PRIMORDIAL OOZE

Like on Earth's biology, the nature of the origin of life in planet Laga is one of the most intriguing questions. Although we have not found intelligent life, there are plenty of life forms all around the planet. The planet Laga is approximately 3.8 billion years old. From the formation of the approximately homogeneous solid planet by planetesimal accretion to the solidification of the crustal surface there has been a period of time of approximately 1.1 billion years. During this time the primordial atmosphere started forming due to the outgasing of molecules from the planet's interior structure caused by gravitational heating during the melting period. The main molecular components of the atmosphere were hydrogen, carbon dioxide, carbon monoxide, nitrogen, and oxygen. Some of the oxygen reacted (3O2 + UV light---> 2O3)to form ozone, which protects the planets from the incoming UV radiation.

We have also found that the accumulation of the carbon-12 isotope over the heavier carbon-13 isotope, which is a sign of biological assimilation, agrees with the estimated age of the planet. These finding made us conclude that the young Laga, still in the throes of volcanic eruptions and battered by falling comets and asteroids, remained inhospitable to life for about half a billion years after its birth. Like on Earth, the chemical evolution leading to cellular life likely passed through a stage where RNA alone performed all of the functions of the modern macromolecules RNA, DNA, and proteins. However, the RNA alone is too complex to evolve directly from organic molecules found on the prebiotic planet. More likely, the RNA emerged from and was supported by a primitive sort of metabolism fueled by the bonds in sulfur-containing compounds called thioesters. These organic compounds are the clue for the protometabolism that predate the modern metabolism observed in multicellular organisms. A thioester forms when a thiol or mercaptan (sulfur compounds analog to alcohols that givethe unpleasant odors to garlic, domestic natural gas and skunks), whose general form is written as an organic compound group, R, bonded with sulfur and hydrogen resulting in R-SH, joins with a carboxylic acid (R'-COOH). A molecule of water (H2O) is released in the process, and what remains is a thioester: R-S-CO-R'. Thioester are the equivalent to sulfur inorganic salts. These type of sulfur compounds are the most likely to arise readily in the kind of volcanic setting, rich in hydrogen sulfide (H2S), likely to have been found on the prebiotic Laga. The thioester bond is a high-energy bond, equivalent to the phosphate bonds in adenosine triphosphate (ATP), which is the main supplier of energy in all living things.

Thioesters are involved in the synthesis of all esters, including those found in complex lipids, peptides, fatty acids, sterols, terpenes, and others. Thioesters could have played the role of ATP, and helped in the formation of bonds between phosphate groups. Nowadays, we find thioesters in a number of bacterial peptides made of several amino acids. In other words, thioesters could have provided the energetic and catalytic framework of the set of primitive chemical reactions that led from the first building block of life (amino acid), then to the first RNA molecule,

and subsequently sustained the RNA molecules until metabolism took over. These thioesters could have developed in a very acidic medium and even in an aqueous medium.

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PRIMORDIAL PROKARYOTES

The actions of the thioesters gave way to the production of the first amino acids, which in time produced the first self-replicating RNA. These nucleotides were capable of producing the first life forms to arise on Laga. These primitive life forms were a rudimentary single celled organism that we named "ß-Prima". These organisms developed in the pockets formed close to the volcanic vents at the bottom of the ocean. Inside these pockets temperature and acidity conditions were adequate for the development of "ß-Prima". The first replication of RNA should have produced a very simple form of ribosomal RNA (rRNA) that led to the formation of the primitive ribosome, in which future proteins would be assembled. The transcriptions were made possible by the action of the first formed RNA polymerize, which is involved in assembling the transcripts. The end result, after hundreds of million of years, were the "ß-Prima" cells. These anaerobic cells contain a very primitive cytoplasm, a cell membrane, no nucleus, and a very primitive form of plastid with a very low content of starch known as "chloroplastids", which later on will give way to modern chloroplasts..

The action of these plastids allowed oxygen to be produced in a proto-photosynthesis reaction. After a period of several hundred years, the ocean temperature began to stabilize, and the process of sedimentation of minerals began to occur, changing the environment surrounding the areas where these prokaryotes began to develop. Gradually, life began to evolve at the bottom of the oceans, making the new forms move toward the surface.

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COMPLEX ORGANISMS

The early multicellular life in Laga began to develop along with the environmental changes that the cooling of the planet produced. Probably, the first primordial cell did not have any mobility mechanism, such as cillia or flagella. The movement for these organisms was provided by the ocean currents, and when they arrived at the surface, the wind was the main source of transportation for these living things. The migration of these organisms must have been possible after the formation of the first plasma membranes in the cellular structures, and the development of nuclei and mitochondrial structures. From the primordial §-Prima cell we have identified three organisms that could, by means of adaptation, give origin to the life on the planet Laga.

First full photosynthetic, autotroph forms of plant cells. Probably descendant from the rhodophyta (red algae) type cell. It has a well organized arrays of chloroplasts with membrane stacks. Chlorophyll is the dominant pigment. It has been found in some variations containing phycobilin pigment, which traps blue-green light, combined with chlorophyll.

Protistan-like cell abundant in the waters of Laga. It seems that they have lost some of their photosynthetic abilities because their reproduction is slower than the euglenids found in the waters of Earth. Like most flagellated protista, these cells reproduce by longitudinal fission.

Chemosynthetic bacteria, they are strict anaerobes that make ATP (storage of energy) by converting carbon dioxide and hydrogen gases to methane, which helped to globally recycle carbon. These cells were the first descendants from ß-Prima cell due to their ability to reproduce in very acidic environments. Back to Complex Mechanisms

Multicelled forms of life, such as invertebrates and vertebrates, have developed through time. All these species have appeared through genetic modification and adaptation to the changing environment on Laga.

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