Let's explore the obvious answer as well as the findings of the paper in more detail. Although I refuse by principle to link to UcD postings, this one has earned the highly coveted link from PandasThumb. In a commentary Gene blocking could help quash malaria the paper is described as follows:Researchers have discovered two proteins essential for reproductive cells to latch onto each other and then to fuse. Changing at least one of these proteins appears to prevent species from interbreeding. This appears to open up a way to stop malaria. A new species would appear to require at least two changed genes, one for the protein change and the other for the matching protein docking change. What is the probability of these simultaneous changes occurring by random mutation & natural selection - versus - this being a key/lock design with complex specified information? Such simultaneous changes appear to be pushing Behe’s limits of Darwinism.
— DLH
So far so good. However, the same article explains:In a study to be published in the April 14 issue of the journal Genes and Development, and available now, researchers from UT Southwestern have found that sexual reproduction begins with two genetically different steps: First, two reproductive cells must latch onto each other with one protein, and secondly, they must fuse their membranes to form a single cell using a different protein.
So what did the researchers do? Wonder about whether the system could have evolved or was 'irreducibly complex'? No, they took a far more applied approachAlthough the study involved only single-celled organisms, Dr. Snell said that the use of two different proteins in the two-step fertilization process may be the case in all species. The gene controlling whether egg and sperm can bind would be unique to each species, while the gene for the second step—fusing into a single cell—could be more universal. For example, the researchers found that HAP2, the gene that controlled whether cells fused, is also present in agriculturally important crops such as corn and wheat. For the parasite that causes malaria, fusion is controlled by a gene not found in mammals, so blocking this step might prove effective in stanching the spread of the disease without harming humans, Snell said.
From the abstract our friend at UcD proposes:The British researchers found that blocking HAP2 in Plasmodium cells stops the fusing step. When mutant Plasmodium organisms lacking HAP2 were injected into mice, mosquitoes that bit the mice did not become infected with Plasmodium and therefore could not spread the infection to other mice. This indicates that without HAP2, Plasmodium could not reproduce in a mosquito’s gut, a vital step in the cycle of infection.
Let's look at the abstract in question:From Janjie’s et al. abstract: Fact 1: “HAP2 is essential for membrane merger” Fact 2 “yet Chlamydomonas minus and Plasmodium hap2 male gametes retain the ability, using other, species-limited proteins, to form tight prefusion membrane attachments with their respective gamete partners.” From these facts and the ID paradigm, following are two proposed ID hypothesis to pursue (as posited by a design engineer): ID hypothesis 1: The membrane merger including HAP2 essential for such “male”-”female” cell merger are irreducibly complex. ID hypothesis 2: This “male”-”female”protein & docking site are part of a species specific reproduction - barrier system that is a species specific irreducibly complex system. Submitted for further evidence to support and/or refine these hypotheses.
— DLH
The overview article explains the relevance:Abstract The cellular and molecular mechanisms that underlie species-specific membrane fusion between male and female gametes remain largely unknown. Here, by use of gene discovery methods in the green alga Chlamydomonas, gene disruption in the rodent malaria parasite Plasmodium berghei, and distinctive features of fertilization in both organisms, we report discovery of a mechanism that accounts for a conserved protein required for gamete fusion. A screen for fusion mutants in Chlamydomonas identified a homolog of HAP2, an Arabidopsis sterility gene. Moreover, HAP2 disruption in Plasmodium blocked fertilization and thereby mosquito transmission of malaria. HAP2 localizes at the fusion site of Chlamydomonas minus gametes, yet Chlamydomonas minus and Plasmodium hap2 male gametes retain the ability, using other, species-limited proteins, to form tight prefusion membrane attachments with their respective gamete partners. Membrane dye experiments show that HAP2 is essential for membrane merger. Thus, in two distantly related eukaryotes, species-limited proteins govern access to a conserved protein essential for membrane fusion
So what is the excitement all about? It starts with the plant Arabidopsis and a gene called HAP2 which is a sterility gene. Remember that plants reproduce sexually and 'sperm cells' develop which are transported to the 'egg' where it fertilizes. HAP2 is a gene found in eukaryotes, including mammals, although as I understand it, the gene has evolved its function. Based on the finding that a mutation in the HAP2 gene in a plant could induce infertility, the researchers set out to find a similar gene in Chlamydomonas, a unicellular green alga. To the surprise of the researchers, the gene identified showed it to encode a homolog of HAP2. The researchers decided to do additional searches for HAP2 and found them in a large variety of genomesIf the first step in reproduction, binding of egg and sperm, is controlled by a single gene per species, then the binding step would serve as a gatekeeper to prevent incompatible cells from getting close, Dr. Snell said. Evolutionarily, this scheme makes sense, he said, because it would take only a mutation in the single gene that controls egg-sperm binding to create a new species.
From an evolutionary perspective this is a very valid question. Since the malaria parasite reproduces both asexually and sexually, it provides for an interesting testing ground. The researchers replaced all the protein coding sequences of HAP2 and found thatOur results showing that Chlamydomonas HAP2 mutants were fully motile and fully capable of flagellar adhesion demonstrated that the protein functions directly in the interactions between minus and plus gametes at a step in fertilization after initial gamete recognition. Moreover, we found that in addition to being present in the human malaria parasite P. falciparum (Mori et al. 2006), HAP2 was also present in the rodent malaria parasite P. berghei (Fig. 1G), in which sexual development is most amenable to experimentation. We therefore chose this species to ask if HAP2 functioned directly in gamete interactions in an organism that is only very distantly related to plants and green algae.
