Botanisches Museum - Galerieausstellung


The universe under the microscope – biodiversity and aesthetics of
diatoms

exhibition at the Botanical Museum Botanical Gardens Berlin

in cooperation with Matthias Burba, Hamburg

from 12 March to 1 June, 2009

Diatoms are single-celled algae. Since they are
smaller than 1mm, they can only be seen with the aid of a
microscope. They live abundantly in lakes, streams and oceans and
exist even in wet habitats as tiny as the bark of a tree. The number
of different diatom species, that is their biodiversity, is
estimated at 1 million, with only 20 000 species having been
described. The ecological significance of these organisms becomes
enormous, if you take notice of diatoms producing about 25% of the
global oxygen.

But apart from the scientific aspects, they
are intriguing to look at: Their glass shells are incomparably
beautiful and their pronounced symmetry fascinates the observer.

Starting in the 19th century,
diatoms became a popular subject of study among (many) amateurs and
(few) scientists. The preparation and arrangement of these small
algae into orderly rows,
circles and other elaborate patterns was
usually the work of amateurs. Johann Dietrich Möller (1844-1907) had
perfected the skill to arrange diatoms into such arrays on
microscope slides. While he made a living by selling these slides,
it was also important to him to have his works published among
experts.

The largest microscope slide of this kind was
prepared in 1891 and is called “The Universe” by J. D. Möller. On
one slide sized 5x6mm, more than 4000 different diatom species are
arranged into even and uniform rows. A printed catalogue, which goes
along with it, identifies every single species and its exact
position on the plate.

This exhibition displays many modern
photographs of different microscope slides from the 19th
century, in which the biodiversity of diatoms is depicted under
different aspects such as aesthetics, geography and systematics.
Furthermore, the exhibition gives an insight into the methods and
techniques of making these complex arrays on microscope slides.

An excursion into the current systematics of
diatoms based on recent molecular data and illustrated by electron
microscope pictures, links the “Universe” of the 19th
century with the present.

The aesthetics, the beauty of the microscopic diatom arrays,
however, is timeless.