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Encyclopedia > Timeline of evolution
Life on Earth
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Formation
of Earth
Atmospheric oxygen
Modern-looking
humans
Axis scale: millions of years ago.
Dates prior to 1 billion years ago are speculative.
For the history of evolutionary biology, see History of evolutionary thought.

This timeline of the evolution of life outlines the major events in the development of life on the planet Earth. For a thorough explanatory context, see the history of Earth, and geologic time scale. The dates given in this article are estimates based on scientific evidence. This article does not adequately cite its references or sources. ... The leaf is the primary site of photosynthesis in plants. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Multicellular organisms are those organisms consisting of more than one cell, and having differentiated cells that perform specialized functions. ... For other uses, see Animal (disambiguation). ... Divisions Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adders-tongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants The embryophytes are the most familiar... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants or angiosperms are the most widespread group of land plants. ... The Late Heavy Bombardment (LHB) was a period approximately 3. ... Dickinsonia costata, an Ediacaran organism of unknown affinity, with a quilted appearance. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ... Evolutionary thought has roots in antiquity as philosophical ideas conceived during the Ancient Greek and Roman eras, but until the 18th century, biological thought was dominated by essentialism, the idea that living forms are static and unchanging in time. ... For other uses, see Life (disambiguation). ... This article is about Earth as a planet. ... Geological time put in a diagram called a geological clock, showing the relative lengths of the eons of the Earths history. ... // For other uses, see time scale. ...


In biology, evolution is the process by which populations of organisms acquire and pass on novel traits from generation to generation. Its occurrence over large stretches of time explains the origin of new species and ultimately the vast diversity of the biological world. Contemporary species are related to each other through common descent, products of evolution and speciation over billions of years. Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: βίος, bio, life; and λόγος, logos, knowledge), also referred to as the biological sciences, is the study of living organisms utilizing the scientific method. ... This article is about evolution in biology. ... In biology, a trait or character is a genetically inherited feature of an organism. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the evolutionary process by which new biological species arise. ... A group of organisms is said to have common descent if they have a common ancestor. ... Charles Darwins first sketch of an evolutionary tree from his First Notebook on Transmutation of Species (1837) Speciation is the evolutionary process by which new biological species arise. ...

Contents

Basic timeline

The basic timeline is a 4.6 billion year old Earth, with (very approximately): Earth as seen from Apollo 17 Modern geologists consider the age of the Earth to be around 4. ...

Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... The leaf is the primary site of photosynthesis in plants. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... The first organisms that existed were undoubtedly unicellular. ... For other uses, see Animal (disambiguation). ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ... For other uses, see Fish (disambiguation). ... Divisions Green algae land plants (embryophytes) non-vascular embryophytes Hepatophyta - liverworts Anthocerophyta - hornworts Bryophyta - mosses vascular plants (tracheophytes) seedless vascular plants Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongue ferns seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ... For other uses, see Amphibian (disambiguation). ... Reptilia redirects here. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... For other uses, see Bird (disambiguation). ... For other uses, see Flower (disambiguation). ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Artists impression of a major impact event. ... Species Homo sapiens See text for extinct species. ...

Detailed timeline

Note that Ma means "million years ago".

Hadean eon

3800 Ma and earlier. The name Hadean refers to the geologic period before 3800 million years ago (mya). ...

Date Event
4567.17 Ma The planet Earth forms from the accretion disc revolving around the young Sun.
4533 Ma The planet Earth and the planet Theia collide, sending countless moonlets into orbit around the young Earth. These moonlets eventually coalesce to form the Moon. The gravitational pull of the new Moon stabilises the Earth's fluctuating axis of rotation and sets up the conditions for the formation of life.[1]
4100 Ma The surface of the Earth cools enough for the crust to solidify. The atmosphere and the oceans form.[2]
Between 4500 and 2500 Ma The earliest life appears, possibly derived from self-reproducing RNA molecules. The replication of these organisms requires resources like energy, space, and smaller building blocks, which soon become limited, resulting in competition. Natural selection favours those molecules which are more efficient at replication. DNA molecules then take over as the main replicators. They soon develop inside enclosing membranes which provide a stable physical and chemical environment conducive to their replication: proto-cells.
3900 Ma Late Heavy Bombardment: peak rate of impact events upon the inner planets by meteors. This constant disturbance probably obliterated any life that had already evolved, as the oceans boiled away completely; conversely, life may have been transported to Earth by a meteor. [3]
Somewhere between 3900 - 2500 Ma Cells resembling prokaryotes appear. These first organisms are chemoautotrophs: they use carbon dioxide as a carbon source and oxidize inorganic materials to extract energy. Later, prokaryotes evolve glycolysis, a set of chemical reactions that free the energy of organic molecules such as glucose. Glycolysis generates ATP molecules as short-term energy currency, and ATP continue to be used in almost all organisms, unchanged, to this day.

