On Transitional Species (SUMMATION MESSAGES ONLY)

There are two senses in which one might use the term transitional. One is the way you've just defined it, but this perspective is a mere artifact of the rate of morphological change of species (i.e., how long the species remained unchanged morphologically), and the fossils that have happened to be preserved and that we have chanced to find. This is a very useful perspective, and by way of example it is the one used to hypothesize the existence of Tiktaalik that was famously found by Neil Shubin.The other sense of the term transitional is more accurate as it recognizes that our fossil window onto the past gives a false impression by providing the appearance of fixed species that do not change until suddenly evolution produces a new species. It understands that all species populations undergo change across all time, whether or not the change is fast or slow, and whether or not they are the type of changes that show up in the fossil record.--PercyEdited by Percy, : Improve wording in last para.

I think there may be a bit of minor confusion involved here. Biologists and paleontologists use both senses of the word "transitional". As with most word usage, which one they intend is usually clear from context.What you're talking about is "transitional fossils," but you're claiming that the word "transitional" has only one definition as a short way of referring to "transitional fossil." That would be incorrect. The word "transitional" can refer to species in transition, and it can refer to a transitional fossil. Context usually reveals the intended meaning.If you read the opening two paragraphs of the Wikipedia article on Transitional Fossils you'll see it makes the distinction fairly clear.This thread is not about transitional fossils. It's about transitional species. The opening post, Message 1, briefly touches on the common confusion of transitional fossils with transitional species.--Percy

This garbled interpretation of what I said comes from my Message 37. Read it again. What you're calling my "second" definition of transitional is actually part of my characterization of the first definition, which is your definition, namely that "transitional" can only refer to a "transitional fossil." It is transitional fossils that I was describing as a window into the past that gives a misleading picture of suddenly emerging new species.I define the two different senses of the word "transitional" in my Message 39 pretty clearly. The word "transitional" can refer to a transitional fossil. It can also refer more broadly to the fact that species are not static but are always in a state of change, a state of transition from what they are to something slightly different. It sounds like you're claiming that you're using the only valid definition of the term in the context of evolutionary biology, and that's not true. The idea that all species are transitional is a key concept within evolutionary biology. That's scary given the number of incorrect admonishments you keep issuing here. Since I actually typed in "Wikipedia Article on Transitional Fossils" as the text for my URL, obviously I knew what article I was linking to. I suggested looking at the first two paragraphs, and I was hoping you would see this lead sentence in the second paragraph: I was just trying to provide you another place that mentions the concept of transitional species. Hopefully now you understand, but next time it might help to think a bit before putting fingers in gear. You're demonstrating the typical hothead's ability to jump to wrong conclusions. Not discuss, but it *did* clearly describe populations as being in transition. Obviously the only one not reading things through is you.It occurs to me that the intended meaning of transitional can be very clear even given very, very little context. Probably the term "a transitional" would almost always be used to refer to a transitional fossil.--PercyEdited by Percy, : Grammar.

Actually, that's not what you were saying. You were saying that biologists and paleontologists only use the word transitional to refer to transitional fossils, and that the other sense of the word transitional was not part of their technical vocabulary. That is incorrect. That all populations everywhere are always in evolutionary transition is a central concept of evolutionary theory.--Percy

Some confusion is resulting from occasionally reading the word transitional with a meaning different than the one intended by the author. Like most words in the English language, transitional has more than one meaning. Often the meaning is clear from context, but not always.This thread is about transitional species, which like a transitional fossil is representative of an intermediate stage of evolutionary history between different groups.But in some cases reference is made to the fact that all species are always in a state of transition, and in this sense all species are transitional. One wouldn't use the phrase "transitional species" in this context because with all species being transitional it would be redundant.--Percy

The topic of this thread is not "Kuresu is too a creationist," and it is not "I think Kuresu misunderstood something so I have to attach a derogatory label to him." More importantly, at EvC Forum we work very hard to keep discussion focused on topics rather than participants.--Percy

Pandion, there is no need cluttering up the thread with reiterations of your opinion of what evolutionary biologists would and wouldn't understand.--Percy

If you have any Hovind news, there's a Hovind thread that hasn't been updated in a while: Hovind's solitary considerations--Percy

There are two problems with this citation.First, it's a bare reference with no supporting explanation or argument. Replies may as well consist as, "The Origin of Species rebuts Denton," and that would be just as pointless. Rule 5 of the Forum Guidelines requires that people not make arguments through bare references (it refers to links instead of references, but the intent is clear):

5. Bare links with no supporting discussion should be avoided. Make the argument in your own words and use links as supporting references.

But I'm curious. Did you cite Denton's book because you read it? Or did you cite it because you saw it used somewhere else to support the same argument you're making? If the latter then tch tch.Second, Michael Denton no longer stands behind much of what he says in that book. He has changed his mind and now, like Michael Behe, is an IDer who accepts much of evolution and evolutionary history.--PercyEdited by Percy, : Grammar.Edited by Percy, : Grammar.

