Geological time put in a diagram called a geological clock, showing the relative lengths of the eons of the Earth's history.

The history of Earth covers approximately 4.6 billion years (4,567,000,000 years), from Earth’s formation out of the solar nebula to the present. Modern geologists and Geophysicists consider the age of Earth to be around 4 EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 The formation and evolution of the Solar System is estimated to have begun This article presents a broad overview, summarizing the leading, most current scientific theories.

Origin

An artist's impression of protoplanetary disk. A protoplanetary disk (or proplyd) is a rotating Circumstellar disk of dense gas surrounding a young newly formed star a T Tauri star or Herbig star

Main article: Formation and evolution of the Solar System

The Earth formed as part of the birth of the Solar System: what eventually became the solar system initially existed as a large, rotating cloud of dust, rocks, and gas. The formation and evolution of the Solar System is estimated to have begun The Solar System consists of the Sun and those celestial objects bound to it by Gravity. Dust is a general name for minute Solid particles with Diameters less than 500 micrometers. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere This page is about the physical properties of gas as a state of matter It was composed of hydrogen and helium produced in the Big Bang, as well as heavier elements ejected by supernovas. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. A supernova (plural supernovae or supernovas) is a stellar Explosion. Then, as one theory suggests, about 4. 6 billion years ago a nearby star was destroyed in a supernova and the explosion sent a shock wave through the solar nebula, causing it to gain angular momentum. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth A supernova (plural supernovae or supernovas) is a stellar Explosion. For the music album by Converter see Shock Front For the 1977 horror film see Shock Waves A shock wave (also called The formation and evolution of the Solar System is estimated to have begun In Physics, the angular momentum of a particle about an origin is a vector quantity equal to the mass of the particle multiplied by the Cross product of the position As the cloud began to accelerate its rotation, gravity and inertia flattened it into a protoplanetary disk oriented perpendicularly to its axis of rotation. A rotation is a movement of an object in a circular motion A two- Dimensional object rotates around a center (or point) of rotation Gravitation is a natural Phenomenon by which objects with Mass attract one another The vis insita or innate force of matter is a power of resisting by which every body as much as in it lies endeavors to preserve in its present state whether it be of rest or of moving A protoplanetary disk (or proplyd) is a rotating Circumstellar disk of dense gas surrounding a young newly formed star a T Tauri star or Herbig star Most of the mass concentrated in the middle and began to heat up, but small perturbations due to collisions and the angular momentum of other large debris created the means by which protoplanets began to form. Protoplanets are moon-sized planets or larger embryos within Protoplanetary discs They are believed to form out of kilometer-sized Planetesimals that attract each The infall of material, increase in rotational speed and the crush of gravity created an enormous amount of kinetic heat at the center. The kinetic energy of an object is the extra Energy which it possesses due to its motion Its inability to transfer that energy away through any other process at a rate capable of relieving the build-up resulted in the disk's center heating up. Ultimately, nuclear fusion of hydrogen into helium began, and eventually, after contraction, a T Tauri star, ignited to create the Sun. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical T Tauri stars ( TTS) are a class of variable Stars named after their prototype – T Tauri. The Sun (Sol is the Star at the center of the Solar System. Meanwhile, as gravity caused matter to condense around the previously perturbed objects outside of the new sun's gravity grasp, dust particles and the rest of the protoplanetary disk began separating into rings. Matter is commonly defined as being anything that has mass and that takes up space. A protoplanetary disk (or proplyd) is a rotating Circumstellar disk of dense gas surrounding a young newly formed star a T Tauri star or Herbig star Successively larger fragments collided with one another and became larger objects, ultimately destined to become protoplanets. ^[1] These included one collection approximately 150 million kilometers from the center: Earth. The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand The solar wind of the newly formed T Tauri star cleared out most of the material in the disk that had not already condensed into larger bodies. The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun.

Moon

Animation (not to scale) of Theia forming in Earth’s L₅ point and then, perturbed by gravity, colliding to help form the moon. Theia is the Hypothetical planet that according to the Giant impact hypothesis of the Moon 's formation collided with Earth over four billion The animation progresses in one-year steps making Earth appear not to move. The view is of the south pole.

Main articles: Origin and geologic evolution and Giant impact hypothesis

The origin of the Moon is still uncertain, although much evidence exists for the giant impact hypothesis. Earth may not have been the only planet forming 150 million kilometers from the Sun. It is hypothesized that another collection occurred 150 million kilometers from both the Sun and the Earth, at their fourth or fifth Lagrangian point. This planet, named Theia, is thought to have been smaller than the current Earth, probably about the size and mass of Mars. Theia is the Hypothetical planet that according to the Giant impact hypothesis of the Moon 's formation collided with Earth over four billion Its orbit may at first have been stable, but destabilized as Earth increased its mass by the accretion of more and more material. Theia swung back and forth relative to Earth until, finally, an estimated 4. 533 billion years ago,^[2] it collided at a low, oblique angle. The low speed and angle were not enough to destroy Earth, but a large portion of its crust was ejected into space. Heavier elements from Theia sank to Earth’s core, while the remaining material and ejecta condensed into a single body within a couple of weeks. Under the influence of its own gravity, this became a more spherical body: the Moon. ^[3] The impact is also thought to have changed Earth’s axis to produce the large 23. 5° axial tilt that is responsible for Earth’s seasons. In Astronomy, axial tilt is the Inclination angle of a planet's rotational axis in relation to its orbital plane. (A simple, ideal model of the planets’ origins would have axial tilts of 0° with no recognizable seasons. ) It may also have sped up Earth’s rotation and initiated the planet’s plate tectonics. Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere

The Hadean eon

Main article: Hadean

Volcanic eruptions would have been common in Earth's early days. The Hadean (ˈheɪdiən is the geologic eon before the Archean.

