Scientists Divine Deep Time in Dead Fish
Scientific experiments can certainly take on a wide variety of methods, from recreating the atmosphere of Titan to testing a drug on a genetic disease. But if educators want to encourage students to become scientists, they had best keep silent about “some very unpleasant experiments” at the University of Leicester reported by the BBC News. The team decided to watch fish heads rot. What they were looking for in this “very smelly” study raises questions about what kind of knowledge can be deduced from experiments.
The researchers had an ostensibly noble purpose. They were interested in knowing what happens to dying fish before they become fossilized, in order to interpret more accurately what is found in the fossil record. Do skeletons and soft tissues undergo dramatic transformations as they rot? If so, it could skew the interpretation of ancient marine fossils. Inquiring minds what to know.
The experiments had a grander evolutionary backdrop. Dr. Mark Purnell said, “We need to understand how they decayed if we’re going to put them in the right place in the tree of life.” Researcher Rob Sansom realized, according to Science Daily, that “spending hundreds of hours studying the stinking carcasses of rotting fish is not something that appeals to everyone.”
Update Jan 31: What this study implies for evolution will not be good news for evolutionary paleontologists. Nature News said the fact that parts can rot away can lead to misinterpretations. “In a series of experiments published online today in Nature, Purnell and his colleagues Robert Sansom and Sarah Gabbott found that the features that are most important in deciding where to place an animal on the tree of life are lost first,” Daniel Cressey’s synopsis explained. The results can be counterintuitive: “In practical terms, this means that as something decays it seems to retreat through its own phylogeny and descend the tree.” Philippe Janvier at the Museum of Natural History in Paris agreed: “Some fossils have clearly been over-interpreted.” Has this happened? Yes, according to Purnell; “decay bias” could be widespread. Interpreting the origin of chordates is particularly fraught with decay bias. Philipp Donoghue at the University of Bristol cautioned, “It’s certainly going to annoy a lot of palaeontologists who have rather blithely interpreted fossils,” he said. “A bunch of fossils we thought were primitive vertebrates actually now fall into a dustbin and tell us nothing about the evolution of vertebrate characters.”
Experimenting on taphonomy (studying the processes under which remains become fossilized) is a worthwhile activity, but the interpretations and assumptions in this article stink worse than the fish heads. Would their experiments help them understand created fish that perished in a great flood? They could not possibly understand all the conditions that might have differed from dying fish in a lab to those who perished in the fossil record. Maybe they need to do some further experiments on what happens to fish who fossilize while giving birth (see National Geographic) or that are preserved in rock instantly while having lunch (see FossilMuseum.net).
These guys cannot possibly interpret their lab experiments correctly. They had the moyboy disease* infecting their brains from the get-go. “Unlike forensics, however,” the team lead said, ”we are dealing with life from millions of years ago.” At least he got one thing right. It’s sure unlike forensics – trying to follow the evidence where it leads, free of bias. It is one of the clearest examples of divination we have seen yet (see commentaries from 07/26/2008, 01/25/2008). If Nebuchadnezzar had been told you had to smell rotting fish heads to see the tree of life, some other heads would have rotted.
*Moyboy: millions of years, billions of years.