This is a ritual we celebrate every year on the Summer Solstice, starting at [Sol 2012](/Sol_2012), to help experience the history of [life](/life) on [Earth](/Earth) by compressing the planet's lifespan to date into 18 minutes and 45 seconds. We use drums to represent the passage of millions of years, one million per drumbeat. One fact made clear by this experience is the dramatic acceleration of events as we get closer to the present, although this may be partly an artifact of the difficulty of studying the extremely deep past.
Event
Approx. date
Number of drumbeats
Time
Beginning of Late Heavy Bombardment
4.1 billion years ago
400
1 min 40 sec
Origin of life
3.8 billion years ago
700
2 min 55 sec
First photosynthetic organisms
3.5 billion years ago
1000
4 min 10 sec
First cyanobacteria
3 billion years ago
1500
6 min 15 sec
Oxygenation of the air
2.4 billion years ago
2100
8 min 45 sec
First eukaryotes
2 billion years ago
2500
10 min 25 sec
Early proto-fungi
1.43 billion years ago
3070
12 min 47 sec
Origin of sex, first multicellular organisms
1.2 billion years ago
3300
13 min 45 sec
Beginning of Cryogenian period
850 million years ago
3650
15 min 12 sec
End of Cryogenian
630 million years ago
3870
16 min 7 sec
Avalon explosion (Ediacaran biota)
575 million years ago
3925
16 min 21 sec
Cambrian explosion
530 million years ago
3970
16 min 32 sec
First vertebrates
485 million years ago
4015
16 min 44 sec
Arthropods appear on land
450 million years ago
4050
16 min 52 sec
First land plants
434 million years ago
4066
16 min 56 sec
First insects
400 million years ago
4100
17 min 5 sec
First amphibians
368 million years ago
4132
17 min 13 sec
First reptiles
320 million years ago
4180
17 min 25 sec
End-Permian extinction event
252 million years ago
4248
17 min 42 sec
First dinosaurs
230 million years ago
4270
17 min 47 sec
First mammals
210 million years ago
4290
17 min 52 sec
Early birds
150 million years ago
4350
18 min 7 sec
Extinction of the dinosaurs
65 million years ago
4435
18 min 29 sec
Earliest hominids/apes
14 million years ago
4486
18 min 41 sec
Appearance of Australopithecus
4 million years ago
4496
18 min 44 sec
First humans
200 thousand years ago
4500
18 min 45 sec