Carl Sagan

Big Bang

15000000000

5000000000

Carl Sagan

Origin of Milky Way Galaxy

10000000000

5400000000

Carl Sagan

Origin of the Solar System

4600000000

200000000

Carl Sagan

Formation of the Earth

4400000000

400000000

Carl Sagan

Origin of life on Earth

4000000000

300000000

Carl Sagan

Formation of the oldest rocks known on Earth

3700000000

300000000

Carl Sagan

Date of oldest fossils (bacteria and blue-green algae)

3400000000

900000000

Carl Sagan

Invention of sex (by microorganisms)

2500000000

500000000

Carl Sagan

Oldest fossil photosynthetic plants

2000000000

100000000

Carl Sagan

Eukaryotes (first cells with nuclei) flourish

1900000000

700000000

Carl Sagan

Significant oxygen atmosphere begins to develop on Earth

1200000000

200000000

Carl Sagan

Extensive volcanism and channel formation on Mars

1000000000

380000000

Carl Sagan

First worms

620000000

50000000

Carl Sagan

Precambrian ends. Paleozoic Era and Cambrian Period begin. Invertebrates flourish

570000000

40000000

Carl Sagan

First oceanic plankton. Trilobites flourish.

530000000

40000000

Carl Sagan

Ordovician Period. First fish, first vertebrates.

490000000

40000000

Carl Sagan

Silurian Period. First vascular plants. Plants begin colonization of land

450000000

40000000

Carl Sagan

Devonian Period begins. First insects. Animals begin colonization of land

410000000

40000000

Carl Sagan

First amphibians. First winged insects.

370000000

40000000

Carl Sagan

Carboniferous Period. First trees. First reptiles.

330000000

40000000

Carl Sagan

Permian Period begins. First dinosaurs.

290000000

40000000

Carl Sagan

Paleozoic Era ends. Mesozoic Era Begins.

250000000

40000000

Carl Sagan

Triassic Period. First mammals.

210000000

50000000

Carl Sagan

Jurassic Period. First birds.

160000000

40000000

Carl Sagan

Cretaceous Period. First flowers. Dinosaurs become extinct.

120000000

38000000

Carl Sagan

Mesozoic Era ends. Cenozoic Era Tertiary Period begins. First cetaceans. First primates.

82000000

41000000

Carl Sagan

First evolution of frontal lobes in the brain of primates. First hominids. Giant mammals flourish.

41000000

23000000

Carl Sagan

Origin of Proconsul and Ramapithecus, probable ancestors of apes and men

18000000

15400000

Carl Sagan

First humans

2600000

900000

Carl Sagan

Widespread use of stone tools

1700000

1290000

Carl Sagan

Domestication of fire by Peking man

410000

290000

Carl Sagan

Beginning of most recent glacial period

120000

62000

Carl Sagan

Seafarers settle Australia

58000

29000

Carl Sagan

Extensive cave painting in Europe

29000

10000

Carl Sagan

Invention of agriculture

19000

7000

Carl Sagan

Neolithic civilization; first cities

12000

7200

Carl Sagan

First dynasties in Summer, Ebla, and Egypt; development of astronomy

4800

500

Carl Sagan

Invention of the alphabet; Akkadian Empire

4300

500

Carl Sagan

Hammurabic legal codes in Babylon; Middle Kingdom in Egypt

3800

400

Carl Sagan

Bronze metallurgy; Mycenaean culture; Trojan War; Olmec culture; invention of the compass

3400

500

Carl Sagan

Iron metallurgy; First Assyrian Empire; Kingdom of Israel; founding of Carthage by Phoenicia

2900

500

Carl Sagan

Asokan India; Ch'in Dynasty China; Periclean Athens; birth of Buddha

2400

500

Carl Sagan

Euclidian geometry; Archimedean physics; Ptolemaic astronomy; Roman Empire; Christ

1900

500

Carl Sagan

Zero and decimals invented in Indian arithmetic; Rome falls; Moslem conquests

1400

400

Carl Sagan

Mayan civilization; Sung Dynasty China; Byzantine empire; Mongol invasion; crusades