This article is about Earth as a planet. ... Artists conception of a binary star system with one black hole and one main sequence star Unsolved problems in physics: Accretion disc jets: Why do the discs surrounding certain objects, such as the nuclei of active galaxies, emit radiation jets along their polar axes? These jets are invoked by... Sol redirects here. ... Theia (THAY-uh) is the hypothetical planet that, according to the giant impact theory of the Moons formation, collided with Earth over four billion years ago. ... This article is about Earths moon. ... The axis of rotation of a rotating body is a line such that the distance between any point on the line and any point of the body remains constant under the rotation. ... Earth cutaway from core to exosphere. ... Air redirects here. ... Animated map exhibiting the worlds oceanic waters. ... This article does not adequately cite its references or sources. ... RNA with its nitrogenous bases to the left and DNA to the right. ... Left: An RNA strand, with its nitrogenous bases. ... For other uses, see Natural selection (disambiguation). ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... The Late Heavy Bombardment (LHB) was a period approximately 3. ... Artists impression of a major impact event. ... In ecology, a disturbance is a temporary change in average environmental conditions that causes a pronounced change in ecosystem structure that lasts longer than the change in the environment. ... Panspermia is a proven process (based on the principles of Biology, Microbiology, Physics, Chemistry, Astronomy, and assumption that life existed already in the universe) that explains how all life in the universe and/or solar system comes from a seed of life. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... Flowchart to determine if a species is autotroph, heterotroph, or a subtype Chemotrophs are organisms that obtain energy by the oxidation of electron donating molecules in their environments. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... For other uses, see Carbon (disambiguation). ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... The word glycolysis is derived from Greek γλυκύς (sweet) and λύσις (letting loose). ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ...

Archean eon

3800 Ma - 2500 Ma The Archean is a geologic eon; it is a somewhat antiquated term for the time span between 2500 million years before the present and 3800 million years before the present. ...

Date Event
3500 Ma Lifetime of the last universal ancestor; the split between the bacteria and the archaea occurs.

Bacteria develop primitive forms of photosynthesis which at first do not produce oxygen. These organisms generate ATP by exploiting a proton gradient, a mechanism still used in virtually all organisms. Last universal ancestor (LUA), the hypothetical latest living organism from which all currently living organisms descend. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Phyla Crenarchaeota Euryarchaeota Korarchaeota Nanoarchaeota ARMAN The Archaea (), or archaebacteria, are a major group of microorganisms. ... The leaf is the primary site of photosynthesis in plants. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) pale blue (liquid) Standard atomic weight 15. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... In cellular biology, an electrochemical gradient refers to the electrical and chemical properties across a membrane. ...

3000 Ma Photosynthesizing cyanobacteria evolve; they use water as a reducing agent, thereby producing oxygen as waste product. The oxygen initially oxidizes dissolved iron in the oceans, creating iron ore. The oxygen concentration in the atmosphere subsequently rises, acting as a poison for many bacteria. The moon is still very close to the earth and causes tides 1000 feet high. The earth is continually wracked by hurricane force winds. These extreme mixing influences are thought to stimulate evolutionary processes. (See Oxygen Catastrophe)

Image File history File links Anabaena sperica, a filamentous cyanobacterium. ... Orders The taxonomy is currently under revision. ... A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ... This heap of iron ore pellets will be used in steel production. ... The Oxygen Catastrophe was a massive environmental change believed to have happened during the Siderian period at the beginning of the Paleoproterozoic era. ...

Proterozoic eon

2500 Ma - 542 Ma The Proterozoic (IPA: ) is a geological eon representing a period before the first abundant complex life on Earth. ...

