Intelligent design proponents make a negative argument for design. According to them, the complexity and diversity of life cannot be accounted for by unguided evolution (henceforth referred to simply as ‘evolution’) or any other mindless natural process. If it can’t be accounted for by evolution, they say, then we must invoke design. (Design, after all, can explain anything. That makes it easy to invoke, but hard to invoke persuasively.)
Because the ID argument is a negative one, it succeeds only if ID proponents can demonstrate that certain instances of biological complexity are beyond the reach of natural processes, including evolution. The problem, as even IDers concede, is that the evidence for evolution is too strong to dismiss out of hand. Their strategy has therefore been to concede that evolution can effect small changes (‘microevolution’), but to deny that those small changes can accumulate to produce complex adaptations (‘macroevolution’).
What mysterious barrier do IDers think prevents microevolutionary change from accumulating until it becomes macroevolution? It’s the deep blue sea, metaphorically speaking. IDers contend that life occupies ‘islands of function’ separated by seas too broad to be bridged by evolution.
In this post (part 2a) I’ll explain the ‘islands of function’ metaphor and invite commenters to point out its strengths and weaknesses. In part 2b I’ll explain why the ID interpretation of the metaphor is wrong, and why evolution is not stuck on ‘islands of function’.
Read on for an explanation of the metaphor.
The ‘islands of function’ metaphor
The ‘islands of function’ metaphor is a variation of another metaphor, the ‘fitness landscape’. If you’re unfamiliar with the concept of fitness landscapes, I encourage you to do some Googling before reading on.
For those who are familiar with fitness landscapes, a brief review. Imagine a three-dimensional landscape, similar to a terrestrial landscape. There are mountains and depressions, ridges and valleys, plains and plateaus. An organism occupies a particular spot on the landscape. Nearby spots represent organisms that are similar, but with slight changes. As you move further away from the spot, in any direction, the organisms represented become less and less like the original organism.
Evolution can be visualized as a journey across such a landscape. Individual organisms don’t move, but their offspring may occupy different nearby spots on the landscape. So too for their offspring’s offspring, and so on. Thus successive generations trace out a path (or paths) on the fitness landscape as changes accumulate.
Clearly, not all paths are possible. Many mutations are deleterious, causing their possessors to die young or to otherwise fail to reproduce. Paths going through such points on the landscape will end abruptly. Other mutations are beneficial, neutral, or only slightly deleterious. Paths going through those points may continue.
Now let’s bring in the third dimension, height. The height of a point on the landscape is an indication of the fitness of the corresponding organism, where fitness equates to the organism’s ability to survive and reproduce. Greater heights correspond to higher fitness, lower heights to reduced fitness. Offspring that move downhill from their parent(s) are less fit, and therefore tend to leave fewer offspring of their own. Offspring that move uphill from their parent(s) are more fit and tend to leave more offspring. Over time, then, a population tends to shift in an uphill direction as the offspring become fitter.
Eventually the population may reach the tip of a peak and get stuck there. From the peak, movement in any direction results in less fitness. Thus the mutants will tend to die off and the population will remain at the tip of the peak.
So far we’ve been imagining a dry landscape. Now suppose that it rains for 40 days and 40 nights. The rain fills up our landscape, forming a vast sea. Only the mountain tops remain above the water as islands – the ‘islands of function’ that IDers are so fond of.
Our populations occupy the islands. Sea level indicates the minimum fitness at which mutants remain viable. Small changes will create viable descendants at different spots on the island, though the population as a whole will gravitate toward the high spots. Larger changes will put the mutants underwater, where they will die out.
The idea, according to ID proponents, is that populations remain stranded on these islands of function. Some amount of microevolutionary change is possible, but only if it leaves you high and dry on the same island. Macroevolution is not possible, because that would require leaping from island to island, and evolution is incapable of such grand leaps. You’ll end up in the water.
There is some truth to the ‘islands of function’ metaphor, but it also has some glaring shortcomings that ID proponents almost always overlook. I will mention some of the strengths and shortcomings in the comments, and I know that my fellow commenters will point out others.
I may add them to the OP as they come up in the comments. If I do this, I will note that I am doing so and I’ll include a link to the place in the comments where each one is discussed.