Based on the conserved similarities between the plant, the alga and the plasmodium, the researchers proposed thatConsistent with this sexual stage-specific transcription, examination of mice infected with hap2 clones showed that the parasites underwent normal asexual develop- ment in erythrocytes. Neither the rate of gametocyte formation nor the sex ratio was affected, and gametocytes were able to emerge from their host cells and differentiate into gametes when exposed to activating conditions (data not shown). To test for a role of HAP2 in fertilization, we first allowed female Anopheles mosquitoes to feed on mice infected with hap2 parasites and 10d later used phase contrast microscopy to examine the walls of midguts from the mosquitoes for the presence of oocysts. As shown in Figure 2E, whereas oocysts were plentiful in midguts of control mosquitoes allowed to feed on mice infected with wild-type P. berghei (Fig. 2E, left panel of photomicrograph and bar graph), we failed to detect oocysts in the mosquitoes that were fed on mice infected with hap2 parasites (Fig. 2E, right panel of photomicrograph and bar graph). Thus, HAP2 is required for transmission of P. berghei to mosquitoes.
Two steps, one involving a well conserved HAP2 gene and the process of membrane fusion and one involving gamete recognition mechanisms which can evolve rapidly. The work supported the 'working model' for gamete fusion, and provided the much needed genetic evidence.Divergence of the prefusion attachment genes could contribute to establishment of barriers to fertilization that might lead to speciation. The functional separation of membrane adhesion and subsequent events resulting in fusion between two different membranes may thus be the way in which many eukaryotes reconcile two opposite evolutionary needs, on the one hand, to ensure reproductive isolation through rapidly changing gamete recognition mechanisms, and, on the other hand, to preserve the machinery for the biophysically complex process of membrane fusion.
In other words, evolutionary theory provided for much of the foundations for the research and exciting new findings, showing that evolutionary science is scientifically fruitful as opposed to for instance Intelligent Design which remains scientifically vacuous. Science has expanded its understanding of the role of HAP2, provided a new approach to deliver a solution to the Malaria problem, provided genetic evidence for the hypothesis of gamete fusion and finally provided us with a much needed source of entertainment when the results were evaluated by ID proponents. What is so fascinating is how amateurs at UcD base a ID hypothesis on their reading of an abstract. As an amateur myself, reading the articles referencing the research as well as the abstract caused me significant concern as to the accuracy of the comments by DLH and with the help of the actual article, it was relatively straightforward to determine that my causes for concern were well founded. I hope to discuss the paper, which outlines how real science is done, in a future posting. For now I sign offAlthough the working model for gamete fusion has been that prefusion attachment and membrane fusion per se depend on separate sets of gene products, the model was not supported by genetic evidence because no mutants were available that allowed adhesion and blocked fusion in any organism. Our results assigning HAP2 function to a step in the gamete membrane fusion reaction after close (10-nm) prefusion attachment is the first gene disruption-based evidence that the gamete membrane fusion reaction depends on at least two separate sets of proteins that function at discrete steps in the reaction.
121 Comments
rog · 2 April 2008
PvM,
Thank you for all you efforts.
PvM · 2 April 2008
My pleasure, it's remarkable how much I enjoy learning about topics of which I have little background knowledge. This paper however outlines a beautiful case of how science proceeds to unravel many small hypotheses to support a larger hypotheses.
Whenever I look at biology, I see how evolution has found ways no intelligent designer would have believed possible...
William Wallace · 2 April 2008
Tex · 2 April 2008
Bobby · 2 April 2008
PvM · 3 April 2008
PvM · 3 April 2008
Oh William, are you willing to defend ID's 'hypothesis' as proposed by DLH?
PvM · 3 April 2008
Bobby · 3 April 2008
ellazimm · 3 April 2008
Mr Wallace: if you agree that DLH got it wrong over at Uncommon Descent will you please post a comment to that effect on the pertinent thread? Show me you have that much of a backbone. I assume you followed PvM's discussion.
Cedric Katesby · 3 April 2008
"Mr Wallace: if you agree that DLH got it wrong over at Uncommon Descent will you please post a comment to that effect on the pertinent thread?"
If he does that, he risks bannination.
:)
Dale Husband · 3 April 2008
Ron · 3 April 2008
No need for the quotes around sperm and egg when you are talking about plants. Sperm are either present in the pollen grain (a three-celled organism in this case) or develop when the two-celled pollen germinates on the stigmatic surface. The egg cell is present in the ovule which is normally deep in the ovary. The pollen tube dumps two sperm cells near the egg cell and central cell and the double fertilization occurs.
386sx · 3 April 2008
ID hypothesis 1: The membrane merger including HAP2 essential for such “male”-”female” cell merger are irreducibly complex.
Okay.
ID hypothesis 2: This “male”-”female”protein & docking site are part of a species specific reproduction - barrier system that is a species specific irreducibly complex system.
Okey dokey. Good work!
Do the ID people have any other hypothesis besides the "irreducibly complex" hypothesis? Everything's always irreducibly complex all the time, but that's about the only thing that ID ever gets used for as far as I know.
Okay, everything is all irreducibly complex all over the place. Good work! You can all go home now. Bye!!