Date Event
By 2100 Ma Eukaryotic cells appear. Eukaryotes contain membrane-bound organelles with diverse functions, probably derived prokaryotes englufing each other via phagocytosis.
By 1200 Ma Sexual reproduction evolves, increasing the rate of evolution.[4][citation needed]
1200 Ma Simple multicellular organisms evolve, mostly consisting of cell colonies of limited complexity.
850–630 Ma A global glaciation may have reduced the diversity of life. Opinion is divided on whether it increased or decreased the rate of evolution.[citation needed]
580-542 Ma The Ediacaran biota represent the first large, complex multicellular organisms - although their affinities remain a subject of debate.
580–500 Ma Most modern groups begin to appear in the fossil record during the Cambrian explosion.
Around 540 Ma The accumulation of atmospheric oxygen allows the formation of an ozone layer. This blocks ultraviolet radiation, permitting the colonisation of the land.

Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Schematic of typical animal cell, showing subcellular components. ... Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... Steps of a macrophage ingesting a pathogen: a. ... Sexual reproduction is a union that results in increasing genetic diversity of the offspring. ... Wild-type Caenorhabditis elegans hermaphrodite stained to highlight the nuclei of all cells Multicellular organisms are organisms consisting of more than one cell, and having differentiated cells that perform specialized functions. ... The first organisms that existed were undoubtedly unicellular. ... One computer simulation of conditions during the Snowball Earth period. ... Dickinsonia costata, an Ediacaran organism of unknown affinity, with a quilted appearance. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ... The ozone layer is a layer in Earths atmosphere which contains relatively high concentrations of ozone (O3). ... For other uses, see Ultraviolet (disambiguation). ...

Phanerozoic eon

542 Ma - present


The Phanerozoic eon, literally the "period of well-displayed life", marks the appearance in the fossil record of abundant, shell-forming organisms. It is subdivided into three eras, the Paleozoic, Mesozoic and Cenozoic, which are divided by major mass extinctions. During the Phanerozoic the biodiversity shows a steady but not monotonic increase from near zero to several thousands of genera. ... An extinction event (also extinction-level event, ELE) is a period in time when a large number of species die out. ...


Paleozoic era

542 Ma - 251.0 Ma

Date Event
530 Ma The first known footprints on land date to 530 Ma, indicating that early animal explorations may have predated the development of terrestrial plants.[5]
475 Ma The first primitive plants move onto land,[6][citation needed] having evolved from green algae living along the edges of lakes.[7] They are accompanied by fungi, which may have aided the colonisation of land through symbiosis.
363 Ma By the start of the Carboniferous period, the Earth begins to be recognisable. Insects roamed the land and would soon take to the skies; sharks predated the oceans,[8] and vegetation covered the land, with seed-bearing plants and forests soon to flourish.

Four-limbed tetrapods gradually gain adaptions which will help them occupy a terrestrial life-habit. For other uses, see Plant (disambiguation). ... Subkingdom/Phyla Chytridiomycota Blastocladiomycota Neocallimastigomycota Glomeromycota Zygomycota Dikarya (inc. ... For other uses, see Symbiosis (disambiguation). ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... Groups See text. ...

251.4Ma The Permian-Triassic extinction event eliminates over 95% of species. This "clearing of the slate" may have led to an ensuing diversification.

The Permian-Triassic (P-T or PT) extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 251 million years ago (mya), forming the boundary between the Permian and Triassic geologic periods. ...

Mesozoic era

Date Event
From 251.4 Ma The Mesozoic Marine Revolution begins: increasingly well-adapted and diverse predators pressurise sessile marine groups; the "balance of power" in the oceans shifts dramatically as some groups of prey adapt more rapidly and effectively than others.
220 Ma
Eoraptor, an early dinosaur.

Gymnosperm forests dominate the land; herbivores grow to huge sizes in order to accommodate the large guts necessary to digest the nutrient-poor plants.[citation needed] The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. ... Image File history File links Download high-resolution version (1000x600, 263 KB) fifth version of eoraptor by me user debivort 12. ... Image File history File links Download high-resolution version (1000x600, 263 KB) fifth version of eoraptor by me user debivort 12. ... Divisions Pinophyta (or Coniferophyta) - Conifers Ginkgophyta - Ginkgo Cycadophyta - Cycads Gnetophyta - Gnetum, Ephedra, Welwitschia The gymnosperms (Gymnospermae) are a group of spermatophyte seed-bearing plants with ovules on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone-like structures. ...