1000

500

Carl Sagan

Renaissance in Europe; voyages of discovery from Europe and from Ming Dynasty China; emergence of the experimental method in science

500

499

Carl Sagan

Widespread development of science and technology; emergence of global culture; acquisition of the means of self-destruction of the human species; first steps in space craft planetary exploration and the search of extraterrestrial intelligence

1

American Museum of Natural History

Big Bang

13000000000

3000000000

American Museum of Natural History

Milky Way forms

10000000000

5500000000

American Museum of Natural History

Sun and planets form

4500000000

700000000

American Museum of Natural History

Oldest known life (single cell)

3800000000

2800000000

American Museum of Natural History

First multicellular organisms

1000000000

450000000

American Museum of Natural History

Cambrian Explosion (burst of new life forms)

550000000

70000000

American Museum of Natural History

Emergence of first vertebrates

480000000

40000000

American Museum of Natural History

Early land plants

440000000

50000000

American Museum of Natural History

Variety of insects begin to flourish

390000000

160000000

American Museum of Natural History

First dinosaurs appear

230000000

40000000

American Museum of Natural History

First mammalian ancestors appear

190000000

50000000

American Museum of Natural History

First known birds

140000000

75000000

American Museum of Natural History

Dinosaurs wiped out by asteroid or comet

65000000

49000000

American Museum of Natural History

Apes appear

16000000

12100000

American Museum of Natural History

First human ancestors to walk upright

3900000

2100000

American Museum of Natural History

Homo erectus appears

1800000

1785000

American Museum of Natural History

Anatomically modern humans appear

15000

8700

American Museum of Natural History

Invention of writing

6300

1700

American Museum of Natural History

Pyramids built in Egypt

4600

4092

American Museum of Natural History

Voyage of Christopher Columbus

508

Encyclopaedia Britannica

Oldest prokaryotic fossils

3500000000

1000000000

Encyclopaedia Britannica

Oxygen begins to accumulate in atmosphere

2500000000

400000000

Encyclopaedia Britannica

Oldest eukaryotic fossils

2100000000

1400000000

Encyclopaedia Britannica

Simple multicellular organisms evolve

700000000

280000000

Encyclopaedia Britannica

Plants colonize land

420000000

50000000

Encyclopaedia Britannica

Amphibians appear

370000000

10000000

Encyclopaedia Britannica

First insects

360000000

20000000

Encyclopaedia Britannica

Reptiles appear

340000000

60000000

Encyclopaedia Britannica

Mass extinction

280000000

50000000

Encyclopaedia Britannica

First dinosaurs and mammals

230000000

30000000

Encyclopaedia Britannica

Birds evolve from reptiles

200000000

60000000

Encyclopaedia Britannica

First flowering plants

140000000

74000000

Encyclopaedia Britannica

Mass extinction

66000000

63600000

Encyclopaedia Britannica

Ice age

2400000

2300000

Encyclopaedia Britannica

Advent of modern humans

100000

99999

Encyclopaedia Britannica

Present

1

ERAPS at University of Arizona

No life; shallow seas

4000000000

200000000

ERAPS at University of Arizona

Origin of simple cells

3800000000

300000000

ERAPS at University of Arizona

Origin of cyanobacteria

3500000000

1000000000

ERAPS at University of Arizona

Oxygen accumulates in atmosphere

2500000000

800000000

ERAPS at University of Arizona

Protists and green algae

1700000000

700000000

ERAPS at University of Arizona

Simple multicellular life (sponges, seaweeds)

1000000000

300000000

ERAPS at University of Arizona

More invertebrates (flatworms, jellyfish)

700000000

180000000

ERAPS at University of Arizona

Early animals with hard parts in oceans

520000000

110000000

ERAPS at University of Arizona

Planets invade land

410000000

60000000

ERAPS at University of Arizona

Vertebrates invade land

350000000

50000000

ERAPS at University of Arizona

Coal forming forests, amphibians, BIG insects

300000000

70000000

ERAPS at University of Arizona

Mass extinction (trilobites)

