What was the first life form on earth?
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.
843438
If the fossilized remains of life is found on Mars, it would be a big deal but still leave a lot of unanswered questions.  Did the Martian life evolve separately from that on earth, or did a single form evolve on one planet and transfer to the other?\n\nOn the other hand, if life is one day discovered on say Europa, and that life is found to be fundamentally different than terrestrial life and uses something other than DNA to carry information, that would be huge.  It would show life evolves naturally whenever conditions allow, and would basically say the universe is full of life.  Earth would once again become a little smaller, and we would doubtless get down to some serious speculation about how low we need to keep our heads, as Hawking would say.
207545
Actually, bacteria weren't the first organisms to inhabit our earth.  Simple-celled prokaryotes that pre-dated bacteria have been discovered in the oldest fossils ever recorded.  It's believed by some that life even existed before these prokaryotic cells, however fossils of these events do not exist (the oldest fossils date 3.5 billion years ago, and are of prokaryotic cells - bacterial fossils started showing up dating only 2.7-3.0 billion years ago).
119171
The first organisms to live on the earth belonged to the kingdom archaebacteria.
835853
I assume you mean life on another planet since you can see the microscopic life here on Earth with a microscope, which is pretty good proof.\n\nThere is some disputed evidence of fossilized microbes in a meteorite that originated on Mars. Nothing more than that though.
715442
Origin of the first life.
589339
The earth is 4.6 billion years old. The sun is close to 5 billion. Liquid water did not exist on earth until about 4 billion years ago. Life seems to have appeared 3.8 billion years ago. By 3.5 billion years ago, we have fossilized stromalites which are IDENTICAL to the ones still made today by prokayote blue-green algae in the Indian ocean.\n\nThe first eukaryote organisms (with cells structures like ours) first show up 1 billion years ago. Within 500 millions years from then, complex forms can be found in the fossil record which are ancestral to modern lineages. But here are NO fish, amphibians, reptiles, mammals or birds. These all arise later in sequence by evolutionary modification as the fossil record clearly shows.\n\nThe bottom line is that only evolution provides a comprehensive argument that explains what we see in the fossil record. The Intelligent Design people are frauds who misrepresent the data and are no more credible that the Gish/Morris combine of liars that plaugued us in the 70s and 80s.\n\nI (Dr. Art Sippo) am a 53 year old cradle Catholic with a BS in Chemistry (Magna cum laude)from St. Peter's College, an MD from Vanderbilt University, and a Masters in Public Health from Johns Hopkins. After Catholic apologetics, paleontology is my favorite hobby. I have been studying it since I was a kid in the 1950s.\n\nWith regard to "macroevolution" that term is actually passe. It is still touted by Creationoids so that they can say they support microevolution but not macroevolution. These terms were used around 30 years ago before the discovery of the complexity of eukaryote genetics. Microevolution was what happened when there were single alterations either in DNA sequences or protein sequences due to mutations. There were other mechanisms that worked in bacteria (eg., conjugation, plasmids) but their utility in eukaryotes was questionable. At that time it was assumed that prokaryote (eg, bacterial) genetics was directly applicable to eukaryotes (eg, mammals). We now know that this is not so.\n\nEukaryote genetics is so complicated that it has not been fully elucidated. There is modification of the transcription of DNA to messenger RNA, a further cropping of m-RNA into introns and extrons, and further modification of the proteins for which they code. None of this happens in prokaryotes.\n\nAlso eukaryotes use a "homeo box" generalized assembly kit which is functionally identical in all lineages and which can with slight tweaks make large changes in how the genotype (DNA data) is expressed into a phenotype (external structure). \n\nAlso, eukaryotes use chromosomes which rearrange themselves spontaneously in several different ways. This helps to contribute to evolution in the absence of any DNA mutations.\n\nAll of these mechanisms -- and more -- contribute to evolution. In fact everything that is necessary for what had been called "macroevolution" is present in these more complex genetic systems.\n\nWith regard to the changes in species of higher animals, many Creationoids have said that there were large systematic gaps between major taxa. They are right, In the linnean system there are large SYSTEMatic gaps, but these gaps are due to the system of classification, and do not correspond to real biological differences. Linnaeus was a Creationoid. He thought that each species was distinctly made by God. So he created a complex classification system that emphasized distinctions and did not assume common descent. In reality, his classifications were merely man-made conventions that limped badly. For example, the Class Reptilia included not only lizards but snakes (some of which bear live young and don't lay eggs), turtles, crocodiles (that all have 4 chambered hearts), dinosaurs (some of which have feathers), ichthyosaurs, mososaurs, plesiosaurs, and pterosaurs (some of which have fur). The problem with fish is even more complex.\n\nIn many cases, an organism does not fit into the Li
354028
Charles Darwin proposed that the first proteins evolved from non-living matter. But how did this happen? Firstly, the earth was not the same today as it was 3 to 4 billion years ago when the first organic compounds where being formed. The early atmosphere was too hot for oxygen (O), nitrogen (N), and other elements to exist alone, as they do today. These elements combined to form methane (CH4), ammonia (NH3), water vapor (H2O), hydrogen sulfide (formula), hydrogen molecules (H2), etc. These where all, and thus the early atmosphere was called a 'reducing atmosphere'. Further, as there was no free oxygen to form an ozone (O3) layer to protect the earth from the harsh ultra-violet radiation (UV Rays) from the sun. Also, there where incredibly violent electrical storms, which where more violent than any which occur today. \n\nIn 1924 Alexander Oparin hypothesized that organic compounds where formed in the early earth when the high energy provided by UV Rays, and storms, caused different molecules to react, and create new organic compounds, such as Amino Acids DNA, and RNA.