386sx · 3 April 2008
ID hypothesis 1: The membrane merger including HAP2 essential for such “male”-”female” cell merger are irreducibly complex.
"Lookee here what I'm a pointin at, I think it's irreducibly complex!! Go check it out will you?"
"Okay I'll go do that. Thanks for the tip on that!!"
PoxyHowzes · 3 April 2008
1) I think it is not always April Fools' day at UcD. It is sometimes January Fools' day, sometimes February Fools' Day, etc.
2) Re 386sx "all irreducible complexity, all the time": I think that most of the time (approaching 100%) it is irreducible perplexity.
Walabio · 3 April 2008
CDK007 ran a simulation of coevolution of receptor/ligand-complex:
http://youtube.com/watch?v=Nnu-O5x_pRU
Philip Bruce Heywood · 3 April 2008
Hello, PvM, I'm derailing your profound, scholarly discussion again. I suppose you had to cut out the big half of my paltry few comments on your previous page because they actually introduced some facts. I notice you left plenty of room for your own comments. You people presumably have to tow the party line. You avoided the temptation of censoring quite everything that was inconvenient. (That's been done before, here.) Of course, there'll be a record of the cuttings, somewhere.
Dashed inconvenient when you can't answer questions and you quote sources that are upstaged by new findings. Been there, done that. And one has to keep the Sponsor happy. There is an element of free speech at PANDA'S THUMB. Still, that comment about backbone a little above is pertinent. I wish I had more, myself.
Since you and all the heavies couldn't get a grip on that previous page - other than with scissors and 50yr old rhetoric- I expect nothing different here. You have species wandering into existence in some all but mystical fashion on that previous page and when someone starts to point out a testable mechanism and quote the latest research to back it up, you pull the scissors. You then go on saying that there is nothing in real research other than Common Descent, natural selection and so on - call it Darwinism, if you wish - and start again at the beginning of the dogma. I'll try again to break into the PANDA'S THUMB tub thumper's te de um.
No, it wasn't common descent in the sense of a "blood" relationship. Yes, species acted as conduits in the automatic revelation of newly appearing, but pre-existing(as information) species. Like I said on that page - can't some people recognize what they are looking at, and add one plus one? Ever heard of quantum information technology? To what sort of information technology might DNA, RNA, autoimmune systems, and so on, appertain?
In envisioning how the information system functions, it is possible to deduce that certain categories of information must be in the species' information banks, before the species that display the modifications outwardly, are actuated - hence the HOX genes-paddlefish discovery. (This is the discovery that you seem to imply is better for the masses not to know about. My sincere apologies if that isn't the case.) On another tack, one minor point that necessarily follows from a rational consideration of the biosphere, is that there is a species lock. Many species have all but identical DNA, they live in each others' back pockets, they hybridize, their hybrid offspring show some appearance of success (such hybrds may indicate very close affinity, a "ghost" of a return towards the common conduit species that was involved in their actuation?) - yet we have, observable, distinct species. If this lock exists, of course, then something must trip the lock when species are transformed. This has been published at www.creationtheory.com for years.
This lock tripping is a very minor component of an extremely sophisticated series of events, implicating, guess what? - an extremely sophisticated information capability of which DNA, autoimmune systems, sex cells .. you know the list .. are part.
Exit the faeries. Bring in the conventional, mainstream science. People forged 'scientific' precedures to 'prove' that electricity equals life and life equals nothing more than electricity. Faraday & co. finished that one: Darwin stepped conveniently into the gap. Perhaps he would prefer to be remembered as inspiring something a little better? But cheer up; there's always the next big topic of Nature we don't know enough about so as to be able to keep the political/religious tub thumpers out of it! I don't suppose you would be interested in researching what actually does happen at species transformation, now that it is no longer mystical?
Ravilyn Sanders · 3 April 2008
Heywood,
Are you the customer care representative reported in Car Talk, one Mr Heywood
U Buzzoff?
Anyway, I think you should put whatever you are smoking in small plastic pockets and sell it at the street corner. Looks like it is great stuff. Will displace heroin in no time.
Scott Reese · 3 April 2008
You know, I've been wandering around blogs like this for a while now and every time a troll like Heywood pops up I see a flurry of responses from blog regulars and newbies alike. Everytime, I would look at that and think to myself "self, why do people respond to such drivel when they know its just an attempt to garner attention?" Then, this latest post appears and Mr. Heywood launches into weird assertions about HOX genes and paddlefish (a lovely study looking at the evolution of tetrapods from early fishes)as well as crazy stories about science trying to prove electricity is life. Suddenly, I had an urge to respond; an almost burning desire in my typing hands. Luckily, I went and got a cup of coffee and it subsided, but finally I understand those folk who always 'feed the trolls.' I'm still going to abstain, I think, but if you feel the need I will forever be a sympathetic supporter for other troll feeders from this point forward.
Robin · 3 April 2008
Bobby · 3 April 2008
Nigel D · 3 April 2008
Nigel D · 3 April 2008
Olorin · 3 April 2008
P.B. Heywood (#149578): "You people presumably have to tow the party line."
Spell checkers can also serve as ignorance detectors. I'm conjuring up an image of someone heaving on a telephone wire connected to several subscribers.
Bobby · 3 April 2008
Nigel D · 3 April 2008
Nigel D · 3 April 2008
James McGrath · 3 April 2008
It is so hard to tell a serious pseudoscience post from a parody. I wondered whether the latest e-mail about Expelled was serious, since last I heard they were paying people to see it, but the e-mail invited people to rent a theater for a showing!
