Michael Denton’s new book is out, Evolution: Still A Theory In Crisis.
Denton’s stance is for structuralism and against functionalism, especially as functionalism appears in it’s current form as the modern synthesis or neo-Darwinism (the cumulative selection of small adaptive changes).
Denton argues for the reality of the types, that “there are unique taxon-defining novelties not led up to gradually from some antecedent form” and that the lack of intermediates undermines the Darwinian account of evolution. He also argues that a great deal of organic order appears to be non-adaptive, including “a great number of the taxa-defining Bauplans,” and that this also undermines the Darwinian account of evolution. Evo-devo is also showing us that “Darwinian selection is not the only or even the main factor that determined the shape and main branches of the great tree of life.”
These arguments are first set forth in Chapters 3 through 5 of the book and then defended throughout the subsequent chapters.
Denton provides a list of some of the Type-Defining Homologs:
The Pentadactyl Limb
The Feather
The Insect Body Plan
The Flower
The Amniotic Membrane
It is not just the major taxa which are characterized by unique defining homologs or novelties:
Centipedes
Beetles
Ants
Butterflies
Even individual species are often defined by unique novelties (autapomorphies in cladist terminology).
To head off a lot of irrelevant objections and nonsense from people who can’t be bothered to read the book, Denton accepts common descent and doesn’t appeal to “goddidit” as a better explanation.
- If types exist, what does that mean for Darwinian evolution?
- Does the existence of non-adaptive order undermine Darwinism?
- Does anyone think neo-Darwinism is even relevant to modern evolutionary theory?
I visualize a tree, as usually drawn, showing multiple branches and branching nodes. What I’m calling an intermediate is a branch naturally falling between two others, due to having common ancestors. In this view, we might say that chimps are intermediate between humans and gorillas.
But my take on the creationist view is that an intermediate is visualized as something halfway between current species, or genera, or whatever. Their view is more like what I’d call a hybrid, like a mule.
When it comes to fossils, we don’t usually know where an “intermediate” falls in the lineage that includes current populations. But I prefer to think of intermediate as the population that gives rise to diverging populations.
OK, then this means that any current population is a potential intermediate, depending on whether it branches someday. It also means that we can’t point to any historical population and say “this turned out to be an intermediate.” And thus we define intermediates away, since we can’t identify a single one.
So I went with organisms sharing characteristics of two “kinds”.
I don’t think our definitions are incompatible. In the fossil record there is usually no way to tell if an individual is an ancestor or a cousin. The closer the cousinship, the more difficult. I think the “official” definition of intermediate is a fossil that provides information about relationships.
I bought Denton’s book, to give him a fair hearing (Kindle edition). Maybe I’ll comment further when I have finished reading it.
What does it even mean to say that a theory is in crisis?
It means the theory is dangerous, and there’s an opportunity to make a buck peddling books.
I’d have appreciated that info much more if I’d not already tried to listen to that podcast again! 😉
It seems to mean two things. First, it means a scientific theory still being fleshed out. Second, it means “I can make a quick buck selling snake oil to the willfully ignorant.”
Apparently evilutionists are not the only ones reviewing the book without reading it:
I find it clearer if imagining there are just three basic events in evolutionary processes, adaptation, speciation and extinction. Groupings above the species level are convenient classifications although recent input from molecular phylogenetics has generally confirmed phylogenetic trees derived by taxonomy.
Hee hee.
Mung is thrilled enough about Denton’s book to post his OP about it, but he hasn’t read it yet. Hours later than his OP, he admits he’s “reading it”; he can’t claim that he’s already read it.
Except we do have reason to believe that Mung has the book in his hand before he starts writing about it, so there’s that at least.
Nor, strangely, does it seem to be for you. Supposedly, this thread is for discussion of the ideas in the book. I asked a simple and obvious question about it, yet you are uninterested in answering. Perhaps someone else can answer: What does Denton think caused the type-defining characters to appear? What, in other words, is his alternative to “Darwinism”?
John Harshman,
Yes, I’d be interested in that too, especially given his self-description as ‘agnostic’.
Hope denton’s book is another game changer like his first.
Evolution is a theory in crisis.
Yet its in crisis first because it was never a theory under the rules.
It was never based on biological scientific evidence but other subjects. So its not a scientific subject because its conclusions are not based on investigation of the process it attempts to explain.
Fossils are not bio sci evidence for anything except the fossil itself.
Id/YEc miss the methodological error of evolution.
