Defending Evolution from ID Distortions

Posts tagged “Scientists

Michael bans Olorin, and then Eelco

A while ago, on a post dated on June, I challenged Michael to answer certain questions about the irreducibly of the bacterial flagellum. I issued it after he banned  Olorin, a constant, critical commentator on his blog. Eelco, another commentator on the blog then took Michael to task for banning him, and I followed suit. Sometime after I published my post in which I presented my challenge, Olorin was allowed to comment again. Well and good, right? Well, not quite, since afterwards, Michael then seemed to have banned Eelco this time. — Olorin then asked him if he did ban him, to which he responded,

Why is it when certain liberals cut and paste numerous postings it’s not spam, but when someone else does it, it is…? I can ban as many IPs as it takes, I make no distinctions…

This was a question I found pretty ridiculous considering that Michael decided to wave around the “liberal” label, and claim there was a double standard. Truthfully, I found it ridiculous because I’m personally not even a “Liberal.” I am a Moderate Christian, and a Conservative leaning Libertarian. All-in-all, I’m a bit right of center. I don’t know how Olorin and Eelco stand on everything, though.

The “numerous cut and paste postings” that Michael mentions are the questions that Eelco has posed to Michael continually, not wanting him to forget them. They’re about:

(1) Blog readership numbers ?

(2) Your qualifications to discuss any scientific subject, in response to the challenge to Olorin.

(3) A substantive review of Signature in the Cell, promised for August 2009.

(4) outstanding question from Upson Downes on mitochondrial Eve.

My comments here come into play:

  • Question #1 is the least important, at least to me, though I have a nagging suspicion that the answer is “not much.”
  • Question #2 is the one I want most to answer of the four, but a simple reading of his blog leads me to belive that this answer is “none.”
  • Question #3 was actually one that Michael should have answered a long time ago. — On a blog post from July 31, 2009, he promised he would write a book-review of Signature in the Cell. It’s been a year since, and we are all still waiting.
  • I’ll let question #4 go for now since I don’t know what the question here is.

Anyway, Eelco constantly posted his questions to Michael who constantly pretended they weren’t there, and the more Michael ignored them, the more often they were posted. I guess Michael got tired of them, since he used the constant cut and paste as a rationale for banning him.

My bone with Michael cannot be that he banned someone per se, though it does give off the impression that he doesn’t like opposition to his views. But I did take issue with his saying that he makes “no distinctions” on the IPs he bans. I then challenged him saying,

Since you say you make no distinctions, then answer me this: Name me one Creationist/Intelligent Design proponent that you have banned from commenting.

This should be a simple thing to answer. — Oh well, I never got an answer, and I cannot base any conclusion based on that.

Eelco was able to post a couple of comments from another IP he had and predicted that he would be banned from there as well. It seems he was right, since he has not appeared on Michael’s blog since. Eelco, as far as I can see, did nothing that warrants being blocked, and I can see no reason for Michael to do it, besides the fact that Eelco (who actually has scientific credentials) spent a lot of time showing how Michael (who seemingly doesn’t) is talking about issues he doesn’t understand. Personally, I’m starting to wonder if I am next.

— Michael, if you are reading this, do yourself a favor. You can redeem yourself somewhat by lifting Eelco’s ban. Your blocking him does nothing to help your image, and it only adds to the perception that Creationists use “Stalinist” tactics on their blogs to silence dissent. Not to mention, you are cutting down your stat numbers by banning him. Also. for the love of God, just answer his questions. They’ll only go away after.

YECs on Fossils and the “Evolutionary Timeline”

Because Young-Earth Creationists are so defensive of their model that requires the earth to be between 6,000 to 10,000 years old, they are always out to discredit the scientific date of the earth with anything they can fish out. They feel that if their interpretation of the Bible is wrong -to hell with other legitimate interpretations,- then their whole world will fall apart. This leads many YECs to make many bogus arguments for a young earth like  the decay of the magnetic field, the recession of the moon, etc, etc., etc., yada, yada, yada…. Then, another favorite tactic they use is to point out a fossil find and claim it is “out-of-place,” and that therefore the timeline is all wrong, and therefore their model of a 6,000 year old universe has to be right. I see this particular argument used more by Brian Thomas who is employed by the Insitute for Creation Research than anywhere else.

