How Life Originated In SpaceApril 12, 2002Life originated on the Earth more than 3.5 billion years ago. However, the scientists are still disputing over the possible sources of the life origin. The matter is that life on our planet evolved from the molecular level to the level of bacteria organisms within 0.5 - 1 billion years, this period being very short for such an important evolutionary step. The researchers are still racking the brains over this mystery. One of the popular hypothesis asserts that some germs of life have been brought to the Earth from space. But what exactly could have been brought from space and how could the germs have originated in space? E.A. Kuzicheva and N.B.Gontareva, research assistants from the Institute of Cytology, Russian Academy of Sciences, have confirmed a possibility of abiogenous synthesis of complex organic compounds (monomeric units of nucleic acids) on the surface of comets, asteroids, meteorites and space dust particles in the outer space. Therefore, it is possible that the above monomeric units of nucleic acids could have got to the Earth and thus could have significantly reduced the time period of the evolution process. On the surface of space bodies the scientists have found all kinds of various organic molecules (amino acids, organic acids, sugars etc.) and the components required for their synthesis. Obviously, it is there that organic substances are being synthesised, but the researchers can not be sure of this fact, until the experiments confirm their assumptions. The scientists from St. Petersburg reproduced synthesis of one of the DNA components - 5`-adenosine monophosphate (5`-AMP) under the conditions specially designed to simulate the space environment. In order to synthesise 5`-AMP it is required to combine adenosine and inorganic phosphate. On the Earth the reaction goes in the solution, but there are no solvents whatsoever in space, therefore the researchers dried them in the air and got a pellicle. Synthesis requires energy. The major source of energy in the outer space both at present and in the prebiotic period of the Earth history has been the solar ultraviolet radiation of different wavelengths. Therefore, the pellicles were irradiated by a powerful ultraviolet lamp. Naturally, the synthesis was carried out in vacuum, and the researchers used the lunar soil, delivered to the Earth by the `Moon-16` station from the Sea of Abundance, as a model of the comet, meteorite, interplanetary or cosmic dust. The soil represented basaltic dust of the dark-grey colour, the diameter of its particles being less than 0.2 millimetres. After 7-9 hours of ultraviolet irradiation of the dry pellicles the scientists acquired several compounds, mainly 5`-AMP, one of the DNA/RNA monomers. The energy of radiation does not promote synthesis alone, it also facilitates decomposition of the initial and newly-synthesised compounds, the more powerful the radiation is, the more extensively the decomposition goes. However, the lunar soil provided some protection. It has appeared that a small pinch of the lunar soil protects organic substances from the destructive ultraviolet impact - the lunar soil helps to increase the 5`-AMP yield by 2.7 times. The researchers have made a conclusion that the organic compounds synthesis could have happened in the outer space environment. The synthesis could have taken place on the surface of space bodies at the initial phases of the solar system formation, along with that the chemical evolution (formation and selection of complex molecules) could have started in space. By the time the Earth was formed the chemical evolution might have approached the phase to be followed by the biological evolution. That implies that life on the Earth most probably did not start from the elementary organic molecules synthesis, but commenced from the polymers formation phase or from a further stage. Hopefully, the above assumptions will help the scientists to deeper penetrate into the mystery of the accelerated development of life on the Earth when the latter was quite a `young` planet. Informnauka (Informscience) Agency |
|||||||||||||||||||||
| Related Evolution Current Events and Evolution News Articles We're off then: the evolution of bat migration Not just birds, but also a few species of bats face a long journey every year. Researchers at Princeton University in the U.S. and at the Max Planck Institute for Ornithology in Radolfzell, Germany studied the migratory behaviour of the largest extant family of bats, the so-called "Vespertilionidae" with the help of mathematical models. Insect Resistance to Bt Crops can be Predicted, Monitored, and Managed Since 1996, crop plants genetically modified to produce bacterial proteins that are toxic to certain insects, yet safe for people, have been planted on more than 200 million hectares worldwide. Multiple health concerns surface as winter, vitamin D deficiences arrive A string of recent discoveries about the multiple health benefits of vitamin D has renewed interest in this multi-purpose nutrient, increased awareness of the huge numbers of people who are deficient in it, spurred research and even led to an appreciation of it as "nature's antibiotic." Supervolcano eruption -- in Sumatra -- deforested India 73,000 years ago A new study provides "incontrovertible evidence" that the volcanic super-eruption of Toba on the island of Sumatra about 73,000 years ago deforested much of central India, some 3,000 miles from the epicenter, researchers report. Is global warming unstoppable? In a provocative new study, a University of Utah scientist argues that rising carbon dioxide emissions - the major cause of global warming - cannot be stabilized unless the world's economy collapses or society builds the equivalent of one new nuclear power plant each day. Scientists at UA, collaborating institutions decode maize genome Scientists from the University of Arizona led by Arizona Genomics Institute director Rod A. Wing and from collaborating institutions have deciphered the complete genetic code of the maize plant for the first time. New Maize Map to Aid Plant Breeding Efforts In a massive survey of genetic diversity in maize, also known as corn, researchers across the United States, have developed a gene map that should pave the way to significant improvements in a plant that is a major source of food, fuel, animal feed and fiber around the world. 'Hobbits' are a new human species -- according to the statistical analysis of fossils Researchers from Stony Brook University Medical Center in New York have confirmed that Homo floresiensis is a genuine ancient human species and not a descendant of healthy humans dwarfed by disease. Research challenges for understanding landscape changes identified Nine research challenges and four research initiatives that are poised to advance the study of how Earth's landscapes change were unveiled today in a new report by the National Research Council. Scientists Unravel Evolution of Highly Toxic Box Jellyfish With thousands of stinging cells that can emit deadly venom from tentacles that can reach ten feet in length, the 50 or so species of box jellyfish have long been of interest to scientists and to the public. Yet little has been known about the evolution of this early branch in the animal tree of life. More Evolution Current Events and Evolution News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||