230000000

30000000

ERAPS at University of Arizona

Pangaea, first mammals, first reptiles

200000000

135000000

ERAPS at University of Arizona

Mass extinction (including dinosaurs)

65000000

35000000

ERAPS at University of Arizona

Small mammals, humanoids

30000000

28000000

ERAPS at University of Arizona

Early Humans

2000000

1999999

ERAPS at University of Arizona

Us

1

Paul Boyer

Big bang

15000000000

10200000000

Paul Boyer

Solar system forms

4800000000

200000000

Paul Boyer

Earth forms

4600000000

600000000

Paul Boyer

Nitrogen atmosphere (for winds) is present or acquired

4000000000

100000000

Paul Boyer

Abundant water is present or acquired, Organic precursors for life forms accumulate, Primitive living organisms arise or (less likely) come from space

3900000000

400000000

Paul Boyer

Land temperature stabilizes so that most of the water is liquid

3500000000

300000000

Paul Boyer

Some life forms get energy from oxidationreduction reactions

3200000000

200000000

Paul Boyer

Organisms evolve to gain many present biochemical characteristics

3000000000

300000000

Paul Boyer

Photosynthetic capacity is acquired, and oxygen evolution begins

2700000000

100000000

Paul Boyer

Land surfaces form and plate tectonics established

2600000000

200000000

Paul Boyer

Evolution produces organisms that can use oxygen to make ATP

2400000000

300000000

Paul Boyer

Abundant microorganisms colonize the entire earth.

2100000000

1400000000

Paul Boyer

Multicellular organisms arise with increased capacity for structural differentiation

700000000

300000000

Paul Boyer

Primitive plant forms begin to evolve stems, roots, and leaves

400000000

397400000

Paul Boyer

First humans

2600000

900000

Paul Boyer

Widespread use of stone tools

1700000

700000

Paul Boyer

Acquisition of spoken language

1000000

995000

Paul Boyer

Acquisition of written language

5000

4500

Paul Boyer

They learn that knowledge comes from observation and experiment (scientific method)

500

300

Paul Boyer

Ability to control nature gives rise to a human population explosion

200

100

Paul Boyer

The above abilities give rise to a remarkable understanding of nature

100

Barrow and Silk

Big Bang

20000000000

1500000000

Barrow and Silk

Galaxies begin to form

18500000000

1500000000

Barrow and Silk

Galaxies begin to cluster

17000000000

1000000000

Barrow and Silk

Our protogalaxy collapses; first stars form

16000000000

1000000000

Barrow and Silk

Quasars are born; Population II stars form

15000000000

5000000000

Barrow and Silk

Population I stars form

10000000000

5200000000

Barrow and Silk

Our parent interstellar cloud forms

4800000000

100000000

Barrow and Silk

Collapse of protosolar nebula

4700000000

100000000

Barrow and Silk

Planets form; rock solidifies

4600000000

300000000

Barrow and Silk

Intense cratering of planets

4300000000

400000000

Barrow and Silk

Oldest terrestrial rocks form

3900000000

900000000

Barrow and Silk

Microscopic life forms

3000000000

1000000000

Barrow and Silk

Oxygen rich atmosphere develops

2000000000

1000000000

Barrow and Silk

Macroscopic life forms

1000000000

400000000

Barrow and Silk

Earliest fossil record

600000000

150000000

Barrow and Silk

First fishes

450000000

50000000

Barrow and Silk

Early land plants

400000000

100000000

Barrow and Silk

Ferns, conifers

300000000

100000000

Barrow and Silk

First mammals

200000000

50000000

Barrow and Silk

First birds

150000000

90000000

Barrow and Silk

First primates

60000000

10000000

Barrow and Silk

Mammals increase

50000000

49900000

Barrow and Silk

Homo sapiens

100000

Jean Heidmann

Big Bang, etc.