One of my favorite examples of  Thomas’s use of the “fossil out-of-place” argument is  from an article entitled “Fossil Footprints Trample Evolutions Timeline.” — It talks about arthropod trace-fossil foot prints which were found in Pre-Cambrian strata in Nevada. Thomas presented this find as if it were a blow to the Evolutionary theory because it would require some reevaluation of determining when arthropods appeared. It never occurred to them that this find actually hurts Creationism more than it could ever hurt the present theory of Evolution. More precisely, this discovery hurts the favorite Creationist argument about the so-called Cambrian”explosion” because it shows that complex, animal life was around 30 million years before.

There are several other examples that the Institute cites, and I’ll address some of them here just to show how they 1) show ignorance of the person making the claim, and 2) how are completely irrelevant to the topic of the “evolutionary timeline.” Further reading of ICR claims on the subject will show any informed person how the Institute takes certain scientific discoveries and takes them out of context to try to refute Evolutionary theory.

  1. One claim that the Thomas makes is that a  newly discovered amber trapped spider web too old for the timeline. A news article he cites of this fossil find, in fact, shows that spider webs had evolved long before it was first thought, however when one does more research on spider evolution, the apparent “harm” done to the timeline really doesn’t exist. This fossilized web’s age is estimated at 140 million years, while  the evolution of spiders is thought to have started some 400 million years ago. That gives the web about 260 million years to evolve, so there is no harm done here.
  2. Another claim that he made is that the T-Rex body structure evolved 60 million years “too early.” This claim is based on a newly discovered relative of the tyrannosaurs now called Raptorex. I seriously cannot help but see the irrelevance of this fossil to debunking the so-called “timeline.” It never crosses Thomas’ mind that rather than hurting the current theory of evolution, this helps it by aiding the construction of a phylogeny of the tyrannosaurs.
  3. Claims of human artifacts, such as evidence of boats and jewelry, are used to say that we have always been the same species. We now know that Homo neandertalensis had fassion sense, but nobody disputes this, so it is irrelevant. Also, multiple mtDNA tests show they are not the same species as Homo sapiens, despite the YEC model’s insistence. And the evidence that Homo erectus was a mariner is really not news since we knew that for over a decade (at least since 1998). Hence, this is also irrelevant.
  4. Another apparent contradiction of the timeline is the discovery of fossil ambers dating to the Carboniferous which lasted from 355 to 300 million years ago, though the first flowering plants known to the fossil record appear during the Cretaceous (125 million years ago). The Brian Thomas criticizes the scientist who discovered them of  evolutionary bias because he said this doesn’t necessarily mean that flowering plants appeared so early, but that it shows that aspects of them were starting to make an appearance. But at the same time, he doesn’t provide any credible evidence to the contrary, so they affectively fail to show how the timeline was falsified.

The only thing some of the examples above show is a slight reevaluation of  some of the current scientific understandings., but that’s all. On the other hand, some of the examples don’t affect out understandings at all. This kind of makes me wonder if the employees at ICR sees any unexpected scientific find as an inherent refutation of Evolutionary theory as we know it.

As I see it, ICR has a very odd definition of an “out-of-place” fossil. In one post entitled Cambrian Fossils Found in the Wrong Place,” it is argued that since soft-bodied creatures were thought to be stem ancestors to the Cambrian fauna were found in some of the same layers, one could not have evolved into the other because  the argument for evolution  “relies on the absence of these creatures in higher layers to support the assumption that they ‘diverged’ into ‘later’ life forms.” –This reminds me of the argument “If humans evolved from apes, why are there still apes.”  Even if  a certain animal evolved into another species, there is no reason to assume that evolutionary ecenario “relies” on the absence of the mother species.

So really, not a single one of the examples given of “out-of-place” fossils given by the Institute refute any of  the important aspects of Evolution, and any revision that is made from them, so far, is only minor. Any fossil that actually refutes our scientific understanding should be unexplainable, like fossil rabbits in the Cambrian, and so far, the Young-Earthers have failed.

