"Blinding New Evidence!"

I have a weakness common to many bloggers--I like to check my site meter to see who's coming to my blog, and from where. Often I wind up discovering intriguing sites run by people whose interests run along the same lines as mine, such as evolutionary biology. Today, however I was surprised to see a lot of traffic coming from Answers in Genesis, a creationist web site.

First off, greetings to all visitors who come through the link. I hope you find some interesting things here.

I decided to investigate the source of the link, and the results were interesting. It turns out that today Answers in Genesis put a new page up in which a writer attacks a recent post of mine about HIV. I explained how recent research on a virulent new strain of the virus relied on evolutionary biology to investigate its origins, and how understanding natural selection helps scientists put together strategies for vaccines, antiviral treatments, and other ways to fight the disease. And I pointed out that creationism appears nowhere in this research, providing no help in understanding this particularly nasty aspect of the natural world.

Answers in Genesis takes pity on me for not having come to them for enlightenment. "Had Zimmer checked this website first, he would have known that far from creationists ducking for cover at this blinding new evidence (as his article, especially its title, implies), we wrote an article years ago Has AIDS evolved which, in principle, raised and dealt with the points his piece makes."

It's important to address some of the erroneous claims raised in the piece, but it's not easy because they are mixed together with non sequiturs and other distractions. "Blinding new evidence"--quote unquote? Do those words appear in my blog? No. Does the writer attribute them elsewhere in his piece to someone else? No. He's just putting quotation marks up arbitrarily.

And then there's the claim that the piece he refers to raised and dealt with my points "in principle." The HIV research I'm discussing was published in 2005. The piece in Answers in Genesis came out in 1990. Did the folks at Answers in Genesis know then that this paper on HIV would be coming out in fifteen years? Could they foretell its contents so well that they could explain how creationism would actually guide the research? Again, no.

What Answers in Genesis actually said in 1990 was this: when scientists observe evolutionary change in viruses such as HIV, they have not found proof that viruses evolved into people. "Viruses can have no evolutionary relationship to any other form, and so whatever may have happened to say, the AIDS virus, has no relevance to the supposed history of truly living organisms in any case," Answers in Genesis claims.

To those who find this claim impressive, I would point out a couple things.

First of all, it evades the actual point of my post, which was that scientists who are working on HIV and other pathogens do not base any of their work on creationism of any flavor, including intelligent design. You can look in medical journals all you want, but it's just not there. Mutation, natural selection, genetic drift, and the adaption to new host species are what's there. (See my follow-up post for some research on the deep history of HIV.)

Second of all, it's just flat-out wrong to say that "viruses have no evolutionary relationship to any other form." Scientists have documented many cases in which the DNA in viruses and the DNA in a bacteria, animal, or some other organisms show an evolutionary link. In some cases, viruses have permanently patched themselves into host genomes, including our own. In other cases, viruses appear to have evolved from a segment of DNA from some organism, having acquired mutations that allow them to break free and infect other hosts. In still other cases, the viruses have grabbed host genes along the way, turning into a veritable genetic mosaic. Viruses appear to have been present since the earliest stages of life on Earth and may have given rise to some of our most important celular machinery. A quick search of the scientific literature brings up a wealth of papers addressing the intimate role of viruses in our evolution--here are just a few gems:

Viruses as the source of new genes in bacteria

A catepillar virus that evolved from the wasps that parasitize catepillars.

A look at the entire range of viruses, and a discussion of how viruses may have preceded cellular life.

Another look at how viruses have been inserting themselves in genomes since the origin of cellular life.

An analysis that indicates that some of the most essential enzymes in our cells come from viruses.

A leading evolutionary biologist writes: "I suggest here that DNA and DNA replication mechanisms appeared first in the virus world before being transferred into cellular organisms."

I heartily suggest that people read the Answers in Genesis piece on viruses--not for any scientific enlightenment, but as an example of the bait-and-switch tactics and omission of evidence that's necessary to create the impression that there has to be some "blinding" line dividing small and large scale evolutionary change. (Quotation marks mine!)

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Excellent points regarding the all too familiar "bait-and-switch tactics." Most media-friendly debates are broken records nowadays.

Unfortunately, I imagine those who disagree with your perspective are unlikely to follow the links you provide. As fascinating and exciting as the "poisonous partnership" between parasitoid wasps and the polydnaviruses residing within them may seem to folks like myself, it will "prove" little to those who believe "viruses have no evolutionary to any other form."