15000000000

7000000000

Jean Heidmann

Age of most distant galaxies

8000000000

3500000000

Jean Heidmann

Formation of the Sun and the Earth

4500000000

1000000000

Jean Heidmann

First bacteria

3500000000

2000000000

Jean Heidmann

First eucaryotic organisms

1500000000

1000000000

Jean Heidmann

Explosion of life in the Cambria era

500000000

496500000

Jean Heidmann

The dawn of Australopithecus

3500000

1000000

Jean Heidmann

Homo habili uses tools

2500000

1500000

Jean Heidmann

Homo erectus masters the use of fire

1000000

960000

Jean Heidmann

Invention of writing

40000

38000

Jean Heidmann

Eratosthenes measures the size of the Earth

2000

1600

Jean Heidmann

Copernicus, Galileo

400

IGPP Symposium

Formation of the Earth

4600000000

600000000

IGPP Symposium

Origin of Life on Earth

4000000000

200000000

IGPP Symposium

Formation of the oldest rocks known on Earth

3800000000

300000000

IGPP Symposium

Date of oldest fossils and stromatolites

3500000000

700000000

IGPP Symposium

Abundant cyanobacteria and stromatolites

2800000000

300000000

IGPP Symposium

Abundant iron formations

2500000000

400000000

IGPP Symposium

Latest detrital uraninite/pyrite

2100000000

200000000

IGPP Symposium

Atmospheric oxygen

1900000000

100000000

IGPP Symposium

Nucleated cells (phytoplankton)

1800000000

700000000

IGPP Symposium

Complex (sexual) phytoplankton

1100000000

250000000

IGPP Symposium

Seaweeds and protozoans

850000000

250000000

IGPP Symposium

Animals without backbones

600000000

100000000

IGPP Symposium

Fish

500000000

100000000

IGPP Symposium

Land plants and animals

400000000

100000000

IGPP Symposium

Coal swamps

300000000

100000000

IGPP Symposium

Dinosaurs and birds

200000000

100000000

IGPP Symposium

Flowering plants

100000000

98000000

IGPP Symposium

Humans

2000000

Phillip Tobias

Divergence of orangutan lineage from Hominoidea

16000000

8500000

Phillip Tobias

Divergence of gorilla from other African hominoids

7500000

1500000

Phillip Tobias

Uplift, cooling, and aridification of Africa

6000000

300000

Phillip Tobias

Chimpanzee hominid divergence, inferred appearance of Hominidae

5700000

200000

Phillip Tobias

"Messinian crisis", the drying up of the Mediterranean / Spread of African savannah / etc.

5500000

700000

Phillip Tobias

Earliest known fossils identifiable as probable hominid

4800000

1000000

Phillip Tobias

Earliest fossil evidence of hominid bipedalism

3800000

1000000

Phillip Tobias

Hominid fossils known

2800000

100000

Phillip Tobias

Differentiation of postulated "derived A. africanus"

2700000

100000

Phillip Tobias

One or more splittings of hominid lineage; earliest known Australopithecus boisei fossils; ���� earliest known stone cultural remains.

2600000

300000

Phillip Tobias

Acquisition of spoken language (as here inferred); many changes in mammalian fauna of � Africa (baboons, elephants, pigs, bovids, hippopotami, sabertoothed cats, rodents)

2300000

200000

Phillip Tobias

Earliest known Homo habilis fossils

2100000

100000

Phillip Tobias

Earliest modern human brain form; earliest signs of marked brain enlargement in hominids.

2000000

200000

Phillip Tobias

Movement of hominids from Africa to Asia and Europe

1800000

100000

Phillip Tobias

Emergence of Homo erectus

1700000

400000

Phillip Tobias

Acquisition of fire by H. erectus

1300000

100000

Phillip Tobias

Extinction of robust and hyperrobust australopithecines

1200000

700000

Phillip Tobias

Emergence of Homo sapiens

500000

390000

Phillip Tobias

Earliest known "anatomically modern Homo sapiens"

110000

10000

Phillip Tobias

Earliest burial of the dead

100000

60000

Phillip Tobias

Emergence of "modern human culture)

40000

5000

Phillip Tobias

Earliest rock art; earliest protowriting

35000

30000

Phillip Tobias

Earliest writing

5000

David Nelson

Planet earth forms

4500000000

500000000

David Nelson

Planet surface cools and bombardment from space slows, so life has the possibility ���� of existing on the planet.� Oldest earth rocks dated by radioactivity.