Have at it!
Let me start the ball rolling by noting that real-life fitness landscapes have many dimensions, not just the three implied by the ‘islands of function’ metaphor.
To see why this is important, let’s start with a two-dimensional landscape and build from there. In a two-dimensional landscape, height still represents fitness, but horizontal motion is limited to one dimension — a line, rather than a plane. Motion is limited to two directions, right and left. In such a landscape, a peak is any point that has lower points on both sides. There may be higher peaks (or equivalently, ‘islands’) further along the line, but you would have to move through the adjacent lower points to get to them. It’s easy to see how evolution could get stuck on a local peak/island.
Now consider a three-dimensional landscape. Height represents fitness, as always, but horizontal motion can now range over two dimensions instead of one. You no longer have to go through the low points. You can potentially go around them, and you have many, many choices of paths, not just two. A peak is no longer defined as having lower points to the right and the left. It has to have lower points in all directions. Thus peaks are more exceptional in three dimensional space than they are in two.
The trend continues. Each time you add a dimension, you exponentially increase the number of potential paths through the landscape. It becomes harder and harder to find a true peak, because a peak has to be surrounded by lower points not only in each dimension, but in every possible combination of each of the dimensions.
By limiting their thinking to three dimensions, IDers drastically overestimate the likelihood of getting stuck on a local peak. Their intuition fails them.
Real fitness landscapes have hundreds or thousands of dimensions, and the likelihood of getting stuck on a peak diminishes exponentially as the number of dimensions increases.
There are a couple of other mistaken ideas that IDCreationists adhere to buckle and thong, lest they be forced to cede more capability to evolution.
They will not accept that slightly deleterious mutations can become fixed in a population, and may later serve as enablers for other mutations when the combination is beneficial
They find it difficult to accept that it’s NOT the case that only one specified aa sequence in a protein is functional; and persist in believing that the slightest change will damage the function of the protein. This is simply not true (or only very rarely so) Quite drastic changes can happen without materially affecting – even improving – function
They will usually fall back on tropes such as “Lenski’s E coli never grew legs in all those generations so yah boo, evolution doesn’t happen”
And they sit pat on that – “show us macroevolution – now! – or it never happened!”
I’d add that the landscape is never static. The contours are perennially shifting as the environment changes (the environment, of course, being everything that impacts on gene persistence, not just the organism’s physical surroundings).
The point about dimensionality it important too. It is easy to block travel round a chessboard – you only have to plug 8 gaps. 3 dimensionally, you need the surrounding 26 squares blocked, and so on up into hard-to-visualise levels of dimensionality (it’s much easier to stop at 3, and make your inferences based on your mental model!).
On a related note, Creationists frequently mislead themselves (following Hoyle) that the size of the protein permutation library forms a constraint***. 20 amino acids gives 20^n different possibilities for a string of length n; permutations obviously increase massively as the library increases. 1 amino acid gives just one permutation for a string of length n. Assuming some (definitely non-catalytic) function for that polymer, have you made evolution more or less likely when another acid is added to the library? And another, and another … you are adding to the toolset, not stifling all development! By adding acids, you increase the space, but the proportion of function within it is likely to increase from that acid’s specific properties. And you also increase dimensionality, and hence connectedness is vastly increased also, leading to (on the face of it) far greater likelihood that traversal of Function World is possible, not tornado-in-a-junkyard less.
***(Though I would be careful about confusing protein space and fitness landscapes)
There are undoubtedly many places that evolution cannot get to. Nothing lives there.
This is where I paste the links I wanted to discuss,
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11500.html
http://toddcwood.blogspot.co.uk/2012/10/biochemistry-tour-de-force-in-nature.html
http://www.icr.org/article/7092/
http://designed-dna.org/blog/files/category-gene-evolution.php
My reading of this is that more than half (up to 75 percent) of the amino acids in a functional protein can be substituted for any arbitrary alternative without any effect at all on function.
Hardly suggesting isolated islands.
But perhaps I have misread the situation. Which is why I wanted a discussion.
I really don’t see any point in debating this with creationists. My interest here is improving my understanding of these issues.