(In the interest of space and time, I won't even get started on the baffling absurdity of believing anything exists without a relationship to its environment, whether you accept evolution or not.)

Open-minded creationists might want to check out Plagiarized Errors and Molecular Genetics by Edward E. Max, M.D., Ph.D. which discusses in details things like ancient viruses which were incorporated into the DNA.

http://www.talkorigins.org/faqs/molgen

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By Mike Hopkins (not verified) on 12 Apr 2005 #permalink

I am a layman, but one who works in the technology field and is well-versed in scientific lingo. As such, I must point out one of the glaring (to me) practices that has been repeated by evolutionists (and journalists, and scientists) over and over and over again. This error is that of representing theory as absolute fact.

In this very article, you title a link A catepillar virus that evolved from the wasps that parasitize catepillars. (By the way, you spelled caterpillar incorrectly). This link, when clicked, displays an article that even a novice would perceive as an hypothesis, as the article itself contains the phrases 'implications of this hypothesis,' and 'suggest that these viruses evolved.' Yet your title of the link makes a statement of fact. As a regular joe of 27 years, I have grown immensely tired of reading scientific articles stating 'facts' which are completely contradicted a few short years later by new evidence. And, viewing the current state of public opinion on evolution, it is no wonder. The public is given the impression that 'you guys' don't know what the hell you're talking about.

I know you can't control when a journalist takes your data and extrapolates fact from it. But instead of leaning back in furtive pleasure, take a stand and make it known that the data does not prove an hypothesis.

LD, you might examine a few journals. Real scientific technical papers often to use such provisional language even when they have a slam dunk case.

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By Mike Hopkins (not verified) on 12 Apr 2005 #permalink

So, LD, you are familiar with scientific "lingo"? That's great! Then you should know that most scientific papers describe hypotheses, which are then either supported or disproved by observation and experiment. (Tiresome, perhaps, but in the long run effective.) The paper on insect viruses is only one of thousands and thousands that illuminate and support the concepts of evolution. This is in contrast to the number zero, which represents the peer-reviewed papers published in reputable scientific journals supporting the concept of intelligent design. Similarly, Mr. Zimmer cites a variety of sources in support of his arguments, while Mr. Wieland provides nothing but hot air.

LD, it may be useful for you to understand the meanings of the words "theory" and "fact" before making further comments. Thanks!

By My other brain… (not verified) on 13 Apr 2005 #permalink

LD-

This confusion isn't made within the scientific community. It has arisen because anti-science types like to equate "theory" with "speculation". I try to use "scientific theory" to avoid the confusion, but how do you communicate with someone who reads this as "scientific speculation"? The most intellectually fulfilling course is to communicate with scientists and to use the term as they use it.

There is a deeper threat to studying how HIV/AIDS works than fending off those quoting scripture. This artice from The Globe & Mail [Toronto, Ontario] suggests the onslaught all science is suffering from today.

http://www.theglobeandmail.com/servlet/story/RTGAM.20050409.wxcover09/BNStory/specialScienceandHealth/?pageRequested=all

This blight is spilling over into Canada and the fight will be joined fully with the upcoming change in government. There's a long slog ahead for us all.

the bunyip

LD:

According to Karl Popper, knowledge of the natural world never advances by direct confirmation of scientific theories, which cannot occur, but only indirectly, through the systematic falsification of their alternatives by reference to our experience.

This may sound shaky to you but this is the only effective way to accumulate knowledge and truth since the beginning of science. That's why scientist always call there discovery a "theory".

By Zhiyun Chen (not verified) on 13 Apr 2005 #permalink

This blog, after Steven Pinker's How the Mind Works, is probably the number-one influence dragging me toward evolutionism today (it's the steady drip, drip, drip of real science being done using the "theory.") Zimmer may be able to do a better job of fighting the creationists by continuing to do what he did before than by arguing with them. It tends to drag you down and raise their profile.

I'd like to point out before everybody piles on to Answers in Genesis that one of the basic rules of blogging is to respond to weak attacks and ignore strong ones. Wieland is not necessarily the face of all reasoned creationist opposition.

In regards to the AIG writer's statement " "Had Zimmer checked this website first, he would have known..."

I believe Wieland's point is that scientists subscribing to a view of biological origins based on evolution and ultimately life arising from a non-living primordial soup are generally ignorant of what creationists (and intelligent design theorists) actually believe.