38211
Check out the source below, there are great animations there as well as the following information:\n\nThe origin of the Earth\nThe age of the Earth was once, and still is, a matter great debate. In 1650 Archbishop Ussher used the Bible to calculate that the Earth was created in 4004BC. Later on in the mid-nineteenth century Charles Darwin believed that the Earth must be extremely old because he recognised that natural selection and evolution required vast amounts of time. \n\nIt wasn't until the discovery of radioactivity that scientists began to put a timescale on the history of the Earth. Rocks often contain heavy radioactive elements which decay over long periods of time, the decay is unaffected by the physical and chemical conditions and different elements decay at different rates (These rates are slow and half-lifes of several hundred million years are not uncommon)\n\nThroughout this century the race has been on to discover the oldest rocks in the world. The oldest volcanic rock found so far has been dated at 3.75 billion years old, but this is not the whole story. Meteorites created at the same time as the Earth hit us all the time, radioactive dating shows that they are about 4.55 billion years old.\n\nTHE EARLY ATMOSPHERE\n\nThe present composition of the atmosphere is: 21% OXYGEN \n 78% NITROGEN \n 0.04% CARBON DIOXIDE \n ~0.9% ARGON \n\nThe atmosphere wasn't like this when the Earth was created over 4½ billion years ago.\n\nTHE FIRST BILLION YEARS\n\nThe Earth's surface was originally molten, as it cooled the volcanoes belched out massive amounts of CARBON DIOXIDE, STEAM, AMMONIA and METHANE. There was NO OXYGEN. The STEAM condensed to form water which then produced shallow seas. \n\nEvidence points to bacteria flourishing  3.8 billion years ago so this means that life got under way about 700 million years after the Earth was created. Such early forms of life existed in the shallow oceans close to thermal vents, these vents were a source of heat and minerals. \n\nTHE NEXT BILLION YEARS\n\nThese primitive life forms then took the next evolutionary step and started to PHOTOSYNTHESISE (using sunlight to convert carbon dioxide and water to food energy and oxygen). This was an important turning point in Earth history because the carbon dioxide in the atmosphere was being converted to oxygen. \n\nThese green plants went on producing oxygen (and removing the CO2).  \nMost of the carbon from the carbon dioxide in the air became locked up in sedimentary rocks as carbonates and fossil fuels. Carbon dioxide also dissolved into the oceans. \nThe ammonia and methane in the atmosphere reacted with the oxygen.  \nNitrogen gas was released, partly from the reaction between ammonia and oxygen, but mainly from living organisms such as denitrifying bacteria. (remember that nitrogen is a very unreactive gas and it has built up slowly).  \n\nTHE LAST 2½ BILLION YEARS OR SO\n\nAs soon as the oxygen was produced by photosynthesis it was taken out again by reacting with other elements (such as iron).This continued until about 2.1 billion years ago when the concentration of oxygen increased markedly. As oxygen levels built up and then . . . . . . \n\nThe ozone layer was formed which started to filter out harmful ultraviolet rays. This allowed the evolution of new living organisms in the shallow seas.
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.
51857
There is a chance that there is life not on earth, but think about the perfect conditions for life that earth has: the perfect temperatures, the correct mixture of oxygen and other gases, and of course, water. If there were life not on earth, it would probally be 1-celled organisms, and not what we would expect.
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.
1176379
any one of those answers, but heres another, "Terrestrial life forms".  sence earth was called tarre by the ancients.  any life on any other world like IO, mooon of jupiter, would be called IOnians
251225
it was a ball of burning gas that seperated from the sun billions of years ago, got trapped in the suns gravity and began revolving around it, and in time it cooled down and formed the earth, but it was still too hot for life, it cooled more and more and the atmosphere shaped from the fumes rising from it, eventually it rained and made huge oceans on earth which later became the home for the first cells that later made all different living things.
