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
Algae their relationship with algae conjectured early. In other cases, some groups were originally characterized as parasitic algae (e.g., "Chlorochytrium"), but later were seen as endophytic algae. Some filamentous bacteria (e.g., "Beggiatoa") were originally seen as algae. Furthermore, groups like the apicomplexans are also parasites derived from ancestors that possessed plastids, but are not included in any group traditionally seen as algae. The first land plants probably evolved from shallow freshwater charophyte algae much like "Chara" almost 500 million years ago. These probably had an isomorphic alternation of generations and were probably filamentous. Fossils of isolated land plant spores suggest land