The evolution of modern humans has been astronomically unlikely; our time on the planet has been fleeting and continually on a knife-edge. The odds are that our species will blink out of existence, just like all of our closest relatives. Earth’s history and future in two 1 year timelines.
1-3 January
Earth forms from small grains of rock and ice revolving around the young Sun.
Image by David A Hardy
4 January
Moon forms from material from a giant impact by a Mars-sized body hitting the nearly formed proto-Earth.
Image by James Garry, Fastlight Artwork
8-24 January
Earth’s surface is mostly molten rock, gradually cooling as heat radiates into space.
24 January – 16 February
Millions of ice rich asteroids and comets bombard Earth. Steamy atmosphere develops, rich with water released from impacting comets. Torrential rains turn to steam on the hot surface, finally collecting into warm seas and oceans above and around the cooling rock of the Earth’s crust.
17 February
As continents form, first life forms and self-replicating molecules evolve. As bombardment diminishes, single-celled microbes spread widely in wet habitats and diversify.
Image by David A Aguilar
5 March
Earth’s oceans achieve their present volumes.
29 March
Bacteria develop primitive forms of photosynthesis.
7 May
Oxygen producing bacteria evolve; oxygen concentration in atmosphere slowly rises. Moon still close to Earth, causing massive ocean tides. Earth wracked by hurricane-force winds. Extreme climate stimulates evolutionary processes.
Image © Brian Smallwood – spaceprime.com
24 June – 18 July
Huronian Ice Age. Ozone layer forms in higher atmosphere, protecting Earth’s surface from harmful ultraviolet radiation. High oxygen concentration causes decrease of methane, an effective greenhouse gas, leading to Earth’s first big ice age. It is so severe that virtually the whole planet freezes over (Snowball Earth hypothesis) killing off nearly all photosynthetic life. Eventually, enough CO2 and methane, mainly emitted by volcanoes, accumulates to cause greenhouse effect to enable Earth to break free of deep freeze.
Image from bbc.co.uk
26 July – 11 August
Formation of supercontinent Nuna. Remaining cellular life adapts to changing environments and evolves in structural complexity.
27 September
Sexual reproduction first appears, increasing rate of evolution and leading to simple multicellular organisms in the form of algae.
5 October
The supercontinent Rodinia assembles.
21 October
Multicellular life evolves into simple animals, resembling modern sponges.
25 October – 12 November
Cryogenian Ice Age. Second and possibly third Snowball Earth global glaciations. Global temperature falls so low that ice sheets engulf the majority of the planet. Refrigeration is maintained by ice reflecting solar energy back into space. There is mass extinction of life.
Volcanic activity, brought about by the break up of Rodinia, emits enough CO2 and methane to enable greenhouse effect to melt the ice.
Image by Christopher Scotese
16-17 November
Melting glaciers supply sediments and nutrients to the oceans, triggering a boom in the first large, complex multicellular organisms and the rapid reoxygenation of the atmosphere.
18 November
Rejoining of the continental masses of current-day Africa, South-America, Antarctica and Australia into supercontinent Pannotia in a position around the South Pole; current-day North America forms a separate continent called Laurentia. Sudden multiplication of large complex life forms known as the Cambrian Explosion, when many modern groups of life come into existence.
19 November
Supercontinent Pannotia breaks apart into the smaller continents Baltica,Siberia and Gondwana.
Image by Christopher Scotese
20-25 November
Major diversification of living things in the oceans, first early animal explorations on land and evolution of first vertebrates with true bones.
26-27 November
Ordovician–Silurian extinction event kills more than 60% of marine species as Gondwana moves into the south polar region. Global cooling, glaciation and falling sea levels eliminate habitats along the continental shelves.
28-29 November
First primitive plants and funghi move onto land.
30 November – 1 December
First tetrapods evolve from fish, their fins becoming limbs allowing them to lift their heads out of the water to breathe air and later venture onto land.
Image by Zina Deretsky, National Science Foundation
2 December
Late Devonian extinctions eliminate about 70% of all species.
Image by Richard Bizley – Science Photo Library
3-11 December
Karoo Ice Age and start of the Carboniferous Period. Earth begins to be recognisable. Insects swarm over land and some start to fly; sharks become top predators in the oceans and vegetation covers the land, with seed-bearing plants and forests soon to flourish. Four-limbed tetrapods gradually adapt to a terrestrial habitat. Formation of the last supercontinent, Pangaea.
Image by Christopher Scotese
12 December
Permian–Triassic extinction event (‘the Great Dying’) eliminates over 95% of marine species. Possibly caused by a supervolcanic event, an asteroid impact, sea level fluctuations, or a combination of these and other events. Marine life eventually recovers.
