room, which would get everyone's attention, versus at a rock concert, which would be heard by few. I've used throwing a rock into the ocean, where it would have little effect, versus a mud puddle, where it would have a huge effect. If you can explain your objections to these explanations, instead of repeating your original objections, then we can offer clarifications and the discussion can move forward.--Percy

So you accept that evolution does not proceed in sudden species-sized steps? I just want to be sure we've got this misunderstanding squared away now, because I'm surprised to see you say this after the way you rejected "spectrum" as an analogy and called "continuous" poor terminology. I think you mean adaptive changes. While the changes will be very small, they won't necessarily be adaptive. Changes at the genetic level, either as allele permutations or as mutations, could have any of these results:

• No expression in the organism whatsoever. The genetic change has no effect.
• An adaptive improvement for the organism in its ecological niche.
• A neutral change relative to its ecological niche.
• A maladpative change relative to its ecological niche.

Thank you for restating your premature conclusions for the umpteenth time. No randman post is complete without them! I believe you that you are perceiving it this way, but could you please believe us that it is our perception that you are failing to make some key connections.The issue is not being dodged. It has been explained to you over and over that small populations under environmental stress are most likely to change in relatively short time periods (thousands of years) and are least likely to be preserved in the fossil record.Let's say that species A lived 5 million years with an average population at any given time of about a million creatures. Multiply 5 millions years by 1 million creatures and you get 5 trillion creature-years.Let's say that species B lived 10,000 years with an average population size of 10,000 creatures yielding 10 billion creature-years.This means that species B is only .5% as likely as species A to leave behind fossils. For every 1000 fossils of species A we find, we can only expect to find 2 of species B.But, as I explained before, there are many other factors at work. This is from Message 111, to which you also haven't replied: If you reject these then you have to explain why. Merely repeating over and over again that "there should be more transitionals" (sic) provides no information about why you continue to believe this. Reaching conclusions about the nature of speciation from horse evolution is valid.Concluding that all evolutionary series should be as well represented in the fossil record as the horse is invalid. I pointed this out to you once before in Message 193: In addition, the horse fossil record is cited so frequently because it is so exceptionally complete. If it weren't so exceptional it wouldn't be cited so often. You cannot expect the average to approach the exceptional. I did not dismiss the horse evolutionary story. I dismissed your drawing conclusions about whale representation in the fossil record based upon horse representation in the fossil record. Your supporting argument so far has been, "They're both mammals." I see no reason why, either. Clearly you don't understand what I was saying if you think I was saying this, but you didn't quote anything specific that I said, so I can't guess what led you to think this.Perhaps it was where I was speaking of evolution as a continuum of gradual change? If so, keep in mind the example of ring species. There can still be fairly significant change while maintaining significant gene flow between two distinctly different populations. Keep in mind the analogy of micro-trips and macro-trips. Just as each step is not a journey to a new city, each small evolutionary change does not create a new species. I think Nosy and I are probably pretty much in agreement that you seem to keep repeating your conclusions with no apparent line of reasoning. You've made some "if this, then that" statements, but it's not logic we can follow. It all seems like "It's too hot outside, so I think we must be out of forks" type of reasoning. Our reaction is often, "Why does he think one follows from the other?" I never said it shouldn't. I said you shouldn't expect to find the fossil records of other groups to be as complete as for the horse. It's good that you're repeating back to me what you think I said, because it is clear you often misunderstand what I'm saying. I would never have said that horse habitats were more varied than for whales. What I believe, and what I likely said if I said anything at all (once again, you don't quote anything, so I can't know what passage from me you're misinterpreting) is that it isn't possible to know how many habitats were involved. The fossil record is serendipitous and incomplete. I think you should continue to try to avoid drawing conclusions until you at least get an indication from those you're debating with that you've got an accurate understanding of what they're saying. Most of what you say you think I said I don't recognize.--Percy

When you think people are being particularly stupid you might consider the possibility that perhaps you've misinterpreted some aspect of what they're saying. If in the end you still decide they're being stupid, be polite anyway, because that way you can remain within the Forum Guidelines.In this case there are two things you're missing. First, you're misapplying the spectrum analogy. It was only intended to illustrate that change is a continuum and is not sudden. It was an analogy to the nature of the small scale of evolutionary change across a single generation, and not as an analogy to evolution itself. Second, if a 1D spectrum is such a significant problem for you then you need only say so. Here's 2D spectrum with a branching tree superimposed: The next time you think you see something dumb, it might do you well to give it a more critical examination to see if perhaps they're saying something different than what you thought. Jumping to conclusions and thinking everyone is dumber than you makes it very difficult to converse with you. Where does any small population come from? The world abounds with species of small populations. Where do you think they came from? Obviously, some evolved from species that also had small populations and so they have always had small populations. Others used to have large populations but now have small populations. Bison once roamed the American west in vast herds then almost went extinct, dwindling, I think, to only a few hundred at one point. Passenger pigeons used to fly in flocks so thick they blotted out the sun, now they're gone.Obviously, large populations can become small populations, and even no population at all. The fate of most species over geological time is extinction, so quite obviously even the most numerous of species, from trilobites to triceratops, from brachiopods to brontosauri, must have reached a point where their populations became very small, and ultimately zero. No one is disputing that evolution is not a straight-line progression, or that some populations are large (our own, for example). Once again you didn't quote anything, so I can't imagine where you picked up this misimpression that anyone was saying this. I again encourage you to give things a second look when you think they sound stupid. You can average out the changes as a mathematical exercise, but that doesn't mean anything about the reality of when speciation actually occurred. You are again restating your conclusion without any rationale. It has been explained that evolution occurs most rapidly in small populations, and that small populations are, because of their size, less likely to leave fossil representatives, and that fossilization is serendipitous anyway. Until you start rebutting the specifics of what we're telling you instead of merely repeating your conclusions, the discussion cannot move forward. I think the first "not" in your paragraph should probably not be there, but even reading it without the "not" I'm not able to make any sense out of this. It doesn't appear to resemble anything I believe or ever said. I never said that the transitionals were barely functional. You must be thinking of where I said that small populations under environmental stress can evolve quickly, for example, into a new species in just some thousands of years, perhaps less. I also provided a number of other reasons that expected fossils might not be found. As we've been telling you, fossilization is not common, and it is not predictable. Jumping ahead to your conclusions is not going to help the discussion until we reach agreement about fossilization.--Percy