Science is the fine art of creating jargon, it seems. I was reminded of that in a recent discussion that brought up the word "facies". This term is nearly impossible to define. At its most basic, it's a packet of rock that someone decides should be grouped together. However, facies analysis is extremely complex. For example, a single stratigraphic formation can be described in terms of lithofacies, biofacies, chemical facies, metamorphic facies, etc. (One of my "pull pin, run away" questions is if there's any true sedimentary rocks--the metamorphic folks and the stratigraphers get intense about that issue!) A biofacies is a group of rocks containing the same organisms, and may include multiple stratigraphic units, or multiple biofacies may exist in a single one. Same with depositional facies--a single unit may have multiple depositional settings, or a single depositional setting may be broken into multiple units.
"Clade" is another one. On the face of it, it seems simple enough: all the organisms coming from a common ancestor, including that ancestor. In practice, though, it's very, very tricky. The issue is, by definition the parent taxa of any clade is going to be more similar to organisms outside the clade than the later ones in the clade. And that makes determining what exactly the clade is, a nightmare. I've had many fun discussions regarding how exactly we can define the first member of a clade. As an aside, if you want to pick up someone [I prefer female, but it will work just as well with men] at a paleo meeting, learn this. It's a great conversation starter, a topic we're ALL interested in, and safe enough that you can strike up a conversation with a stranger and not come off as creepy.
Anyway, my point is these types of terms strike me as odd. They take a minute to learn; I can give you the definition of these in seconds. But they take a lifetime to master--I know folks who have made careers out of trying to figure out how to work with these definitions.
I'm curious: what other terms are there that seem simple on the face of it, but which are nearly impossible to pin down once you actually get into the details?
"Clade" is another one. On the face of it, it seems simple enough: all the organisms coming from a common ancestor, including that ancestor. In practice, though, it's very, very tricky. The issue is, by definition the parent taxa of any clade is going to be more similar to organisms outside the clade than the later ones in the clade. And that makes determining what exactly the clade is, a nightmare. I've had many fun discussions regarding how exactly we can define the first member of a clade. As an aside, if you want to pick up someone [I prefer female, but it will work just as well with men] at a paleo meeting, learn this. It's a great conversation starter, a topic we're ALL interested in, and safe enough that you can strike up a conversation with a stranger and not come off as creepy.
Anyway, my point is these types of terms strike me as odd. They take a minute to learn; I can give you the definition of these in seconds. But they take a lifetime to master--I know folks who have made careers out of trying to figure out how to work with these definitions.
I'm curious: what other terms are there that seem simple on the face of it, but which are nearly impossible to pin down once you actually get into the details?
Aucun commentaire:
Enregistrer un commentaire