Siliceous and Delicious

Maybe it was the sudden surge in temperature (from snow to over 60˚ in a day), or maybe it was the release in tension from finding out that I have one whole chapter less to write than I had thought, but I woke up feeling under the weather and spent half the day in bed feeling sick and sorry for myself. Eventually rallied and spent the afternoon at work, but wasn’t much more productive there—JC came by to talk over her post-doc options, and Tinker came by for a lengthy chat since he, too, has come down with the bug.

Did catch up on some of the diatom evolution reading that I’d been wanting to do, both in search for biologically driven hypotheses for particular characters as well as hunting for a more general biological framework from which to hang the papers.

Nothing much jumped out at me—the papers I read seemed mostly obsessed with phylogeny and relating morphology to it in some way (but still largely divorced from function or ecology). There was some talk of apical pore fields being for mucilage secretion, which may be related to attachment (either to substrates or to other cells for colony formation). Labiate processes, too, seemed to get some attention and were mentioned in conjunction with mucilage secretion and nutrient uptake. I did get the sense that most of the multipolar centrics and certainly most of the pennates were benthic—which was quite surprising since I had worked under the assumption that the vast majority, if not all, of the taxa in my morphospace would be planktonic (due to the very great water depths under which the sediments were drilled—one wouldn’t expect photosynthesis in the benthos below >1000m of water).

This prompted me for one idea, which was to try to plot the occurrence distribution of the different taxa in the morphospace—i.e. how “densely” populated are different bits of the morphospace. This would involve recoding the plotting function such that the plot symbol would be scaled by the number of occurrences in the time bin. It might be interesting to see whether some areas of the morphospace support greater populations (or, strictly greater preserved populations—perhaps they’re just more likely to fossilize!)…