Four Days of Fusion Chromosome Freak-Out

By Carl Zimmer | July 22, 2012 6:05 pm

[Note: This is the third of a four-part series

Part One: The Mystery of the Missing Chromosome (With A Special Guest Appearance from Facebook Creationists)

Part Two: The Mystery of the Missing Chromosomes, Continued: An Update From Your Preening Blogger

Part Four: And Finally the Hounding Duck Can Rest]

On Wednesday, I asked creationists for evidence. Over the past four days, I’ve been ordered to buy their book, offered it for free, invited to a debate and to guest blog. I’ve also been accused of lies and misdemeanors, of harrassing innocent creationists, and of being a duck. Actually, a hounding duck. But I still haven’t gotten my answer.

There is, of course, a lesson here.

Briefly, here’s the background. (For more details, read this post I wrote Thursday.) The Discovery Institute promotes intelligent design, which a Federal judge has declared “the progeny of creationism.” They have a staff, along with fellows, who write books (many of which are published by the Discovery Institute Press), run web sites, appear on cable TV, all to attack evolutionary biology and promote intelligent design. Their ranks include a few scientists (ie, people with Ph.D.’s who’ve published research in peer-viewed scientific journals), but in none of their published papers, to my knowledge, do they say anything like, “Our experiment thus provides clear evidence of intelligent design.” Instead, they make their big claims about intelligent design in their non-peer reviewed books and on their web sites. In 2005, the Discovery Institute set up an outfit called the Biologic Institute, where some scientists are supposedly doing the research that will show the world that Intelligent Design is the real deal. So far, they haven’t published any scientific papers in peer-reviewed journals to that effect.

On Wednesday, David Klinghoffer, the editor-in-chief of one of their sites, Evolution News and Views, published a piece promoting a new book from the Discovery Institute Press about human evolution, co-authored by two people from the Biologic Institute and one from the Discovery Institute. It was called, “A Veil Is Drawn Over Our Origin As Human Beings.” Along the way, Klinghoffer raised the issue of our fused chromosome, which, as I wrote Thursday, preserves clues to its origin as two separate chromosomes long ago. Klinghoffer claimed that the structure was not what you’d expect if the chromosome had fused six million years ago.

So here we have a claim. Scientific claims are based on evidence, or at least they should be. I wanted to know what the evidence was for this particular claim, but I couldn’t ask on Evolution News & Views (no comments allowed). So I went over to Facebook. There, the Biologic Institute has set up a page where they posted links to other web pages, one to including Klinghoffer’s page. And on Facebook, you have to let people comment. The biologist Nick Matzke was using the comments to set them straight with various lines of evidence about human evolution, which prompted the Biologic Institute to lay down a 100-word-or-less rule for comments. So I jumped in to ask–briefly–for the evidence about the claim about the human chromosome.

Whoever runs the Biologic Institute’s page responded by telling me to buy their new book. After all, as a book author myself, I wouldn’t just deliver the contents of my book to anyone who asked on my blog, would I?

Well, no, I replied. I then asked again, this time only requesting a citation to a paper that backed up their claim about the fused chromosome.

Now the Biologic Institute stopped replying. Other people left comments to let me know that they had read the book, and that the cited evidence amounted to nothing but a cherry-picked sentence from a ten-year-old paper. (Some of these comments have since been deleted.)

I asked the Biologic Institute if this account was true. Again, no answer.

Instead, I got an email from Klinghoffer himself. Rather than answer my question, he invited me to write a couple thousand-word pieces on Evolution News and Views as a debate with an unnamed co-authors. The debate would be on the various issues in the book. (Klinghoffer added that he wanted a debated focused on “ideas, not personalities.” This civility-minded person is the same guy who once wrote that one my blog posts was “preening and self-congratulatory.”) I hadn’t asked for such a debate, so I said no.

Instead, I asked again for the evidence. No answer.

Klinghoffer responded instead by publishing a piece on Evolution News and Views entitled, “We Called Out Darwinian Critic Carl Zimmer and He Folded.” Instead of answering my question, he condemned me for not reading the Discovery Institute’s book. “So you see what we’re up against,” he moaned. “Carl hasn’t read the book and now, having ducked out of a proper debate, he can go on denouncing it without ever having read it. He’s perfectly willing to waste our time on Facebook, where the phrase ‘pecked to death by ducks’ comes to mind.”