Its fine to attack thier non bio evidence but the flaw was there was no bio evidence.
Evolution is a process and so its difficult to study processes that took place in the past, if they did, and results came and went in the past.
its not like physics which is easy since the process can be tested easily.
Robert Byers,
Yes, I’m sure it will be as much a game changer as his first.
petrushka,
Yes, it exists (also rendered ‘transitional’). Both words invite the usage you suggest, but in practice it can also apply to later descendants of that node, since they are assumed to ‘freeze’ some of its features. For good reason, all discovered transitionals are assumed to be branches off the main line, not part of it, but the length of those branches does not change the designation. Discussed here, in Michael Ghiselin’s rather scathing (“[…] an author who is obviously incompetent, dishonest, or
both […]”) review of the first TiC book.
But it was a game changer
What precisely would Denton consider to be an intermediate form? What features would it possess?
Larry Moran has some relevant thoughts
http://sandwalk.blogspot.com/2016/02/what-is-structuralism.html
Not a book review, but an interesting discussion of Denton’s main idea.
The mammalian diaphragm is a muscular wall that inflates the lungs by creating a partial vacuum. The crocodile diaphragm is a muscular wall that inflates the lungs by creating a partial vacuum. What was your point again?
Moran: It’s not a kooky creationist invention.
Moran: Structuralism is anti-evolution but only in the sense that it requires something (“form”) that has to be added to evolutionary theory (“functionalism”) in order to explain the history of life.
Moran: You can be confident that when you visit another planet you will not find vertebrates.
Or biochemists.
I read the first five chapters which was enough, as I explained in the OP, to get a sense of the book. I had at least read a substantial portion of the book before commenting on it.
(I of course have not seen the book). Does anyone know whether Denton continues, in the new version, to repeat the same howler that he had in the first version: that there is a big problem with molecular phylogenies since the molecular differences show that humans and frogs are equidistant from fishes, when frogs should be closer to fishes? He had mixed up present-day frogs with the common ancestor of us and frogs. He had forgotten that frogs might have undergone molecular evolution since that ancestor.
I was told that when this was (forcefully) pointed out to him in many reviews and responses, he finally admitted the error. So what does he say about that issue now?
I’m too lazy to type this up.
The Function of the Crocodilean Diaphragmaticus
Hopefully this will settle the matter of the diaphragm. They are not homologous.
What do you mean by “homology”? I know what biologists mean, but I don’t understand what creationists mean.
John Harshman,
You’re confused. It’s not what I mean by homology that matters, it’s what Denton means by it. Maybe you think Denton is a creationist. Maybe you think Denton is not a biologist.
https://en.wikipedia.org/wiki/Michael_Denton
ETA: Maybe this still isn’t the thread for you.
Why is evolution still a theory in crisis?
Its a no-brainer. What has darwinian evolution done for medicine? Agriculture? Ecology? Pyscology? Engineering? Physics? Sociology?
Nada.
Who even thinks in terms of non-teleological step-wise incremental change anyway?
It’s just a skeptic’s muse.
Why do scientifically ignorant Creationists still claim evolution is a theory in crisis when it’s still going strong and shows no signs of slowing after 160 years?
According to your link, he’s not a biologist.
Is this a poe?
This still doesn’t seem to be the thread for you, as you seem completely uninterested in saying anything. You’re the person who said that crocodylian and mammalian diaphragms aren’t homologous, not Denton. You’re the one whose understanding of homology is relevant to that statement. And you, as I understand it, are a creationist.
Still, if you would also like to explain what you think Denton means by “homologous”, feel free.
Arrrgh, I give up. Denton is not a biologist. He’s a Dishonesty Institute Fellow.
The thread is chock full of comments that amount to little more than insults padded by the occasional “skeptic” that can’t be bothered to read the book. Apparently this is precisely what Lizzie is hoping for. The skepticism of ignorance.
Denton defines what he means by “homolog” as early as page 13 of his book.
Whether or not I am a creationist is a red herring. You’re a male, so obviously you’re wrong. You’re an ID “critic,” therefore you are wrong.
If you have evidence to present that the mammalian diaphragm and the crocodilian “diaphram-like” are homologs, do present it. I already presented sources that say otherwise.
One of them explicitly writes;
Maybe they are creationists and non-biologists. Maybe you can’t be bothered to read the reference. Maybe they don’t know the meaning of homolog.
