The document provides a conversion multiplier to compare various timescales in geology, biology and human lifespan. It shows that 3.5 billion years ago the Earth formed without free oxygen in the atmosphere. Around 2.5 billion years ago, eukaryotic cells first evolved and oxygen began accumulating in the atmosphere. The Cambrian explosion of animal diversity occurred around 543 million years ago. Major extinction events occurred at the ends of the Permian and Cretaceous periods, wiping out many marine and land species. The first hominids evolved around 1.8 million years ago in the Quaternary period.

1. Timeperiod
Majorevolutionary
event
Generalconversion
multiplier
Distancerunina10-
kilometerrace
Distanceonafootball
field(100yards)
Distanceonasoccer
field(100meters)
Ageinanave.human
lifespan(76yrs)
Dayinacalendaryear
No.ofthe407M&M’sin
1lbbag
Timepassedina3-hour
exam
Timeremainingina3-
hourexam
4500
mya
Earth is formed; 0 0 m 0 yds 0 m 0 yrs Jan. 1st 0 eaten 0 min 180 min
no free oxygen
3800
mya
Prokaryotes evolve; 0.1556 1556 m 15 yds 20 in 15.56 m 12 yrs old Feb. 25th 63 eaten 28min 152 min
hydrosphere present
2500
mya
Eukaryotes evolve; 0.4444 4444 m 44 yds 16 in 44.44 m 34 yrs old June 13th 181 eaten 80 min 100 min
oxygen present in
atmosphere
543
mya
Cambrian Period; 0.8793 8793 m 87 yds 33 in 87.93 m 67 yrs old Nov. 15th 357 eaten 158.3 min 21.7 min
explosion of animal phyla
500
mya
Ordovician Period; 0.8889 8889 m 88 yds 32 in 88.89 m 67.5 yrs old Nov. 19th 361 eaten 160 min 20 min
evidence of complex plants
on land
440
mya
Silurian Period; 0.9022 9022 m 90 yds 8 in 90.22 m 68.5 yrs old Nov. 24th 367 eaten 162.4 min 17.6 min
vascular plants and
arthropods on land
409
mya
Devonian Period; 0.9091 9091 m 90 yds 33 in 90.91 m 69 yrs old Nov. 27th 370 eaten 163.6 min 16.4 min
mountain building in North
America; fresh water
increasing
354
mya
Carboniferous Period; 0.9213 9213 m 92 yds 5 in 92.13 m 70 yrs old Dec. 1st 374 eaten 165.8 min 14.2 min
major radiation of insects

2. 290
mya
Permian Period; 0.9356 9356 m 93 yds 20 in 9.56 m 71 yrs old Dec. 6th 380 eaten 168.4 min 11.6 min
mammal-like reptiles
predominate; huge land and
sea extinction event at
period’s end
245
mya
Triassic Period; 0.9456 9456 m 94 yds 20 in 94.56 m 72 yrs old Dec. 9th 384 eaten 170.2 min 9.8 min
ancestors of dinosaurs
present and diversifying
206
mya
Jurassic Period; 0.9542 9542 m 95 yds 15 in 95.42 m 72.5 yrs old Dec. 13th 388 eaten 171.8 min 8.2 min
Pangaea begins breaking
up; dinosaurs continue to
diversify
144
mya
Cretaceous Period; 0.968 9680 m 96 yds 28 in 96.80 m 73.5 yrs old Dec. 18th 394 eaten 174.2 min 5.8 min
angiosperms rapidly
diversify
65
mya
Tertiary Period; 0.9856 9856 m 98 yds 20 in 98.56 m 75 yrs old Dec. 24th 401 eaten 177.4 min 2.6 min
terrestrial and marine
reptiles and many marine
invertebrates go extinct
1.8
mya
Quaternary Period; 0.9996 9996 m 99 yds 35 in 99.96 m 76 yrs, 355
days
8:30 p.m. 406.8 eaten 179.9 min 0.1 min
first hominids present Dec. 31st