When the Biologic Institute posted a link to the piece on Facebook, I asked them again for an answer. No reply.

But David “Ideas Not Personalities” Klinghoffer was not through with me. The next day he returned to his comment-free platform to accuse me of “hounding our Biologic Institute colleagues on their Facebook page about a particular pet subject that he thinks he knows something about–chromosomal fusion at human chromosome two.”

Klinghoffer then got on Facebook to add a link to this piece on the Biologic Institute page. So I asked him my question again there. What is the evidence for the claim he made?

Again, nothing. By this point I had lost count of how many times I had asked the question.

Meanwhile, I put together this post to explain the latest research on the evolution of our fused chromosomes, from the world’s experts on primate genomes. By comparing the genomes of humans, chimpanzees, and gorillas, they could reconstruct what the original chromosomes were like, and how they evolved in each lineage–thanks to the kinds of mutations that scientists can see today in humans, as well as in many other species.

Unlike Klinghoffer, I let people comment on my posts. As of this writing, there are 70. A fair number of them claimed that intelligent design was the best explanation for our chromosomes. On Saturday, one of these commenters scoffed at the idea that mutations and evolutionary mechanisms could bring it about. If even just two mutations were required, I was out of luck.

Two? Again, I asked for the evidence. And this time I got an answer. I was directed to this 2008 paper in Genetics.

And this is why I ask for evidence. Because I can go do some research to see if the evidence holds up. The paper is a model, informed by experiments, of the rate at which mutations arise. It inspired another Discovery Institute fellow to claim it was evidence that evolution was too slow to have produced enough mutations in six million years to give rise to humans. And then the authors of the paper themselves wrote a letter to make it explicitly clear that the Discovery Institute was wrong. (Here’s a more recent paper that shows that the wait for mutations is not long, courtesy of another comment.)

On Saturday, I got another email from an Intelligent Design web site. This one is called Uncommon Descent. “We sponsor guest posts from people who disagre with us but are civil and well-informed on the issues,” wrote Denyse O’Leary. Would I want to write one?

I replied by pointing out that writing a guest blog post would be a redundant waste of time, since I had already asked my question many times over, and Uncommon Descent had actually just linked to my own blog post. I also found it strange that O’Leary would politely describe me as “civil and well-informed” in a message to me, when she had just written on Uncommon Descent that I am the sort of “Darwinist” who “only needs to pretend to know what they are talking about.”

Well, that little burst of politeness was fleeting indeed. Today, Uncommon Descent featured a new piece about me: “Carl Zimmer Doubles Down on Chromosome Two Lifes and Misdemeanors.”

Hey now!

Today’s attack comes from Discovery Institute fellow Cornelius Hunter. Hunter got a Ph.D. in biophysics at the University of Illinois, where he published three papers on protein structure a decade ago according to PubMed. Now he’s an adjunct professor at Biola University, an evangelical university in California.

Hunter claims that the evidence for a chromosome fusion in our ancestors only makes sense if we have already bought into the theory of evolution. It’s a long post that only gets around to what’s happened to the chromosomes at the very end.

The site of the fusion event on human chromosome number two does not provide an obvious picture of a past fusion event. There certainly are suggestions of such an event, but it is far from obvious as evolutionists claim.

Furthermore such an event, if it could survive, would have to take over the pre human population. In other words, the existing 48 chromosome population would have to die off. This is certainly not impossible, but there is no obvious reason why that would occur.

There are problems with the evidence. Perhaps the fusion event occurred, but the evidence carries nowhere near the certainty that evolutionists insist it does…

If evolution is not taken as an a priori, then these evidences are far less compelling. From this theory-neutral perspective, what is important is not reconciling chromosome counts or chimp-human chromosome similarities (after all, those are found throughout the respective genomes). What is important is the more direct evidence of a fusion event, such as in the region where the two chromosomes would fuse, and other tell-tale signs in the chromosome two.

Here the evidence is mixed. Certainly it is far less compelling than evolutionists ever tell their audiences. This need not be controversial. But it is.

That’s it. It’s not obvious. The evidence is mixed. How is it mixed? Hunter never says. What would be obvious evidence to him? He never says. What does he make of the latest research supporting the evolution of the fused chromosome? We have no idea. And–to sing the old refrain–what is the evidence for Klinghoffer’s claim? Hunter  never says.