The early Earth, during the very early Hadean eon, was very different from the world known today. The Hadean (ˈheɪdiən is the geologic eon before the Archean. There were no oceans and no oxygen in the atmosphere. It was bombarded by planetoids and other material left over from the formation of the solar system. This bombardment, combined with heat from radioactive breakdown, residual heat, and heat from the pressure of contraction, caused the planet at this stage to be fully molten. During the iron catastrophe heavier elements sank to the center while lighter ones rose to the surface producing the layered structure of the Earth and also setting up the formation of Earth's magnetic field. The iron catastrophe was a crucial event early in the History of Earth with respect to the future of life on our planet The interior of Earth, similar to the other Terrestrial planets, is Chemically divided into layers Earth 's magnetic field (and the surface magnetic field) is approximately a Magnetic dipole, with one pole near the North pole (see Earth's early atmosphere would have comprised surrounding material from the solar nebula, especially light gases such as hydrogen and helium, but the solar wind and Earth's own heat would have driven off this atmosphere. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun.

This changed when Earth was about 40% its present radius, and gravitational attraction allowed the retention of an atmosphere which included water. Temperatures plummeted and the crust of the planet was accumulated on a solid surface, with areas melted by large impacts on the scale of decades to hundreds of years between impacts. Large impacts would have caused localized melting and partial differentiation, with some lighter elements on the surface or released to the moist atmosphere. ^[4]

The surface cooled quickly, forming the solid crust within 150 million years;^[5] although new research^[6] suggests that the actual number is 100 million years based on the level of hafnium found in the geology at Jack Hills in Western Australia. In Geology, a crust is the outermost solid shell of a planet or moon Hafnium (ˈhæfniəm is a Chemical element that has the symbol Hf and Atomic number 72 The Jack Hills are located in the Narryer Gneiss Terrane of the Yilgarn Craton, Western Australia, and comprise an 80 km long northeast-trending belt of From 4 to 3. 8 billion years ago, Earth underwent a period of heavy asteroidal bombardment. The Late Heavy Bombardment (commonly referred to as the lunar cataclysm, or LHB) is a period of time approximately 3800 to 4100 million years ago ( mya ^[7] Steam escaped from the crust while more gases were released by volcanoes, completing the second atmosphere. Outgassing (sometimes called offgassing, particularly when in reference to indoor Air quality is the slow release of a Gas that was trapped Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Additional water was imported by bolide collisions, probably from asteroids ejected from the outer asteroid belt under the influence of Jupiter's gravity. The planet cooled. Clouds formed. Rain gave rise to the oceans within 750 million years (3. The question of the origin of water on Earth, or more accurately put the question of why there is clearly more Water on the Earth than on the other planets of the Solar 8 billion years ago), but probably earlier. Recent evidence suggests the oceans may have begun forming by 4. The question of the origin of water on Earth, or more accurately put the question of why there is clearly more Water on the Earth than on the other planets of the Solar 2 billion years ago^[8]. ^[9] The new atmosphere probably contained ammonia, methane, water vapor, carbon dioxide, and nitrogen, as well as smaller amounts of other gases. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. General properties of water vapor Evaporation/sublimation Whenever a water molecule leaves a surface it is said to have evaporated Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Any free oxygen would have been bound by hydrogen or minerals on the surface. Volcanic activity was intense and, without an ozone layer to hinder its entry, ultraviolet radiation flooded the surface. Plate tectonics and hotspots Divergent plate boundaries At the The photochemical mechanisms that give rise to the ozone layer were worked out by the British physicist Sidney Chapman in 1930 Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays

Life

The replicator in virtually all known life is deoxyribonucleic acid. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known DNA is far more complex than the original replicator and its replication systems are highly elaborate.

Main article: Origin of life

The details of the origin of life are unknown, though the broad principles have been established. In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic Two schools of thought regarding the origin of life have been proposed. The first suggests that organic components may have arrived on Earth from space (see “Panspermia”), while the other argues for terrestrial origins. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Panspermia ( Gk. πάς/πάν (pas/pan all and σπέρμα ( sperma, seed is the Hypothesis that "seeds" of Life exist already The mechanisms by which life would initially arise are nevertheless held to be similar. ^[10] If life arose on Earth, the timing of this event is highly speculative—perhaps it arose around 4 billion years ago. ^[11] In the energetic chemistry of early Earth, a molecule (or even something else) gained the ability to make copies of itself–the replicator. The nature of this molecule is unknown, its function having long since been superseded by life’s current replicator, DNA. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known In making copies of itself, the replicator did not always perform accurately: some copies contained an “error. ” If the change destroyed the copying ability of the molecule, there could be no more copies, and the line would “die out. ” On the other hand, a few rare changes might make the molecule replicate faster or better: those “strains” would become more numerous and “successful. ” As choice raw materials (“food”) became depleted, strains which could exploit different materials, or perhaps halt the progress of other strains and steal their resources, became more numerous. ^[12]

Several different models have been proposed explaining how a replicator might have developed. Different replicators have been posited, including organic chemicals such as modern proteins, nucleic acids, phospholipids, crystals,^[13] or even quantum systems. Phospholipids are a class of Lipids and are a major component of all Biological membranes All phospholipids contain a Diglyceride, a Phosphate In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating ^[14] There is currently no method of determining which of these models, if any, closely fits the origin of life on Earth. One of the older theories, and one which has been worked out in some detail, will serve as an example of how this might occur. The high energy from volcanoes, lightning, and ultraviolet radiation could help drive chemical reactions producing more complex molecules from simple compounds such as methane and ammonia. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor ^[15] Among these were many of the relatively simple organic compounds that are the building blocks of life. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation As the amount of this “organic soup” increased, different molecules reacted with one another. Sometimes more complex molecules would result—perhaps clay provided a framework to collect and concentrate organic material. Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and ^[16] The presence of certain molecules could speed up a chemical reaction. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst All this continued for a very long time, with reactions occurring more or less at random, until by chance there arose a new molecule: the replicator. This had the bizarre property of promoting the chemical reactions which produced a copy of itself, and evolution began properly. eVolution is the third Album by eLDee, it was due to be released in 2008 Other theories posit a different replicator. In any case, DNA took over the function of the replicator at some point; all known life (with the exception of some viruses and prions) use DNA as their replicator, in an almost identical manner (see genetic code). A prion (ˈpriːɒn is thought to be an infectious agent that according to current scientific consensus is comprised entirely of a propagated, mis-folded The genetic code is the set of rules by which information encoded in genetic material ( DNA or RNA sequences is translated into Proteins

