Siliceous and Delicious

Another day, the same café… Starting a much more pleasant-feeling day sipping Darwin’s light roast coffee as the world goes by on a cloudy August day outside. The task for today is to draft up the summary of my diatom diversity/E-O chapter.

In the midst of this, got an email from Dave about Neptune—he sent a report of the old version of the database with a remark that I ought to be able to match my entries to those in the MRC database using the “mbsf” sample depth field. This, of course, was a bit of lightbulb/smack-the-forehead moment! Who needs the exact curatorial identifier if we have sample depth? There is still the minor matter of the different ways of calculating sample depth, which I read about at some point in the bowels of the IODP website somewhere (I think it’s drilling depth vs. curatorial depth), but it should be OK.

Well, that’s one thing taken care of. In the process of starting to write the summary, I got sidetracked writing a script in R to calculate the range-through diversity, something I hadn’t yet done, as I was wanting to place a figure of that plot into the text. It was fun re-engaging with R, but it took quite a bit of time…

Picked up Kate for a downtown lunch and spent the afternoon working at VSA. Messed around with R until I got the range-through diversity script working; tricky, but hugely rewarding when it worked out. The fascinating thing I noticed happened when I added the lovely color timescale: it seems that the ‘diversity crash’ that’s I had associated with the E/O boundary in all my discussions is nowhere near the E/O (the green line is range-through, the lower, grey line is sampled in-bin diversity):

This raises a whole bunch of questions—how does the curve compare to oxygen isotopes (I know this is something that was examined in the whale evolution paper)? Where on this timescale does the preservation low fall—at the same place as the diversity crash, or at the E/O boundary?