Darwin’s Dilemma: My Take on the Discovery Institute’s Claims

I know it’s several months late, but I just got through watching a film done by the Discovery institute, on the Cambrian “explosion,” called “Darwin’s Dilemma: The Mystery of the Cambrian Explosion.” There are a few details that should be addressed about it. But, before I go into any kind of detail, yes, it should be pointed out that this is mostly the same kind of Creationist bull that I thought it would be, just a bit more sophisticated than the usual Creationist arguments made about the Cambrian radiation.

At first, typical of Creationist claims, Jonathan Wells makes the well-worn claim about life forms before and during the Cambrian. He compares the entire 3.8 to 4 billion years of life to a twenty-four hour day saying that for the first 21 hours, there were only unicellular life forms, and then the Cambrian life forms came into existence on the scale of a two minutes. This is an attempt to make the Cambrian radiation appear “sudden” A few minutes later, Wells then says something on the lines of that it could have happened over night which is complete bogus because it lasted at least 10 to 25 million years. Though there are higher estimates that go as high as 35 million years or more. The film says that fossil evidence shows that those estimates are too high, but it doesn’t give convincing details.

The film, however does mention the existence of other life forms, like the Ediacaran fauna which existed before the Cambrian, as well as fossil embryos. . . . Oh, about the fossil embryos, the film uses them to address the idea that pre-Cambrian fossils are not preserved because they were too soft. It is pointed out that these embryos were from soft-bodied organisms, and that they existed tens of millions of years before the Cambrian. From that, it is reasoned that if the appeal to pre-Cambrian organisms being too soft for preservation cannot be used. As the film argues this, the Discovery Institute seems to have missed a major implication of fossil embryos several millions of years before the Cambrian “explosion.” Think about it: Those embryos had to have come from precursor ancestors, and that would therefore show that the Darwinian prediction of the existence of simpler pre-Cambrian life. It shows, therefore, that such organisms did in fact exist, but that they were rarely ever fossilized. Fossilization is already a rare enough occurence without the organisms being much softer than is accustomed. But, another detail the DI seems to have missed: I do not remember any scientist ever saying that soft-bodied, pre-Cambrian fossils could never be preserved. They can be, it’s just much more of a novelty. Correct me if I am wrong, but I think the Discovery Institute is attacking a strawman.

Something I find exceptionally interesting is the interest that the film takes in fossils from southern China. All along, citing these fossils as evidence for their conclusion, I’m left to wonder why other fossils from China are ignored. In pre-Cambrian deposits dating from the Doushantou Formation, evidence of animal life in the form of adult Cnidirians was found. Among the finds were fossilized embryos and larvae tat resembled Anthrozoans. Not to mention, there s also evidence of cnidirian body plans with anthozoan affinity. An implication of this find is that  stem groups of bilaterians were also present between 25 to 45 million years before the Cambrian “explosion.” — Then, also there is more recent evidence from the same formation that complex, bilatarians existed between 40 to 55 million years before the Cambrian. — These fossil finds I cited were made in the first half of the last decade, between 2002, and 2005. These finds alone would show that the Cambrian “explosion” was likely less explosive. In contrast, the film Darwin’s Dilemma was released in September, 2009. Why didn’t the Discovery Institute include these fossil finds? Because of ignorance or bias? You make the call. — I go into more detail in my previous post entitled “The Truth on the Cambrian ‘explosion.’

Between scenes, the Discovery Institute indulges in the usual Creationist quote mining from well-known scientists about the appearance of the Cambrian fauna in the fossil record, but prominently Stephen Gould. Personally, I found that somewhat disrespectful since he is dead with his statements still being hijacked. Then also, they use a very selective quote from Richard Dawkins about the Cambrian’s abruptness in which he says, “It’s as though they were just planted there, without any evolutionary history.” You just have to realize that Dawkins is an Atheist and a major anti-Creationist to realize that he ultimately was not endorsing that view.  Besides, as he proposes a little later that “it might be that many of these animals had only soft parts to their bodies: no shells or bones to fossilize,” a view which the film goes out of its way to attempt refuting.  — The Quotes from Charles Darwin can be dismissed since they are 151 years out of date, and do not reflect the research accomplished since he published his theory.

