Making a Timeline of the Evolution of the Universe


The following table shows significant evolutionary/geological events, when they happened,
and where they would be placed on a time line 15 meters long.

The events and when they occurred were taken from Niel Brandt's web page: Niel Brandt's Timelines and Scales of Measurement

Time (Myr ago)

distance from present

1 meter = 1 billion years

12-15 billion yrs Big Bang 12-15 meters
4600 Formation of the approximately homogeneous solid Earth by planetesimal accretion
4.6 meters

Melting of the Earth due to radioactive and gravitational heating which leads to its differentiated interior structure as well as outgassing of molecules such as water, methane, ammonia, hydrogen, nitrogen, and carbon dioxide
4.3 meters
4300 Atmospheric water is photodissociated by ultraviolet light to give oxygen atoms which are incorporated into an ozone layer and hydrogen molecules which escape into space
4.3 meters
4000 Bombardment of the Earth by planetesimals stops
4.3 meters
3800 The Earth's crust solidifies---formation of the oldest rocks found on Earth
Condensation of atmospheric water into oceans
3.8 meters
3500--2800 Prokaryotic cell organisms develop
Beginning of photosynthesis by blue-green algae which releases oxygen molecules into the atmosphere and steadily works to strengthen the ozone layer and change the Earth's chemically reducing atmosphere into a chemically oxidizing one
3.5-2.8 meters
1500 Eukaryotic cell organisms develop
1.5 meters
1500--600 Rise of multicellular organisms
1.5-.6 meters
580--545 Fossils of Ediacaran organisms are made
54-58 cm.
545 Cambrian explosion of hard-bodied organisms
54.5 cm.
500--450 Rise of the fish---first vertebrates
45-50 cm.
430 Waxy coated algae begin to live on land
43 cm.
420 Millipedes have evolved---first land animals
42 cm.
375 Appearance of primitive sharks
37.5 cm.
350--300 Rise of the amphibians
30-35 cm.
350 Primitive insects have evolved
35 cm.
350 Primitive ferns evolve---first plants with roots
35 cm.
300--200 Rise of the reptiles
20-30 cm.
300 Winged insects have evolved
30 cm.
280 Beetles and weevils have evolved
28 cm
250 Permian period mass extinction
25 cm.
230 Roaches and termites have evolved
23 cm.
225 Modern ferns have evolved
22.5 cm.
225 Bees have evolved
22.5 cm.
200 Pangaea starts to break apart
20 cm.
200 Primitive crocodiles have evolved
20 cm.
200 Appearance of mammals
20 cm.
145 Archaeopteryx walks the Earth
14.5 cm.
136 Primitive kangaroos have evolved
13.6 cm.
90 Modern sharks have evolved
9 cm.
The Chicxulub impact occurs
6.5 cm
65 K-T Boundary---extinction of the dinosaurs and beginning of the reign of mammals 60 Rats, mice, and squirrels have evolved
6.5 cm
60 Herons and storks have evolved
6 cm.


Rabbits and hares have evolved
5.5 cm
50 Primitive monkeys have evolved
5 cm
28 Koalas have evolved
2.8 cm
20 Parrots and pigeons have evolved
2 cm.
20--12 The chimpanzee and hominid lines evolve
1.2-2.0 cm.
4 Development of hominid bipedalism
4 mm
4--1 Australopithecus exist
1-4 mm
3.5 The Australopithecus Lucy walks the Earth
3.5 mm
2 Widespread use of stone tools
2 mm
2 Most recent ice age
2 mm
1.6 Homo erectus exist
1.6 mm
0.05--0 Homo sapiens sapiens exist
.05 mm
To the Future
+4500 Sun's nuclear fusion ends (in 4.5 billion years) +4.5 meters

If the time from the big bang to the present is reprsented by a 15 meter line, all of human existance is in the last 20th of a millimeter.

Time (Myr ago) Event

5000--1500 Archeozoic (Archean) era
1500--545 Proterozoic era Paleozoic era ``Ancient life''
545--505 Cambrian period
505--438 Ordovician period
438--410 Silurian period
410--355 Devonian period
355--290 Carboniferous (Mississippian/Pennsylvanian) period
290--250 Permian period Mesozoic era ``Middle Life''
250--205 Triassic period
205--135 Jurassic period
135--65 Cretaceous period Cenozoic era ``Recent Life'' Tertiary (Paleogene/Neocene) period
65--55 Paleocene epoch
55--38 Eocene epoch
38--26 Oligocene epoch
26--6 Miocene epoch
6--1.8 Pliocene epoch Quaternary period
1.8--0.01 Pleistocene epoch
0.50--0.25 Lower Paleolithic0.25--0.06 Middle Paleolithic
0.06--0.01 Upper Paleolithic
0.01--0 Holocene epoch