A tale of lungs, mistaken identity, and the importance of negative results

The results are not of sufficiently general interest. That’s what the journal said. What they were turning down, however, was proof that research they previously had deemed interesting enough to publish, was wrong. Not just a bit wrong. Flat wrong.

Although it’s a bit of a complex tale biologically, the basics are this: some amphibians have evolved away from lungs and nostrils, instead exchanging gases through their skin. The dominant theory of why this happened was that it helped amphibians living in fast-flowing waters be less buoyant, and thus less likely to be swept away.

Caecilita Iwokramae
Caecilita Iwokramae is a ceacilian amphibian, like this guy. They basically look like a cross between a worm and a snake.
Franco Andreone, Wikimedia Creative Commons.

All known amphibians found without lungs so far lived in such an environment. Until Caecilita Iwokramae came along. Having clearly evolved on land, and described as possessing no lungs or open nostrils, C. Iwokramae seemed to bury the reduced buoyancy theory.

Regardless of how interesting you find this personally, it was widely reported in the science press, making a splash in National Geographic, for example.

Exploration and discovery

The paper describing C. Iwokramae for the first time, published in the esteemed journal Proceedings of the Royal Society B, based the diagnosis on a single specimen. Intrigued, scientists led by a pair at the Natural History Museum set out to find more of the creature.

(So yes, this is how I came to the story, I wrote a news piece for it for the Museum today, where you can find more details, but I’ve been burning to write this post for a while to tell this other part of the story.)

The team found many more specimens – but all of them with obvious nostrils. They then re-examined the original specimen, and found not only open nostrils, but one obvious lung (it’s not unusual for amphibians to only have one).

So now they had the proof, C. Iwokramae was not lungless, and the reduced buoyancy theory was not, in fact, overturned. Two questions beg to be asked.

1. How did the original authors miss the lung and open nostrils?

“The bottom line is that the scientists who described this animal made a fairly spectacular mistake and that the species is actually not relevant to our understanding of why lunglessness has evolved in some species.” This is what one of the co-authors of the new paper, Dr Mark Wilkinson, said.

One of the authors of the original paper is apparently a ‘big cheese’ in the field. Yet they missed a lung found in exactly the spot expected, and confirmed by several morphologists at the Museum. Is it all honest mistake?

‘The story shows how even the greatest reputation and standing in the field doesn’t immunise a scientist from the possibility of making a mistake,’ said Wilkinson. ‘With observational sciences the lesson is to get others to check your findings when you can especially if the findings are of something highly unusual.’

At least this allowed me to use one my favourite skeptical lines in the news piece: ‘Extraordinary claims require extraordinary evidence.’

2. Why didn’t Proceedings of the Royal Society B want to print the refutation?

In journalism, we learned that if you make a mistake, you’re obligated to make sure the correction reaches the same audience as the original, i.e. the same broadcast mechanism, time, etc. Sure, the journal didn’t make a ‘mistake’ as such, the research was true at the time they published it, but given the impact of the original report, don’t they have some kind of responsibility to print the updated truth?

Unfortunately, a lot of people don’t know that’s not how these big journals tend to work. They don’t want to print negative results. Journals are more interested in sensational, sexy news than you might think.

Bypassing the big journals

Still, the new paper did find a home in a journal, albeit one of less impact (but open access, go take a look). Interestingly though, despite the paper only coming out today, the Wikipedia page for Caecilita has been updated already! At least if the slimy amphibian is googled, the truth will out after all.


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