A final claim made is on genetic information, and questioning whether or not Darwinian mechanisms can produce it. After deciding that it cannot, they resort to their typical “designer did it” cop-out. They try to rationalize their logic by saying that information is the product of intelligence, yada, yada . . . .  I’m not going to even bother to refute the typical argument from ignorance.

Basically, the film really doesn’t address anything that hasn’t been debunked before, it just seems to be a bit more sophisticated, and a bit more informative than other pieces of Creationist propaganda, but that’s probably because it admits to the existence of some fossils from before the Cambrian. I guess from that, it is the “best” Intelligent Design film I’ve ever seen, but that isn’t saying much. Mostly, the only real thing this film has going for it is its graphics, though I have seen better. I guess one of its goals is to dazzle the uninformed layperson with its computer graphics?  Who can tell? The Discovery Institute may accept the scientific age of the earth, but other than that, they aren’t much better than ICR.

Precambrian Animal Life: Probable Developmental and Adult Cnidarian Forms from Southwest China, by Jun-Yuan Chena, Paola , Feng Gaoa, Stephen Q. Dornbos, Chia-Wei Lid, David J. Bottjer and Eric H. Davidson. From Science Direct, and Developmental Biology.
The Early Evolution of Animals by David J. Bottjer, from Scientific American.

Recommended Reading:
Transitional Forms and the Evolution of Phyla, by Glenn R. Morton, from American Scientific Affiliation. Published in Perspectives on Science and Christian Faith.
Cambrian Explosion, from SkepticWiki

The “Global” Deluge – Is it Unbiblical?

To explain the geologic record, Creationists read the Biblical story of Noah and the flood into the evidence. They look at the fossil record and reason that these are creatures that just didn’t make it in the Ark and perished when the flood waters overtook them. The story of Noah is one of the most famous stories in the Bible, and gives a lesson about renewal of the old. But Young-Earth Creationists propose that Noah is more than myth: He is real, historical person, and that his flood covered the entire planet.

I will not argue against the existence of  Noah as a historical person. Personally, I have no reason to believe that he didn’t exist, being a Christian. But what I will argue against is that the flood covered the entire planet since I believe the evidence in the geologic record points against it. — And I have yet more reasons than just geology to suspect the flood was a “local” event, and not universal which I will focus on in this post.

The reason why YECs insist on a global flood is because their model demands it. It is supposed to account for the fossil record, and it is based on their interpretation of the story found in the book of Genesis. There are also some “hard” atheists that use the same arguments against the idea that Genesis allows for a local flood in an attempt to say that acceptance of an old earth or Evolution is incompatible with Christianity. My personal assessment of the claims made by both groups is that they are wrong and misguided. In fact, I think the reading of  a “local” flood in Genesis is not only plausible, but also Biblical.

The basic Biblical support that Creationists have for a global flood is the universal language which is used in the Genesis account:

  • I am going to bring floodwaters on the earth to destroy all life under the heavens, every creature that has the breath of life in it. Everything on earth will perish. (Genesis 6: 17)
  • Seven days from now I will send rain on the earth for forty days and forty nights, and I will wipe from the face of the earth every living creature I have made. (Genesis 7: 4)

The language from these verses is most definitely universal, so it is no wonder that modern readers, Creationists and “hard” atheists alike, understand the “global” deluge as the only viable interpretation of the flood account. — Notice my stress on the term “modern readers.” — Though somewhat convincing at first glance, universal language is hardly an indicator that the Biblical account was intended to teach that the planet as a whole was covered in water. Such usages of the term  “All under heaven” have been used to describe geographically limited areas. For example, during the time of the Roman Empire, the Romans claimed to rule the “whole earth.”  Also, In ancient China, the domain of the emperor was said to be “all under heaven,” but obviously this only applied to China and neighboring states, and not to nations far out its reach.