As I expected, you guys have captured the key failures of the ‘islands’ metaphor – the permissive nature of amino acid substitution, the changing of the landscape over time and, most important, the incredibly high dimensionality of the space.
To these I would like to add a specific aspect of the ‘changing landscape’: the sea-level has been rising, metaphorically. We look around and see highly optimized kludges and thus an environment in which the competition is healthy; in this environment, slow movers, slow replicators and the otherwise inefficient will be quickly out-competed. But in an earlier world, these same mediocrities would have been superstars. Early organisms did not have to compete with their modern-day ‘counterparts’, but with their own second and third cousins, which is a wonderful driver of change.
Since that time, the requirements for ‘good enough’ have increased. A lot. Borneo is now an island. Failure to appreciate this leads to the “what good is half a [wing / ear / eye]” idiotrope, and the cartoon version of abiogenesis where a mycobacterium must leap, fully formed, from the Creator’s forehead. This shows their lack of imagination: early replicators could have been horrendously slow and inefficient, by modern standards.
Great comment. Only by “forgetting” the massive amount of “hidden history” of the “losers” (apologies for all the scare quotes) can their argument survive the first skirmish.
A comment I’ve seen made occasionally is that Creationists don’t see life springing out of the abundance of organic chemicals in the world now, therefore if it is not happening now it is even more unlikely to have happened then. Except that, as you say DNA_Jock it’s a very different landscape now – primitive life would no doubt be out-competed before it knew it.
These arguments were made by Darwin, of course.
The isolated island argument and the continuous OOL argument. Both arguments were addressed in Origin.
It should also be pointed out that the concept of “fitness peaks” has a tendency to produce misconceptions in the minds of students approaching this for the first time. Climbing peaks evokes images of getting better and better, or of accomplishing something difficult.
ID/creationists, – beginning with Henry Morris back in the 1970s, and continuing up to the present with more of the same here, and here – hammered home the notion that evolutionary “hill climbing” meant tending toward “perfection” and lower entropy.
The most complete video I can find on the teachings of the ICR at that time is by Thomas Kindell. Kindell is using the same material found in What is Creation Science? by Morris and Parker, published in the early 1980s. That material goes back to at least the early 1970s.
One can also find comments from ID/creationists that suggest that these ideas can be traced even further back to A.E. Wilder-Smith.
Fitness peaks and hill climbing are firmly rooted it basic physics and chemistry because they ultimately trace back to the concept of “settling into potential wells.” Biologists are simply making use of a measure of that “settling in” that appears in the number of viable offspring that are produced by a population of organisms. The number of viable offspring is an observable and measurable quantity that can be related to genotype and phenotype; so it is rooted in objective science.
The gaps in understanding on the part of ID/creationists are a result of something like 50 years of carefully constructed and interlocking pseudoscience on their part. Their pseudoscience fits together and makes sense to them, while real science does not.
Their pseudoscience has to comport with narrow ranges of sectarian dogma; and they have been bending and breaking concepts in order to give such dogma the patina of “rationality” and “scientific” respectability. For them it has always been a socio/political war; not science. Hence their “science” is simply wrong to the core.
It is a repeatedly observable fact that ID/creationists simply cannot pass elementary concept tests in basic science even at the high school level, yet they always try to jump directly into “advanced” topics in debates. Their aggressive dumps of copy/paste material may temporarily obscure that fact for those not familiar with the tactical, debating history of ID/creationism; but the fact remains that all the concepts that they want to bring to a debate are theirs and not those of science.
Knowing the detailed history of the misconceptions and socio/political tactics of the ID/creationists is crucial to understanding why they say and do what they do. They are now scrambling to eradicate that history; but all that history is now available to the public in books and in court records. They can no longer run from it.
The creationist argument is historically interesting, but I hoped this thread would allow some discussion that would improve my personal understanding.
I do not seem to fully understand the implications of the article I linked. Part of the reason is I can’t get past the paywall to read the original article.
What the blog article seems to be arguing is that most of the structure of a protein is determined by a few (25 percent or less) key amino acids.
Does this mean that the DNA coding sequence is similarly flexible? Am I missing something or is my understanding deficient? If most of the sequence can have any value, why are sequences conserved? I think I must be missing something or misunderstanding something.
