The collodion process is one of the earliest photographic process, invented by Frederick Scott Archer that replaced the glass photographic plates. These plates were able to record microscopically fine details that could be used for specified purposes and these plates lived for a long time till the discovery of the gelatin dry plate. These were later used in the printing industry and for other larger work that was cheaper than gelatin films.
The universal tree of life depicts the planned evolutionary relationships in all the cellular life forms, that has been categorized under three primary heads or urkingdoms. These are the Archaea (archaebacteria), Bacteria (eubacteria) and Eucarya (eukaryotes) (Forterre & Philippe, 1999). This universal tree of life has raised a number of vital questions on life. However, the whole genome deoxyribonucleic acid (DNA) sequences from the species of the three domains had given rich data to reconstruct the universal tree. The presently accepted Universal tree of life is supported by the molecular phylogenies. Particularly, the early genome evolution has assisted in shaping the extensive occurrence of the horizontal or lateral gene transfer between the species from variety of domains that are remotely related. In the 1970s it was Carl Woese who proposed the variety in the sequencing of the DNA encoded ribosomal RNA in organisms that would provide vital information regarding the evolutionary process of life (Forterre & Philippe, 1999).
Stromatolites are bio-chemical accretionary structures which are layered and are formed in shallow water when sedimentary grains by biofilms of microorganisms, such as cyanobacteriaare trapped or bound or cemented (Sanderson, 2008). These structures give the oldest records of life on Earth through fossil remains that exist for almost 3.5 billion years ago.
Scientific institutes such as California Institute of Technology and Jet Propulsion Laboratory (JPL) have given proof that some of the extremely old stromatolites on earth were made by the help of those ancient microorganisms that are also extinct and this research helped to understand the earliest record of life in our planet (Sanderson, 2008). Geologists state that most of the young stromatolites that are present now are of biological origin and are nearly billion years old. These stromatolites are formed with the layer of microbes that generally grows in thin film on seafloor.
The Great Oxygenation Event is also known as the Oxygen Crisis or the Oxygen Catastrophe or the Oxygen Revolution (Kerr, 2009). This was the period when DiOxygen was introduced in the Earth’s atmosphere. The evidence based on the chemical, geological and isotopic analysis state that a huge environmental change took place 2.3 billion years ago.
Cyanobacteria, an organism that appeared two hundred years ago before the GOE had begun producing free Oxygen by the process of Photosynthesis. Before the GOE, free Oxygen was produced chemically through dissolved iron. When these Oxygen sinks became saturated and was not able to capture all the Oxygen the Great Oxygenation Event occurred and after this event the free Oxygen accumulated in the atmosphere (Kerr, 2009). This free Oxygen was toxic for the anaerobic organisms and when the concentration of Oxygen increased in the atmosphere and lead to the extinction of the anaerobic organisms. Moreover, this free Oxygen reacted with other gases such as methane, which reduced its concentration and led to the Huronian glaciations.
Saturn’s largest moon is called Titan and in the entire solar system it is the second largest moon. It is the only moon that is surrounded with clouds and exhibits a thick atmosphere similar to planets (Perrot & Giordani, 1998). The moon is surrounded by an orange haze which makes the mystery surrounding the satellite more dense. The mystery was solved by the Cassini/Huygens mission.
The atmosphere of this satellite is complicated but active and is primarily made up of nitrogen (95 percent) and methane (5 percent). Scientists claim that these conditions are same as that of Earth during the early years of the planet. The only difference being that being closer to sun earth was comparatively warm (Mitchell, 2008).
During the missions of the Cassini it came up with the basic data of the structure and organic chemistry of the atmosphere. Cassini also discovered enough materials that have compelled the scientists to suspect the presence of ocean in the planet that may be composed of water and ammonia.
Forterre, P., & Philippe, H. (1999). Where is the root of the universal tree of life?. Bioessays, 21(10), 871-879. doi:10.1002/(sici)1521-1878(199910)21:10<871::aid-bies10>3.0.co;2-q
Kerr, R. (2009). GEOCHEMISTRY: Great Oxidation Event Dethroned?. Science, 324(5925), 321a-321a. doi:10.1126/science.324.5925.321a
Mitchell, R. (2008). The Cassini Mission exploring Saturn. Acta Astronautica, 63(1-4), 61-67. doi:10.1016/j.actaastro.2007.12.064
Perrot, B., & Giordani, R. (1998). Cassini Huygens mission : the exploration of the Saturn system. Radio science experiments : Radio Frequency Instrument Subsystem. Planetary And Space Science, 46(9-10), 1333-1338. doi:10.1016/s0032-0633(97)00212-2
Sanderson, K. (2008). Shining a light on ancient stromatolites. Nature. doi:10.1038/news.2008.529