Debate over dinosaur extinction in The Atlantic

I thought this article might be of interest to Forum participants, a recent #1-most-read article-of-the-day on The Atlantic’s website:

It’s of course just generally very interesting, but I share it here also because it speaks to issues like the human side of science, and what it’s like to be an outlier to the scientific establishment. Interestingly, unlike many in the ID movement, Keller continued to publish her findings in scientific journals. (I don’t offer this as a critique of ID, necessarily, but just as an observation.)

Would love to hear our community’s thoughts if anyone cares to read & discuss. I haven’t actually finished reading it yet, but I knew it was destined for the Forum when I read this line:

“This dispute illuminates the messy way that science progresses, and how this idealized process, ostensibly guided by objective reason and the search for truth, is shaped by ego, power, and politics.”


Interesting article. My feeling is that like most things in life, it was multifactorial and a perfect storm type situation, so both may be right.

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I made up an activity for the kid version of this story. It is a great example of how the scientific community works to refine theories. What Killed the Dinos?: A Model for Exploring the Scientific Process with your Kids - Article - BioLogos


The stegosaurs roamed, then died, and tyrannosaurs took their place. (More time separates stegosaurs from tyrannosaurs—about 67 million years—than tyrannosaurs from humans, which have about 66 million years between them.)

Wait, so that whole stegosaur/T-rex fight scene in Fantasia couldn’t have actually happened? :astonished:

But seriously, this was very interesting – thanks for sharing. The degree to which the pursuit of science mixes with personal beliefs is interesting too, though it is good to see that the conclusion is not “see, that’s why you can’t trust science.”

“That the asteroid hit, and that the impact triggered the extinction of much of the life of the sea … are no longer debatable points,” he said in a 1982 lecture. “Nearly everybody now believes them.”

Yikes. Is that a scientist appealing to popularity? Or did “nearly everybody” mean “nearly every scientist”?

But the use of “belief” (here and elsewhere) is interesting, and it seems to me that that is also similar to one of the underlying criticisms of ID, which is that it’s just “creationism in disguise” – in other words, “I fear your science is motivated by inappropriate beliefs.” So it appears that criticism is not limited to ID.

Keller uncovered 20 inches of limestone and other sediment between the fallout from the asteroid and the forams’ most pronounced die-off. This was evidence that thousands of years had elapsed in between, she argued. (Smit’s findings from the same samples were diametrically opposed; he countered that a tsunami, triggered by the asteroid, had deposited the sediment essentially overnight.)

Gee, I feel like I’ve grown up hearing these same kinds of debates about deposit times…

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Thanks for sharing that article. It does a wonderful job giving an inside look at the real (interior) world of science.

Around here, many of us tend to be so eager to repudiate science denialism that we tend to venerate anything that seems established by mainstream science. So articles like this one that give a more sympathetic hearing to someone who has pushed from the fringes, could seem uncomfortably close to “aiding and abetting the adversary”.

So naturally, the discerning mind works to justify a distinction between denialism and legitimate science-challenging inquiry. In this case, one clear difference is that Keller actually has evidence (and a plausible alternate scenario or model) she can point to. Whereas those who don’t like a present consensus but they don’t have any alternate on offer (much less evidence to back it) are not in the same class as a stubborn outlier who does.

It surely does lay to rest though, the delusion of dispassionately objective scientific thinkers just “following the data” wherever that leads.


Thanks for sharing that piece; it is very interesting and probably important for scientific leaders (and editors like me) to know. I found some aspects of it surprising, and even after reading it, I’m a little skeptical of its portrayal of such hardened extreme positions. (But OTOH the author documents beyond question a “debate” of epic nastiness, on a scale I have not personally seen in any subfield of biology.) Specifically, it was not my impression that the asteroid theory had hardened into an established “fact”; on the contrary I have heard the volcanic hypothesis continuously for decades, and am aware of the fact that many Cretaceous fauna were apparently in steep decline before the impact. (On the latter topic, read “Dinosaur in a Haystack” by Stephen Jay Gould.)