I mentioned this on one of the other threads, but perhaps it is not as well known to others.
Organic chemists learned very early on – back in the 1800s – that the behaviors of organic molecules was highly dependent on structure and not entirely on the specific molecules attached to parts of that structure.
Thus, they were at first puzzled when they could substitute, say, a nitrogen molecule – or even a whole structure – into a given position, and the “chemical behavior” of the entire structure was not changed very much.
At those early times, chemists didn’t have very good ways to assess structure, so there was a tendency to think – based on experience with inorganic chemistry – that different atoms substituted into reactions would produce entirely different compounds with entirely different properties. For example CO2 is completely different from SiO2.
So one might think that substituting a different atom into an organic structure – not knowing that structure has a lot to do with behavior – would produce something that has entirely different properties. It didn’t turn out that way.
This means that complex structures – such as amino acids and proteins – are somewhat “insensitive” to the insertions of different molecules, and that the overall structure has a lot to do with how such a change will ultimately manifest itself in other reactions further along.
The changes in behavior are far more subtle and nuanced. This is pretty common in organic chemistry. It is a much more complicated and subtle subject.
I glanced at the links you posted. I am not sure what your question is about; but the fact that you linked to an ICR “critique” would suggest you want to know what the “dispute” is about.
The ID/creationist “critiques” are nothing more than that of a bunch of crabby magpies sitting on the sidelines kvetching, sneering, and jeering at the process of scientific research. They do this with all science, including physics and the Higgs boson.
Modern scientific research is difficult, subtle, and takes time. Ever since the 1970s, creationists have been “publication hijacking” the work of others and putting their own spin on it for their audiences. That is exactly what they are doing with this research.
They are trying to portray scientists as a bunch of bungling no-nothings who keep finding things that contradict what another no-nothing researcher just did a few months or years ago.
It is nothing more than creationists demonizing science and scientists to their audiences.
I don’t understand why ID scientists haven’t tried to map the real-world boundaries of a functional island on which an exemplar species is stranded. Surely there have been enough genome studies that such an attempt is warranted.
Does this mean that the DNA coding sequence is similarly flexible? […] If most of the sequence can have any value, why are sequences conserved
The acid at many – probably most – sites is pretty labile. The active site tends to consist of just two or three key acids, binding sites are just ‘wire-frames’ that can be formed in many different ways, and the rest is mainly scaffolding. For many sites, it doesn’t matter at all, for others, it only matters that the substitution has similar properties. If you look at this schematic (http://quizlet.com/2855398/amino-acids-structure-to-full-name-flash-cards/) the side-chains in pink are the only thing that distinguishes one acid from another. And there isn’t a huge difference between a lot of ’em. Because proteins tend to adopt their lowest-energy configuration, the initial driver is that hydrophobic residues (no charge in the side chain) tend towards the inside, away from the water, and the charged residues tend towards the outside. Then when acids start to get close to each other, electrostatic charge comes into play, and ‘spare’ electrons, or those suffering an unequal force, particularly around hydrogen atoms, tend to be attracted to regions of opposing charge density, while the bulk of all the atoms provides an opposing tension.
This is why these ‘digital’, primary-structure games are so pointless. Proteins may be specified ‘digitally’, but they roll up into more ‘analogue’ structures. Much of sequence is simply repeats of various hydrophobic-hydrophilic alternations that lead to helixes with a certain number and angle of twist, or sheets – structural elements. It doesn’t tend to matter hugely, certainly not down to every site, how many twists there are or what the angle of coil is for each.
DNA sequence is more labile still, because there are 20 acids and 64 codons, so ‘silent substitution’ giving exactly the same acid is likely to have absolutely no phenotypic effect. Silent substitutions give an idea of the baseline rate of change within a coding sequence. Replication is pretty accurate, so there is a source of conservation right there. DNA polymerase has an error rate, but also proofreading capacity (yeah, design fans, it’s an absolute bloody marvel!), and there appear to be post-replicative error correction mechanisms as well, so there tend to be few mistakes.