In fact, the Bible itself uses this universal term in geographically limited contexts as well. For example, Acts 2: 5 says, “Now there were staying in Jerusalem God-fearing Jews from every nation under heaven.” — Obviously, “all under heaven” does not mean the entire planet. It most certainly does not include other regions like North America, Japan, as well as China and Korea. These terms were simply a way of expressing one’s self in ancient times, and they didn’t have the same meaning as they do today.

Another detail to take into account is the Hebrew word for “Earth” which is אֶרֶץ (pronounced as “eretz”) which is used in the flood story. — Though this word can be understood and the entire planet, it also has several other meanings like ground, soil, land, country, territory, district, and region. Most of these can actually be substituted for “Earth,” showing that the flood can be understood as covering a local region or territory.

A couple of Atheist and Creationist rebuttals to the “local” flood that I read object on the basis that the flood story says that the mountains were covered,

The waters rose and increased greatly on the earth, and the ark floated on the surface of the water. They rose greatly on the earth, and all the high mountains under the entire heavens were covered. The waters rose and covered the mountains to a depth of more than twenty feet. (Genesis 7: 18: 20 )

Certainly this could falsify the local flood, right? — Wrong! Objections made of the basis that the waters covered the “mountains” are only dependent on English literalism which is not a legitimate reading of the Bible if the word in the original language can be understood differently. — The Hebrew word for “mountains” is הַר (pronounced as “Har”) which also means hill or even hill country. So the passage can simply be understood as saying that the flood waters elevated over the hills by over twenty feet.

Granted, this information doesn’t prove that  global flood isn’t what the writers of Genesis intended to write about. It only shows that a local flood is a legitimate understanding from the Biblical text. — If we left it all here, we would think that both interpretations, though different from each other, are harmonious with the Bible itself, but I have no intention of leaving it to that. It is my contention that the global flood is unbiblical, not just simply irrational. — Now, is there any Biblical evidence to back me up? You bet there is! — One of the best pieces of evidence comes from the prelude to the flood story itself,

The Nephilim were on the earth in those days—and also afterwardwhen the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown. (Genesis 6: 4)

The Nephilim were a race of pre-flood people. Some commentators blame them for the evil in the world which caused God to bring the flood. But notice that the story says they were “on the earth in those days — and also afterward.” This implies that not only wasn’t the flood sent to destroy this race of people, they survived the flood.  They are mentioned to still be living in the time of Moses (Numbers 13: 33 ). This could only logically be true if the flood was a local event, and not global. — The one objection I ran across for this point is that the Nephilim that were around before the flood were probably not the same as those that existed afterwards. However, even if I grant that Numbers 13:33 is talking about an unrelated race, that doesn’t explain why Genesis 6:4 implies that  pre-flood and post-flood Nephilim shared a common progeny as they are both associated with “the sons of God who went to the daughters of man”  implying that they managed to survive the flood.

Then there is also the drainage of the flood. Genesis 8: 1 says that a wind was used to cause the waters to recede which would have been pointless if the flood were global because the water that got blown away would simply have been replaced my different water that wasn’t there previously. — Also, Noah is said to have sent a dove which returned with an olive leaf (Genesis 8: 11). This is also evidence against a global flood because the time allowed in the Bible for the recession of the waters would not allow an olive tree to have grown by then. Also, the salt water of the flood would have destroyed much of the plant lifeeven the olive trees, not to mention the terrestrial conditions on the earth wouldn’t have been suitable for plant growth for a while.

Interestingly enough, even the writings of Flavius Josephus, the first century Jewish historian, seem to give credence to a local flood when one reads between the lines. After his retelling of the flood, he mentions other historians which mention similar events, and then quotes Nicolaus of Damascus,

Nicolaus of Damascus, in his ninety-sixth book, hath a particular relation about them; where he speaks thus: There is a great mountain in Armenia, over Minyas, called Baris, upon which it is reported that many who fled at the time of the Deluge were saved; and that one who was carried in an ark came on shore upon the top of it; and that the remains of the timber were a great while preserved. This might be the man about whom Moses the legislator of the Jews wrote.” (Antiquities of the Jews 1: 94-94)

This is significant for two reasons: 1) Because Josephus believes that Nicolaus is describing the flood of Noah, and 2) he mentions that there were many that fled and were saved from the deluge, and he seemingly differentiates them from the passengers on the ark. This implies that these other non-Noachian survivors had different means of escape besides the Ark of Noah.  This would only make sence in the light of a local flood, not a global one. — Also, it is notable that Josephus does not correct Nicolaus as to others escaping the flood besides the passengers on the ark, implying that he agrees with him. It would be out of character for Josephus to not correct him if he disagreed with him.