Those who take ten minutes to read a couple articles on either the creationist or ID websites will find no argument against "Mutation, natural selection, genetic drift, and the adaption to new host species"

Natural selection is just as important to a creationist as to an evolutionist in explaining the world we see around us. The denial is not that organisms change. The argument is that mutation does not create new information rather it corrupts information and while the net result may be a benefit to the mutated organism in a specific situation, upon full examination one will see a loss of genetic information.

For example from Zimmer's original article "Often drug-resistant pathogens have to pay a reproductive cost for their ability to withstand attack from our medicines."

If there is ever to be resolution to the debate Evolutions and Creationists need to agree on a clear and specific definition of Evolution to eliminate the perceived "bait and switch," "strawman" and "just-so stories" that seem to pervade the discussion by both sides.

Doug wrote:

Natural selection is just as important to a creationist as to an evolutionist in explaining the world we see around us. The denial is not that organisms change. The argument is that mutation does not create new information rather it corrupts information and while the net result may be a benefit to the mutated organism in a specific situation, upon full examination one will see a loss of genetic information.

The claim that information doesn't increase has not gone unanswered. In fact it has been answered here before, on the 'Loom'. Take a look and see what you think.

Please explain how you became convinced that natural selection does occur. What evidence did you see, and what arguments did you accept?

By John Hill (not verified) on 13 Apr 2005 #permalink

If there is ever to be resolution to the debate Evolutions and Creationists need to agree on a clear and specific definition of Evolution to eliminate the perceived "bait and switch," "strawman" and "just-so stories" that seem to pervade the discussion by both side

Evolution: Change in allele freqency in a population over time.

That's the definition I've heard in all of my classes and texts, and I feel fits very nicely, if you know all the data. I believe Mayr coined that definition, but I could very well be mistaken (I'm horrible with names and who did what).

For example from Zimmer's original article "Often drug-resistant pathogens have to pay a reproductive cost for their ability to withstand attack from our medicines."

How does that even remotely contradict evolution, or support what you assert? That adaptations have costs associated with them is pretty old news, and is in no way contradictory to evolution. In fact, it's evolution that, using data on the costs and advantages of a trait compared to an alternative form, can predict the future alterations in trait frequency in the population under specific conditions.

For instance, if we know that an allele allows bacteria to resist antibiotics, but it pays a reproductive cost, then we can predict that allele will spread through the population *only* when antibiotics are present, and, when removed, it's frequency will decrease again.

Traits are never "good" or "bad". With the exceptions of mutations that are lethal or sterilizing, the selective value of any trait is defined by the environment (in the above case, the presence or absence of antibiotics). Again, this in no way contradicts evolution, and, in fact, supports it.

The argument is that mutation does not create new information rather it corrupts information and while the net result may be a benefit to the mutated organism in a specific situation, upon full examination one will see a loss of genetic information.

That arguement is provably false. Gene duplication events. Unequal crossing over during meiosis. Both of these (as well as other types of mutations) can not only add genetic material, but can add *LOTS* of it, sometimes adding duplicate chunks of DNA containing hundreds of genes (which, because their function is being fulfilled elsewhere, can then evolve to suit new functions).

Of course, there's also the favorite of plants: polyploidy. Normaly, a seedling gets 1 set of chromosomes from mom, and one from dad. But, if there's a mess up in meiosis, it might get 2 from dad and 1 from mom (or vice versa or sometimes even 2 from each). This *instantly* doubles the DNA in the organism, with all the duplicate DNA being free to evolve new functions.

Ever wonder why farm strawberries are so huge compared to wild ones? They're octoploid, having been the result of 2 sequential "doublings" (and the excessive gene products result in their huge size).

Oh, and incidentally, because organisms that get only 2 from one parent and 1 from the other are sterile, those that get 2 from each cannot back-cross with the parent plants. Result: instant speciation.

By Henry Astley (not verified) on 13 Apr 2005 #permalink

I guess the main problem that I have with the evolution argument is not that living things change over time, but how they came into existance to begin with. If evolution is the explanation of how I came into being then you first have to show me how life originated from non-living chemicals. That is the biggest obstacle in my mind. The Urey-Miller experiment that I studied In my earlier days now appears to have all the wrong chemicals and conditions of the early primordial soup. The difference between making simple chains of amino acids and RNA and DNA is too big a leap of faith. The problem of chirality in a random undirected system. Some of these things take too much faith to believe. Until we can explain how life originated in the evolutionary process, most of the public will never buy into it!