So the conservation we see in apparently neutral sequence is the baseline. More ‘visible’ change can be acted upon by selection. This will tend to concentrate beneficial change more rapidly and more often, but also make it more resilient to further change, as having gone uphill a notch, more moves from the new sequence are ‘downhill’ than was formerly the case.
The difficulty of extrapolating lab substitution experiments to evolution is that you don’t know what selection thinks of each new arrangement. You can assay ‘function’ and find it better or worse than the native enzyme, in terms of reaction rate or substrate specificity or whatever. But whether each variant is ‘fitter’ or not, you have no way of knowing other than to release each variant into the population and see how it fares. Too much interplay (as you often say, trial-and-error appears to be the only viable design option in biology).
So … conservation is the resultant of a low ‘baseline’ rate of neutral substitution, with an additional restraint caused by the possibility that fitness will be diminished by many substitutions that don’t actually destroy function in lab conditions, particularly in long-term ‘optimised’ proteins. More recent proteins are always more likely to be uphill in the fitness landscape than their distant forebears, cementing the change. We come along after evolution has done most of its work, but this may also be true when we look at conservation across quite wide taxonomic groups – evolution had already ‘done its work’, and extracted a near-enough ‘optimal’ solution prior to the common ancestor of that group.
Allan Miller’s descriptions of the issues of coiling, folding, charge redistribution due to proximity, hydrophobic and hydrophilic properties, etc., are extremely important and common. As Allan points out, the medium in which complex molecules are immersed is also important.
Not only are these phenomena common in complex organic molecules, they are common in all complex interrelationships between atoms and molecules; and they are the primary reason that matter condenses despite the fact that a complex structure is technically neutrally charged. Complex organic molecules making up living organisms happen to fall into the category of soft matter, in which kinetic energies and potential well depths are comparable.
The net geometrical configurations of complex, coiled and folded molecular systems provide all sorts of patterns that are not discernable by simply looking at the static, digital diagrams of chemical structures. These are, instead, dynamic structures because they exist at finite temperatures where the thermal energies and potential energies allow very complicated interactions and binding possibilities that don’t appear in static pictures of the structure.
Thus we see another of the horrendous set of misconceptions promulgated by the ID/creationists regarding the behaviors of complex systems of molecules. Condensed matter and chemistry is not just a bunch of atoms lying around waiting to be sampled with a uniform sampling distribution and then placed into positions that are essentially an infinitesimal subset of all possible positions. It’s not tinker toys or Lego blocks.
That bogus, ID/creationist picture betrays not only an amateurish understanding of basic physics and chemistry, it also reveals complete ignorance of the how and why of research activity in this area. You don’t just “see and say” in these areas of research; you do the grueling work of actually checking out what happens.
I’ve often said that, but it is based on intuition rather than knowledge. If “most” substitutions are synonymous or nearly neutral it makes a hash of “intelligent” selection.
To have a plausible theory of design, one needs to demonstrate that it is at last possible in principle.
EDIT:
The reason it makes a hash of intellegent selection is that you don’t know what you are selecting for. Just making a protein having certain measurable properties doesn’t cut it. Fitness is apparently more subtle and requires consideration of many dimensions. That is why evolution is smarter than designers.
Yep – Orgel’s second Rule: “Evolution is cleverer than you are”.
I think it’s based on intuition for most people, but also a degree of experience with complex designs. I don’t know what kind of perfect projects the ID crowd work on, but for the most part our intent gets extensively modified as the result of Unintended Consequences, and we end up kludging our way through. Evolution just takes the route of all-kludge, which is OK because there is no ‘finished product’. The intermediates merely need to be viable, as ‘solutions’ in themselves. (Man, I’m getting sick of putting quotes round every metaphorical usage!).
To add a small correction to my ‘protein folding’ above – charge isn’t the only determinant of whether an acid has hydrophilic or hydrophobic character. Uncharged residues can be hydrophilic.
Here is a PDF of the McLaughlin paper (provided by the lab) that is behind a paywall at “Nature” via Petrushka’s link.
See the McLaughlin paper. That’s exactly what they are doing. See Todd Wood’s blog for a straightforward analysis.
Reposting the link.
The pdf has maps showing functional loss and gain. It doesn’t look like a needle in a haystack.