Cells

A small section of a cell membrane. This modern cell membrane is far more sophisticated than the original simple phospholipid bilayer (the small blue spheres with two tails). Proteins and carbohydrates serve various functions in regulating the passage of material through the membrane and in reacting to the environment. Carbohydrates (from ' Hydrates of Carbon ' or saccharides ( Greek σάκχαρον meaning " Sugar " are the most

Modern life has its replicating material packaged neatly inside a cellular membrane. The cell membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer" is a Selectively permeable Lipid bilayer It is easier to understand the origin of the cell membrane than the origin of the replicator, since the phospholipid molecules that make up a cell membrane will often form a bilayer spontaneously when placed in water. Phospholipids are a class of Lipids and are a major component of all Biological membranes All phospholipids contain a Diglyceride, a Phosphate A bilayer is a double layer of closely packed atoms or molecules See also Monolayer Lipid bilayer Under certain conditions, many such spheres can be formed (see “The bubble theory”). In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic ^[17] It is not known whether this process preceded or succeeded the origin of the replicator (or perhaps it was the replicator). The prevailing theory is that the replicator, perhaps RNA by this point (the RNA world hypothesis), along with its replicating apparatus and maybe other biomolecules, had already evolved. Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units The RNA world hypothesis proposes that a world filled with life based on Ribonucleic acid (RNA predated current life based on Deoxyribonucleic acid (DNA Initial protocells may have simply burst when they grew too large; the scattered contents may then have recolonized other “bubbles. In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic ” Proteins that stabilized the membrane, or that later assisted in an orderly division, would have promoted the proliferation of those cell lines. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl RNA is a likely candidate for an early replicator since it can both store genetic information and catalyze reactions. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst At some point DNA took over the genetic storage role from RNA, and proteins known as enzymes took over the catalysis role, leaving RNA to transfer information and modulate the process. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins There is increasing belief that these early cells may have evolved in association with underwater volcanic vents known as “black smokers”. A black smoker or sea vent is a type of Hydrothermal vent found on the Ocean floor. ^[18] or even hot, deep rocks. ^[19] However, it is believed that out of this multiplicity of cells, or protocells, only one survived. Current evidence suggests that the last universal common ancestor lived during the early Archean eon, perhaps roughly 3. The last universal ancestor ( LUA) also called the last universal common ancestor ( LUCA) the cenancestor or "number one" 5 billion years ago or earlier. ^[20],[21] This “LUCA” cell is the ancestor of all cells and hence all life on Earth. It was probably a prokaryote, possessing a cell membrane and probably ribosomes, but lacking a nucleus or membrane-bound organelles such as mitochondria or chloroplasts. The prokaryotes (proʊˈkærioʊts singular prokaryote /proʊˈkæriət/ are a group of Organisms that lack a Cell nucleus (= karyon or any other Ribosomes ( from ribo nucleic acid and "Greek soma ( meaning body") are complexes of RNA and Protein that In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed In Cell biology, an organelle (pronunciation /ɔː(rgəˡnɛl/ is a specialized subunit within a cell that has a specific function and is usually separately enclosed In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. Chloroplasts are Organelles found in Plant cells and eukaryotic Algae that conduct Photosynthesis. Like all modern cells, it used DNA as its genetic code, RNA for information transfer and protein synthesis, and enzymes to catalyze reactions. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Some scientists believe that instead of a single organism being the last universal common ancestor, there were populations of organisms exchanging genes in lateral gene transfer. ^[20]

Photosynthesis and oxygen

The harnessing of the sun’s energy led to several major changes in life on Earth. The Sun (Sol is the Star at the center of the Solar System.

It is likely that the initial cells were all heterotrophs, using surrounding organic molecules (including those from other cells) as raw material and an energy source. A heterotrophs, or chemoorganotrophy ( Greek heterone = (another and trophe = nutrition is an Organism that requires ^[22] As the food supply diminished, a new strategy evolved in some cells. Instead of relying on the diminishing amounts of free-existing organic molecules, these cells adopted sunlight as an energy source. Sunlight, in the broad sense is the total spectrum of the Electromagnetic radiation given off by the Sun. Estimates vary, but by about 3 billion years ago^[23], something similar to modern photosynthesis had probably developed. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. This made the sun’s energy available not only to autotrophs but also to the heterotrophs that consumed them. An autotroph (from the Greek autos = self and trophe = nutrition is an Organism that produces complex Organic compounds from simple Photosynthesis used the plentiful carbon dioxide and water as raw materials and, with the energy of sunlight, produced energy-rich organic molecules (carbohydrates). Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Water is a common Chemical substance that is essential for the survival of all known forms of Life. Carbohydrates (from ' Hydrates of Carbon ' or saccharides ( Greek σάκχαρον meaning " Sugar " are the most

Moreover, oxygen was produced as a waste product of photosynthesis. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the At first it became bound up with limestone, iron, and other minerals. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 There is substantial proof of this in iron-oxide rich layers in geological strata that correspond with this time period. The oceans would have turned to a green color while oxygen was reacting with minerals. When the reactions stopped, oxygen could finally enter the atmosphere. Though each cell only produced a minute amount of oxygen, the combined metabolism of many cells over a vast period of time transformed Earth’s atmosphere to its current state. ^[24] Among the oldest examples of oxygen-producing lifeforms are fossil Stromatolites. Stromatolites (from Greek στρώμα strōma, mattress bed stratum and λιθος lithos, rock are layered accretionary Structures formed in

This, then, is Earth’s third atmosphere. Some of the oxygen was stimulated by incoming ultraviolet radiation to form ozone, which collected in a layer near the upper part of the atmosphere. OZONE is an object oriented Operating system written in the C programming language. The ozone layer absorbed, and still absorbs, a significant amount of the ultraviolet radiation that once had passed through the atmosphere. It allowed cells to colonize the surface of the ocean and ultimately the land:^[25] without the ozone layer, ultraviolet radiation bombarding the surface would have caused unsustainable levels of mutation in exposed cells. In biology mutations are changes to the Nucleotide sequence of the Genetic material of an organism Besides making large amounts of energy available to life-forms and blocking ultraviolet radiation, the effects of photosynthesis had a third, major, and world-changing impact. Oxygen was toxic; probably much life on Earth died out as its levels rose (the “Oxygen Catastrophe”). The Oxygen Catastrophe was a massive environmental change believed to have happened during the Siderian period at the beginning of the Paleoproterozoic ^[25] Resistant forms survived and thrived, and some developed the ability to use oxygen to enhance their metabolism and derive more energy from the same food.

