Ice algae terrestrial ice algae occur in freshwater systems, the species composition differs greatly from that of sea ice algae. These communities are significant in that they often change the color of glaciers and ice sheets, impacting the reflectivity of the ice itself. Microbial life in sea ice is extremely diverse, and includes abundant algae, bacteria and protozoa. Algae in particular dominate the sympagic environment, with estimates of more than 1000 unicellular eukaryotes found to associate with sea ice in the Arctic. Species composition and diversity vary based on location, ice type, and irradiance. In general, pennate diatoms such as "Nitschia frigida"
The Spiral of Life Mural Series The Spiral of Life Mural Series The Spiral of Life mural series is a collection of phylogenetic tree public art murals currently housed by the Pittsburgh Zoo & PPG Aquarium, the National Aviary and the Carnegie Science Center. The murals reinterpret Charles Darwin's Tree of Life model appearing in "On the Origin of Species" by using the spiral shape in order to show the evolutionary relatedness among species over time. The models accurately depict a modern phylogenetic tree, along with a time scale and illustrations of various plants, animals, fungi, insects, and bacteria. Opposite Darwin's illustration, which has often led