Image by Chris Butler – Science Photo Library
13 December
Earliest dinosaurs appear. Herbivore dinosaurs begin to grow to huge sizes to accommodate the large guts necessary to digest nutrient-poor plants.
14 December
First mammals appear (resembling modern shrews). Very few are any larger than mice and they are mostly nocturnal, as dinosaurs dominate the landscape.
15 December
Triassic–Jurassic extinction event kills over half of all species, but spares many of the dinosaurs. Small mammals also survive.
17-22 December
Pangaea breaks up into Laurasia and Gondwana. Gondwana then separates into multiple continents (Africa, South America, India, Antarctica, and Australia).
Image by Christopher Scotese
23-25 December
The first bees spread the pollen of early flowering plants. This innovation causes a major burst of animal evolution through co-evolution. The earliest snakes then the first ants appear.
26 December
Tyrannosaurus, one of the largest terrestrial dinosaurs predators appears, along with the first species of Triceratops. Within 6 hours, the K–T extinction event occurs. A 6 mile-wide meteorite strikes Earth off the Yucatán Peninsula, ejecting vast quantities of dust and vapour into the atmosphere blocking out sunlight. 75% of all animal species and all of the dinosaurs (except their descendants the birds) are eradicated.
Image – The End of the Dinosaurs by Maspix
Image by Christopher Scotese
27-28 December
Mammals become the dominant species; some evolving to become carnivorous. Earliest true primates appear. Modern bird groups diversify (first song birds, parrots, swifts, woodpeckers), first whales, bats, rhinoceroses, camels, sabre-toothed cats and modern type butterflies and moths. Laurasia splits when North America/Greenland breaks free from Eurasia, opening the Norwegian Sea and expanding the Atlantic Ocean.
29 December
Start of the current major ice age. Grasses evolve and grasslands begin to expand. Many modern mammal groups begin to appear, including dogs, pigs and cats, plus the first eagles and hawks. Over the last 12 hours, a series of supervolcanic eruptions occur in Yemen, Brazil, New Mexico, Nevada/Utah, Colorado and the Great Basin,USA.
30 December
The modern continental arrangement is recognisable. Appearance of first deer, giraffes, kangaroos and bovids (ancestors of bison, buffalo, gazelle and domestic cattle). Savannas are established. Horses increase to modern body size and there is major diversification in grassland mammals. Supervolcanic eruptions in Chile, Bolivia and Nevada.
31 December
12 noon – First hominin appears (Sahelanthropus).
14:51 – First mammoths.
15:48 – Supervolcanic eruption in Idaho.
16:23 – Supervolcanic eruption inChile.
18:17 – Ice Age intensifies with the spread of ice sheets into the Northern Hemisphere.
19:03 – Earth’s continents assume their current position.
19:25 – First member of the genus Homo appears (Homo habilis).
19:48 – Supervolcanic eruption in Argentina.
20:06 – Supervolcanic eruption at Yellowstone, USA.
20:10 – Evolution of Homo erectus.
20:23 – Evolution of Homo ergastor.
21:08 – Homo erectus develops ability to control fire.
21:30 – Volcanic eruption at Yellowstone.
21:31 – 22:40 – Period of Glaciation which sees the extinction of Homo habilis, Homo ergastor and Homo erectus. Homo antecessor evolves then becomes extinct within the same period.
22:42 – 22:50 – Glaciation. Supervolcanic eruption at Yellowstone at 22:47.
22:51 – Evolution of Homo heidelbergensis.
23:03 – 23:15 – Glaciation.
23:20 – Extinction of Homo heidelbergensis. Evolution of Neanderthals.
Image from bbc.co.uk
23:30 – Supervolcanic eruption at Whakamaru, New Zealand.
23:37 – Anatomically modern humans appear inAfrica.
23:38 – 23:47 – Glaciation.
23:49 – Start of last period of Glaciation.
23:52 – Supervolcanic eruption at Toba, Indonesia. World population of modern humans plunges to as low as 1,000.
Image by Darkside Animation
23:53 – Modern humans start colonising the other continents outside of Africa.
23:56:55 – Supervolcanic eruption – Taupo, New Zealand.
23:57:15 – Extinction of Neanderthals.
23:57:57 – Last Glacial Maximum
Image by Christopher Scotese
23:58:38 – End of last period of Glaciation.
23:58:45 – Giant short-faced bears, horses and related species vanish from North America.
23:58:51 – Last mainland species of woolly mammoth and sabre-tooth cat die out.