Bobby · 3 April 2008
Henry J · 3 April 2008
Henry J · 3 April 2008
fnxtr · 3 April 2008
@Bobby:
Monitor, meet tea.
jeh · 3 April 2008
Every day is April fool's day at UCD. Especially with the zany madcap humor of Dembski et al.
Frank B · 3 April 2008
I enjoy Heywood's use of the term "autoimmune system". As a blood banker I deal with the unfortunate affects of autoimmune disease all the time. There is the immune system, and when it malfunctions, we get autoimmune disease. There is no such thing as an autoimmune system. Heywood tries to sound so scholarly but fails miserably.
Robin · 3 April 2008
jeh · 3 April 2008
this being a key/lock design with complex specified information...
Lock and key? Wow, that's so 1950s. Have you ever heard of induced fit? Conformational flexibility of proteins? Daniel Koshland?
A new species would appear to require at least two changed genes, one for the protein change and the other for the matching protein docking change.
How about you reading up on compensating suppressor mutations? There is a rich literature documenting this genetic phenomenon, and I've seen it at work in my research. You don't suppose that there was divine intervention in the course of my experiments, do you? I explained the results in terms of chemistry and physics--so should I submit a retraction now?
ellazimm · 3 April 2008
Mr Wallace? Mr Wallace? Mr Heywood? Mr Heywood? Anyone? Anyone?
Saddlebred · 3 April 2008
I never remember Heywood's shit being this off the deep end. First Keith Eaton went totally batshit insane and now PBH too.
William Wallace · 3 April 2008
ellazimm, I'm still working my way through Behe's book, and cannot speak to the soundness of DLH or PvM's arguments.
HDX · 3 April 2008
waldteufel · 3 April 2008
Hey, Mr. Wallace, lemme help you with that . . . .
Dr. Behe's book is a bag of shit. It's just a rehash of the
same old creationist hogwash that Behe has been peddling
for years.
Gary Bohn · 3 April 2008
Gary Bohn · 3 April 2008
It seems that PBH is under the misapprehension that the change from one species to another is a single generational affair where the sole member of the new species cannot interbreed with the old timers because some magical pair of switches have been simultaneously thrown. Of course he presents this at the molecular level to make it sound more sciency. Then, just for good measure, he adds a little woo into the equation, in the form of an abstraction, by mentioning not just 'information' but 'quantum information'.
To back this interbreeding limitation up he suggests the example of hybrids, where mules are formed, as if the inability of two separate species to produce a third species is proof of his 'species lock' hypothesis. Two distinct species, already some distance from their common ancestor, I might add.
Is the breeding success of two distinct species really the same as the breeding success of two less than distinct generations?
Bill Gascoyne · 3 April 2008
Stanton · 3 April 2008
Unsympathetic reader · 3 April 2008
ellazimm · 3 April 2008
Mr Wallace: have you given a thought to what other books you will read to throw light on this issue aside from The Edge of Evolution? I'm sure there are lots of people here who would have good recommendations.
David Utidjian · 4 April 2008
Unsympathetic reader,
That was an excellent dissection of one of the core IDist arguments. Thank you for posting it.
-DU-
Nigel D · 4 April 2008
Nigel D · 4 April 2008
Philip Bruce Heywood · 4 April 2008
Laplace, the French mathematician, tells this story of Alfonso x (1221- 1284), king of Castille. "Alfonso was one of the first sovereigns who encouraged the revival of astronomy in Europe. The science can reckon but few such zealous protectors, but he was ill seconded by the astronomers whom he assembled at a considerable expense and the tables which they published did not answer to the great cost they had occasioned. Endowed with correct judgement, Alfonso was shocked at the confusion of the circles, in which the celestial bodies were supposed to move; he felt that the expedients employed by nature ought to be more simple. 'If the Deity', said he, 'had asked my advice, these things would have been better arranged'."
Alfonso hadn't seen anything yet, until he hired the crew of eager beavers writing in above here. Ah, hello all people, humorists and scholars - I know you exist, yea, some contribute at PANDA'S T., even on this page; hello LightningRose, if you are there; I can remember that you made an entry classifiable as such back on that previous page. My reply you will find in the sin bin.
It is apparent that ID or whatever it is these beavers are gnawing on, need have no fears. I suspect this whole imbroglio appears laughable from the outside. It isn't, really. We start with a species lock, which bye and bye doesn't exist. We have species (as even Darwin recognized), but bye and bye we don't have them. We wish to be mainstream scientists, but bye and bye we claim that a quote from SCIENCEDAILY (an evolution-allowing publication, the Internet's biggest mainstream science news spot) is creationist. This quote was sin binned on a previous page, yet the objection is raised that I don't quote mainstream scientific research. We call on the laws of science, then make them fit our incomplete observations or ideas. And, folks, if you are now enlightened on hybridization, I'm a long horn beeffalo.
I learned something. I must toe the line. I must toe the line. Yes, I believe that is correct. Until now, I always thought it was tow. Never say you are too far gone to learn something.
ellazimm · 4 April 2008
Mr Heywood: in your book, The Tree of Life and the Origin of Species you seem to take a strictly biblical creationist point of view and that the information for all species existed before the animals were created. Where was that information stored?
http://www.creationtheory.com/printed.html
slang · 4 April 2008
Saddlebred, this is the guy who proposes that our moon was miraculously moved by god to its current location from its supposed place of origin, namely Mercury. god stored it temporarily because he was too busy making the earth and planning life. I'm not kidding. What do you mean, never this far off the deep end?