That’s where our story now stands. I’ll end this post the way this whole adventure began, with the question that has gone unanswered in so many, many ways:

An article on Evolution News & Views stated that the evidence for the fusion of human chromosome two “appears in a ‘degenerate,’ ‘highly diverged’ form that should not be the case if the joining happened in the recent past, circa 6 million years ago, as the Darwinian interpretation holds.” Where is the scientific evidence for this?

Update: The day after posting this, I got my answer. And, as I suspected, it shows why the creationists are wrong about chromosomes.

CATEGORIZED UNDER: Evolution, Top posts

Comments (41)

  1. Great response Carl, but I think you should go back to ignoring them. I suspect they draw their energy from attempting to stupify intelligent life forms.

    I think they know their day has passed …

  2. They’re the evidence against intelligent design.

  3. MonkeyBoy

    “Furthermore such an event, if it could survive, would have to take over the pre human population. In other words, the existing 48 chromosome population would have to die off.”

    Isn’t this the old “If humans evolved from monkeys then why do monkeys still exist?” argument?

  4. Skippy

    Great clip by Ken Miller on ancestral chromosomal fusion to 23 pairs in humans used as evidence against intelligent design. Neat discussion of centromeres and telomeres to elucidate the query of chromosome number 2:

  5. How does anybody know that the fusion occured 6 million years ago, Carl?

    [CZ: I’m just quoting David Klinghoffer using that figure. In fact, it is conceivable that the fusion occurred at any point after our ancestors branched off from chimpanzees (because chimpanzees lack the fusion) and before the common ancestor of living humans (because all living humans have fused chromosome) and Neanderthals (the Neanderthal genome contains a version of chromosome two). The current estimate for the last common ancestor of humans and Neanderthals is 800,000 years ago. The human-chimp split is somewhere around six million. I haven’t encountered any estimate any more narrowed than that.]

  6. @MonkeyBoy No. I think the point is that consider that a mutation occurred that fused the two chromosomes. At that point there is only a single individual with this mutation. For the species to lose the chromosome entirely, that mutation would have to become pervasive and all the individuals with the extra chromosome would need to die out.

    However, this kind of chromosomal mutation tends to trigger speciation events. You end up with sub-populations that are infertile with each other and one or the other type dies out within the group.

  7. As trying as this sort of exercise can be, I’m glad that there are people who take up the painstaking effort to confront and articulate the problems with this creationist assault on science, in this case showing that they’re unwilling to respond meaningfully to even the most straightforward, repeated requests for evidence to support a particular claim. The question I have is do they know quite consciously that they’re being evasive, or have they gotten their heads in such a muddle that they can’t even process the meaning of a simple request?

  8. David

    Don’t sweat this. Strict creationists will become the modern day flat earth proponents. Religion can only hold a view for so long before another generation finally accepts the scientific facts and reinvents the interpretation of their scriptures.

    What’s going to be really great, is when we find life off-world. That’s going to fundamentally rearrange the religious dogma. As a religious person myself, I can’t wait, although I tend to be the minority.

  9. ophu

    Maybe they should switch to covering Loch Ness Monster and Bigfoot sightings. Their style sounds appropriate for the job.

  10. Carl, I agree with Dr. X that it is important that people like yourself keep up this fight. Science is hard for the best of us, and the process needs to be taught widely, as it appears to go against many of our natural cognitive habits.

    And when your adversaries claim they are being “pecked to death by ducks,” you can refer them to travel writer Tim Cahill’s excellent book by that name.

  11. Steve

    Keep up the good work Carl. Illegitimi non carborundum.

    [Yes, I know it’s not real latin.]

  12. Herman Cummings

    If pastors, priests. rabbis, and “so called” Christians
    would stop their false (old Earth) and foolish (young Earth)
    teachings, and start promoting the truth of Genesis (Observations
    of Moses), then there would hardly be any room for the ridiculous
    teaching of evolution.

    Collectively, Bible believers are so “blind”, that their approach
    to Genesis is a joke. Instead of seeking the truth, they continue
    to support the current lies and foolishness of Creationism. Genesis
    does not have any “Creation accounts”. When you keep telling a
    person that their car is running out of gas, and they refuse to look
    at the fuel gauge and go to the gas station, you begin to wonder
    how “dumb” they are.