The argument is that mutation does not create new information rather it corrupts information and while the net result may be a benefit to the mutated organism in a specific situation, upon full examination one will see a loss of genetic information.

Your use of the word "information" here is unfortunate. I provide you with information when I tell you something you don't already know. So, information lies in the unpredictability of what I have to say to you (if you can predict what I have to say, then I haven't provided you with any information). Random alterations increase the information in a code sequence; in information theoretic terms, a completely random code sequence has maximum information content. On the other hand, very regular, predictable, non-random sequences have low information content.

Another way to look at this is as follows. The fact that all members of a species share so many of their characteristics (body plan, proteins, etc) means that the genome for that species carries relatively little information (compared to what it could carry) -- you can predict much of its content, given you know what species is being talked about. Mutation increases variation of characteristics -- given only the same initial information about the species involved, your prediction of what any particular individual's genome looks like will become less accurate as time goes by. This is, very clearly, an increase in the information content of the genome, and it was caused by a random process. If the process were completely deterministic, such as might be the case if a Designer were involved, then knowledge of it's existence would make future genomes predictable again, and therefore no additional information is added.

Henry's proposed definition of evolution: "Change in allele freqency in a population over time." is exactly the problem. It is much to vague for the discussion. I've never read a single piece of creationist literature that suggests any doubt that allele frequency changes. Darwin himself made this same mistake adopting the belief that the Bible suggests God created each living thing exactly as it is today. Creationists do not believe this and the Bible actually suggests the opposite from the very beginning. Read about Jacob and Laban in Genesis 30 for a lesson in breeding sheep for specific physical characteristics.

Speciation is also not problematic for a creationist. The key word for the debate is "kind." God created each "kind" to reproduce after its own kind. Unfortunately there is not a perfect correlation between a taxonomic class and a "kind". People often make the mistake of associating a kind with a species but a species is far too narrow.

A viable definition of evolution must include something about providing new useful genetic information. I'm not nearly well versed enough to extemporaneously come up with a thorough definition on which both sides can agree. I only know that in high school debate I learned that the first step in debating is to clearly define terms, and I've never seen that done satisfactorily as the first step of a debate on this subject.

I guess the main problem that I have with the evolution argument is not that living things change over time, but how they came into existance to begin with. If evolution is the explanation of how I came into being then you first have to show me how life originated from non-living chemicals. That is the biggest obstacle in my mind.

However, that isn't an objection to evolution, it's an objection to abiogenesis. The two are entirely separate. God could have created the first life, but that in no way invalidates evolution, because the life would still be changing and evolving. Evolution isn't an origin, it's process.

Think of it like this: If I hold up a ball and let go, gravity will govern it's motion. Whether I do it or my friend does it doesn't matter, nor does what store we bought the ball from.

Point is, abiogenesis and evolution are two separate questions, and the veracity of lack thereof of abiogenesis has no effect on the veracity of the past and ongoing process of evolution.

(I'm not actually going to go into abiogenesis because 1: it's off topic and 2: I find most chemisty kinda boring, fires and explosions excepted, of course)

Henry's proposed definition of evolution: "Change in allele freqency in a population over time." is exactly the problem. It is much to vague for the discussion.

Well, first, it's not mine, it's Mayr's, IIRC. Just making sure nobody thinks I'm taking credit for it.

But yes, it does *look* vague, but the problem is that evolution is so expansive that it *has* to be vague to fit it all in. You've got to factor in natural selection (disruptive, directional and stabilizing), sexual selection, genetic drift, founder effect, all of these things that can result in evolution, and cast their marks on the genetic changes of organisms. More "precise" definitions always wind up leaving something significant out.

Speciation is also not problematic for a creationist. The key word for the debate is "kind." God created each "kind" to reproduce after its own kind. Unfortunately there is not a perfect correlation between a taxonomic class and a "kind". People often make the mistake of associating a kind with a species but a species is far too narrow.

Yet anything above species is a fiction. "Primates" don't exist, that's just a word we made for a group of species. Once groups of organisms are reproductively isolated, it doesn't matter whether their common ancestor was 10 mya or 100 mya (million years ago), since they can't exchange genetic information. Taxonomy (and the various levels) don't exist in the fabric of evolution, but merely as a human concept to help scientists communicate about life.

I mean, how do you define "family" or "class"? There's no real set of criteria. Sure, you can note levels of differences, but is that truly meaningful, especially given varying rates of evolution for varying species over time?