Ichthyic · 4 April 2008
Never say you are too far gone to learn something.
if that's the max of your learning potential, Phil, you're pretty far gone.
but bye and bye
how 'bout just bye.
Torbjörn Larsson, OM · 4 April 2008
Nigel D · 4 April 2008
Nigel D · 4 April 2008
Unsympathetic reader · 4 April 2008
Nigel D: "Plus, (3) all of Behe’s examples of IC have actually been shown not to be irreducible."
It really all hinges on what is meant by 'function' in any particular biological context. And things are a bit squirrelly because the term carries the not so faint taint of teleology and a presumed 'linearity' of purpose that fits to biology like a fish to a bicycle. But, taken at face value, there certainly are systems which contain parts that if removed, inhibit or block a particular function, as measured by relative fitness.
For example: Today, humans cannot live without a blood clotting system. There are any number of mutations in the 'system' that result in death and so, as things stand *today*, clotting can be claimed to be 'irreducibly complex', at least as the term was originally presented by Behe. But that's a far cry from being it unevolvable. From a historical perspective, blood clotting in humans is a 'ratcheted' system -- What was once nonessential or redundant in earlier organisms (and thus could develop under lighter 'demands') has become essential and locked in by historical contingency. The path taken to evolve blood clotting is no longer easily reversible once organisms grow large enough to actually require it. The problem with Behe's first book was that he made the case for irreducible complexity as a necessary product of interruptive design by ignoring the historical aspects. When he talked about how essential many clotting components are humans *today*, he ignored the uncomfortable fact that clotting didn't *begin* with humans -- It's an old system that evolved in creatures that didn't already need a wickedly competent clotting system.
I'm sympathetic to the view that IC systems may not be 'irreducible' in the sense that substitutions can be made to some of the parts, but I think it helps to use Behe's original formulation that an IC system is one in which removal or 'damage' of some components reduces 'breaks' its function (or at least one of its 'functions'). In that case there certainly are 'irreducible complex' systems in biology and I would argue that many of the systems Behe described do meet that criteria.
Maybe it helps not to parse 'irreducible' as a distinct, independent criterion in the term 'irreducible complexity' (IC). Some systems may be 'reducible' in the sense that evolution can alter or eliminate a system's components over time, yet still be 'irreducibly complex', pace Behe.
Philip Bruce Heywood · 4 April 2008
Ellazimm: Regards. Firstly, speaking of information as it relates to species: the person running this page has picked on a relevant and useful topic. We see in the head of this page, how information and biology are intimately intertwined. This is one area of big advances in science and medicine. To answer your question: as you have probably deduced, if you store all the information appertaining to a species,and have a mechanism that will automatically transfer that information, and have activated a living cell that is destined to receive that information, you have created a living species. Creation occurs at the moment the living cell, and the automatic information mechanism, are activated. Creation can therefore occur long before the revelation of a particular species. I don't claim to know any precise details of where the information was stored, but from what the biologists here are jumping up and down about, it's obvious 1). Information already present in one species can pass on to another:2). I can guarantee you that some smart information technologist will sooner or later show how another storehouse of information - the environmental conditions - are "read" and subsequently programmed in at transformation. 3) This is achieved through a combination of the synchronized workings of the information devices within the cell and quantum category (e.g., photons travelling through a specialized magnetic field) information available in the biosphere. The source of this quantum category signalling is primarily the solar system. This signalling from outside the biosphere is ,one suspects, general and empowering in nature, rather than containing specific, detailed information. So there are at least 3 storehouses, operating in symphony: Pre-existing information in the cell: Environmental conditions: and Bodies of Space, especially the earth-sun-moon.
Er, Mr. Slang, would you care to quote from THE COMMON DONOR CAPTURE THEORY, to substantiate your claim that God is mentioned?
Eh, Torbjorn, if you are referring to the Wilkins of TalkOrigins fame, a biologist (and no slouch at it) who works or did work in Queensland, Australia -- I have done my best in the past to extract his views - after all, there is what is known as The Species Problem - and what I came up with - hopefully without misrepresenting him - is that, yes, there is a species problem. And, yes, distinct, clearly defined species exist. As you show, nature isn't always as cut and dried as a physicist or a chemist might like it to be. Wilkins, as I read him, allowed that there are reproductively self-contained units.
Nigel D, You certainly expressed yourself well. I regard Science as a discovery of mathematical realities. My mind just doesn't register unless it's something I can grasp in those terms. (I failed university Maths). You know - add this much reagent to this much reagent and always, invariably get this much precipitate. I still can't understand how a feather and a ball bearing fall with the same acceleration in a vacuum but I know it must be so. That's why, to me, if Common Descent as currently espoused, works, I believe it 100% If I see it doesn't meet the requirements, under no circumstances do I regard it as anything but theory, i.e.,a theorem: a proposition to be proved. (Chambers's 20th Century Dictionary). That's why I spend my life treading on other peoples' toes. For example, it has been conjectured that Common Descent Evolution is brought about partly as a result of random mutations. O.K., now explain how the mutation occurs. Movement of a proton within a DNA component through the action of a specifically oriented photon, I can comprehend. Acheivement of the same result, somehow, by a chance cosmic ray - this has never been explained. At the risk of being repetitive - fix the science.
