Scientists now have a plausible, and likely theory for what created the Burgess Shale:

By looking over hundreds of micro-thin slices of rock taken from the famous shales, the researchers have reconstructed the series of catastrophic underwater landslides of “mud-rich slurry” that killed tens of thousands of marine animals representing hundreds of species, then sealed them instantly – and enduringly – in a deep-sea tomb.

The mass death was “not a nice way to go, perhaps, but a swift one – and one that guaranteed immortality (of a sort) for these strange creatures,” said University of Leicester geochemist Sarah Gabbott, lead author of a study published in the U.K.-based Journal of the Geological Society.

I use the scare quote because that’s the word used in the headline. This kind of language, I think, is (at least partly) what bothers people who continue to rebel against evolution, and science. It is a certainty of language (like “fact,” rather than “theory”) that they consider hubristic, and arrogant. After all, when Sherlock Holmes “solved” a case, it generally was the last word, case closed.

In this case, what the word means is that scientists have come up with a plausible explanation for an event for which they’d been struggling to come up with one for a long time, and it is sufficiently plausible that there are few scientists who argue against it, thus presenting a consensus. Does it mean that they have “proven” that this is what happened? No. As I’ve written many times, science is not about proving things–scientists leave that to the mathematicians. What scientists do (ideally) is to posit theories that are both reasonable and disprovable, yet remain undisproved.

There may be some other explanation for what happened up in what is now Yoho National Park that corresponds better to what really happened, but until someone comes up with one that makes more sense, or comes up with some inconvenient indisputable fact that knocks this one down, it (like evolution itself) is what most scientists, particularly the ones who study such things for a living, will believe.

And of course, I won’t even get started on how upset some anti-science (and yes, that’s what they are, even if they don’t recognize it) types will get over the statement that one of the ancestors of humans is in that shale.

[Update a few minutes later]

Oh, the main point about which I put up this post. This is an excellent illustration of how rare are the circumstances in which we find the keys to our biological past. Those that demand that we cannot know the history of life until every creature has died on the body of its parents, perfectly preserved, are being unreasonable. To paraphrase Don Rumsfeld, we do science with the (rare) evidence that we have, not the evidence we’d like to have. There will always be many huge holes in the fabric of the evidence, barring the development of a time machine to the past. We simply do the best we can with what we have, and put together theories that best conform to it. To say that God (or whoever) did it isn’t science–it’s just a cop out. And that is true completely independently from the existence (or not) of God (or whoever).