Endosymbiosis and the three domains of life

Main article: Endosymbiotic theory

Some of the pathways by which the various endosymbionts might have arisen. The endosymbiotic theory concerns the origins of mitochondria and Plastids (e An endosymbiont is any Organism that lives within the body or cells of another organism i

Modern taxonomy classifies life into three domains. Taxonomy is the practice and science of classification The word comes from the Greek, taxis (meaning 'order' 'arrangement' and, nomos The three-domain system is a Biological classification introduced by Carl Woese in 1990 that divides cellular life forms into Archaea, The time of the origin of these domains are speculative. The Bacteria domain probably first split off from the other forms of life (sometimes called Neomura), but this supposition is controversial. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Neomura is a speculative Clade composed of the two domains of life of Archaea and Eukarya. Soon after this, by 2 billion years ago,^[26] the Neomura split into the Archaea and the Eukarya. Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex Eukaryotic cells (Eukarya) are larger and more complex than prokaryotic cells (Bacteria and Archaea), and the origin of that complexity is only now coming to light. Around this time period a bacterial cell related to today’s Rickettsia^[27] entered a larger prokaryotic cell. The proto-mitochondrion is the ancestral bacterial Endosymbiont from which all Mitochondria are thought to be derived Rickettsia is a Genus of motile, Gram-negative, non-sporeforming, highly Pleomorphic bacteria that can present Perhaps the large cell attempted to ingest the smaller one but failed (maybe due to the evolution of prey defenses). Perhaps the smaller cell attempted to parasitize the larger one. In any case, the smaller cell survived inside the larger cell. Using oxygen, it was able to metabolize the larger cell’s waste products and derive more energy. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Some of this surplus energy was returned to the host. The smaller cell replicated inside the larger one, and soon a stable symbiotic relationship developed. This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek Over time the host cell acquired some of the genes of the smaller cells, and the two kinds became dependent on each other: the larger cell could not survive without the energy produced by the smaller ones, and these in turn could not survive without the raw materials provided by the larger cell. Symbiosis developed between the larger cell and the population of smaller cells inside it to the extent that they are considered to have become a single organism, the smaller cells being classified as organelles called mitochondria. This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek In Cell biology, an organelle (pronunciation /ɔː(rgəˡnɛl/ is a specialized subunit within a cell that has a specific function and is usually separately enclosed In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. A similar event took place with photosynthetic cyanobacteria^[28] entering larger heterotrophic cells and becoming chloroplasts. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy A heterotrophs, or chemoorganotrophy ( Greek heterone = (another and trophe = nutrition is an Organism that requires Chloroplasts are Organelles found in Plant cells and eukaryotic Algae that conduct Photosynthesis. ^[29],[30] Probably as a result of these changes, a line of cells capable of photosynthesis split off from the other eukaryotes some time before one billion years ago. There were probably several such inclusion events, as the figure at left suggests. Besides the well-established endosymbiotic theory of the cellular origin of mitochondria and chloroplasts, it has been suggested that cells gave rise to peroxisomes, spirochetes gave rise to cilia and flagella, and that perhaps a DNA virus gave rise to the cell nucleus,^[31],[32] though none of these theories are generally accepted. Peroxisomes are Ubiquitous Organelles in Eukaryotes that participate in the metabolism of Fatty acids and other metabolites Spirochaetes is a phylum of distinctive Gram-negative bacteria, which have long helically coiled cells A cilium (plural cilia) is an Organelle found in eukaryotic cells Cilia are tail-like projections extending approximately A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it A DNA virus is a Virus that has DNA as its Genetic material and replicates using a DNA-dependent DNA polymerase. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed ^[33] During this period, the supercontinent Columbia is believed to have existed, probably from around 1. In Geology, a supercontinent is a Landmass comprising more than one Continental core or Craton. Columbia is the name of one of the Earth's oldest Supercontinents It was first proposed by J 8 to 1. 5 billion years ago; it is the oldest hypothesized supercontinent. ^[34]

Multicellularity

Volvox aureus is believed to be similar to the first multicellular plants. This article is about Volvox a colony of microorganisms For the rock music band with the same name see Volvox (band Volvox

Archaeans, bacteria, and eukaryotes continued to diversify and to become more sophisticated and better adapted to their environments. Each domain repeatedly split into multiple lineages, although little is known about the history of the archaea and bacteria. Around 1. 1 billion years ago, the supercontinent Rodinia was assembling. In Geology, a supercontinent is a Landmass comprising more than one Continental core or Craton. For the Genus of Metalmark butterflies, see Rodinia (butterfly. ^[35] The plant, animal, and fungi lines had all split, though they still existed as solitary cells. Plants are living Organisms belonging to the kingdom Plantae. A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ Some of these lived in colonies, and gradually some division of labor began to take place; for instance, cells on the periphery might have started to assume different roles from those in the interior. Division of labour or specialization is the specialization of cooperative labour in specific circumscribed tasks and roles intended to increase the Productivity Although the division between a colony with specialized cells and a multicellular organism is not always clear, around 1 billion years ago,^[36] the first multicellular plants emerged, probably green algae. Multicellular organisms are Organisms consisting of more than one cell, and having Differentiated cells that perform specialized functions The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged ^[37] Possibly by around 900 million years ago,^[38] true multicellularity had also evolved in animals. At first it probably somewhat resembled that of today’s sponges, where all cells were totipotent and a disrupted organism could reassemble itself. The sponges or poriferans (from Latin porus "pore" and ferre "to bear" are Animals Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an Organism, including extraembryonic tissues ^[39] As the division of labor became more complete in all lines of multicellular organisms, cells became more specialized and more dependent on each other; isolated cells would die. Many scientists believe that a very severe ice age began around 770 million years ago, so severe that the surface of all the oceans completely froze (Snowball Earth). The Snowball Earth Hypothesis as it was originally proposed]] Evidence The Snowball Earth hypothesis was originally devised to explain the apparent presence of Eventually, after 20 million years, enough carbon dioxide escaped through volcanic outgassing; the resulting greenhouse effect raised global temperatures. ^[40] By around the same time, 750 million years ago,^[41] Rodinia began to break up.