The problem is that "kinds" has no biological meaning at all, and so the creationist request for showing evolution between "kinds" becomes nothing more than a shifting goalpost they can plant wherever is safely out of reach. It's a logical fallacy, pure and simple.

A viable definition of evolution must include something about providing new useful genetic information.

Why? If there are multiple versions of a trait already around, can't the frequencies change? And is that not evolution? Genetic change over time?

I think the problem is that you're focusing on macroevolutionary change and mutation, the former of which is just a form of microevolution on a long time scale, and the latter of which is just chemical errors in DNA replication or maintenance.

What about loss of information? That can be evolution, or even adaptive; you don't see cave-fish wasting energy on eyes (for more depth on that, see one of the prior articles on this sight (pun intended)). Loss of genes that are no longer useful can be evolution as well, so a definition that focuses on gain neglects vital aspects of evolution. See what I said before about vagueness?

Personally, I like Mayr's definition, since it incorporates *everything*, without an exclusions. Plus, and most importantly, it gives us a quantifiable basis. If I want to study evolution of a local population of frogs, I can take samples blood at various times and compare the genetic changes. From those, I can see various types of evolution: founder effect (do they all share a single gene because that was all that was around in the ancestral population that first came to the pond?), natural selection (are selective pressures driving the gene frequency in one way or another, or splitting them, or maintaining the frequencies?), etc.

While I agree the definition does seem vague, IMHO the benefits of this definition far outweigh any drawbacks.

By Henry Astley (not verified) on 14 Apr 2005 #permalink

For this discussion the vagueness of the definition is exactly the drawback.

The reality is that evolutionist and creationist theories have more common ground than most people realize. Until the debate centers on the actual differences it is pointless. I would contend that the vast majority on the evolutionist side of the argument are quite unfamiliar with what creationists actually believe. This is not meant in any bad way, its just logical, given what is generally covered in mainstream media (ie. it was never a belief of Christians that the world is flat), it would likely seem a waste of time.

An evolutionist may bring up the blind fish in a dark cave as an example of or evidence for evolution because it fits the definition of "change in allele freqency in a population over time"

The creationist will agree with the fact that the dark cave led to the blind fish. He will agree that it is evidence for a "change in allele freqency in a population over time." He will contend that this is strong evidence for the creation model because it shows the fish was created with eyes but over time and in a specific circumstance the fish gained a competitive survival advantage by not having eyes. Finally he will point out that a fish becoming blind is not evidence that the fish could "evolve" eyes in the first place. He will also assert that when introduced back into the general fish population the blindness will become a hindrance to survival and the fish will die out.

Neither side denies the fish are blind. Both agree that the populations changed over time. Both agree that a genetic mutation for blindness was able to flourish as it provided a survival advantage and was therefore naturally selected. The facts are not in question but the interpretation as it pertains to a scientific philosophy is.

Remember the Raymond Dart Thesis ... "The Predatory Transition From Ape To Man" in which he describes fossil evidence for a male 'weapons fetish' among Australopithecus africanus, our immediate ancestor.
xx enjoy xx

By DEAN BEHNCKE (not verified) on 15 Apr 2005 #permalink

Henry
I get the point of your argument:
However, that isn't an objection to evolution, it's an objection to abiogenesis. The two are entirely separate. God could have created the first life, but that in no way invalidates evolution, because the life would still be changing and evolving. Evolution isn't an origin, it's process.
Point is, abiogenesis and evolution are two separate questions, and the veracity of lack thereof of abiogenesis has no effect on the veracity of the past and ongoing process of evolution.

The two are not mutually exclusive however. To say a supernatural process caused life and then left it to completely nautral processes without intervening is not what most evolutionists believe. Nor is it what most text books teach. The Big Bang.... coalescing gasses.... primordial soup..... amino acids..... single celled organisms..................... us. Im just saying I can't get past the initial premise of nothing to something, non-life to life by completely naturally causes. Too much faith involved. The majority of the public feels the same way according to the polls. Until we can adequately explain the "beginnings" naturally, I can't believe the molecules to man naturally!

I would contend that the vast majority on the evolutionist side of the argument are quite unfamiliar with what creationists actually believe.

I will say that there are wide variety of creationists, but I feel you a presenting a biased picture, in only noting the thoughts of the most reasonable extreme of creationists. I've met creationists, and discussed with them enough to know they come in all flavors, from the reasonable ones you note to the "Dinosaur fossils are fakes made by Satan to trick us" ones. And this isn't from the media, this is direct from the fundamentalist's mouth, so to speak.