The idea of a local, non-global, flood has plenty of support. The original Hebrew shows that this particular understanding id viable, and the Bible itself confirms it by implying that other people (i.e., the Nephilim) survived it. That latter detail should surely be a stumbling block to anyone who believes in a global flood. However, it is not problematic if one embraces the local flood. — In fact, for these reasons, I consider the local flood the only viable understanding of the Genesis story, and that the “global” flood is not only irrational but also unbiblical.

Chinese imperialism: Encyclopedia – Chinese imperialism
Blue Letter Bible Lexicon, Hebrew word for Earth
Blue Letter Bible Lexicon, Hebrew word for Mountains.
CH542: Plant survival in the Flood, by Mark Isaak, from the Talk.Origins Archive.

Further Reading:
The Noachian Flood: Universal or Local?, by Carol A. Hill. From the American Scientific Affiliation, and published in Perspectives on Science and Christian Faith.
Yes, Noah’s Flood May Have Happened, But Not Over the Whole Earth, by Lorence G Collins
Noah’s Flood: Global or Local? by Donald Hochner
The Genesis Flood: Why the Bible Says It Must be Local, by Rich Deem. From
Universality of the Flood, by Greg Neyman. From
THE GENESIS FLOOD: The Biblical Argument for its local extent, by J. Reed. From J. Reed’s Christian Expositions.

UPDATED: December 23, 2010

Debates Between Scientists and Creationists

Scientists have overwhelming evidence to demonstrate that Evolution is not only a theory, but also a fact. So considering that, how is it that Creationists seem to win the debates? — Of course, a Creationist may simply assume that the Creationist wins because the Evolutionist is wrong. But a better look at the subject shows that this isn’t the case at all. There are several reasons Creationists seem to carry the day, and none of them have anything to do with being on the right side. And there are several reasons why Scientists are reluctant to debate with Creationists, and it isn’t because they are on the “wrong” side either.

If you have studied Evolution and know the scientific method, then you will know how Evolution works — I hope, at least. Therefore, I would also hope that you would also be able to pick out arguments made by Creationists that are totally absurd, though they may seem reasonable to the lay person. I see this happen a lot in Kent Hovind debates. — I just watched one, and I found myself getting a headache when he made an illustration about the “evolution of silverware.” Knowing what was coming, I simply fast forwarded through that. In another video I saw, he debated  Ben Waggoner from the University of Central Arkansas who, although he undoubtedly knew his stuff, was not prepared for the beating he received.  — In fact, the only hostile audience that he had that I know about was when he spoke at Berkley University in which several students called him out.

A major important reason why Creationists seem to win debates is that they seem to usually debate in front of friendly audiences. In other words, most people in the audience have already decided that Evolutionary theory is false, and the reason they are there is to see the “lost” evolutionist get trounced by their champion. — Donald  Prothero, a leading professor of Geology, described a time when he accepted a challenge to debate Duane Gish. In the end, during the questions and answers segment, he received several irrelevant and offensive questions such as “Are you going to hell?” or “Are you a sexual pervert?” The audience was not interested in the evidence, but only in seeing the Evolutionist get defeated. Ultimately, he decided not to debate Gish again since it was a waste of time.

Another reason is that Creationists tend to dominate the debate. They have better debating skills than most Scientists because they have more practice at it. Scientists are usually busy with research, so they don’t have as much time to go out and debate. — Creationists also tend to shoot out too much drivel in only a few seconds which is very difficult to refute as quickly as it gets said. And due to the formats and time limits of these debates, the poor scientist is not free to give an adequate answer.