Colonization of land

For most of Earth’s history, there were no multicellular organisms on land. Parts of the surface may have vaguely resembled this view of Mars, one of Earth’s neighboring planets.

Oxygen accumulation from photosynthesis resulted in the formation of an ozone layer that absorbed much of Sun’s ultraviolet radiation, meaning unicellular organisms that reached land were less likely to die, and prokaryotes began to multiply and become better adapted to survival out of the water. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Prokaryotes had likely colonized the land as early as 2. The prokaryotes (proʊˈkærioʊts singular prokaryote /proʊˈkæriət/ are a group of Organisms that lack a Cell nucleus (= karyon or any other 6 billion years ago^[42] even before the origin of the eukaryotes. For a long time, the land remained barren of multicellular organisms. The supercontinent Pannotia formed around 600 million years ago and then broke apart a short 50 million years later. Pannotia, first described by Ian W D Dalziel in 1997 is a hypothetical Supercontinent that existed from the Pan-African orogeny about 600 million years ago to the ^[43] Fish, the earliest vertebrates, evolved in the oceans around 530 million years ago. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Prehistoric fish are various groups of Fishes that lived before recorded History. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes ^[44] A major extinction event occurred near the end of the Cambrian period,^[45] which ended 488 million years ago^[46]. The Cambrian–Ordovician extinction event occurred approximately 488 million years ago

Several hundred million years ago, plants (probably resembling algae) and fungi started growing at the edges of the water, and then out of it. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms ^[47] The oldest fossils of land fungi and plants date to 480–460 million years ago, though molecular evidence suggests the fungi may have colonized the land as early as 1000 million years ago and the plants 700 million years ago. ^[48] Initially remaining close to the water’s edge, mutations and variations resulted in further colonization of this new environment. The timing of the first animals to leave the oceans is not precisely known: the oldest clear evidence is of arthropods on land around 450 million years ago^[49], perhaps thriving and becoming better adapted due to the vast food source provided by the terrestrial plants. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " There is also some unconfirmed evidence that arthropods may have appeared on land as early as 530 million years ago^[50]. At the end of the Ordovician period, 440 million years ago, additional extinction events occurred, perhaps due to a concurrent ice age. The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets ^[51] Around 380 to 375 million years ago, the first tetrapods evolved from fish. Tetrapods ( Greek τετραποδη tetrapoda, Latin Quadruped, "four-footed" are Vertebrate Animals ^[52] It is thought that perhaps fins evolved to become limbs which allowed the first tetrapods to lift their heads out of the water to breathe air. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five This would let them survive in oxygen-poor water or pursue small prey in shallow water. ^[52] They may have later ventured on land for brief periods. Eventually, some of them became so well adapted to terrestrial life that they spent their adult lives on land, although they hatched in the water and returned to lay their eggs. This was the origin of the amphibians. Prehistoric amphibian Amphibians (class Amphibia such as Frogs Toads Salamanders Newts Gymnophiona, Sirens and About 365 million years ago, another period of extinction occurred, perhaps as a result of global cooling. The Late Devonian extinction was one of five major Extinction events in the history of the Earth's Biota. ^[53] Plants evolved seeds, which dramatically accelerated their spread on land, around this time (by approximately 360 million years ago). A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored ^[54],[55]

Pangaea, the most recent supercontinent, existed from 300 to 180 million years ago. Pangaea, Pangæa or Pangea (pænˈdʒiːə from παν pan, meaning entire, and Γαῖα Gaea, meaning Earth in The outlines of the modern continents and other land masses are indicated on this map.