Stanton · 4 April 2008
Stacy S. · 4 April 2008
Rolf · 4 April 2008
Torbjörn Larsson, OM · 4 April 2008
Bill Gascoyne · 4 April 2008
ellazimm · 4 April 2008
Mr Heywood: Thanks, I think I've heard all I need to hear. Who are you going to vote for in November?
Nigel D · 4 April 2008
Nigel D · 4 April 2008
Torbjörn Larsson, OM · 4 April 2008
Torbjörn Larsson, OM · 4 April 2008
Sorry, true knowledge respectively falsehoods of course.
PvM · 4 April 2008
Philip Bruce Heywood · 5 April 2008
Thanks for contributing, Stacey S. You have comprehended something too profound. Too profound. If a complex, functional structure exists, you can't change it into another complex, functional structure by reading Mickey Mouse comics to it. At least, put it in the sun, or give it a drag on a cigarette. You are way ahead of the pack. (I mean, you could be saying that if you are going to change the tyre on a car, it could be useful to get a spanner that fits the nuts.) The remainder of the pack - forgive the generalization - have not yet discovered that DNA is complex. Well, I'm not too sure that one or two allow that DNA exists. Autoimmune systems don't, at one chap's blood bank. That's the one where they sell the blood and substitute it with stuff from an abattoir - no automatic rejection of foreign organs/implants occurs, you know. Well that's not exactly what he meant. But let's stop here a moment and think. Hey, an immune system can be 'turned off'. Hey, let's follow that information technology lead, and see what else might be 'do-able' in relation to deducing what actually happens to the complex structures at the times of species transformation. Except, of course, that another contributor asserts that biology and information have nothing to do with each other, so we are left with reading Mickey Mouse over the problem.
Then we have all those who are trying to decide whether there are species or not. One chap has solved that problem by deciding there are none. (What did Darwin write about, now?) I do note that the comment on bird hybridization, should it be intended as an honest observation and not as a suggestion that hybridization shows there are no such things as reproductively definable species, is just that - an honest observation. (How could you detect hybridization if there were no such things as reproductively definable species? Hybridization, in its popularly understood meaning, is a cross between two genetically distinguishable entities.) So if Robin and Stacey are girl's names - my apologies if otherwise - the girls are way ahead. Even if Darwin hinted that the female intellect is inferior.
Now I have been asked who I am going to vote for in November, and if that is a reference to the U.S. Presidency, why Hilary, of course. Did she get nominated? I get out of touch, being a citizen of Queensland, Australia. Golly, there aren't any elections coming up this year here in Qld, are there?
PvM Thanks you all for educating our confused christian friend Heywood One could place a comma at various places in that sentence: if indeed I am the one who is to benefit from this education, why, I am honoured, I am honoured. I have certainly been benefitted in some small ways by this Page. I haven't laughed so much since the time I was on Panda's Thumb, back when it didn't have pictures down the side, and Lenny Flank pounced on people and he and I were in the bathtub together. Don't ever stop this publication.
Wolfhound · 5 April 2008
Wonder why PBH feels the constant need to repeat stuff. Repeat stuff.
Stacy S. · 5 April 2008
Ummmm... should I be insulted? I couldn't bring myself to read that whole thing.
Rolf · 5 April 2008
David Stanton · 5 April 2008
Philip wrote:
"How could you detect hybridization if there were no such things as reproductively definable species? Hybridization, in its popularly understood meaning, is a cross between two genetically distinguishable entities."
Well you seem to have answered your own question there. Species can be defined by genetic discontinuity. Reproductive isolation does not have to be complete in order for discontinuities to arise. However, once reproductive isolation is complete, the discontinuity will increase due to divergence over time.
There is no hard and fast rule about when a discontinuity becomes large enough to identify distinct species. Some populations represent incipient species, some sub-species and some sister species. That is why the definition of a species is best considered in genetic rather than just morphological terms.
Now Philip, do you acknowlwdge Nigel's response or not? Do you acknowledge that scientists really do know a great deal about the molecular mechanisms of mutations or not? Do you still claim that the "species lock" (whatever that may mean) is a barrier to speciation or not? Do you concede that there is such a thing as a species, but that the definition and identification of species is problematic or not? Do you agree that this problem is precisely what is predicted by the modern theory of evolution or not? Do you really think that repeating "too profound" - "too profound" - "too profound" is going to convince anyone of anything or not? Are you going to "tow the line" away or not?
Science Avenger · 5 April 2008
If Ann Coulter smoked marijuana, she'd be PBH. His posts are just one long string of colorful half arguments, gotcha semantic games and insinuations. Nothing is ever flushed out in detail, no clarity of argument sought. It's "Why should I care about Rhode Island when I live on the mainland?" kind of stuff. It's getting pitched five softballs at a time. You don't know where to start.
He's also the kind of guy you'd least want to debate live, because your stunned amazement at what he just said would be mistaken by a credulous audience as being stumped. I'll give him this, he's our most entertaining troll, and he gives Nigel job security.
Dale Husband · 5 April 2008
Henry J · 5 April 2008
Nigel D · 5 April 2008
Nigel D · 5 April 2008
Stacey S. Sorry, I just realised I misspelled your name in my preceding post. It's late in the evening after a tiring week.
Nigel D · 5 April 2008
Aargh. And again. Stacy has no "e".