Hi Trev777,This is going to be difficult to explain in a way that you will find reasonable, but the short of it is that that New Scientist article (Evolution: hacking back the tree of life) is just plain way over the top in what it says about complexity trends, specifically: Increasing complexity has never been a rule within evolutionary biology. I have no idea why the article's author, Laura Spinney, would say such or thing, or why the editors let it through. There may be contexts in which increasing complexity is expected, but she doesn't qualify what she says in any way, and so in the way that she states it she is just plain wrong.There are plenty of examples of diminishing complexity, and Spinney even mentions some, like the lost legs of snakes and whales. The example I usually use is cave fish who have lost their eyes, and there are many other examples. In fact, there are so many examples of diminishing complexity that no one familiar with evolution would ever make the mistake of claiming that increasing complexity is a rule.Early in the article Spinney quotes Detlev Arendt: Maybe this is what led Spinney astray. Not having access to the whole conversation it is difficult to tell why Arendt would have phrased things in this way, but as others have already said, the article is actually about something we've known about for a long time, that the tree of life as originally constructed based upon outer appearance often has to be revised in light of genetic information. The hippo being more closely related to whales instead of pigs was one example in the article.The significant new information that is the reason for the article is that some of the genetics-driven revisions to the tree of life are turning out to be surprisingly larger than originally expected.There's only one overriding rule in evolutionary biology, and it's the same one as in the annual NCAA basketball tournament, with which you're probably unfortunately as unfamiliar as I am with Premier League soccer, but the rule is, "Survive and advance." If survival requires getting simpler then that's what will happen, the only other alternative being diminishing populations and eventual extinction.--Percy

I see the same contradictions others have noted. I would reinterpret what you're saying as that the whale evidence might support evolution, but that the rest of the evidence does not, and that whale evidence by itself is insufficient to conclude that evolution happened.But there are many examples of evolution as well evidenced as the whale, the horse being one that is very well known. It would indeed be evidence against the current evolutionary model of gradual species change over time if there were evidence for a flood around 4500 years ago followed by species change radiating from the Middle East to all points around the globe. Were such evidence found we would certainly have to consider the possibility you suggest of "innate triggers" and so forth. But there is no evidence for a flood, no evidence for a world wiped clear of life and repopulated 4500 years, and no genetic evidence for "innate triggers" that would cause the kind of species change you have in mind. The geologic column contains a fossil record of species change over time, with increasing differences from modern forms with increasing depth. That they appear to have evolved through lines of descent was readily apparent long before Darwin ever conceived his theory. Relatedness and the appearance of descent has been apparent to so many for so long that it seems perverse to deny it now.And yet you do, thereby introducing yet another contradiction. You claim (in another message) that the designer designed in the nested hierarchy that is reflected in the evidence of relatedness and lines of descent while denying that the nested hierarchy exists. Odd.--Percy

Hi Robert,No need to quote my entire post. A link to my message is already placed with your message, so anyone who wants to read it in its entirety can click on that link. Plus if you don't trim the quoted portion down I can't tell which part of what I said you're replying to. So would I. Why do you think that's a rebuttal? And your evidence for this is? Could you clarify what you're talking about by providing an example or two? I suggest you stop saying this. It is clear from the number of times you've repeated this that you think it is an effective point, and as I explained in my previous message (the one you quoted in full, look at the top) I think I know what you're trying to say, but when you say it like this it doesn't make any sense. It's like you're taking the old saying "The exception that proves the rule" literally. Exceptions don't prove rules, they test them, which is what the old saying originally meant before the meaning of the word "prove" <ahem> evolved.--Percy

Interesting, I hadn't heard that one before. If you go to this link at Widipedia, it describes the interpretation I was using.--Percy

I think what you mean to say is that creatures do not have anatomical evidence that their very distant ancestors were anatomically different, and of course you are wrong. Mammals, for one, all share the same basic body plan of four legs (or two arms and two legs), four feet (or two hands and two feet), a head, a jaw, teeth, mammary glands, etc., etc., etc., yet all the species of mammals are different. And if you examine the fossil record you'll find the fossils of some of the creatures intermediate between modern forms. If evolution never happened there could be no reasonable expectation that such fossil forms would exist, and yet they do.About these "bits and pieces" you keep talking about, it seems that you must think that, for example, for a protohorse to evolve into the modern horse that the protohorse's clawed paws had to become vestigial and replaced by a new hoof structure. And that if the modern horse actually evolved from some protohorse then we should be able to see vestigial paw structures inside the foot of a modern horse. It certainly sounds like this is how you think evolution works, with your claims that we should find all sorts of bits of pieces of distant ancestors.Vestigiality doesn't deserve the attention it gets, but it is very true that some structures do, because of changing environmental circumstances, find that their original purpose no longer exists. They can't suddenly disappear. What happens is that they're gradually selected against, often becoming smaller and retaining less of their original but now unused capabilities. This happened to the human appendix and to the whale's and snakes legs.But what is much more common is that one structure evolves into a new or modified structure. No bits and pieces of the old structure are left because they've all become incorporated into the new structure. The hooves of the modern horse evolved from the paws and claws of some ancient protohorse. Bones from the reptilian jaw became the middle-ear bones of mammals. There are not bits and pieces left over because they've all become incorporated into new structures with modified and sometimes completely novel functions. The opposable thumb of apes evolved from earlier mammals with no opposable capability, while the panda evolved a "thumb" from a wrist bone, and there are no bits and pieces to be left over. Of course vestigial organs exist, they're part of the evolutionary history of life, but they are dwarfed in sheer volume by the co-opting of existing body parts for modified or new functions, which is far, far, far more common than vestigiality.--PercyEdited by Percy, : Typo.

I didn't want to get into the additional complexity of "some of the paw became vestigial and some didn't." If you present too much detail you lose the audience. Accuracy and brevity are often incompatible, but then the same is true of detail and clarity. You can have brevity and clarify, or you can have accuracy and detail, but you can't easily have both.--Percy