Some 20 million years later (340 million years ago^[56]), the amniotic egg evolved, which could be laid on land, giving a survival advantage to tetrapod embryos. The amniotes are a group of Tetrapod Vertebrates that include the Synapsida ( Mammals and Mammal-like reptiles and Sauropsida Tetrapods ( Greek τετραποδη tetrapoda, Latin Quadruped, "four-footed" are Vertebrate Animals This resulted in the divergence of amniotes from amphibians. The amniotes are a group of Tetrapod Vertebrates that include the Synapsida ( Mammals and Mammal-like reptiles and Sauropsida Prehistoric amphibian Amphibians (class Amphibia such as Frogs Toads Salamanders Newts Gymnophiona, Sirens and Another 30 million years (310 million years ago^[57]) saw the divergence of the synapsids (including mammals) from the sauropsids (including birds and non-avian, non-mammalian reptiles). Synapsids ('fused arch' also known as theropsids ('beast face' are a class of Animals that includes Mammals and everything closer to mammals than Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Other groups of organisms continued to evolve and lines diverged—in fish, insects, bacteria, and so on—but less is known of the details. 300 million years ago, the most recent hypothesized supercontinent formed, called Pangaea. Pangaea, Pangæa or Pangea (pænˈdʒiːə from παν pan, meaning entire, and Γαῖα Gaea, meaning Earth in The most severe extinction event to date took place 250 million years ago, at the boundary of the Permian and Triassic periods; 95% of life on Earth died out,^[58] possibly due to the Siberian Traps volcanic event. The Permian–Triassic (P–Tr extinction event, informally known as the Great Dying, was an Extinction event that occurred, and 70 percent of terrestrial The Permian is a geologic period and system that extends from 299 The Triassic is a geologic period and system that extends from about 251 to 199 Ma (million years ago The Siberian Traps (Сибирские траппы form a Large igneous province in Siberia. The discovery of the Wilkes Land crater in Antarctica may suggest a connection with the Permian-Triassic extinction, but the age of that crater is not known. Wilkes Land crater is an informal term that may apply to two separate cases of conjectured giant Impact craters hidden beneath the Ice cap of Wilkes Land ^[59] But life persevered, and around 230 million years ago ^[60], dinosaurs split off from their reptilian ancestors. An extinction event between the Triassic and Jurassic periods 200 million years ago spared many of the dinosaurs,^[61] and they soon became dominant among the vertebrates. Though some of the mammalian lines began to separate during this period, existing mammals were probably all small animals resembling shrews. ^[62] By 180 million years ago, Pangaea broke up into Laurasia and Gondwana. Laurasia (lɔˈreɪʃiə lɔˈreɪʒə was a Supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic Gondwana (ɡɒnˈdwɑːnə originally Gondwanaland) was a southern Supercontinent that existed about 500 to 200 Ma ago The boundary between avian and non-avian dinosaurs is not clear, but Archaeopteryx, traditionally considered one of the first birds, lived around 150 million years ago. Archaeopteryx, sometimes referred to by its German name Urvogel ("original bird" or "first bird" is the earliest and most primitive Bird Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. ^[63] The earliest evidence for the angiosperms evolving flowers is during the Cretaceous period, some 20 million years later (132 million years ago)^[64] Competition with birds drove many pterosaurs to extinction, and the dinosaurs were probably already in decline for various reasons^[65] when, 65 million years ago, a 10-kilometer meteorite likely struck Earth just off the Yucatán Peninsula, ejecting vast quantities of particulate matter and vapor into the air that occluded sunlight, inhibiting photosynthesis. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of For other meanings see Pterodactyl (disambiguation. Pterosaurs (ˈtɛrəsɔr from the Greek πτερόσαυρος pterosauros A meteorite is a natural object originating in Outer space that survives an impact with the Earth 's surface The Yucatán Peninsula, in Southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico. Most large animals, including the non-avian dinosaurs, became extinct. The Cretaceous–Tertiary extinction event, which occurred approximately ( Ma) was a large-scale mass extinction of animal and plant species in a geologically ^[66] marking the end of the Cretaceous period and Mesozoic era. The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. Thereafter, in the Paleocene epoch, mammals rapidly diversified, grew larger, and became the dominant vertebrates. The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65 Perhaps a couple of million years later (around 63 million years ago), the last common ancestor of primates lived. A primate is a member of the biological order Primates ( Latin: "prime first rank" the group that contains Lemurs the Aye-aye ^[67] By the late Eocene epoch, 34 million years ago, some terrestrial mammals had returned to the oceans to become animals such as Basilosaurus which later gave rise to dolphins and whales. The Eocene epoch (558 ± 02 - 339 ± 01 Ma) is a major division of the Geologic timescale and the second epoch of the Palaeogene period in Basilosaurus ("King Lizard" is a Genus of Cetacean that lived from 40 to 34 million years ago in the Eocene. Dolphins are Marine mammals that are closely related to Whales and Porpoises There are almost forty species of dolphin in seventeen genera. Whales are marine mammals which are neither Dolphins (ie members of the families Delphinidae or Platanistoidae) nor Porpoises Orcas ^[68]

Humanity

Australopithecus africanus, an early hominid. The Genus Australopithecus ( Latin australis "of the south" Greek πίθηκος pithekos "ape"

Main article: Human evolution

A small African ape living around six million years ago was the last animal whose descendants would include both modern humans and their closest relatives, the bonobos, and chimpanzees. Human evolution, or anthropogenesis, is the part of biological Evolution concerning the emergence of Homo sapiens as a distinct Species The Bonobo (bə'noʊboʊ Pan paniscus) until recently usually called the Pygmy Chimpanzee (and less often the Dwarf or Gracile Chimpanzee Chimpanzee (often shortened to chimp) is the common name for the two extant Species of Apes in the Genus Pan. ^[69] Only two branches of its family tree have surviving descendants. Very soon after the split, for reasons that are still debated, apes in one branch developed the ability to walk upright. Bipedalism is a form of Terrestrial locomotion where an organism moves by means of its two rear limbs ^[70] Brain size increased rapidly, and by 2 million years ago, the very first animals classified in the genus Homo had appeared. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain Homo is the Genus that includes modern humans and their close relatives ^[71] Of course, the line between different species or even genera is rather arbitrary as organisms continuously change over generations. Around the same time, the other branch split into the ancestors of the common chimpanzee and the ancestors of the bonobo as evolution continued simultaneously in all life forms. The Common Chimpanzee ( Pan troglodytes) also known as the Robust Chimpanzee, is a great ape. The Bonobo (bə'noʊboʊ Pan paniscus) until recently usually called the Pygmy Chimpanzee (and less often the Dwarf or Gracile Chimpanzee ^[69] The ability to control fire likely began in Homo erectus (or Homo ergaster), probably at least 790,000 years ago^[72] but perhaps as early as 1. Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. Homo erectus ( Latin: "upright man" is an extinct species of the genus Homo, believed to have been the first hominin Homo ergaster ("working man" is an extinct Hominid Species (or subspecies according to some authorities which lived throughout eastern 5 million years ago. ^[73] In addition it has sometimes suggested that the use and discovery of controlled fire may even predate Homo erectus fire was possibly used by the early Lower Paleolithic (Oldowan) hominid Homo habilis and/or by robust australopithecines such as Paranthropus^[74] However it is more difficult to establish the origin of language; it is unclear whether Homo erectus could speak or if that capability had not begun until Homo sapiens. The robust australopithecines, members of the Extinct Hominin genus Paranthropus (Greek para "beside" Greek anthropos "human" The origin of language ( glottogony) is a topic that has attracted considerable speculation throughout human history ^[75] As brain size increased, babies were born sooner, before their heads grew too large to pass through the pelvis. The pelvis (pl pelvises or pelves) or pelvic girdle is the irregular bony structure located at the base of the spine (properly known As a result, they exhibited more plasticity, and thus possessed an increased capacity to learn and required a longer period of dependence. Neuroplasticity (variously referred to as brain plasticity, cortical plasticity or cortical re-mapping) refers to the changes that occur in Social skills became more complex, language became more advanced, and tools became more elaborate. This contributed to further cooperation and brain development. ^[76] Anatomically modern humans — Homo sapiens — are believed to have originated somewhere around 200,000 years ago or earlier in Africa; the oldest fossils date back to around 160,000 years ago. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus In Paleoanthropology, the recent African origin of modern humans is one of two hypotheses of the origin of anatomically modern humans Homo sapiens sapiens ^[77] The first humans to show evidence of spirituality are the Neanderthals (usually classified as a separate species with no surviving descendants); they buried their dead, often apparently with food or tools. Spirituality, in a narrow sense concerns itself with matters of the Spirit, a concept closely tied to religious belief and Faith, a transcendent reality The Neanderthal (neɪˈændərtɑːl also with /niː-/ and /-θɔːl/ or Neandertal, is an extinct member of the Homo genus that is known from ^[78] However, evidence of more sophisticated beliefs, such as the early Cro-Magnon cave paintings (probably with magical or religious significance)^[79] did not appear until some 32,000 years ago. Cro-Magnon ( French) is one of the main types of Homo sapiens of the European Upper Paleolithic, living approximately 40000 to 10000 years Cave paintings are Paintings on Cave walls and ceilings and the term is used especially for those dating to Prehistoric times ^[80] Cro-Magnons also left behind stone figurines such as Venus of Willendorf, probably also signifying religious belief. The Venus of Willendorf, also known as the Woman of Willendorf, is an 11 ^[79] By 11,000 years ago, Homo sapiens had reached the southern tip of South America, the last of the uninhabited continents. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a ^[81] Tool use and language continued to improve; interpersonal relationships became more complex.

