From the Linux Journal Flickr pool:

A paleocommunity "metanetwork." The spheres represent types of ecological guilds: green - primary producers, cyan - freshwater fish and invertebrates, brown - insects, red - amniote tetrapods, and yellow - amphibian tetrapods. This is a representation of a terrestrial community, the Dicynodon Assemblage Zone community of the Late Permian (~251 million years ago) Karoo Basin in South Africa. Collective responses to disturbance of ecological groups, and entire communities, emerge when the community is viewed in this hierarchical scheme. This was rendered with POVRay for Linux. Blogged about at Climate Change Blog.