200 Ma The first accepted evidence for viruses - the group Geminiviridae at least exists.[9] Viruses are still poorly understood and may have arisen before "life" itself, or may be a more recent phenomenon.
130 Ma The rise of the Angiosperms: These flowering plants boast structures that attract insects and other animals to spread pollen. This innovation causes a major burst of animal evolution through co-evolution.

This article is about biological infectious particles. ... Genera Mastrevirus Curtovirus Begomovirus Topocuvirus Geminiviruses are plant viruses which have ambisense single-stranded circular DNA genomes and are members of class II of the Baltimore classification of viruses. ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also angiosperms or Magnoliophyta) are one of the major groups of modern plants, comprising those that produce seeds in specialized reproductive organs called flowers, where the ovulary or carpel is enclosed. ... For other uses, see Flower (disambiguation). ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ... Bumblebees and the flowers they pollinate have co-evolved so that both have become dependent on each other for survival. ...

Cenozoic era

65.5 Ma - present The Cenozoic Era (pronounced ); sometimes Caenozoic Era or Cainozoic Era (in the United Kingdom), meaning new life (Greek (kainos), new, and (zoe), life), is the most recent of the three classic geological eras. ...

Date Event
65.5 Ma

The Cretaceous–Tertiary extinction event eradicates about half of all animal species, including all non-avian dinosaurs. Image File history File links KT_Impact2. ... Artists impression of a major impact event. ...

35 Ma Grasses evolve from among the angiosperms; grassland dominates many terrestrial ecosystems.
14,000 years ago The term Anthropocene has been used to describe the period of time during which Man has had a major impact on the planet and its inhabitants. Its beginning is marked by the megafaunal extinction in the Americas which signify the onset of the Holocene extinction event. Fierce debate rages about the influence of man in the initiation of this extinction, but no one can deny that humanity is contributing to its propagation.
Present day With a human population approaching 6.6 billion,[10] the impact of humanity is felt in all corners of the globe. Overfishing, anthropogenic climate change, industrialisation, intensive agriculture, clearance of rain forests and other activities contribute to a dramatically rising extinction rate.[11] At current rates, humanity will have eradicated one-half of life's biodiveristy over the next hundred years.[12]

Subfamilies There are 7 subfamilies: Subfamily Arundinoideae Subfamily Bambusoideae Subfamily Centothecoideae Subfamily Chloridoideae Subfamily Panicoideae Subfamily Pooideae Subfamily Stipoideae The true grasses are monocotyledonous plants (Class Liliopsida) in the Family Poaceae, also known as Gramineae. ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also angiosperms or Magnoliophyta) are one of the major groups of modern plants, comprising those that produce seeds in specialized reproductive organs called flowers, where the ovulary or carpel is enclosed. ... The term Anthropocene is used by some scientists to describe the most recent period in the Earths history, starting in the 18th century where the activities of the human race first began to have a significant global effect on the Earths climate and ecosystems. ... The Dodo, a bird of Mauritius, became extinct during the mid-late 17th century after humans destroyed the forests where the birds made their homes and introduced animals that ate their eggs. ... Map of countries by population — China and India, the only two countries to have a population greater than one billion, together possess more than a third of the worlds population. ...

See also

Plant evolution is an aspect of the study of biological evolution, involving predominantly the evolution of plants suited to live on land, the greening of the various land masses by the filling of their niches with land plants, and the diversification of the groups of land plants. ... An extinction event (also extinction-level event, ELE) is a period in time when a large number of species die out. ... // For other uses, see time scale. ... Geological time put in a diagram called a geological clock, showing the relative lengths of the eons of the Earths history. ... Table of natural history, 1728 Cyclopaedia Natural history is an umbrella term for what are now often viewed as several distinct scientific disciplines of integrative organismal biology. ... In the unilineal evolution model at left, all cultures progress through set stages, while in the multilineal evolution model at right, distinctive culture histories are emphasized. ... This article does not cite any references or sources. ...

Further reading

The Ancestors Tale cover The Ancestors Tale (subtitled A Pilgrimage to the Dawn of Life) is a 2004 popular science book by Richard Dawkins, with contributions from Dawkins research assistant Yan Wong. ... Clinton Richard Dawkins, FRS (born March 26, 1941) is a British ethologist, evolutionary biologist and popular science writer who holds the Charles Simonyi Chair for the Public Understanding of Science at the University of Oxford. ...