23:59:00 – Beginning of agriculture.
Image from The First Farmers
23:59:22 – First human civilization at Sumer.
23:59:46 – 23:59:49 – Roman Empire.
23:59:58 – Industrial Revolution.
23:59:59.7 – Man walks on the Moon.
On this 12 month timescale:
The continents have zoomed around the planet like speedboats on a lake. When India separated from Antarctica on 22 December it moved northward toward Eurasia at 22 metres per second. When it hit the Asian landmass around 29 December the impact zone crumpled up to create the Himalayas – in fact they are still colliding, the Himalayas are growing at a rate of 7.3 metres per second.
Asteroids with a 1 km diameter have struck the Earth on average every hour. Collisions with 5 km objects have happened every day. The last known impact of an object of 10 km or more in diameter was the K-T extinction event 5 days ago.
Supervolvanoes explode with frightening regularity, ejecting thousands of cubic kilometres of ash and rock into the atmosphere, blocking out the sun and sending the Earth into devastating volcanic winters. The most recent supervolcanic eruption was just over 3 minutes ago. Yellowstone has super-erupted at three regular intervals – 4 hours ago, 2½ hours ago and 1¼ hours ago.
Glaciation occurs with monotonous regularity every few minutes, as ice sheets miles thick advance from the poles, carving up the landscape, freezing the oceans and tying up so much of the Earth’s water that large parts of the remaining temperate zones are turned to desert. At least twice, virtually the whole planet has resembled a giant snowball. Glacial periods are the longer periods of cold that separate shorter periods of warm interglacial periods, occurring within the major ice ages – we are in the middle of a major ice age which began 3 days ago. The last glacial period ended just over a minute ago; the current interglacial period will last anywhere between 2 and 5 minutes.
The presence of modern humans on the planet has been a fleeting 23 minutes. We have lived on a knife edge throughout this short time. Species continually blink in and out of existence. Our closest relatives, the Neanderthals, came and went in just 37 minutes. In the final 6 weeks, 5 global extinction events have killed off over 50% of animal species. With just one slight tweak at any point on the timeline, if just one of our ancestor species had gone the way of the other 99%, and we wouldn’t be here at all.
But modern humans did make it, thriving to the point that our population has exploded ten-fold in the last 2 seconds. We have evolved into a uniquely intelligent species of animal, capable of piloting itself out of the Earth’s atmosphere and walking on the Moon 0.3 of a second before the year ended. Looking back over the year, this achievement has been astronomically unlikely.
So what about Year 2? Well, things look a bit bleak:
1 January
Within the first 4 minutes the current interglacial will end and the ice sheets will return.
Image by artist Kenn Brown of Mondolithic Studios from Alan Weisman: The World Without Us
Within 10 minutes it is likely that there will be another supervolcanic eruption at Yellowstone.
Image from National Geographic
Within an hour it is likely that Earth will be impacted by a meteorite 1 km in diameter.
Before New Year’s Day is over the Rift Valley in East Africa will have widened to the point that it is flooded by the Red Sea, causing a new ocean basin to divide the continent of Africa.
4 January
Africa will collide with Eurasia. The Mediterranean Sea will become the Mediterranean Mountains, similar in scale to the Himalayas.
Image by Christopher Scotese
8 January
It is likely that the Earth will have been hit by a meteorite 10km wide, similar in size to the one which wiped out the dinosaurs.
20 January
All the continents on Earth will have fused into a new supercontinent – ‘Pangea Ultima’
Image by Christopher Scotese
21 March
The Sun’s ever-increasing brightness will have rendered the Earth’s surface largely uninhabitable, resembling a bleached version of the barren landscape of Mars. The average global surface temperature will be almost 50°C (it is currently 15°C). The oceans will evaporate and most of the planet will be a dry desert, though some water may be retained at the poles. Any remaining life left clinging to the Earth’s surface will be microbial, at best multi-cellular.
For humans it will be Game Over, unless somehow our game continues elsewhere. By the end of Year 2 the surface temperature will rise sufficiently to melt surface rock and all life will be gone.
By July of Year 3, the dying Sun will reach its maximum size as a red giant, its surface extending 20% beyond Earth’s current orbit, engulfing and vaporising it.
So thank whichever god you follow that you exist right here and now, in the comfort of this mild interglacial period, with the intelligence to consider your good fortune. Enjoy it while it lasts!
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Loved it, very interesting and for the most part historically accurate as well! Awesome graphics. Take Care.
David
Loved the article and graphics, it makes me want to build a spaceship and fly away.