Panspermia previously thought to be inhospitable for life. Living bacteria found in ice core samples retrieved from deep at Lake Vostok in Antarctica, have provided data for extrapolations to the likelihood of microorganisms surviving frozen in extraterrestrial habitats or during interplanetary transport. Also, bacteria have been discovered living within warm rock deep in the Earth's crust. In order to test some these organisms' potential resilience in outer space, plant seeds and spores of bacteria, fungi and ferns have been exposed to the harsh space environment. Spores are produced as part of the normal life cycle of many plants, algae, fungi and
Red algae Science Foundation as part of the Assembling the Tree of Life Program. Some sources (such as Lee) place all red algae into the class "Rhodophyceae". (Lee's organization is not a comprehensive classification, but a selection of orders considered common or important.) A subphylum - Proteorhodophytina - has been proposed to encompass the existing classes Compsopogonophyceae, Porphyridiophyceae, Rhodellophyceae and Stylonematophyceae. This proposal was made on the basis of the analysis of the plastid genomes. Over 7,000 species are currently described for the red algae, but the taxonomy is in constant flux with new species described each year. The vast majority of