    Herman Cummings

  13. Brian

    I’m a bit surprised that time is being wasted on this sort of ad hominem attack against the Discovery Institute. It doesn’t advance anyone’s knowledge and makes you appear petty.

  14. RBH

    Brian wrote “I’m a bit surprised that time is being wasted on this sort of ad hominem attack against the Discovery Institute.”

    Ad hominem? I don’t think that phrase means what you think it means.

  15. LOL at RBH – indeed ‘ad institutum’ might have been appropriate if not for the fact it was not an attack on the organisation or individuals but on the failure of the argument they presented to reflect evidence or reality.

    And Brian – it certainly advanced my knowledge. I admit to being a small sample size but since you claimed it “doesn’t advance anyone’s knowledge” and I am someone, then as a sample size I am sufficient.

  16. Jon Pastor

    Brian, I saw ad hominem attacks by the loonies on the Creationist side against CZ, but he showed admirable restraint in not calling them a pack of DISINGENUOUS CHARLATANS who are trying to co-opt the teaching of science by pretending that their wholly-religiously-based “theories” have any scientific merit.

    That’s not an ad hominem attack, it’s just a slightly less tactful version of U.S. Middle District Court Judge John E. Jones III’s decision against them in Kitzmiller, et al. v. Dover Area School District, et al.

    These people have no shame and no honor among them, and arguing with them is like arguing with a brick wall. They have no evidence of any kind to support their views, just a rabid desire to snow as many ignorant people as possible while stonewalling anyone with sufficient knowledge to see through their charade.

    I learned not to engage with them back in 2005, and as far as I’m concerned Tammy Kitzmiller et al. had the right idea: let them have enough rope, and then yank it. Hard.

    Thinking that it’s possible to “advance [their] knowledge” is fantasy. They are not interesred in knowledge, just in imposing their religious dogma on the teaching of science.

  17. zackoz

    One aspect that intrigues me about the fusion is less how it happened – which Carl has explained very clearly – than what happened afterwards.

    Presumably it occurred in only one human ancestor originally, say about 5-6 million years ago.

    It then spread through selection or genetic drift until it reached fixation, so that now every human has it. (I am not a scientist, so sorry if I am misusing technical terms.)

    I can see no particular reason why a fused chromosome would convey a genetic advantage – maybe specialists have some hypotheses about that.

    Or (more likely?) perhaps the individual concerned had by chance some unrelated competitive edge which contributed.

    I wondered if the genetic bottleneck we are supposed to have suffered had something to do with this, but I don’t recall offhand when we think that occurred.

    Anyway, I gather that numbers were reduced to only a few thousand human ancestors at some stage, and we were lucky to pull through; this bottleneck explains why humans are so genetically similar.

  18. You still have not told me how anyone knows when the fusion occured. Seems you are just quoting somebody else´s guess.
    The next commentator here, Mr Utterback at Comment 6, says that fusions of this sort tend to lead to sympatric speciation events.
    But that too is just speculation. Nobody has ever seen a speciation event neither via sympatry nor allopatry.
    Fair´s fair, Carl: if you want to have a go at these guys for not producing evidence to support their claims then be prepared, in the name of fair play, to turn that microscope upon your own thinking.

    [CZ: Whether or not this fusion led to speciation is an irrelevant question. The fusion occurred after the split of human and chimpanzee ancestors, and before the common ancestor of humans and Neanderthals (because Neanderthal also have the fusion, if I read the Neanderthal genome browser correctly). So that’s a range of 6-7 million years to 800,000 years ago.]

  19. John Kwok

    Carl, I didn’t realize that the Neandertal genome does show the same chromosomal fusion. Wow! Why is the lower limit at approximately 800,000 years? I thought it’s possible that it could be as low as 300,000 to 400,000 years. (Oh wait, I didn’t see your earlier comment regarding the likely split, but still wonder why it couldn’t be lower. Do you have a citation of a scientific paper that points out the split as being around 800,000 years? Thanks.)

  20. John–Svante Paabo’s latest estimate is in his paper on the Denisova genome. He’s pushed it back from 300k to 800k.

  21. Dave Wisker

    My discussion of the issues surrounding human chromsome 2’s fixation within the human population can be found as a series of posts on The Panda’s Thumb. The link is to the last article; the links to the others are included.