I agree that it is valuable and important to think about this, but I’m not sure that this feud is likely an exemplar of scientific disputes. In the piece, Alvarez and Keller both come off sounding like prodigies of inappropriate, unprofessional, and perhaps unethical conduct. Heated debate about scientific theories will always entail the risk of offense, even when the debate doesn’t require one side to be wrong. But this feud seems to be toxic and, as one scientist says in the piece, an embarrassment. Is this typical of scientific dispute? For what it’s worth, in my experience in biology, no.

But then there’s the comparison to ID. (To be specific, on my part: the ID movement.) The ID movement is a sector of creationism, which is a form of science denial. Ditto for climate change denialism, anti-vax propaganda, and various other politically-motivated “disputes” about science that are not actually scientific disputes. In my opinion, it is potentially misleading to compare the ID movement to Keller or even to more-fringe gadflies. Science must protect dissenters like Keller or Peter Duesberg, even when it becomes clear that they are or were wrong (Duesberg famously so), but at the other extreme we have flat earthers with arguments that must not be confused with scientific dissent.


I can identify with that – coming from one extreme (denialism) can make it too easy to find solace in the other extreme, as if it were some kind of personal penance.

That’s a good distinction – I hadn’t really looked at the ways that “dissent” and “denial” are such different things. As a layperson, I suppose I can’t put too much stock in simply “what some scientists think of person x” but look a little deeper into why. I’m glad you don’t see this level of feud as being common in science though.


I read the article yesterday and thought it both biased and too gossipy. To be clear, I suspect that both the asteroid and the volcanoes probably played a role in causing the extinctions, but the author seemed to want to portray it as a morality play and wasn’t interested in explaining scientific details even when they could be explained to laypeople. Kolbert did a good job, for instance, explaining the Signor Lipps effect in her book The Sixth Extinction. On the gossip, we only hear details about the alleged unfairness of the attacks on the volcano advocates such as Officer. She depicts Officer as unfairly hounded from the field when in fact he was wrong twice— first he denied that the iridium layer was evidence of an impact and then when Chixculub was discovered he refused to accept it was an impact crater. Keller wanted to claim that there were multiple impacts based on the fact that impact related layers are separated by meters of sedimentary rock at Chixculub and other places. Smit says those are tsunami deposits. He and others say that in North America, further away, the layers are right on top of each other. Keller says that is due to gaps in the record, but Smit claims these are deposits in coal swamps and there are no gaps. The impact experts say there simply is no evidence of a much larger impact at that time, a claim that Keller has made though I don’t recall seeing it mentioned in the Atlantic article.

A good science writer could present at least some of the scientific arguments from both sides, but this writer wasn’t interested in doing that. I hate this kind of science writing.


I am going to post links to papers on the pro impact side, for those curious. The first one was mentioned in the article and supposedly shows, contrary to Keller, that the impact and the Cretaceous Paleocene boundary were simultaneous to within measurement error which is currently give or take 30,000 years for that time period.


Here is a link to a debate between asteroid and volcano advocates in the pages of Science. I find this much more interesting than the Atlantic gossip column, even though I am not a geologist.


And here is the paper that triggered the letters in the preceding link.

This paper was mentioned in the Atlantic article. And yes, I think a competent science writer could have summarized the evidence and arguments, many of which are aimed at Keller’s criticisms of the impact theory.

Added note— This is weird. I was able to read the full article a few minutes ago, but now you have to log in or pay. Too bad. The details were interesting, but now you can only read the abstract.


I know, right? I had actually heard about this sort of inaccuracy in dino movies, but didn’t realize the time difference was quite that stark!

