how did life originate?
80189
The short answer is that no one knows, exactly.  That said, there are some things we do know.  Life originated on the Earth, shortly after the Earth itself formed.  Most agree that the presence of liquid water was an important factor for the creation of life.\n\nThe prevailing theory is that life spontaneously originated, from complex chains of amino acids which were common in tidal pools, over a very long period of time, during the first 500 million years of the Earth's existence. \n\nMore complex life evolved as a result of 'natural selection' again over a very long period of time (2 billion years or so).  The process continues to this day, with large numbers of organisms competing for limited resources within a very stable (some say self-regulating) environment.\n\nSome people claim that life is a consequence of the fundamental mathematical properties of the universe, and inevitable where the right conditions exist.\n\nMany people argue over the definition of 'life.'  For example, one could say that 'fire' shares many of the same qualities of 'life,' in that it grows, reproduces, breathes, eats, and eventually dies. Most would agree however that 'fire' is not 'alive.'  By the same argument, 'viruses' have been hotly debated as to whether or not they constitute life.
331335
There are three possibilities.\n\n1) There is an almighty, omniscient power (aka God) that created the entire universe.  Somehow it loves and cherishes all life, but is so petty that it performs miracles based on how much time you spent praying to it instead of on how much you really need the help.\n\n2) There is a being or group of beings (aka aliens) that did not create the universe, but tried to influence the development of life on earth by introducing religion that would worship them as God.\n\n3) When primitive humans couldn't explain why things in nature happened, they invented religion to do so.  God is an illusion.\n\nI would consider option 3 to be the most likely, with option 2 as a very remote possibility.  Option 1 is laughable.
247560
It depend if you are a religions person or believe in facts. Me, as a geologist I believe in facts and science.\nThe earth forms 4.6 billions years ago. How did we know? By using the radioactive decay method. \nNobody really knows how it form but you can get differrent references. Try historical geology books. \nEarth solidifies around 3 billion years ago, how? From the dated rocks namely Banded Iron Deposits. Life began at PreCambrain era. Meaning 512 millions years ago. Dinosaurs came to life at least 100 million years ago and died 65 miilion years ago because of  a comet hitting the earth.\nActually there are a lot more happend but for your satisfaction try to look for a Historical geology book. A very interesting book.
1169955
It's an age-old question, and one that is the very basis of religion.  It's incredible that we can understand both the creation of the universe and the creation of life itself.  We're very lucky to live in this time!\n\nGood comment for "brainless".
795743
Maybe the tree of life is rooted to the 'nutrient soil?' What I mean is that organic compounds were thought to form before any cell. They provided the nutrients for these early cells, so my best guess is that they would be your roots.
31639
There is no meaning to life. You evolved from single cell organism by accident.
898093
The basics on the origin of life:\nPhospholipids formed into micelles, or little circles.  They were arranged such that the polar head groups were facing into aqueous solution and the polar lipid tail groups were facing in toward the other polar lipid group:\nH---T  T---H into a sphere.  Inside these closed environments, it was possible for certain reactions to take place.  The reactions eventually needed to be self-replicating; that is, they needed to react to form something to pass the information for the reaction down to another micelle.  Eventually, the micelles evolved into actual cells.  Alberts "Molecular Biology of the Gene" has a great explanation of this process.\nThere so far hasn't been an experiment to create life- that process took millions of years naturally.  However, Stanley Miller did an experiment that showed that organic molecules, such as nucleic acids, amino acids, etc. could be formed from basic molecules under the conditions present in early Earth.  This experiment was incredibly reproducible- many people tried it, changing around different variables, trying to disprove it, but it kept working.  That's an incredible testament.
140896
kooolcha is right, the first forms of life on Earth were most likely bacteria.  They were probably prokaryotic cells (eukaryotes are thought to have evolved from several prokaryotes joining together, organelles are thought to be evidence of this) that lacked internal structures, including the nucleus.
499892
It all depends who you're asking. To some, life is a journey. To others it's a mystery. I'm going to give you a definition of life, that scientifically, explains it best: Now, put on your seatbelt before you read this: Life, is nothing more that the organization of the unorganized. Just think about that. If you look at the way our genome is complexed together to make us work, you'll realize that it's nothing more than an accumulation of 'organized' proteins. These proteins are synthesized in accordance with a blueprint, which happens to correspond with each one's unique genetic code. Nothing more, nothing less. Incidentally, our creators are masters at protein synthesis. They've done it for a long time and perfected it well.
1057616
No one found life on Earth as life was made on Earth, we evolvolutionised from bacteria that was by nothing but infectious static.\nAliens found life on Earth and put you on it as everything that I know that is from this planet didn't come from another world we were made from the soil.