4000000000

100000000

David Nelson

Evidence for life seen in Greenland rocks enriched in C12 isotope. Prokaryotes diverge  from archaea. Chlorophyll and photosynthesis evolve in the bacterial lineage.

3900000000

200000000

David Nelson

First banded iron formation seen. Implies oxygen made by photosynthesis

3700000000

200000000

David Nelson

First stromatolites seen.

3500000000

1400000000

David Nelson

First tentative evidence of a eukaryotic microfossil

2100000000

100000000

David Nelson

Oxygen begins to rise in the atmosphere after oxygen sinks saturated.

2000000000

500000000

David Nelson

Oxygen level in the atmosphere reaches present day level and stabilizes. More convincing evidence of eukaryotic microfossils.� Chloroplasts and mitochondria present.

1500000000

300000000

David Nelson

Major eukaryotic phyla diverge. Plants branched before animals/fungi

1200000000

600000000

David Nelson

Invertebrates and vertebrates diverge. Hox gene cluster exists.

600000000

70000000

David Nelson

Cambrian explosion of fossil record.

530000000

130000000

David Nelson

Fish and other vertebrates diverge. Plants and fungi invade the land

400000000

20000000

David Nelson

Vertebrates move onto land

380000000

20000000

David Nelson

Gymnosperms (naked seed plants) diverge from angiosperms (flowering plants)

360000000

60000000

David Nelson

Birds and other vertebrates diverge.

300000000

120000000

David Nelson

Monocots diverge from dicots

180000000

40000000

David Nelson

Oldest angiosperm fossil

140000000

80000000

David Nelson

Last common ancestor of all polymorphism sequences

60000000

55000000

David Nelson

Chimpanzees and humans diverge

5000000

3300000

David Nelson

Homo sapiens

1700000

1500000

David Nelson

Last common ancestor of all human mitochondrial DNA types

200000

141000

David Nelson

Modern humans

59000

Goran Burenhult (ed.)

Purgatorius

60000000

5000000

Goran Burenhult (ed.)

Petrolemuridae

55000000

10000000

Goran Burenhult (ed.)

Adapiformes, omomylformes

45000000

5000000

Goran Burenhult (ed.)

Aegyptopithecus, Propliapithecus, Oligopithecus, Catopithecus

40000000

2000000

Goran Burenhult (ed.)

Afrotarsius

38000000

11000000

Goran Burenhult (ed.)

Omomylformes, Branisella

27000000

9000000

Goran Burenhult (ed.)

Prohylobates, Micropithecus, Afropithecus Proconsul

18000000

3000000

Goran Burenhult (ed.)

Kenyopithecus, Dryopithecus

15000000

4000000

Goran Burenhult (ed.)

Krishnapithecus

11000000

1000000

Goran Burenhult (ed.)

Sivapithecus

10000000

500000

Goran Burenhult (ed.)

Ouranopithecus

9500000

3000000

Goran Burenhult (ed.)

Samburu maxilla

6500000

1500000

Goran Burenhult (ed.)

Gigantopithecus

5000000

3200000

Goran Burenhult (ed.)

Orangutans, emergence of stone tools

1800000

300000

Goran Burenhult (ed.)

Appearance of the erectines

1500000

870000

Goran Burenhult (ed.)

Acheulian technology

630000

80000

Goran Burenhult (ed.)

Homo erectus

550000

200000

Goran Burenhult (ed.)

Homo heidelbergensis

350000

120000

Goran Burenhult (ed.)

Control of fire

230000

30000

Goran Burenhult (ed.)

Homo sapiens, modern humans

200000

70000

Goran Burenhult (ed.)

Neanderthalis

130000

60000

Goran Burenhult (ed.)