He will agree that it is evidence for a "change in allele freqency in a population over time." He will contend that this is strong evidence for the creation model because it shows the fish was created with eyes but over time and in a specific circumstance the fish gained a competitive survival advantage by not having eyes. Finally he will point out that a fish becoming blind is not evidence that the fish could "evolve" eyes in the first place. He will also assert that when introduced back into the general fish population the blindness will become a hindrance to survival and the fish will die out.

Ok, I must admit I'm confused. How are any of those points even cogent or relevant? The first one, that the fish had eyes in the past, is a given, but claiming that means there were "created" with eyes is nothing short of a basless assumption. Just because something had a former state does *not* in any way offer even the slightest evidence it was 'created' in that state. That's like looking at the leftovers of a chicken dinner and stating "it was once a chicken dinner, so it must have been created by God, de novo, as a chicken dinner." Further, by accepting that the fish could lose the eyes, the individual accepts evolution, period.

As for that "not proving eye could have evolved in the first place", that's simple because I didn't chose the example for that purpose. For that, the solution is polychaete worms, which prove it nicely. Email me and I'll send you a nice JPG of it (because I don't remember the source of the JPG). As for pointing out the fish will be disadvantaged if moved to 'wild' population, I fail to see how that supports creationism in the least, nor how it refutes evolution. In fact, it *supports* evolution: evolution states that traits which are beneficial will propagate through the population, and, since the benefit or penalty of any trait is entirely dependent upon the environmental circumstances of the animal, evolution itself predicts the same thing.

For this discussion the vagueness of the definition is exactly the drawback.

It is also accurate. Would you rather a definition which is not vague, but is also wrong? Any "less vague" definition would be, quite simply, wrong, and ergo of even *less* use to a debate.

The facts are not in question but the interpretation as it pertains to a scientific philosophy is.

How so? The facts are obvious, as are their implications. Attempts to hide from the masses of evidence behind philosophical gibberish are nothing more than denial.

The two are not mutually exclusive however. To say a supernatural process caused life and then left it to completely nautral processes without intervening is not what most evolutionists believe.

As I pointed out, they *are* distinct, and can be interpreted entirely separately. That most who acknowledge evolution also seek an abiotic source of life is a product of personal preferences, not a necessary logical link. For example, most vegetarians are liberal. Does that mean there is a necessary logical link between the two, or just that both appeal to the same type of person? Obviously it's latter, which is also the explanation for the preference for non-divine origins of life by those who accept evolution.

Im just saying I can't get past the initial premise of nothing to something, non-life to life by completely naturally causes. Too much faith involved.

That is, of course, your perogative, and I know that my grasp of current abiogenesis work is far from adequate to sway you.

However, as I pointed out, that does not in any way reflect on the veracity of evolution. Whether life got here via God, aliens or abiogenesis, evolution is the process that acts on it.

The majority of the public feels the same way according to the polls.

Irrelevant, truth is not democraticly decided. The majority of the public probably doesn't believe that time itself can be distorted by the speed of an object, but it's a proven part of physics.

Until we can adequately explain the "beginnings" naturally, I can't believe the molecules to man naturally!

As I said, your beliefs are your perogative, but this statement is basically combining two distinct theories and then arguing against one from the lack of evidence of the other.

Regardless of how often most are presented together, that does not mean there are any necessary logical links, and that one's veracity or lack thereof affects the other. They both appeal to the same worldview, and thus co-occur at the individual level (and within books), but are not directly and logically dependent upon each other.

By Henry Astley (not verified) on 16 Apr 2005 #permalink

This one will be brief.

First I'd like to say that I'm enjoying this discussion and I especially applaud the lack of personal attacks that so often surface in this forum.

Next I'm not suggesting that the fact that a fish has eyes means they were created. I'm making the point that both creationists and evolutionists will agree on the process that caused the blindness to prevail in the fish population. It is the same process that will extinguish the trait if that population of fish gets out of the dark cave. I suggest this process is called Natural Selection. The cause is either a loss or corruption of the "information" that codes for eyes.

Further, by accepting that the fish could lose the eyes, the individual accepts evolution, period.

This is exactly why the definition needs to be more specific.