References

  1. ^ Planetary Science Institute page on the Giant Impact Hypothesis. Hartmann and Davis belonged to the PSI. This page also contains several paintings of the impact by Hartmann himself.
  2. ^ "However, once the Earth cooled sufficiently, sometime in the first 700 million years of its existence, clouds began to form in the atmosphere, and the Earth entered a new phase of development." How the Oceans Formed (URL accessed on January 9, 2005)
  3. ^ " Between about 3.8 billion and 4.5 billion years ago, no place in the solar system was safe from the huge arsenal of asteroids and comets left over from the formation of the planets. Sleep and Zahnle calculate that Earth was probably hit repeatedly by objects up to 500 kilometers across" Geophysicist Sleep: Martian underground may have harbored early life (URL accessed on January 9, 2005)
  4. ^ "'Experiments with sex have been very hard to conduct,' Goddard said. 'In an experiment, one needs to hold all else constant, apart from the aspect of interest. This means that no higher organisms can be used, since they have to have sex to reproduce and therefore provide no asexual control.'
    Goddard and colleagues instead turned to a single-celled organism, yeast, to test the idea that sex allows populations to adapt to new conditions more rapidly than asexual populations." Sex Speeds Up Evolution, Study Finds (URL accessed on January 9, 2005)
  5. ^ "The oldest fossils of footprints ever found on land hint that animals may have beaten plants out of the primordial seas. Lobster-sized, centipede-like or slug like animals such as Protichnites and Climactichnites made the prints wading out of the ocean and scuttling over sand dunes about 530 million years ago. Previous fossils indicated that animals didn't take this step until 40 million years later." Oldest fossil footprints on land
  6. ^ "The oldest fossils reveal evolution of non-vascular plants by the middle to late Ordovician Period (~450-440 m.y.a.) on the basis of fossil spores" Transition of plants to land
  7. ^ "The land plants evolved from the algae, more specifically green algae, as suggested by certain common biochemical traits" The first land plants
  8. ^ "The ancestry of sharks dates back more than 200 million years before the earliest known dinosaur. Introduction to shark evolution, geologic time and age determination
  9. ^ "Viruses of nearly all the major classes of organisms—animals, plants, fungi and bacteria/archaea—probably evolved with their hosts in the seas, given that most of the evolution of life on this planet has occurred there. This means that viruses also probably emerged from the waters with their different hosts, during the successive waves of colonisation of the terrestrial environment." Origins of Viruses (URL accessed on January 9, 2005)
  10. ^ An United States Census Bureau estimate of the number of people alive on Earth at any given moment. United States census bureau
  11. ^ The American Museum of Natural History National Survey Reveals Biodiversity Crisis (URL accessed on February 23, 2006)
  12. ^ E. O. Wilson, Harvard University, The Future of Life (2002)

is the 9th day of the year in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 9th day of the year in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 9th day of the year in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... A trace fossil consisting of the imprints made by the walking activity of an unknown arthropod. ... Climactichnites is a genus of trace fossil formed on sandy tidal flats in portions of Canada and northern United States around 510 Ma during late Cambrian time. ... is the 9th day of the year in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... The United States Census Bureau (officially Bureau of the Census as defined in Title ) is a part of the United States Department of Commerce. ... is the 54th day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... Edward Osborne Wilson (b. ...

External links


  Results from FactBites:
 
Encyclopedia4U - Timeline of evolution - Encyclopedia Article (1154 words)
This timeline outlines the major events in the development of life on Earth.
The evolution of the angiosperms cause a major burst of animal evolution.
Half of all known dinosaur species are from the last 30 MY of the Mesozoic, after the rise of the angiosperms.
Timeline of human evolution - Wikipedia, the free encyclopedia (2793 words)
This timeline is based on studies from Paleontology, Developmental biology, Morphology and from anatomical and genetic data.
The origin of the eukaryotic cell is a milestone in the evolution of life: their higher level of organizational complexity permits the development of truly multicellular organisms.
Timeline of evolution - For an explanation of the evolution of a wide variety of animals living today.
  More results at FactBites »

 
 

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