Mousterian technology

70000

35000

Goran Burenhult (ed.)

Art

35000

Johanson and Edgar

Ardipithecus ramidus

4400000

200000

Johanson and Edgar

Australopithecus anamensis

4200000

300000

Johanson and Edgar

Australopithecus afarensis

3900000

1100000

Johanson and Edgar

Australopithecus africanus

2800000

100000

Johanson and Edgar

Australopithecus aethiopicus

2700000

200000

Johanson and Edgar

Homo sp?

2500000

100000

Johanson and Edgar

Homo rudolfensis

2400000

100000

Johanson and Edgar

Australopithecus boisei

2300000

400000

Johanson and Edgar

Homo habilis / Australopithecus habilis

1900000

100000

Johanson and Edgar

Homo ergaster

1800000

600000

Johanson and Edgar

Homo erectus

1200000

600000

Johanson and Edgar

Homo heldelbergensis

600000

300000

Johanson and Edgar

Homo neanderthalensis

300000

200000

Johanson and Edgar

Homo sapiens

100000

Modis 2002

Big Bang / quarks / protons & neutrons / atoms of elements

15000000000

3000000000

Modis 2002

First stars

12000000000

7400000000

Modis 2002

First planets / rock solidification / solar system

4600000000

800000000

Modis 2002

First life / cooling of Earth / formation of first rocks / water forms

3800000000

2800000000

Modis 2002

First multicellular life (sponges, seaweeds)

1000000000

470000000

Modis 2002

Cambrian explosion / invertebrates / vertebrates

530000000

330000000

Modis 2002

First mammals

200000000

135000000

Modis 2002

First primates / asteroid collision

65000000

48000000

Modis 2002

First orangutan

17000000

11000000

Modis 2002

First hominids

6000000

3400000

Modis 2002

First stone tools

2600000

1600000

Modis 2002

Development of speech / Homo sapiens

1000000

500000

Modis 2002

Discovery of fire / hunting gathering society

500000

400000

Modis 2002

Emergence of "modern humans" / earliest burial of the dead / agrarian pastoral � / sociocultural systems

100000

65000

Modis 2002

Rock art / protowriting

35000

25000

Modis 2002

Agriculture / prehistoric nomadic bands / techniques for starting fire

10000

5000

Modis 2002

Discovery of the wheel / writing / archaic empires / large civilizations / Egypt ��� / Mesopotamia

5000

2500

Modis 2002

Democracy / city states / Greeks / Buddha

2500

500

Modis 2002

Christianity

2000

1325

Modis 2002

Gunpowder

675

175

Modis 2002

Renaissance (printing press) / discovery of new world / the scientific method

500

275

Modis 2002

Industrial revolution (steam engine) / political revolutions (French, USA)

225

125

Modis 2002

Modern physics / radio / electricity / automobile / airplane / capitalism & colonialism