If this is based on a simple test for function, it indicates that such simple tests are useless for determining biological fitness. So how does a designer determine what to intelligently select?
Any bets as to whether gpuccio has an answer?
keiths,
If you had any evidence whatsoever that unguided evolution (whatever that is) or any other mindless natural process (what does that even mean) could account for the complexity of life you would post it. You don’t have evidence so instead you attack ID with falsehoods and misrepresentations. Elizabeth would be proud.
A true skeptic, however, demands not just evidence, but strong evidence. And this, you most assuredly do not have. So where are the true skeptics here?
Define evolution. If you mean changes in gene frequencies, yes. Changes in gene frequencies do not explain the complexity present in even the simplest of living organisms. Do you have any evidence that changing gene frequencies can explain complexity?
Did you read the post or the comments following? Because you don’t appear to be responding to any of them.
Is this the OOL argument?
Not relevant. this thread is about isolated islands of function.
peanut gallery,
If you can’t discern the association between my comments and the OP i suggest you remain silent. Otherwise your comments amount to no more than spam, which is not exactly in the spirit of what is expected from posts here at TSZ.
keiths,
From the fact that you have no mechanism capable of producing the effects in question, it does not follow that design can produce that effect. And contrary to your baseless assertion, that is not how the ID argument is framed. It should be no wonder that you (and your ilk – including this site’s founder) were banned from Uncommon Descent.
Considering that your original premise is false, your conclusion is not one that any reasonable person should accept as having been demonstrated. So now what?
What is your definition of evolution?
It’s not up to ID proponents to demonstrate that which cannot be demonstrated. It’s up to you to show that your proposed mechanism is up to the task of producing the effect in question. Your failure to do so is noted.
What is your definition of evolution?
Keeping in mind that you have decided to assert that evolution [an as yet undefined term] is an unguided or mindless natural process [see your OP] how do you propose to establish by evidence and reasoning that evolution is in fact an unguided or mindless natural process?
So no, IDers don’t conclude that the evidence for evolution (as you have labelled it) is “too strong to dismiss out of hand.”
IDers are willing to accept what the strong evidence has shown to be the case. They are not willing to accept wild extrapolations that the evidence does not support. They are the true skeptics.
Mung, you deserve many congratulations on your courage to leave the safe haven of UD for the more-intellectual environment of TSZ. So, yes, congrats! But having done so, you also need to leave your bullying habits behind. You’re not the one who has authority to loudly proclaim what “is expected from posts here at TSZ” Dearie me, not at all.
While you suggest that at least some persons here remain silent (because their comments are what you pretend “amount to spam”) I am going to make a countersuggestion. I suggest that you earn respect here by avoiding snark and politely-worded insults. I suggest you retract those portions of your comment:
After you’ve corrected that, maybe we can start fresh with your questions on the actual topic of islands of function.
hotshoe,
Thank you for the red herrings, they were delicious. How are they relevant to the OP?
The comments made by keiths in the OP which he attributed to intelligent design proponents do not represent the beliefs of intelligent design proponents. s such they are in fact false and misleading. Lies and misrepresentations.
My comment that Elizabeth would be proud is obvious sarcasm, which seems to have been lost on you. (Or is sarcasm not allowed?)
keiths offered not one shred of evidence in support of his assertions about what ID proponents believe, and it of course follows that he offered no strong evidence. No one called him on it. Thus my query concerning whether there are in actuality any true skeptics here at TSZ is relevant.
Where were your own challenges to his lack of evidential support for his assertions? Were you just assuming they were true?
Elizabeth Liddle:
True at UD. True here at TSZ.
But TSZ is supposed to be different, right?
Aw shucks.
You mean there is a percentage of posters here at TSZ open to intelligent design? According to Elizabeth, “in most venues, one view dominates.”
Which view dominates here at TSZ?
Is that what you think Elizabeth had in mind when she founded this site?
keiths,
An assertion for which no evidence is offered. None.
Not a skeptic.
There is no point in saying that. It is just empty name calling.
If that is your view, then pick out (and quote) a few specific statements that you are referring to, and explain why you believe them to be “false and misleading.”
Allan Miller:
In what sense then are they a part of the fitness landscape?