  22. Shrunk

    @ zackoz,

    This paper by Francisco Ayala suggests some mechanisms by which chromosome rearrangements such as this fusion could contribute to speciation. IIRC (haven’t read the paper in a while) it is not that the fusion represents an advantage in and of itself. Rather, it contributes to the reproductive isolation of a particular population, so that other genetic traits will tend to accumulate in that one subgroup and not others, eventualy resulting in speciation.

  23. John Kwok

    @ Brian –

    The Discovery Institute has been in existence since the mid 1990s, along with its Intelligent Design “think tank”, the Center for (the Renewal of) Science and Culture. (I put parentheses around “the Renewal of” since that was its original name and its original intent, as outlined by the “Godfather” of the Intelligent Design movement, retired Berkeley law professor Phillip E. Johnson, who serves currently as the Center’s program advisor: .) Despite having received millions of dollars in funding from a diverse range of sources, it has yet to produce any demonstrable peer-reviewed published science in support of any of the major principles of so-called Intelligent Design “theory”. (Even Johnson, himself, has admitted publicly that we do not have yet an Intelligent Design theory.) Instead, its staff has published books, including those that claim to be “scientific”, like, for example, Stephen Meyer’s “Signature in the Cell” and Michael Behe’s “The Edge of Evolution: The Search for the Limits of Darwinism” (both of which have been soundly rejected by reputable scientists and others; as an aside, back in 2007, both Dave Wisker and I recognized, independently of each other, that Behe’s book demonstrated his profound ignorance and understanding of evolutionary ecology, especially with regards to coevolution.), has crafted so-called “Academic Freedom” bills like those that have been passed (unfortunately) by the state legislatures of Louisiana and Tennessee, and has engaged systematically in ad hominem attacks on its critics, of which its ongoing behavior against Carl Zimmer is but the latest of a rather extensive line of examples that have been documented extensively online elsewhere, starting with The Panda’s Thumb ( The Discovery Institute, along with its “research arm”, the Biologic Institute, does not produce any valid science period, in support of Intelligent Design creationism. Instead, it is interested merely in promoting its absurd Intelligent Design propaganda, replete in its mendacity, at a target audience comprised of both a predominantly science illiterate public, and especially, a much narrower target audience comprised of Fundamentalist Christians and Jews. (Of which, a notorious example is none other than DI Senior Fellow David Klinghoffer.) In seeking to engage in a “debate” with Carl Zimmer – whom many, including yours truly, regard as our foremost science journalist reporting on biology and medicine – the Discovery Institute isn’t interested in having a meaningful “dialogue”, but instead, in scoring rhetorical points off him, as evidenced by David Klinghoffer’s bizarre screeds about Carl being posted over at ENV. Carl is wise to reject Klinghoffer’s offer, and the others he’s received at Uncommonly Dense (which is an apt summation of the posting behavior at the Uncommon Descent website) and elsewhere.

    On “Saturday Night Live”, William Shatner once advised “Star Trek” fans attending a “Star Trek” convention (a SNL skit of course) to “Get a life!”. IMHO that very advice should be heeded by Klinghoffer and his colleagues at both the Discovery Institute and the Biologic Institute.

  24. Odin

    Meanwhile, here in the Philippines, people who objected to removing science from public grade school curriculum and replacing it with religion are getting pecked to death for being anti-God. Science is not child-friendly, so they say, which is why it has to be replaced with a subject that is all about proper ‘fear of the Lord’, as well as other anti-science stuff(teaching anti-science dogma in public schools since first grade). Damn, it was hard enough trying to present evolution to high school biology instructors who insist on biblical accounts, it’s about to get worse.

  25. Renee Marie Jones

    Hm. I googled “hounding duck” and I still do not know what it is, but I’m pretty sure you are not a duck, hounding or otherwise, so I would not worry. I had a duck (we called her daisy, of course) that nested in my yard a couple of years. You do not look anything like her.

    I read creationist “literature” sometimes. I do not really know why any more, it just seems fair (though they do not seem to care about fairness themselves). But it does make my head hurt. I actually find it surprising that they would fool anyone with their stuff. They change the meanings of words in mid-sentence, make completely unsupported allegations and act as if the allegations themselves are evidence, and use virtually every other dishonest debate tactic ever devised.