Would that make it any better? I suppose a little bit, but not much…

I thought the same thing! But Donald in his comments below gives some information in Smit’s defense, which makes it sound slightly less of the Creationist ad-hoc variety of explanation…

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I think you’re probably right, in general. However, it’s not without parallels, at least in the “softer” sciences. The Chomsky–anti-Chomsky divide in linguistics, for instance, is pretty darn acrimonious.

Right. And I made the point in a recent discussion with a YEC brother here (though he ignored it, unfortunately) that science is ultimately self-correcting. You can have a firebrand like Alvarez who by force of both evidence and narcissistic-esque personality may manage to strong-arm entire disciplines … for a few years, a decade, even a couple of decades. But eventually, his and his acolytes’ influence (it’s usually a he) wanes, or he dies, and other voices can put the scientific train back on its rails.

The thing about the evolutionary consensus of common descent by modification is that it’s now been around for over 150 years. Depending on how you count generations, that’s at least 5-6 generations. It’s not going anywhere…


Hello Donald,

I haven’t read all the articles you linked, but I just wanted to say thanks for weighing in with this richness of useful links! I agree, the piece was quite biasedly pro-Keller, and I myself wondered, “Well, if they say Keller was unethical, do they have any evidence for that?” and “What would a piece written by the other side sound like?”

While I’m at it, let me say I hadn’t seen you on here before, so, welcome! =)


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It is available online here.

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I think I posted something a year or two ago. Mostly I am just an occasional lurker.

The Atlantic article, as you can tell, irritated me because a lot of people are going to read it and walk away with the false impression that advocates of the asteroid theory have mainly dominated by bullying the opposition. Wherever the truth lies between the two extremes, this simply isn’t the case. For one thing, if one wants to focus on the human frailties involved, it was initially the anti - asteroid camp that reacted with kneejerk dismissals and weirdly you still see echoes of that in the language of this article. The asteroid theory became the leading contender because of the evidence. It started with the iridium layer, then discovery of shocked quartz and then a crater of the size predicted. This was by far the largest impact known in the Phanerozoic and by some weird coincidence, around the world the iridium layer coincided with the Cretaceous Paleogene boundary. At every step the skeptics denied first that the iridium meant an asteroid impact and then that Chixculub was a crater and now Keller insists that the layer deposited shows the crater formed 300,000 years before the Cretaceous ended.

The tsunami deposit explanation is not silly and not comparable to Flood geology, because we are talking about a 100 million megaton explosion in the Gulf of Mexico. One would expect some fairly big waves under the circumstances. But you can read the paper below that Bill successfully linked.

I am not saying that the asteroid theory is completely right. There is a legitimate debate about the extent to which the asteroid vs the volcanic eruptions caused the mass extinction. Quite likely both factors contributed.

I think there is a similarity to creationism though, in that the Atlantic article relies heavily on rhetoric and a very poor presentation of the science to give laypeople a misleading impression of the strength of the asteroid theory. The one legitimate point that is made is that the volcano theory is not dead. But this could have been done in a serious fairminded way with some attempt made to explain the scientific disagreements.


Thank you for that.

Anyway, for anyone who wants to see the best presentation of the asteroid theory as of 2010, that is the paper to read, along with the exchanges in the link that I was able to post.

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It makes me wonder should we Trust Scientific Experts?

Assuming this isn’t just a rhetorical nod to the neighboring thread …

The answer is … a qualified yes. If they aren’t “lone-wolf” or renegade experts and if they have plausible evidence on offer. The politics and egoism should in most cases show through less by the time it all filters down through a lot of peer review, and has taken all the punishing, critical challenges, and has, over time adapted / survived accordingly. Still not a perfect guarantee, but it is much more likely true after all that, than opinions that have not been run through any such gauntlets. Those unchallenged opinions are much more exposed to the vagaries of power, politics, and personal preference than the weathered opinions of large bodies of experts.


Well, it’s a fair question! Did you read the rest of our Forum participants’ exchange here? Plenty to think about on that very question. My own rejoinder to that question was buried in there in this paragraph:

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