Gee, I went to the first link you provided, and it said he has a degree in biochemistry. Now if you are arguing that biochemistry and biology are the same thing, you might ask a biologist.
No one here claimed they were homologs. The dispute was your claim that such features such as a diaphragm cannot be found in organisms not classified as mammals. You were wrong.
People keep trying to discuss claims made in the book you’ve related here but you seem unwilling or unable to address the criticisms. You’re just shilling for more IDiot nonsense.
Denton said they are not. You’d know that if you’d read the book.
You claimed the link stated that he was not a biologist.
Flint: According to your link, he’s not a biologist.
You are probably the exact sort of “skeptic” Lizzie was hoping for at this site. Willing to deny to the death that a biochemist qualifies as a biologist.
Maybe he’s trying to say that the crocodile breathing-muscles work the same way and serve the same purpose as mammalian diaphragms, but are in fact different structures because they evolved as modifications of different structures? In that case, they wouldn’t be homologs, but they would indicate that evolution can find lots of ways to solve common problems.
The link stated he has a degree in biochemistry, not biology. Behe also has a degree in biochemistry, and is not a biologist. These are distinctly different fields.
I just pointed out that your link did not support your claim. You might as well argue that an electrical engineer and a suspension bridge designer are the same thing, since both are engineers, right?
Not all biochemists are biologists Mung.
I haven’t read the book. I haven’t seen the book. I was hoping to learn something about the book from you, but apparently you don’t want to talk about it. What is Denton’s definition of homology? What is your definition?
I looked into this just out of curiosity. And the deeper you look, you simply get confused at a higher level and about more important things. For one thing, the curricula for these two fields can have a great deal of overlap at some schools, and essentially none at another. In one school, biochemistry is part of the chemistry department, at another it’s in the biology department. But the subject matters these fields deal with are different, as are their tools (both physical and theoretic), and their language.
A biologist might study ecology, evolution, botany, zoology, etc. A biochemist would likely work for Big Pharma developing new drugs. Biologists tend to deal more with cells and DNA, biochemists deal more with proteins.
But probably all of this is beside the point. Denton is a Dishonesty Institute fellow, just like Jonathan Wells, who DOES have a biology degree. In practice, both are anti-evolutionists and both carefully ignore all biology which refutes their claims, which is basically about all of it.
Mung knows this which is why he’s doing his usual romp and stomp and act all indignant instead of presenting or defending any of Denton’s claims.
When I looked at Denton’s argument, I got a different far more subtle take. If all present day species of fish and tetrapods were diverging from some fish ancestor, then all fish should be as separated from each other as humans are from fish.
The fish members of Sarcopterygii members are too close to each other in similarity compared to the Sarcopterygii fish vs. tetrapods.
In otherwords, the fish INTRA-group divergence is too small. The way to solve this is to assume all Sarcopterygii fish came through a bottle neck as recent as the tetrapod emergence. That seems a bit unbelievable.
All the descendant lines of the founding ancestor of Sarcopterygii should be approximately equidistant from each other. That is the humans should be equidistant from the lungfish as lungfish are from the coelecanth. I don’t think that is the case at all.
This is confirmed by this paper:
I’m not at all surprised, the same problem is apparent in the Dayhoff diagram of cytochrome C. The lack of INTRA-group divergence is apparent as well:
http://i96.photobucket.com/albums/l188/dhawkinsmo/dayhoff_chart.jpg
Why aren’t the yeast as diverged from each other as they are from the mammals unless one assumes the absurd scenario that all extant yeasts diverged from a single ancestor about the same time the tetrapods diverged from their common ancestor. The INTRA-group divergence (yeast between other yeasts) seems all wrong unless one posits a common ancestor as recent as the tetrapod common ancestor.
Granted the molecular clock is not exact as you say, but it surely looks like it’s not ticking as fast between one species of yeast to another species of yeast — that just seems plain wrong to me unless we invoke are common ancestor for all yeast that was recent.
The yeast-to-yeast divergence is 27 at most, compared to at least 40 yeast vs. anything non-yeast.
Mung,
Followed, in Mung’s excerpt, by Denton’s definition itself? Sadly, no. We are merely told he defines it.
stcordova,
I think you should have a look at a tree. Imagine making a series of mutations, one per inch of every growing twig. Would all twig tips be separated by the same number of differences?
I have a degree in biochemistry. I wouldn’t call myself a biologist. Mind you, I wouldn’t call myself a biochemist either.