You must admit the difference between:

a process that eliminates, corrupts, reshuffles or copies DNA that already exists (natural selection) and ;

a process that creates new information with new function (is there a name for this half?).

Reputable creationists have no doubts about the first clause. The doubt is that mutaions and time are the only additional ingredients necessary for the second clause to prove out.

I suggest this process is called Natural Selection. The cause is either a loss or corruption of the "information" that codes for eyes.

Agreed, but natural selection is simply a process by which evolution occurs. If natural selection is occuring, then, by definition, evolution is occuring.

a process that eliminates, corrupts, reshuffles or copies DNA that already exists (natural selection) and ; a process that creates new information with new function (is there a name for this half?).

The second half is simply mutation. I listed some of the forms of mutation that could do such in a prior post.

However, I agree yet disagree with your separation. I agree that mutation is not a necessary part of the definition, but not with your specificity about gain of information. Evolution can only act on what is in the gene pool at any given time, and does not cause nor diminish mutations. If evolution were not true, there would still be mutation (both adding and substracting info), and even in situations where there is no mutation, evolution could still occur, modifying the gene frequencies of existing genes (which is all it really does anyway).

Furthermore, loss-of-function mutations (like the eyes of the cave fish) can be beneficial adaptations, so I'm not really sure why there needs to be a distinction between the mutations that add and substract info. Both introduce new alleles, so, from evolution's POV, they're the same.

Evolution, change in gene frequency, can occur by many means, including natural selection. Any you're right, natural selection *does* decrease diversity of the gene pool, which is counteracted by mutation. It's like a car. Movement of the car is the outcome (evolution) accomplished via a motor (natural selection) which must be replenished with new fuel constantly (mutation). If the car runs out of gas, it stops moving, but it starts right back up when you put more gas in. Furthermore, the engine itself doesn't cease to exist when the gas runs out, it merely has nothing to work with for the moment.

I think I'm a bit overly fond of analogies...

The doubt is that mutaions and time are the only additional ingredients necessary for the second clause to prove out.

But, if you'll read back to one of my prior posts, you'll find that there's ample evidence this is so, both in terms of the traces such creation of new info has left, and in modern direct observation of the processes.

First I'd like to say that I'm enjoying this discussion and I especially applaud the lack of personal attacks that so often surface in this forum.

As am I. It' so rare that one can have a fruitful discussion of the subject that those occaisions become all the more valuable.

By Henry Astley (not verified) on 16 Apr 2005 #permalink

Well I've not a lot more to add to the subject at this time. I don't know whether we've made much ground or not. I still contend that before any ground can be made the evolutionist must recognize the that there are 2 directions for evolution.

A simple organism (relatively speaking as not even the most primitive cell is the least bit simple), through a host of successfully adopted mutations accumulates the genetic information to develop new function such as vision, the physical lens to recieve data and the means to process it in some useful way.

And

An organism with vision, through some mutation loses the ability to see as the genetic information responsible is corrupted.

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I think we can generally agree that a vast majority of mutations cause a loss of useful genetic information. I've never seen this point refuted, even when one claims that some mutations do add useful information. Therefore one must consider if there really is enough time for the vast amount of genetic information to accumulate.

How much time are we talking about? According to generally accepted dating methods we have multicellular organisms appearing around 1000 million years(my) ago. After 400 my we have evolved into sponges, worms and jellyfish. Then in only 50 my we hit the cambrian explosion, fossils representing every modern phyla.

Over this time frame mutation(X) must occur. X must provide a selective advantage. Then X must propogate through the population completely enough that when the next mutation (Y) occurs it is in an organism with X. One could argue that more than one mutation can occur at once but given that most mutations are detrimental and corruptive the probability becomes pretty scary for the organism. Even generously granting a 10% chance a given mutation is "good." If you add Y simultaneously you're down to a 1% chance. For bacteria with fast reproduction with a generation timespan of hours Evolution might get a running start if everything follows a best-case scenario. Eventually the bacteria must evolve into the creatures that reproduce slow and live longer. Try typing the encyclodedia 1 letter at a time and only typing one letter every couple of years.

I realize the simplicity of the above scenario and one might argue that it doesn't account for genetic drift and the like, where an organism might adopt a larger amount of information at once. On the other hand I think a 10% success probablity for a mutation is more than generous (I think 1% might be generous).

