I’m a big fan of Bill Bryson’s writings and especially loved his A Short History of Nearly Everything book in which he gave an example of the Earth’s history if it had been compressed into a single day. The example highlighted how insignificant our time on Earth has been and really put things in perspective (and clears up some misconceptions too). Below is how the Earth and its inhabitants would have evolved if the entire saga took place in the span of 24 hours.
If you imagine the 4,500 billion odd years of Earth’s history compressed into a normal earthly day, then life begins very early, about 4:10 AM, with the rise of the first simple, single celled organisms, but then advances no further for the next sixteen hours. Not until almost 8:30 in the evening has Earth anything to show the universe but a restless skin of microbes. Then, finally, the first sea plants appear, followed twenty minutes later by the first jellyfish and the enigmatic soft-bodied Ediacaran fauna first seen by Reginald Sprigg in Australia.
At 9:04 PM, the marine arthropods trilobites, swim onto the scene, followed more or less immediately by the shapely fossilized creatures found at the Burgess Shale. Just before 10:00 PM plants begin to pop up on the land. Soon after, with less than two hours left in the day, the first land creatures follow. Thanks to ten minutes or so of balmy weather, by 10:24 PM, the Earth is covered in the great carboniferous forests whose residues give us all our coal, and the first winged insects are evident. Dinosaurs plod onto the scene just before 11:00 PM and hold sway for about 40 minutes. At twenty-one minutes to midnight they vanish and the age of mammals begins with birds following 8 minutes later. Humans emerge one minute and seventeen seconds before midnight.
The whole of our recorded history, on this scale, would be no more than a few seconds, a single human lifetime barely an instant. And throughout the whole about once every six minutes, somewhere on the planet there is a flashbulb pop of light marking the impact of a large meteor, one that is large enough to impact the weather patterns or even cause mas extinctions. It’s a wonder than anything at all can survive in such a pummeled and unsettled environment. In fact, not many things do for long.
Timescale in table form
Life on Earth (app. 3.8 Ga) 4:10 AM
Eucaryots (app. 2.1 Ga) 13:02 PM
Metazoans (1.2 Ga?) 17:44 PM
Chordates (565 Ma) 21:03 PM
Phanerozoicum (CAMBRIAN 542 Ma) 21:10 PM
ORDOVICIAN (488.3 Ma) 21:27 PM
Land dwelling plants (475 Ma) 21:31 PM
SILURIAN (443.7 Ma) 21:41 PM
Land dwelling animals 21:46 PM
DEVONIAN (416.0 Ma) 21:49 PM
Semi-aquatic vertebrates (360 Ma) 22:07 PM
CARBONIFEROUS (359.2 Ma) 22:07 PM
Reptiles (340 Ma) 22:13 PM
PERMIAN (299.0 Ma) 22:26 PM
TRIASSIC (251.0 Ma) 22:41 PM
Dinosaurs (235 Ma) 22:46 PM
Mammals (225 Ma) 22:49 PM
JURASSIC (199.6 Ma) 22:57 PM
Birds (147 Ma) 23:14 PM
CRETACEOUS (145.5 Ma) 23:14 PM
PALEOCENE (65.5 Ma) 23:39 PM
EOCENE (55.8 Ma) 23:42 PM
OLIGOCENE (33.9 Ma) 23:49 PM
MIOCENE (23.03 Ma) 23:52 PM
Common ape-human ancestor (7 Ma) 23:57 PM
PLIOCENE (5.33 Ma) 23:58 PM
PLEISTOCENE (1.81 Ma) 23:59:26 PM
Homo sapiens (165.000) 23:59:56,9 PM
“Out of Africa” (100.000) 23:59:58,1 PM
Homo s. sapiens (35.000) 23:59:59,3 PM
Extinction of neanderthals (25.000) 23:59:59,5 PM
HOLOCENE (0.01 Ma) 23:59:59,8 PM
Oldest civilizations (3.500) 23:59:59,9 PM
Industrial revolution (250) 23:59:59,999 ?