A Giant Leap?

Skimming the digital waves this evening, I noted that an awful lot of zeros and ones are being consumed by a single presentation among the many hundreds of papers at this year’s Geological Society of America meeting. Unlike the commentators whose pieces I saw concerning this talk, I actually attended Mark McMenamin’s presentation about an ichthyosaur death assemblage in Nevada this afternoon. Therefore, I have seen rather more than those writers about this idea that the bones of Shonisaurus had been laid out by giant cephalopods as some sort of Mesozoic environmental art installation (imagine, perhaps, a monstrous molluscan Richard Long working with enormous vertebrae as his medium).

The bloggers are quite correct that this presentation travelled some considerable distance into the realm of pure conjecture and imagination, and that many in the media exhibited bad journalistic practice by homing in on this talk without seeking comment from other scientists.

As I sat through McMenamin’s presentation it struck me that, taken individually, most stages in the exposition were unremarkable and in fact similar to sections of many other scientific presentations. Scientists work by making inferences from the available data, and most of us try to be as thorough and cautious as humanly possible. Nevertheless, the discussion part of a scientific paper will typically have some elements that reach into speculation. If the solid data are considered as “A”, then a paper’s discussion will typically say, “since A is known to have taken place, therefore B is likely.” And I have seen countless conference presentations (particularly in fields such as dinosaur paleontology) where the presenter felt the freedom to speculate further, saying, “since A took place, and B is almost certain, therefore C is also likely.”

The basic issue with today’s presentation is that McMenamin took this several stages farther, saying effectively, “since A is true, B is almost certain, and C is likely, so therefore D may have occurred, and thus E followed, and F, and …” Each step in the progression was a relatively small one, but their cumulative effect was a giant leap into a place where the suggestions were no longer supported by science. Like a stealth predator, conjecture crept up on science, overwhelmed and consumed it, and then placed the few robust facts into an artistic and intriguing arrangement.

This is unfortunate; it was an interesting idea, and I would love to see McMenamin follow this up with the years of field- and lab-based work that would be required to demonstrate whether his conjecture is at all likely. But without this sort of slogging to support it, it will remain just that: conjecture.

Incidentally, this talk followed after an excellent student presentation about fossil lungfish burrows in Madagascar; why don’t the media consider taking a look at some of the superb student work that is being shared with us here?