Nigel D · 5 April 2008
Nigel D · 5 April 2008
Philip Bruce Heywood · 5 April 2008
I wasn't intending to darken the page further and this is definitely my final, thanks. I have a sarcastic way of arguing which I am working on. If Stacey S. does read the whole of my previous entry, she will find she is praised, not insulted. Modern technology as it relates to information transfer has found that photonics is way ahead of electronics regarding communications. Living things receive information via photons that have been 'processed' by our magnetic field. On another level, the complex molecule, DNA, receives information feedback via the action of other molecules of specific shape and charge, and so on. So the sun, and nicotine, are not irrelevant. In fact, the mention of both, in relation to DNA, makes sense.
I have explained higher up why I find it impossible to discuss this topic on any other basis than conventional methods i.e., Galileo's method, not the Aristotle's. Muster the facts, clear the mind of everything other than the laws of science, and only then, evaluate the theory. Let no preconception cloud the process. The hybridization - speciation question is illustrative. It is a clouding of the process. Hybrids are indicators that genetically distinct units exist. Hybridization has long been discounted as an engine of speciation. The record of the fossils and of the existing biosphere is of genetically 'locked' units. Come, come. If species turn into new species gradually, species would be defined on the basis of statistical percentages.
You could now be interbreeding with any number of different 'species'.
Come up with a basis upon which to stand to evaluate the theories - e.g., something camparable to Galileo rolling diffent sized weights down a slope with a timer - the let's proceed from that basis. Regards.
Stacy S. · 5 April 2008
Thank you Nigel! :-) ... Goodbye Phillip :-)
David Stanton · 5 April 2008
Philip wrote:
"Hybrids are indicators that genetically distinct units exist. Hybridization has long been discounted as an engine of speciation. The record of the fossils and of the existing biosphere is of genetically ‘locked’ units. Come, come. If species turn into new species gradually, species would be defined on the basis of statistical percentages. You could now be interbreeding with any number of different ‘species’."
Perhaps you did not read my post, or perhaps you did not understand it. Of course genetically distinct units exist, that is the outcome of reproductive isolation. But that does not mean that species are fixed or that reproduictive isolation always occurs between presumptive species. Hybridization prevents genetic divergence and thus speciation, but when reproductive isolation does occur, speciation can still occur.
The fossil record does not support the view of "locked" units. With few exceptions, gene sequences are not available for fossils and thus the genetic divergence between different species cannot be evaluated. As for morphological divergence, the fossil record clearly shows that species can and do change over time and that speciation occurs.
I already explained how species could be defined on the basis of genetic divergence. You can consider this a statistical percentage if you wish. And yes, interbreeding between presumptive species is often observed.
You do not seem to be making ony coherent points let alone any real argument. Your rambling commentary has not addresed any real issues. You never did admit that the molecular mechanisms of muatation are well known, even though you originally asked the question. Mindless blubbering about photons and magnetic fields might sound scientific, but I defy you to explain how phoitons deliver information that is processed by the magnetic field. If the magnetic field disappears will evolution cease or will it go faster? Come on, use you irreducibly complex "autoimmune system" before it destroys your brain completely.
Torbjörn Larsson, OM · 5 April 2008
Igmana van Krankij · 5 April 2008
Nigel D · 6 April 2008
Nigel D · 6 April 2008
PvM · 6 April 2008
R Ward · 6 April 2008
Finally, something Phillip Bruce wrote was comprehensible,
"Hybridization has long been discounted as an engine of speciation."
and was predictably untrue. As one example of hybridization as a mechanism for speciation (there are many more) see:
http://www.nature.com/nature/journal/v441/n7095/abs/nature04738.html
Sorry, Nigel, I know you addressed this but I was bored and googled 'hybridization' and 'speciation' before I saw your post.
John Kwok · 6 April 2008
Hi all,
Much to my amazement, there's apparently a "fan club" devoted to me over at Uncommon Descent (If you type my name in the GOGGLE feature of its website, www.uncommondescent.com, you will come up with at least twenty citations of it.). Some of the latest posters seem obsessed over my one star Amazon.com reviews critical of the works of Behe, Dembski, Johnson and Wells. If any of you are fellow Amazon.con customers, then please give them more reason to be "obsessed" by voting yea on my Amazon.com reviews.
Appreciatively yours,
John
Philip Bruce Heywood · 6 April 2008
I said I was going but will temporarily reneg on that. This page is chock full of untruths and absurdities, which any thinking person can sus. out for himself. You don't need me. E.g., the assertion that electricity-life controversy didn't exist is just one of many inconsidered statements plucked out of the air. The denials of the discoveries of modern science - such as the ability of photons to carry information to living organisms - can easily be found out by the reader. The facts aren't going to run away anywhere. But a post just come in, by R. Ward, warrants attention. Follow the link, and you will discover that, contrary to Ward's assertion, hybrid speciation is considered extremely rare. One might be forgiven for suspecting that it doesn't exist. This one, of butterflies, was done in a laboratory. It does not necessarily follow that it will happen in nature, unassisted by man. Good luck if it does.
PvM, How does one attempt a rebuttal of arguments that first have to be debunked because they are all but fraudulent? You correct the trash science, then I won't need to point out the errors.
PvM · 6 April 2008
Ichthyic · 6 April 2008
PBH said:
You don’t need me.
True, dat.