100

50

Modis 2002

DNA / transistor / nuclear energy / W.W.II / cold war / sputnik

50

45

Modis 2002

Internet / human genome sequenced

5

Richard Coren

Big Bang

15000000000

11500000000

Richard Coren

Solidification of Earth Prokaryotic life

3500000000

2750000000

Richard Coren

Eukaryotic radiation

750000000

575000000

Richard Coren

Appearance of class Mammalia

175000000

142500000

Richard Coren

Appearance of superfamily Hominoidea

32500000

25500000

Richard Coren

Appearance of family Hominidae

7000000

5250000

Richard Coren

Appearance of genus Homo

1750000

1500000

Richard Coren

Appearance of archaic Homo sapiens

250000

180000

Richard Coren

Appearance of H. sapiens sapiens

70000

55000

Richard Coren

Development of communal villages

15000

11000

Richard Coren

Development of writing

4000

3441

Richard Coren

Development of printing

559

500

Richard Coren

Development of digital electronics and computing

59

Modis 2003

Big Bang

15500000000

5500000000

Modis 2003

Origin of Milky Way

10000000000

6000000000

Modis 2003

Origin of life on Earth

4000000000

2000000000

Modis 2003

First eukaryotes

2000000000

1000000000

Modis 2003

First multicellular life

1000000000

570000000

Modis 2003

Cambrian explosion

430000000

220000000

Modis 2003

First mammals

210000000

71000000

Modis 2003

First flowering plants

139000000

84400000

Modis 2003

Asteroid collision

54600000

26100000

Modis 2003

First hominids

28500000

12000000

Modis 2003

First orangutan

16500000

11400000

Modis 2003

Chimpanzees and humans diverge

5100000

2900000

Modis 2003

First stone tools

2200000

1645000

Modis 2003

Emergence of Homo Sapiens

555000

230000

Modis 2003

Domestication of fire

325000

125000

Modis 2003

Differentiation of human DNA types

200000

94300

Modis 2003

Emergence of "modern humans"

105700

69900

Modis 2003

Rock art, protowriting

35800

16600

Modis 2003

Invention of agriculture

19200

8200

Modis 2003

Techniques for starting fire

11000

6093

Modis 2003

Development of the wheel, writing

4907

2470

Modis 2003

Democracy

2437

997

Modis 2003

Zero and decimals invented in Indian arithmetic

1440

901

Modis 2003

Renaissance (printing press)

539

314

Modis 2003

Industrial Revolution (steam engine)

225

125

Modis 2003

Modern physics

100

50

Modis 2003

DNA structure described, transistor invented, nuclear energy

50

45

Modis 2003

Internet, human genome sequenced

5

Paradigm Shifts for 15 Lists of Key Events, Time to Next Event (Years), Logarithmic Plot, page 19

Source:

T.Modis,“Forecasting the Growth of Complexity and Change,” Technological Forecasting and Social Change 69.4 (2002); http://ourworld.compuserve.com/homepages/tmodis/TedWEB.htm.

Carl Sagan, The Dragons of Eden: Speculations on the Evolution of Human Intelligence
(New York: Ballantine Books, 1989). Exact dates provided by Modis.

American Museum of Natural History. Exact dates provided by Modis.
The data set “important events in the history of life” in the Encyclopaedia Britannica.

Educational Resources in Astronomy and Planetary Science (ERAPS), University of Arizona, http://web.archive.org/web/20040616074756/http:/ethel.as.arizona.edu/~collins/astro/subjects/evolve-26.html.

Paul D. Boyer, biochemist, winner of the 1997 Nobel Prize, private communication. Exact dates provided by Modis.

J. D. Barrow and J. Silk, “The Structure of the Early Universe,” Scientific American 242.4 (April 1980): 118–28.

J. Heidmann, Cosmic Odyssey: Observatoir de Paris, trans. Simon Mitton (Cambridge, U.K.: Cambridge University Press, 1989).

J.W. Schopf, ed., Major Events in the History of Life, symposium convened by the IGPP Center for the Study of Evolution and the Origin of Life, 1991 (Boston: Jones and Bartlett, 1991).

Phillip Tobias,“Major Events in the History of Mankind,” chap. 6 in Schopf, Major Events in the History of Life.

David Nelson, “Lecture on Molecular Evolution I,” http://drnelson.utmem.edu/evolution.html, and “Lecture Notes for Evolution II,” http://drnelson.utmem.edu/evolution2.html.

G. Burenhult, ed., The First Humans: Human Origins and History to 10,000 BC (San Francisco: HarperSanFrancisco, 1993).

D. Johanson and B. Edgar, From Lucy to Language (New York: Simon & Schuster, 1996).

R. Coren, The Evolutionary Trajectory: The Growth of Information in the History and Future of Earth,World Futures General Evolution Studies (Amsterdam: Gordon and Breach, 1998).

T.Modis,“Forecasting the Growth of Complexity and Change,” Technological Forecasting and Social Change 69.4 (2002); http://ourworld.compuserve.com/homepages/tmodis/TedWEB.htm.

T. Modis, “The Limits of Complexity and Change,” The Futurist [May–June 2003], http://ourworld.compuserve.com/homepages/tmodis/Futurist.pdf.