Civilization

Main article: History of the world

Vitruvian Man by Leonardo da Vinci epitomizes the advances in art and science seen during the Renaissance. Prehistory See also Prehistory Paleolithic See also Paleolithic, Recent African Origin, Early Homo sapiens The Vitruvian Man is a world-renowned Drawing with accompanying notes created by Leonardo da Vinci around the year 1487 as recorded in one of his journals Leonardo di ser Piero da Vinci ( April 15 1452 – May 2 1519 was an Italian Polymath, having been a scientist Mathematician, Engineer

Throughout more than 90% of its history, Homo sapiens lived in small bands as nomadic hunter-gatherers. A hunter-gatherer society is one whose primary subsistence method involves the direct procurement of edible plants and animals from the wild Foraging and Hunting ^[82] As language became more complex, the ability to remember and transmit information resulted in a new sort of replicator: the meme. A meme (miːm consists of any idea or behavior that can pass from one person to another by learning or imitation ^[83] Ideas could be rapidly exchanged and passed down the generations. Cultural evolution quickly outpaced biological evolution, and history proper began. Sociocultural evolution(ism is an umbrella term for theories of cultural evolution and Social evolution, describing how Cultures and societies eVolution is the third Album by eLDee, it was due to be released in 2008 Somewhere between 8500 and 7000 BC, humans in the Fertile Crescent in Middle East began the systematic husbandry of plants and animals: agriculture. The Fertile Crescent is a Crescent -shaped region in the Middle East, originally incorporating the Levant and Ancient Mesopotamia, and often The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture ^[84] This spread to neighboring regions, and also developed independently elsewhere, until most Homo sapiens lived sedentary lives in permanent settlements as farmers. Not all societies abandoned nomadism, especially those in isolated areas of the globe poor in domesticable plant species, such as Australia. Domestication (from Latin domesticus) refers to the process whereby a Population of Animals For a topic outline on this subject see List of basic Australia topics. ^[85] However, among those civilizations that did adopt agriculture, the relative security and increased productivity provided by farming allowed the population to expand. Agriculture had a major impact; humans began to affect the environment as never before. Surplus food allowed a priestly or governing class to arise, followed by increasing division of labor. Division of labour or specialization is the specialization of cooperative labour in specific circumscribed tasks and roles intended to increase the Productivity This led to Earth’s first civilization at Sumer in the Middle East, between 4000 and 3000 BC. A Civilization is a society in which large numbers of people share a variety of common elements Sumer ( Sumerian: sux-Latn [[Ki (earth ki]]-[[EN (cuneiform en]]-'''ĝir15''', Akkadian: Šumeru; possibly Biblical Shinar The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. ^[86] Additional civilizations quickly arose in ancient Egypt, at the Indus River valley and in China. Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now The Indus Valley Civilization (Mature period 2600&ndash1900 BCE abbreviated IVC, was an ancient Civilization that flourished in the Indus River basin The Three Sovereigns and Five Emperors ( were mythological rulers of China during the period from c

Starting around 3000 BC, Hinduism, one of the oldest religions still practiced today, began to take form. Hinduism is a religious tradition that originated in the Indian subcontinent. ^[87] Others soon followed. The invention of writing enabled complex societies to arise: record-keeping and libraries served as a storehouse of knowledge and increased the cultural transmission of information. A library is a collection of information sources resources and services and the structure in which it is housed it is organized for use and maintained by a public body an institution Humans no longer had to spend all their time working for survival—curiosity and education drove the pursuit of knowledge and wisdom. Various disciplines, including science (in a primitive form), arose. Science (from the Latin scientia, meaning " Knowledge " or "knowing" is the effort to discover, and increase human understanding New civilizations sprang up, traded with one another, and engaged in war for territory and resources: empires began to form. War is an international relations Dispute, characterized by organized Violence between National Military units An empire (from the Latin " Imperium " denoting military Command within the ancient Roman government) is a State that By around 500 BC, there were empires in the Middle East, Iran, India, China, and Greece, approximately on equal footing; at times one empire expanded, only to decline or be driven back later. ^[88]

