The History of Life

  • Solar System Found
    4530 BCE

    Solar System Found

    Earth and the other planets of the solar system formed, condensing from a vast cloud of dust and roach that surrounded the young sun.
  • Period: 4530 BCE to

    Scale

    Multiple the year by 1,000,000 to find the correct year.
    Example:
    4,530 BCE --> 4,530,000,000 BCE or 4.53 Billion BCE
  • Rocks on Earth
    4500 BCE

    Rocks on Earth

    Oldest known rocks on Earth’s surface, located at a site called Issua in Greenland, existed.
  • Life from Space
    4500 BCE

    Life from Space

    Fragments of a 4.5-billion-year-old chondrite collected in southern Australia containing more than 80 amino acids shows that first life on Earth may have come from space.
  • Earth began to cool
    3900 BCE

    Earth began to cool

    Earth began to cool to a temperature at which liquid water could exist, and thus life could exist.
  • First Life
    3800 BCE

    First Life

    First life may have developed in undersea alkaline vents
  • Oldest known fossils created
    3500 BCE

    Oldest known fossils created

    Oldest known fossils, fossils of stromatolites, come into existence
  • First cells use solar energy
    3500 BCE

    First cells use solar energy

    The first cells began to use the sun's energy and convert it into their own energy.
  • Single-celled Organisms
    3460 BCE

    Single-celled Organisms

    Some single-celled organisms may be feeding on methane by this time.
  • The Great Oxidation Event
    2400 BCE

    The Great Oxidation Event

    Supposedly, the poisonous waste produced by photosynthetic cyanobacteria – oxygen – started to build up in the atmosphere. Dissolved oxygen makes the iron in the oceans “rust” and sink to the seafloor, forming striking banded iron formations and making life more viable.
  • Snowball Earth
    2300 BCE

    Snowball Earth

    Earth freezes over in what may have been the first “snowball Earth”, possibly as a result of a lack of volcanic activity. When the ice eventually melts, it indirectly leads to more oxygen being released into the atmosphere.
  • Algae emerges
    2200 BCE

    Algae emerges

  • Eukaryotic cells emerge
    2000 BCE

    Eukaryotic cells emerge

  • Eukaryotes divide
    1500 BCE

    Eukaryotes divide

    Eukaryotes divide into three groups
  • Animal phyla originated
    1000 BCE

    Animal phyla originated

    Animal phyla originated and began to diverge, showing the creation of varying species and new animals.
  • First multicellular life develops
    900 BCE

    First multicellular life develops

  • Multicellular animals undergo their first splits
    800 BCE

    Multicellular animals undergo their first splits

    First they divide into, essentially, the sponges and everything else – the latter being more formally known as the Eumetazoa.
  • Second Snowball Earth
    770 BCE

    Second Snowball Earth

    The planet freezes over again in another “snowball Earth“.
  • Ice Age
    750 BCE

    Ice Age

    Severe ice age occurred, reducing the speed at which life was being formed.
  • Comb jellies split
    730 BCE

    Comb jellies split

    The comb jellies (ctenophores) split from the other multicellular animals.
  • Cnidarians emerge
    680 BCE

    Cnidarians emerge

    The ancestor of cnidarians (jellyfish and their relatives) breaks away from the other animals – though there is as yet no fossil evidence of what it looks like.
  • Bilateral symmetry begins
    590 BCE

    Bilateral symmetry begins

    Around this time, some animals evolve bilateral symmetry for the first time
  • Bilateria splits into protostomes and deuterostomes
    590 BCE

    Bilateria splits into protostomes and deuterostomes

    The Bilateria, those animals with bilateral symmetry, undergo a profound evolutionary split. They divide into the protostomes and deuterostomes.
  • Moving animals emerge
    565 BCE

    Moving animals emerge

    Fossilised animal trails suggest that some animals are moving under their own power.
  • The Cambrian explosion
    541 BCE

    The Cambrian explosion

    The Cambrian explosion was the relatively short evolutionary event, beginning around 541 million years ago in the Cambrian period, during which most major animal phyla appeared, as indicated by the fossil record.
  • First vertebrates appear
    530 BCE

    First vertebrates appear

    The first true vertebrate – an animal with a backbone – appears. It probably evolves from a jawless fish that has a notochord, a stiff rod of cartilage, instead of a true backbone. The first vertebrate is probably quite like a lamprey, hagfish or lancelet.
  • Macroscopic life colonizes land
    500 BCE

    Macroscopic life colonizes land

    Macroscopic life in the form of plants, fungi, and animals did not colonize land until about 500 million years ago. This gradual evolutionary venture was associated with adaptations that helped prevent dehydration and made it possible to reproduce on land.
  • The Great Ordovician Biodiversification Event
    489 BCE

    The Great Ordovician Biodiversification Event

    The Great Ordovician Biodiversification Event begins, leading to a great increase in diversity. Within each of the major groups of animals and plants, many new varieties appear.
  • Plants arrive on land
    465 BCE

    Plants arrive on land

    Plants begin colonizing the land.
  • Centipedes first land creature
    428 BCE

    Centipedes first land creature

    Pneumodesmus newmani is a species of millipede that lived 428 million years ago, in the Late Silurian. It is the first myriapod, and the oldest known creature to have lived on land.
  • Tetrapods evolve
    397 BCE

    Tetrapods evolve

    The first four-legged animals, or tetrapods, evolve from intermediate species such as Tiktaalik, probably in shallow freshwater habitats. The tetrapods go on to conquer the land, and give rise to all amphibians, reptiles, birds and mammals.
  • First amphibians
    370 BCE

    First amphibians

    The first major groups of amphibians developed in the Devonian period, around 370 million years ago, from lobe-finned fish which were similar to the modern coelacanth and lungfish. These ancient lobe-finned fish had evolved multi-jointed leg-like fins with digits that enabled them to crawl along the sea bottom.
  • End of the world, almost.
    250 BCE

    End of the world, almost.

    The Permian period ends with the greatest mass extinction in Earth’s history, wiping out great swathes of species, including the last of the trilobites.
  • Dinosaurs control world
    200 BCE

    Dinosaurs control world

    By the year 200,000,000 BCE, dinosaurs reigned through and ruled throughout the entire world, being the dominant inhabitiants of Earth.
  • First birds emerge
    168 BCE

    First birds emerge

    A half-feathered, flightless dinosaur called Epidexipteryx, which may be an early step on the road to birds, lived in China.
  • First flowering plants
    130 BCE

    First flowering plants

    The first flowering plants emerge, following a period of rapid evolution.
  • Ocean becomes oxygen-deprived
    93 BCE

    Ocean becomes oxygen-deprived

    The oceans become starved of oxygen, possibly due to a huge underwater volcanic eruption. Twenty-seven percent of marine invertebrates are wiped out.
  • Dinosaur extinction
    65 BCE

    Dinosaur extinction

    By the year 65,000,000 BCE, all dinosaurs had gone extinct. According to scientists who maintain that dinosaur extinction came quickly, the impact must have spelled the cataclysmic end.
  • First simians
    40 BCE

    First simians

    New World monkeys become the first simians (higher primates) to diverge from the rest of the group, colonizing South America.
  • Gorillas evolve
    7 BCE

    Gorillas evolve

    Gorillas branch off from the other great apes.
  • Humans evolve
    6 BCE

    Humans evolve

    Humans diverge from their closest relatives; the chimpanzees and bonobos.