Creationists shoot out arguments like “Life could not have originated by chance,” and “the big bang is false.” — The bull of Creationists using these arguments is that they are not part of Evolutionary theory, even though Creationists don’t seem to see the difference between Biology and Cosmology.  These arguments are made to leave the impression that the Evolutionist has no basis for his acceptance of Biological Evolution, and that the theory of evolution is therefore nonsense or “stupid,” as Kent Hovind puts it. — Were I to debate a Creationist who brings these two subjects up, I would simply say “I am here to defend Evolution, not the Big Bang, and not Abiogenesis.”

On the occasions that I do talk with Creationists, I usually run into arguments made against strawman versions of evolution rather than the recognized theory at all. One of them is the idea that evolution “must” lead to increasing complexity, and that the Uniformitarian principle (of Geology, not of evolutionary biology) means that accumulation of all geologic layers was all done slowly with no exception. These arguments are common in the Young Earth Creationist community in particular, however they are based on false premises. Evolutionary theory does not make the prediction that everything has to become more complex, and the principle of uniformitarianism (which is Geology, not evolution) does not dictate that all layers took long periods of time to form.

There is also the fact that it is near impossible to give enough information about how evolution works in just one day. There are reasons why evolution related classes such as Biology and Physical Anthropology take whole semesters. It takes whole semesters to teach the basics of these classes. So the playing field for debates is hardly even at all.

Then there is the fact that Creationists tend to move the goal posts on the scientists. — Kent Hovind’s $250,000 challenge is a great example of this. His challenge pretty much says that even if we could produce evolution, abiogenesis, and the big bang in the lab, it still wouldn’t count because we would still have to prove God had nothing to do with it. Considering that I am a Christian, and therefore believe in God, I see this as ludicrous. The requirements are so unreasonable, it is no wonder not many (if any) scientist has even bothered with this challenge. –Also when given antibacterial resistence as an example, he simply said that no matter what, that bacteria would still not be immune to a sledge-hammer, as if Evolutionary theory makes any such prediction.

Then when it comes to the fossil record, he says “Fossils can’t be used as evidence for evolution because you can’t prove they had any kids.” In other words, no evidence is good enough. Also, it demonstrates he has no understanding about why and how fossils are used. Nobody is saying that a particular fossil is our ancestor, but that it has traits we would expect of what a potential ancestor would have. Hovind was positioning himself in a way that he could be able to dismiss any and all evidence for that abominable theory that he despises so that he wouldn’t have to truly deal with it.

The final reason why Scientists don’t debate with Creationists is they just don’t think it’s worth it. — Richard Dawkins, for example, refused to debate with the Muslim Creationist Harun Yahya when he was challenged saying he didn’t want to give him status.  — Also, Kenneth Miller, another top scientist described a time when he accepted a Creationist challenge and asked Steven Gould for help,

I called Steve up and then I explained to him that I was preparing for a debate with a scientific creationist. And I asked him if he could help me out with a couple of arguments. And to my amazement, he stopped me short. And he said, `Ken, I’d like to remain your friend. I’d like to be on good terms with you, but I don’t think it’s wise to debate these guys. I don’t think it’s appropriate to give them a platform for their misguided and misleading views. And if you’re going to debate this fellow, I won’t help you, I won’t provide any assistance, and I won’t even talk with you.’

The truth is, Scientists don’t want to debate Creationists simply because they don’t want to give Creationists status where status is not due. It is not because they are “wrong” and have no evidence to support their claims. It is that the playing field is hardly level which, by the way, also doesn’t make for a good debating forum when you have a whole audience that is intellectually hostile to the scientist.  — Also, another reason why they may not want to debate with them is because it may create the impression that Evolutionary theory is controversal in the scientific community.

29+ Evidences for Macroevolution: The Scientific Case for Common Descent, by Douglas L. Theobald, Ph.D. From the Talk.Origins Archive
Evolution: What the Fossils Say and Why it Matters, pages 46 and 47, by Donald R. Prothero.
Kent Hovind’s $250,000 Offer, by John Pieret, From the Talk.Origins Archive
Scientists Hesitant to Debate Intelligent Design, from National Public Radio.