I would encourage anyone less familiar with the Creation side of the controversey to visit the site that started this thread topic http://www.answersingenesis.org/

and if you like analogies I would especially check out this short article.
http://www.answersingenesis.org/creation/v24/i2/evolution_train.asp

There are extant organisms with extremely "primitive" light-sensitive cells (consider that the red, green, and purple-sensitive constituents that allow plant cells to photosyntesize--and their precursors all the way back to the free-living bacteria that many scientists have reason to believe they originally were--contain proteins similar to those that allow many more-evolved eyes to function). Some solid computer modeling has been done that strongly suggests an organism with such light-sensitive cells can evolve toward a much more complex eye in a reasonable number of generation.

What tends to be forgetten in discussions of this kind is that selective pressure is just that--the operation of a non-random force which can seive through the available variation in a remarkably effective way. Mutations, whether info-adding, info-detracting, beneficial, or deleterious, are not just thrown out to be acted upon in a "random" manner. The environment in which a characteristic is expressed is not "random," but makes sterm demands on the organisms which inhabit it.

A bunch of worms and jellyfish, blindly wriggling and munching their way through the algal mats and floating foodstuffs of over a half-billion years ago--and perhaps "clearing" the seas of obscuring clouds of simpler organisms as they did so--were in severe competition with each other. Any trait which afforded any of them with an advantage in out-eating and out-reproducing each other-- interfering with each other, eluding each other, imbibing each other--would have been VERY strongly selected for. Hard body parts for armor and weapons. Light sensitivity, to gather information beyond the reach of those physical body parts. The progression from genotypes which could reliably "build" soft multicellular bodies of varying plans to those which could concentrate minerals in shells, skeletons, and mouthparts, to those who were able to envision the environment around them, is an entirely reasonable one.

With all due respect, the creationist "statisticians" tend to forget or ignore this non-random aspect to selection. The biologists began working out the math in this area in the 1930s, and have a long head start. Their calculations have been impressively confirmed--not just by computer modelling--but by experiment and observation over many decades.

And while it may SEEM sensible, after mentally performing a few iterations (generations) of statistically "unlikely" events, to conclude that no amount of time would allow for the "random" accumulation of beneficial complexity, that conclusion overlooks both the non-randomness of the selection process (above) and the sheer amount of time involved. The continents "move" at less than the pace your fingernails grow--but over millions of years they nonetheless migrate thousands of miles around the globe and interact with stupendous force.

The Cambrian "explosion" took place, conservatively, over tens of millions of years. And that's the part of the replay film of this "explosion" that can be run backwards and forwards using the frozen glimpses that the fossils of hard-bodied creatures provide. Light sensitive structures could well have been evolving for many millions of years before that, during the lengthy period between the dawn of multicellular life and the emergence of hard body parts, during the easy-to-overlook Age of Worms.

Remember also that the apparent emergence of modern "phyla" or "body plans" over a relatively-short span is illusory in several respects. Phyla and body plans are just convenient mental categories that WE impose upon the diverging lifeforms in order to organize them for thought and discussion. There's an interesting debate on this whole topic going on over at the Panda's Thumb site, which is useful to understand before slinging about concepts like "macro-evolution," concepts which one may easily feel are self-evident and well-understood, but which are far slipperier than you may think. There is no reason whatsoever to believe that the generation of "fixed" body plans happened any differently than any other evolutionary event--one mutation and "micro"evolutionary event at a time.

By Steve Russell (not verified) on 20 Apr 2005 #permalink

> it was never a belief of Christians that the world is flat

Actually, that's untrue. As recently as the 1930s (if I remember correctly), there was a Christian preacher who was debating scientists about the reality of a flat earth. His basis for belief was Biblical references. (He even attacked Christians for believing in a flat earth in a way that's similar to the way AIG attacks evolution-believing Christians.) Unfortunately, I can't recall the preacher's name right now.

Here's a Catholic website which defends the belief in a geocentric earth (they even offer a reward for anyone who can prove them wrong):
http://www.catholicintl.com/epologetics/articles.htm#8

Another Christian flat-earther:
http://www.lhup.edu/~dsimanek/febible.htm

> Change in allele freqency in a population over time.

I don't care for that definition very much either. I think there are far better definitions of evolution. As far as evolution being constructive, you might want to look up information on genetic algorithms. They use the forces of mutation, natural selection, and reproduction to form random information into something complex and organized. It's "constructive" evolution and I've never read a good creationist rebuttal (I've read the AIG rebuttal, but it's not a very good one). Check out the Avida Digital Life project.
http://www.discover.com/issues/feb-05/cover/