Allan Miller:
Let me expand on that for the benefit of our UD interlocutors. The fitness landscape faced by an organism can change
a) as the physical surroundings change (e.g. climate change);
b) as organisms move about their geographic ranges (e.g. a mountainside species experiencing different selective pressures at higher vs. lower elevations);
c) as the species evolves (e.g. a subpopulation moving into a particular niche, pressuring others in the same species to exploit different niches);
d) as other species evolve (e.g. predator-prey arms races);
e) as the genome itself evolves (e.g. changes to one part of the genome altering the prospective fitness of changes to another part);
f) as population sizes cycle (e.g. predator boom-bust cycles leading to the marvelous prime-number adaptation in cicada life cycles).
So in addition to the other questionable or invalid assumptions made by the ‘islands of function’ folks, we need to add one more: the assumption that fitness landscapes are either static or that they change too little to allow populations to get unstranded. It’s a silly assumption, given all the ways in which fitness landscapes can change over time.
Sorry, m’dear, you’ve confused yourself.
You weren’t talking about strong evidence in regards to what ID proponents believe, you were talking about strong evidence in regards to unguided evolution.
Here, I’ll quote you to refresh your memory:
Clearly, you are insulting us here for being insufficiently skeptical about the evidence for evolution.
But that’s not what you just said, where you claim to be insulting us for being insufficiently skeptical about keiths’ version of IDer’s beliefs.
Please don’t infect yourself with confusion again. It might be contagious.
Now, as for the substance of your most recent complaint:
Quote a specific “comment” made by keiths in the OP which he attributed to an ID proponent. Demonstrate your claim that it does “not represent” the beliefs by quoting a specific IDer’s comment from a UD thread (or elsewhere) which directly addresses and contradicts keiths’ attributed comment.
Otherwise, apologize for pretending that keiths lied.
keiths,
For your information, the landscape changes in response to the population.
God bless, Mung. Is this going to be typical of the shallowness of your participation?
You have a new assignment. Go back to the beginning of keiths’ post and read the whole thing, word by word.
keiths’ whole essay following the one line you just snipped explains how “fitness landscape” is related to “islands of function” conceptually. They’re concepts, Mung; evidence for or against their actual existence in our natural world is not needed at this stage.
Do you not see the word “metaphor” right there in the very part you quoted? Do you not have any idea what the word “metaphor” means?
An assertion for which no evidence is offered. None.
Not a skeptic.
Apparently the only response UD has to their complete impotence to suppress the critiques here on TNZ is to send one of their thugs over here to do the same Joe Guano dance that got Joe G banned.
I don’t think the people over at UD know it – or would admit it if they did know it – but such thuggery has been a regular feature of the ID/creationist movement from its very beginning. They just can’t seem to hide their true nature behind that façade of civility they try to maintain.
This comes as no surprise.
Heh.
Neil Rickert:
“Intelligent design proponents make a negative argument for design. – keiths”
How does one make a negative argument for a proposition?
What is a negative argument? Does keiths tell us what constitutes a negative argument? No, he doesn’t. So he’s given us no reason to believe the truth of the very first sentence in his OP.
“If it can’t be accounted for by evolution, they say, then we must invoke design. – keiths”
Patently false. keiths knows it’s false. You know it’s false.
Mike,
Your post belongs in Guano. You know it, I know it, the moderators here at TSZ know it.
damitall2:
And the evidence to support this assertion consists of…
Does anyone other than damitall2 believe it’s true?
Pretty much every person who understands the real-science definition of “slightly deleterious”, “fixed”, “population”, “mutations”, and “beneficial” accepts the likely truth of that. It’s only creationists and the IDer cousins who don’t; well, them and plain old ignoramuses. But the ignoramuses don’t deliberately disbelieve it, unlike the IDers who make their disbelief in reality a point of pride.
You’re just another data point for damitall2’s [meta] statement that IDers don’t accept the truth about biological reality.
Or, do you accept, after all, that slightly deleterious mutations can become fixed in a population and later become part of a beneficial combination? In which case, welcome to the real world, but in said case why in hell are you posting your unworthy question about who believes it?
P.S. Did you finish your assignment of reading/re-reading keiths entire essay?