Stanton · 6 April 2008
Henry J · 6 April 2008
David Stanton · 6 April 2008
Henry J,
Naw, you got it all wrong. The photons have to be processed by the magnetic field remember. So they must be charged particles, not photons of visible light. And they have to deliver complex specified information directly to the DNA, otherwise how would evolution occur, or not occur, or something. Don't forget the Mickey Mouse connection either.
Man I am sure glad that this guy set everybody straight on the real science issues. They were just too profound for mortals to comprehend apparently. So now we know for certain that speciation can sometimes occur through hybridization and sometimes through lack of hybridization. So much for the species lock concept. Guess that was all just made up stuff as well.
Henry J · 6 April 2008
Philip Bruce Heywood · 6 April 2008
Confound it all, I'm being a fool. I suggest you get help from somewhere if you wish to continue here. This whole page ultimately was triggered by a paper from the University of Texas or some such place - don't quote me - which was speculating in an almost unknown field, namely, the investigation of why species don't simply cross with other species and make new species. The paper itself either says or implies that if they ever do, there is not a lot of it going on. The paper is about why they DON'T, not why they DO.
Another paper, introduced not far above here, says, I quote; "Hybrid speciation, considered extremely rare....".
It then goes on to recount how some insects were hybridized into something seemingly new, IN A LABORATORY.
Why is someone going on about speciation through hybridization? To spite the provider of the page? I suggest you either shut down, or get help. And what does all this tail-chasing prove? Augustine, eh. Yes, an old-earth creationist. A man who couldn't help himself, transformed in an instant. The world's leading Bible expositor. Loved by thousands. That's if it's Augustine of Hippo. Now we are getting somewhere. This speciation trivia is a vain pursuit. I wish you well.
Stanton · 6 April 2008
David Stanton · 6 April 2008
Philip,
New species can arise through hybridization. However, far more comonly new species arise due to divergence between different populations of an ancestral species. Now, do you agree or do you not? Can new species arise or not? Is there a "species lock" or not? Is there information in photons or not? Is the information processed by the magnetic field or not? How is the information delivered to germ cells which photons cannot even penetrate to? Is the magnetic field responsible for evolution, or is it responsible for preventing evolution? What would happen if the magnetic field were to disappear?
You have not answered a single question. You have not provided a single explanation. You have not demonstrated anything but ignorance of even the most basic biological principles. Quite frankly I find it impossible to agree with anything you claim since I am not certain exactly what it is you are claiming. The least you could do would be to give people the courtesy of responding when they answer the questions you ask. Nigel has patiently explained the molecular mechanisms of mutation. Can you do the same for your photon hypothesis?
Henry J · 6 April 2008
If hybrid species weren't rare between distantly related species, there wouldn't be an overall nested hierarchy of eukaryotes (animals, fungi, plants, protists).
Henry
Ichthyic · 6 April 2008
New species can arise through hybridization. However, far more comonly new species arise due to divergence between different populations of an ancestral species.
It might depend on whether you are a botanist or a zoologist, actually, as to which method might be considered more commonplace:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Polyploidy.html
Stanton · 6 April 2008
Mike Elzinga · 6 April 2008
Stanton · 6 April 2008
That is, speciation through hybridization occurs more frequently in plants primarily because plant hybrids tend to survive longer than animal hybrids.
Nigel D · 7 April 2008
Nigel D · 7 April 2008
Nigel D · 7 April 2008
Ichthyic · 7 April 2008
That is, speciation through hybridization occurs more frequently in plants primarily because plant hybrids tend to survive longer than animal hybrids.
...and polyploidy is orders of magnitude more common in plants than animals, which is why I added the link.
Ichthyic · 7 April 2008
...also, there was a paper we were discussing last year that suggested genome duplication in angiosperm evolution might be more common than once thought.
Being an ichthyologist myself, I find I have tended to ignore evolution in plants overly much, but every once in a while, something like this penetrates.
let's see...
ah, here 'tis:
Widespread genome duplications throughout the history of flowering plants
Cui, et. al.
Genome Research 16:738-749 (actually came out in 2006)
I'm not saying this has much to do with what PBH spewed, but then that was irrational nonsense anyway. The issue of polyploidy, hybridization, and the overall effect on the evolution of plants is far more interesting.
Stanton · 7 April 2008
Torbjörn Larsson, OM · 7 April 2008
Saddlebred · 7 April 2008
get this...lungfish.
David Stanton · 7 April 2008
Oh, now I get it. Speciation is possible because of the Northern lights! So I guess speciation goes more quickly near the poles and there is information in the twinkling of the lights. Man, why didn't he just say so in the first place. All this confusion, confusion. Now he can publish and become rich and famous. After all, there must be tons of evidence for this hypothesis if everyone already knows about it.
Now if we could just get the Northern lights to run the Frankenstein experiment that would be the clincher. Especially if Mickey Mouse would throw the switch.
slang · 7 April 2008
Hybrid speciation is rare. There are only about 20 or so recently documented cases of speciation by hybridisation. Amongst mechanisms of speciation, hybridisation is one of the less important ones. However, just because it is rare does not give you the excuse to doubt its existence.
Stars within 1 Astronomical Unit distance of Earth are extremely rare. So far we've found only one. So.. the Sun doesn't exist.
*stuffs fingers in ears and yells "LALALALA" *
slang · 7 April 2008
Henry J · 7 April 2008
And, stars within 0.9 AU are even rarer than that... ;)
(I almost said 0.99 AU but caught myself in time.)
Henry