    They are, however, very good at it, and an honest man does not stand a chance against them unless he is very adept and very careful.

    Anyway, thanks for keeping up the good fight, Carl. Hey, at least your posts make sense and you actually have evidence on your side. Thanks, and do not forget to “duck.” :-)

  26. timbebinder

    If hounding ducks evolved from Carl Zimmer, how come there aren’t any fossils of houzimmers?

  27. Dan Tillman

    Ah, God. The Great Chromosome Fuser in the Sky!

  28. Electronaught

    I love science fiction as much as the next guy and so the idea of creationism actually sounds pretty fun in a warped way. But what ruins it all for me is that they aren’t just trying to prove that some unknown intelligent force created us but that they also somehow know all about this unknown force. As if creationism will justify and prove Christianism it self.

  29. SLC

    Re John Kwok @ #19

    If the clowns at the Dishonesty Institute want to argue that the human and Neanderthal fusions took place sep0arately, they not only have to overcome the stratospheric odds against that happening at the same location but they also have to explain how the fused chromosome became fixed in both populations. That’s a tall order.

  30. Paul Havlak

    Carl, regarding your responses to #5 & #18, I wouldn’t be too sure that the Neandertal genome browser implies independent evidence that they had a modern-human style chromosome 2. The browser might just show it that way for convenience. The DNA was rather fragmented, and shouldn’t have allowed any long-range chromosome mapping or end-sequencing of fragments that could span the former telomeric repeats. The genome paper ( says they aligned the reads to genomes for human, chimp, and an inferred human-chimp ancestor, which is how they got any chromosome-scale structure at all.

    Even though modern humans and Neandertals interbred a little, differing chromosome numbers wouldn’t necessarily prevent that.

    However, if there are distinctively mutated former telomeric sequences in human chromosome 2, and those were found in the Neandertal reads, that could be direct evidence for Neandertals having the modern karyotype (beyond any argument based on the number and rate of mutations). I haven’t yet found any references checking that.

    [CZ: Thanks. I was unsure of myself using the browser, and I didn’t find anything addressing this explicitly in the papers.]

  31. Of course you’re right about the absence of real evidence to support ID claims. There is not and never will be scientific evidence to support ID–but the absence of evidence will never shut them up.

    The ID people claim their argument is about science, but it isn’t. It’s about the authority of science in American culture. I and half a dozen other historians of science wrote about this in The Panda’s Black Box (Johns Hopkins, 2007). I’ll be glad to send you a copy if you like. It might give you some different perspectives on this debate, if it’s heating up once again.

    Hit me up on Twitter (@nccomfort) if you want a copy–no strings, no promotion required, just fyi.

  32. John Kwok

    Nathaniel Comfort,

    You may be familiar with Ken Miller’s “Only A Theory: Evolution and the Battle for America’s Soul”. Ken may have made a similar argument. So too, I believe, has Shawn Otto in his recently published “Fool Me Twice”. Unfortunately, this debate as been rather “fast and furious” for years.

  33. Shrunk

    @ SLC #29

    You don’t understand how the creationist mind works. If both Neanderthals and modern humans possess the fused chromosome 2, and this is so astronomically unlikely to have happened by chance, then that can only mean one thing: God magically intervened as an Intelligent Designer and caused both fusions to occur. Praise Jesus!

    (I’m just joking, of course, but watch: It’s only a matter of time before some creationist makes this claim in earnest, if they haven’t already.)

  34. The whole truth

    Carl, there’s a typo in your article you might want to fix.

    “…Chromosome Two Lifes and Misdemeanors.”

    Should be:

    “…Chromosome Two Lies and Misdemeanors.”

  35. Stephen

    Here is the article that they cited:

    Yuxin Fan, Elena Linardopoulou, Cynthia Friedman, Eleanor Williams, and Barbara J. Trask, “Genomic Structure and Evolution of the Ancestral Chromosome Fusion Site in 2q13-2q14.1 and Paralogous Regions on Other Human Chromosomes,” Genome Research, 12 (2002): 1651-62.

    Here is the article that discusses the matter on ENV:


  36. amphiox

    I can see no particular reason why a fused chromosome would convey a genetic advantage – maybe specialists have some hypotheses about that.