Jesus fuck, Mung, nobody died and made you hall monitor. Your repeated attempts to assume the position are stupid and boring. Stop.
Mung:
Mung,
It’s probably unwise to try to speak for ID proponents, considering how little you know about what they actually believe: (Dembski, Upright BiPed, gpuccio).
However, if your own views differ from those of most IDers, express them and I will consider responding to them. Be advised, though, that your presence at TSZ does not change my general policy regarding your comments.
I am not interested in spoon-feeding ID or evolution to you, and I will not answer questions that have already been addressed in the OP or in preceding comments. So take hotshoe’s advice and do your homework before spamming the threads here with irrelevant or misguided comments.
I’m going to disagree with that. For one thing, I doubt that UD is well enough organized to be able to “send one of their thugs over here.” I’ll assume that Mung’s decision to participate here was voluntary.
On the other hand, I will be watching the discussion, and I have made sure that I know how to move posts to Guano, should that be needed. I am asking all concerned, including Mung, to keep a positive tone to the discussion and not allow it to degenerate into petty squabbles.
How did my name get into your comment? You don’t seem to be responding to anything that I said.
He did explain that in the next sentence.
A new member joining TSZ is automatically marked for moderation. The effect is that all new comments go into the moderation queue, where most members cannot see them until they are released.
I took you out of moderation and approved your first two comments, in spite of their tone. I would like to see a genuine attempt at discussion, rather than accusations of lying. If the tone of your comments does not improve, then I’ll be putting you back in moderation.
Mung,
It’s a fair question.
The fitness landscape is constructed (notionally) from the set of all possible genotypes. Actual genotypes are little pinpricks in that space. Some possible genotypes will be fitter than others (different heights) and they will be more or less closely related (different locations). A mutation lights up a pinprick – one of the set-of-all-possible-genotypes becomes an actual genotype, which will be uphill, downhill or on the same level, and near or far away depending on the extent of the mutational rearrangement. It doesn’t become part of the fitness landscape by existing, it was already there waiting to be landed upon.
So when I say that evolution cannot get to certain points in the space, this is because all paths to those points are blocked to current genotypes by excessive detriment somewhere along the way. Mutations could leap right across that, but it is generally agreed that such hopeful leaps are extremely likely to end badly. Populations can trickle round the space if there are holes*** through which they can trickle. They explore the explorable extremely well. But most outriders who attempt shortcuts end up eliminated.
*** [yeah, I know, mixed metaphors!]
But my request for this thread was inspired by the paper indicating that function is not isolated needles in a haystack. And the sea surrounding the islands is more like a wading pool. Sorry about the metaphors. I didn’t invent them.
ID proponents wo wish to be taken seriously need to address thes facts of chemistry. The meaning of coding sequenced is not bound to a single value the way a lock is bound to a single combination. The lock is very forgiving. Pretty much the way internet forums are forgiving of typos.
The Lenski experiment is a classic demonstration that nearly neutral mutations can arise in a population and later enable a new function.
I have asked this question repeatedly: how does an intelligent designer know which neutral mutations are going to be useful when combined with later mutations, and why does it take 20,000 generations to do it? (Assuming, as some ID supporters claim, that there is some inner intelligence producing the correct mutations.)
Well, I guess the metaphors can be misleading. In pointing out that some of the space is inaccessible, I’m not saying that every sequence is stuck on an island. Rather, Life on Earth has been exploring an ‘island’ that’s an island the way Europe, Asia and Africa form an island. There’s plenty of places that are simply too far away or blocked by detriment; they may well be (and probably are) function-rich. But Life has been accessing the places it can get to.
Say we simply colour blue all points in the space which are currently below a particular threshold of fitness relative to the current ‘actual’ sequences. How does that look? As populations climb an adaptive peak, the ‘sea’ rises – inevitably, points more than a certain distance downhill will be blue. Does that mean evolution must always stall? Not if the contours shift and fitness is stochastic, it doesn’t. And in fact, as regards points at the same ‘level’ – neutral sequence, the baseline process – a population simply cannot remain at that spot, any more than an untethered atom can resist Brownian motion. Even in a flat landscape, evolution must happen, inevitably. Only selection can oppose it, ironically.