debor042

I admit that I ended that last post a bit unclear. But diatoms, it should be said, aren’t (or, rather, shouldn't be said since I shouldn't use double negatives. Ah, well.). Not physically, that is; you see, diatom cell walls are made of silica (glass), and that feature is actually incredibly important (not to mention gives rise to beautiful 'micromanipulations' like this one by Klaus Kemp - different colors in part because of different thicknesses of their glass). Diatoms arose between 180 and 225 million years ago – youngsters in the algal world (compare that to the geezer cyanobacteria of 3+ billion – way vintage) – and in so doing utilized an under-used, widely available resource that set them apart. The genealogy (or “systematics”) of diatoms has since expanded to include anywhere from 20,000 to over 1 million species that span almost every aquatic or semi-aquatic habitat imaginable – oceans, lakes, rivers, moss, soil. In those habitats they can be suspended in ...