    It doesn’t have to, and on the face of it, would not be expected to.

    Genetic drift alone is enough to bring it to fixation.

    It could also be that some time after the chromosome fusion, when the fused chromosome existed only at a low frequency in the population, a new mutation conferring a genetic advantage arose in an individual possessing the fused chromosome in one of the genes on the fused chromosome. The spread of this gene through natural selection would automatically increase the frequency of the chromosome that contained it.

    But it would not an advantage specific to the fusion itself.

  37. john naddaf

    hi carl,
    i must tell you,this is an issue that i can seem to be able to avoid lately…
    having grown up in beirut,at the height of the civil war,i lived in what was known as the green line,,,(dividing east from west beirut),,,our appartment on the third floor,had three big holes in the stairway,before the entry door…our kitchen had been hit 4 time,we lost half the ceiling in the living room,,,and the roof was mostly inaccessible,as it was under continuous sniper attention,,,as was my primary school,,,but the time i was 5 i had been shot at 3 on three occasions by snipers,,,around the same age when i began sleeping with a loaded shotgun under my bed,,,thats how i was able to sleep,with the constant shelling,and gunfire,,,24 hrs,7 days…till i came to australia…but wasnt that bad really,,it was my home,,all i knew,,and like any people in war,we learn to depend on our faith,,,and i had,still have,and will long after im dead,,,,i dont like to say i believe in god,i feel that understates it for me,,i love god,my most cherished friend…to say i believe in god assumes a leap of faith,,for me there is no leap,,,i have felt his presence,and that is a privilege that remain with me for eternity….but im not here to boast about god,or to try to convince anyone in god…just wanted to explain my relationship with good,so you get a clearer picture of my motivation….
    Now the second part of the story,,,science,,i have a deep passion for science,love anything i can learn,im self taught,but i learnt from the teachings of science,,in grade 2,primary school,,when science was intriduced,i had to memorise some pages after the first class,,,and i did,,and from 10 to 19 yrs old,,i could recite the first three pages of my book,word perfect….now im trying to further my understanding of physics,particle,astrophysics,,,
    as you can clearly see,my two greatest loves are god,and science,so when i hear creationists refuting scientific claims,i realise how they are distancing intelligence from religion,,,creationists have a very narrow view about god,,,which is why their scientific view is even narrower,,,,,their faith is threatened by truth,,so they close their minds to knowledge,becoming protective of their faith,,which itself becomes even weaker from its dependence on untruths to sustain it…eventually science develops contempt for anything religion,,and religion is perceived as fairytale……
    creating a rift,alienating both science,and religion,,,my two sweethearts,,at war,through no fault of their own,,,and i hate that,,,my faith is not threatened by science,,science helps me understand god better,,god didnt expect us to be stubborn,or stupid,one of jesus’ more repeated sayings in the bible is;listen if you have ears:,,said for the sole purpose of provoking thought,,,if you can hear listen,,if you have a brain think,,,use your faith to go deeper not to hold you back….
    i could talk abou this for another 5 years,,but i wont,,,but id love to help where i can in this reguard,,,if i can assist with any thing in the future,please let me know,as i d like to have more involved….
    meanwhile this is a short paragraph from the old testament(genesis)which sort of hints of evolution,,,see how you perceive it,,,me,i think the best example of intelligent design,,is evolution itself….after all its was suggested by a monk in the first place….hope you like it…

    these are the generations of the heavens and of the earth when
    they were created, in the day that the Lord God made the earth
    and the heavens,
    and every plant of the field before it was in the earth, and every
    herb of the field before it grew : for the Lord God had not caused it
    to rain upon the earth, and there was not a man to till the ground.
    But there went up a mist from the earth, and watered the whole
    face of the ground.

  38. YA

    “a few scientists (ie, people with Ph.D.’s who’ve published research in peer-viewed scientific journals”

    By that definition get rid of the journals and the universe will collapse from unanswered questions.


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The Loom

A blog about life, past and future. Written by DISCOVER contributing editor and columnist Carl Zimmer.

About Carl Zimmer

Carl Zimmer writes about science regularly for The New York Times and magazines such as DISCOVER, which also hosts his blog, The LoomHe is the author of 12 books, the most recent of which is Science Ink: Tattoos of the Science Obsessed.


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