1142498
No. Most life forms did not evolve from plants. Simple single-celled life was first, microscopic organisms at one point called protists and at another point moved into its own kingdom, bacteria. The first primitive multicellular animals preceeded plants by a few million years.
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.
338860
4600 Formation of the approximately homogeneous solid Earth by planetesimal accretion  \n4300 Melting of the Earth due to radioactive and gravitational heating which leads to its differentiated interior structure as well as outgassing of molecules such as water, methane, ammonia, hydrogen, nitrogen, and carbon dioxide  \n4300 Atmospheric water is photodissociated by ultraviolet light to give oxygen atoms which are incorporated into an ozone layer and hydrogen molecules which escape into space  \n4000 Bombardment of the Earth by planetesimals stops  \n3800 The Earth's crust solidifies--formation of the oldest rocks found on Earth  \n3800 Condensation of atmospheric water into oceans  \n3500-2800 Prokaryotic cell organisms develop  \n3500-2800 Beginning of photosynthesis by blue-green algae which releases oxygen molecules into the atmosphere and steadily works to strengthen the ozone layer and change the Earth's chemically reducing atmosphere into a chemically oxidizing one  \n2400 Rise in the concentration of oxygen molecules stops the deposition of uraninites (since they are soluble when combined with oxygen) and starts the deposition of banded iron formations  \n2000 The Oklo natural fission reactor in Gabon goes into operation  \n1600 The last reserves of reduced iron are used up by the increasing atmospheric oxygen--last banded iron formations  \n1500 Eukaryotic cell organisms develop  \n1500-600 Rise of multicellular organisms  \n580-545 Fossils of Ediacaran organisms are made  \n545 Cambrian explosion of hard-bodied organisms  \n528-526 Fossilization of the Chengjiang site  \n517-515 Fossilization of the Burgess Shale  \n500-450 Rise of the fish--first vertebrates  \n430 Waxy coated algae begin to live on land  \n420 Millipedes have evolved--first land animals  \n375 The Appalachian mountains are formed via a plate tectonic collision between North America, Africa, and Europe  \n375 Appearance of primitive sharks  \n350-300 Rise of the amphibians  \n350 Primitive insects have evolved  \n350 Primitive ferns evolve--first plants with roots  \n300-200 Rise of the reptiles  \n300 Winged insects have evolved  \n280 Beetles and weevils have evolved  \n250 Permian period mass extinction  \n230 Roaches and termites have evolved  \n225 Modern ferns have evolved  \n225 Bees have evolved  \n200 Pangaea starts to break apart  \n200 Primitive crocodiles have evolved  \n200 Appearance of mammals  \n145 Archaeopteryx walks the Earth  \n136 Primitive kangaroos have evolved  \n100 Primitive cranes have evolved  \n90 Modern sharks have evolved  \n65 K-T Boundary--extinction of the dinosaurs and beginning of the reign of mammals  \n60 Rats, mice, and squirrels have evolved  \n60 Herons and storks have evolved  \n55 Rabbits and hares have evolved  \n50 Primitive monkeys have evolved  \n28 Koalas have evolved  \n20 Parrots and pigeons have evolved  \n20-12 The chimpanzee and hominid lines evolve  \n10-4 Ramapithecus exist  \n4 Development of hominid bipedalism  \n4-1 Australopithecus exist  \n3.5 The Australopithecus Lucy walks the Earth  \n2 Widespread use of stone tools  \n2-0.01 Most recent ice age  \n1.6-0.2 Homo erectus exist  \n1-0.5 Homo erectus tames fire  \n0.3 Geminga supernova explosion at a distance of roughly 60 pc--roughly as bright as the Moon \n0.2-0.03 Homo sapiens neanderthalensis exist  \n0.05-0 Homo sapiens sapiens exist  \n0.04-0.012 Homo sapiens sapiens enter Australia from southeastern Asia and North America from northeastern Asia  \n0.025-0.01 Most recent glaciation--an ice sheet covers much of the northern United States  \n0.02 Homo sapiens sapiens paint the Altamira Cave \n0.012 Homo sapiens sapiens have domesticated dogs in Kirkuk, Iraq  \n0.01 First permanent Homo sapiens sapiens settlements  \n0.01 Homo sapiens sapiens learn to use fire to cast copper and harden pottery  \n0.006 Writing is developed in Sumeria\n\n\nFor a Visual representation of all this go here:\nhttp://www.lpi.usra.edu/education/timeline/