In the fourteenth century, the Renaissance began in Italy with advances in religion, art, and science. The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest ^[89] Starting around 1500, European civilization began to undergo changes leading to the scientific and industrial revolutions: that continent began to exert political and cultural dominance over human societies around the planet. The period which many historians of science call the Scientific Revolution can be roughly dated as having begun in 1543 the year in which Nicolaus Copernicus published The Industrial Revolution was a period in the late 18th and early 19th centuries when major changes in agriculture manufacturing and transportation had a profound effect on the Hegemony (hɨˈdʒɛməni (Amer /hɨˈɡɛməni/ (Brit (ἡγεμονία hēgemonía) is a concept that has been used to describe and explain the dominance of one social ^[90] From 1914 to 1918 and 1939 to 1945, nations around the world were embroiled in world wars. A world war is a War affecting the majority of the world's most powerful and populous nations Established following World War I, the League of Nations was a first step in establishing international institutions to resolve disputes peacefully; after its failure to prevent World War II and the subsequent end of the conflict it was replaced by the United Nations. World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All The League of Nations was an International organization founded as a result of the Treaty of Versailles in 1919–1920 World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including The United Nations ( UN) is an International organization whose stated aims are to facilitate cooperation in International law, International security In 1992, several European nations joined together in the European Union. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in As transportation and communication improved, the economies and political affairs of nations around the world have become increasingly intertwined. This globalization has often produced discord, although increased collaboration has resulted as well. Globalization (or globalisation) in its literal sense is the process of transformation of local or regional phenomena into global ones

Recent events

Four and a half billion years after the planet's formation, one of Earth’s life forms broke free of the biosphere. The biosphere is the broadest level of ecological study the global sum of all Ecosystems. For the first time in history, Earth was viewed first hand from the vantage of space. History is the study of the past particularly the written record Those who study history as a Profession are called Historians Etymology

Change has continued at a rapid pace from the mid-1940s to today. The 1940s decade ran from 1940 to 1949 Events and trends The 1940s was a period between the radical 1930s and the conservative 1950s which also leads the period to be Technological developments include nuclear weapons, computers, genetic engineering, and nanotechnology. A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. A computer is a Machine that manipulates data according to a list of instructions. Genetic engineering, Recombinant DNA technology, genetic modification/manipulation (GM and gene splicing are terms that apply to the direct Nanotechnology, sometimes shortened to nanotech, refers to a field of Applied science whose theme is the control of matter on an Atomic and Molecular Economic globalization spurred by advances in communication and transportation technology has influenced everyday life in many parts of the world. Globalization (or globalisation) in its literal sense is the process of transformation of local or regional phenomena into global ones Cultural and institutional forms such as democracy, capitalism, and environmentalism have increased influence. Democracy is a form of government in which the supreme power is held completely by the people under a free electoral system Capitalism is the Economic system in which the Means of production are owned by private Persons and operated for Profit and where Environmentalism is a broad philosophy and Social movement centered on a concern for the conservation and improvement of the environment. Major concerns and problems such as disease, war, poverty, violent radicalism, and more recently, global warming have risen as the world population increases. A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly War is an international relations Dispute, characterized by organized Violence between National Military units Poverty (also called penury) is deprivation of common necessities that determine the quality of life including food clothing shelter and safe Drinking water, and Global warming is the increase in the average measured temperature of the

In 1957, the Soviet Union launched the first artificial satellite into orbit and, soon afterward, Yuri Gagarin became the first human in space. Year 1957 ( MCMLVII) was a Common year starting on Tuesday (link displays the 1957 Gregorian calendar) The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Sputnik 1 ( "Спутник-1", "Satellite-1" ПС-1 ( PS-1, i Neil Armstrong, an American, was the first to set foot on another astronomical object, the Earth's Moon. Neil Alden Armstrong (born August 5 1930 is a former American Astronaut, Test pilot, University Professor, and United States The United States of America —commonly referred to as the Unmanned probes have been sent to all the major planets in the solar system, with some (such as Voyager) having left the solar system. The Soviet Union and the United States of America were the primary early leaders in space exploration in the 20th Century. The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 The United States of America —commonly referred to as the Five space agencies, representing over fifteen countries,^[91] have worked together to build the International Space Station. Aboard it, there has been a continuous human presence in space since 2000. ^[92]

See also

• Timeline of the Big Bang
• Geologic time scale
• Timeline of evolution
• Detailed logarithmic timeline
• Natural history
• History of the world
• End of civilization
• Timetable of the Precambrian
• Geological history of Earth

References

External links

• Cosmic Evolution — a detailed look at events from the origin of the universe to the present
• Valley, John W. “A Cool Early Earth?” Scientific American. Scientific American is a Popular science magazine, published (first weekly and later monthly since August 28, 1845, making it 2005 October 58–65. – discusses the timing of the formation of the oceans and other major events in Earth’s early history.
• Davies, Paul. Paul Charles William Davies (born April 22, 1946) is a British-born Physicist, Writer and broadcaster, presently a professor “Quantum leap of life”. The Guardian. The Guardian (until 1959 The Manchester Guardian) is a British Newspaper owned by the Guardian Media Group. 2005 December 20. Events 69 - Vespasian, formerly a general under Nero, enters Rome to claim the title of Emperor. – discusses speculation into the role of quantum systems in the origin of life
• Evolution timeline (uses Shockwave). Adobe Shockwave (formerly Macromedia Shockwave) was Macromedia 's first and most successful multimedia player prior to the introduction of Macromedia Flash (now Animated story of life since about 13,700,000,000 shows everything from the big bang to the formation of the earth and the development of bacteria and other organisms to the ascent of man.
• Scientific American Magazine (October 2005 Issue) A Cool Early Earth?
• Artist's Conception of Cold Early Earth