221223
While I believe in an intelligent design, (for scientific purposes) the first cell was believed to come about through chemical evolution.  Supposedly, our world use to be a rather hostile environment, composed of very few elements.  Through some process, these elements reacted together and formed chemical compounds, specifically nucleic acids, or genetic material.  As the environment continued to change, more chemicals were formed (amino acids, etc.) and began interacting until eventually, they organized in such a fashion they formed a cellular organism, capable of reproducing itself.  From this cell, more cells were produced, leading to evolutionary changes between the cells, eventually leading to different types/kinds of cells, and ultimately different organisms.  So while cells do come from other cells, supposedly there was a "first cell".\n\nI'm not sure if this makes sense or even answers the question.........?
1084895
Origin of Life\nBacteria appeared on earth between 3.4 and 4 billion years ago. Precambrian evidence of filamentous bacteria-like structures, found making up fossilized sediments called stromalites, has been discovered in Australia and southern Africa. These fossils date back between 3.4 and 3.5 billion years old. Environmental conditions of earth 4 billion years ago were much different than those of today. It has been theorized that the atmosphere was a reducing atmosphere with intense lightning, tremendous volcanic activity, very little oxygen, intense ultraviolet radiation, and meteorite bombardment. These conditions made it impossible for any type of aerobic life to exist. The first cells may have originated by chemical evolution in an anaerobic environment.\n\nAbiotic Synthesis Theory of Life: A.I.Oparin postulated, in the 1920's, that primitive earth with its reducing atmosphere favored chemical reactions that produced simple monomers that eventually formed complex organic compounds necessary for life. Stanley Miller and Harold Urey tested this hypothesis by building an apparatus to simulate the conditions of the earth at that time.\n\n \n\n\n \n\nTheir experiments produced 20 amino acids and other organic compounds including: ATP, lipids, some sugars, and the bases of RNA and DNA. The main problem of organic synthesis is how did these molecules develop without the aid of enzymes to speed up the reactions? Sidney Fox, of the University of Miami, dripped a dilute solution of organic monomers onto hot sand, clay , and rock. The water vaporized and left behind polypeptides he called proteinoids. Clay was abundant in prebiotic earth. Clay has the ability to act as a substrate for this type of chemical reaction. The charged sites on the clay attracted monomers in such concentrations to bring them into close proximity for chemical binding. Once these organic compounds were produced, aggregates of these proteinoids self-assembled into small spheres called protobionts. These small spheres were capable of osmotic swelling and shrinking and even able to produce a membrane potential.\n\nRNA the first Genetic Material: Evidence to support the idea that RNA was the first genetic material includes: short polymers of self-replicating RNA have been abiotically produced in a test tube without enzymes. RNA has the ability to act as a catalyst to help make mRNA, tRNA or rRNA. The RNA folding is unique depending on its sequence. This along with mutations, creates a variety of closely related molecules. Through chance this self-replicating material was captured by the protobionts and the entire structure developed under the guide of natural selection.\n\nOther Origin Theories:\n\nPanspermia. Extraterrestrial organic compounds located on the surface of meteorites could well have contributed to the pool of material found on prebiotic earth. Modern meteorites have given up specimens of simple organic compounds such as amino acids.\n\nSome researchers believe that life began on the sea floor away from the harsh surface environments. The discovery of deep sea vents showed the scientific community that the materials needed for life to begin were present away from the harsh surface.\n\nJulius Rebek produced a simple organic molecule in 1991 that served as a template for self-replication. This discovery suggests that RNA was too complex to have come first and a much simpler self-replicating molecule preceded it.
624279
this is a difficult one. theres the initial 'soup' of early compounds that spawned life, theres the meteorite theory of cells from other planets gettin a start here, and theres a possible link between both. this may be that chemicals from the many rocks from outer space, the heat of the planet then, and the interaction of all the early substances may have harboured a good environment for a cell 2 form, with a membrane, enclosing some of these compounds within it.
39430
Some believe that before DNA and protein, life existed in the form of RNA, evidenced by catalytic RNA in existence today (forming part of the ribosome: a protein building cellular machine) \n\nLess philosophically, amino acids (of which there are 20 types) are put together in sequences predetermined by DNA sequences. These DNA sequences are transcribed (copied) into an intermediary molecule of RNA, which is "read" by the ribosome (which gathers the correct amino acids to build the protein)
604819
1) No animals started the evolutionary chain. Animals didn't appear for over a billion years after the first life appeared.\n\n2) The first lifeforms most definitely were not amoebae. Amoebae are very complex EUKARYOTE. The lifeforms were of prokaryotes. \n\n3) The first lifeforms that we would definitely recognise as living were Archae, primitive relatives of the bacteria.
1003505
the earliest known form of life is cyanobacteria which grew in bluish green pod like colonies approximately 3.4 billion years ago.
82794
The concept of evolution as an explanation for the origins of life is flawed. The theory of evolution explains the origins of species, but not the origins of life. A lump of premordial goo, no matter how well it could adapt to its environment, lacks DNA. The first cell must have had DNA to reproduce. Therefore, the first cell must have been created; that would not conflict with neither the Theory of Evolution nor the Bible. (Doesn't it say something like, "God created man from earth"? Anything organic is made from earth.)\n\nAnd that's why both the Bible and the Theory of Evolution are correct.