Human evolutionary history

The evolutionary history of humans

Major events

13,700 mya

The Big bang - Origin of Universe.

4,568 mya

Earth forms

4,540 mya

Hadean eon begins

4,100 mya

Possible first signs of life (Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon, 2015 study)

4,031 mya

The Hadean eon ends; the Archean eon and Eoarchean era begin

4,000 - 3,800 mya

Prokaryotes appear

3,600 mya

The Eoarchean era ends; the Paleoarchean era begins

3,500 mya

Cyanobacteria appear

3,200 mya

The Paleoarchean era ends; the Mesoarchean era begins

2,800 mya

The Mesoarchean era ends; the Neoarchean era begins

2,500 - 2,200 mya

The first organisms to use oxygen
Great Oxidation Event

2,500 mya

The Archean eon and Neoarchean era end; the Proterozoic eon, Paleoproterozoic era and Siderian period begin

2,300 mya

The Siderian period ends; the Rhyacian period begins

2,200 - 1,800 mya

Eukaryotes appear

2,050 mya

The Rhyacian period ends; the Orosirian period begins

1,800 mya

The Orosirian period ends; the Statherian period begins

1,600 mya

The Paleoproterozoic era and Statherian period end; the Mesoproterozoic era and Calymmian period begin

1,400 mya

The Calymmian period ends; the Ectasian period begins

1,200 mya

The Ectasian period ends; the Stenian period begins
Sexual reproduction evolves

1,000 mya

The Mesoproterozoic era and Stenian period end; the Neoproterozoic era and Tonian period begin

720 mya

The Tonian period ends; the Cryogenian period begins

635 mya

The Cryogenian period ends; the Ediacaran period begins

538.8 mya

The Proterozoic eon, Neoproterozoic era and Ediacaran period end; the Phanerozoic eon, Paleozoic era, Cambrian period and Terreneuvian epoch begin.
The entire span from Earth’s formation up to this point is collectively called the Precambrian.
Cambrian explosion

521 mya

The Terreneuvian epoch ends; the Cambrian Series 2 begins

506.5 mya

The Cambrian Series 2 ends; the Furongian epoch begins

500 - 450 mya

First vertebrates.

486.85 mya

The Cambrian period and Furongian epoch end; the Ordovician period and Early Ordovician begin

471.3 mya

The Early Ordovician ends; the Middle Ordovician begins

458.2 mya

The Middle Ordovician ends; the Late Ordovician begins

445-444 mya

Late Ordovician mass extinction

443.1 mya

The Ordovician period and Late Ordovician end; the Silurian period and Llandovery epoch begin

433.4 mya

The Llandovery epoch ends; the Wenlock epoch begins

426.7 mya

The Wenlock epoch ends; the Ludlow epoch begins

423.0 mya

The Ludlow epoch ends; the Pridoli epoch begins

419.62 mya

The Silurian period and Pridoli epoch end; the Devonian period and Early Devonian begin

393.47 mya

The Early Devonian ends; the Middle Devonian begins

382.7 mya

The Middle Devonian ends; the Late Devonian begins

372–359 mya

Late Devonian mass extinction

365 mya

Fish evolve lungs and walk on land.

358.86 mya

The Devonian period and Late Devonian end; the Carboniferous period and Early Mississippian begin

346.7 mya

The Early Mississippian ends; the Middle Mississippian begins

330.3 mya

The Middle Mississippian ends; the Late Mississippian begins

323.2 mya

The Late Mississippian ends; the Early Pennsylvanian begins

315.2 mya

The Early Pennsylvanian ends; the Middle Pennsylvanian begins

307.0 mya

The Middle Pennsylvanian ends; the Late Pennsylvanian begins

298.9 mya

The Carboniferous period and Late Pennsylvanian end; the Permian period and Cisuralian epoch begin

272.95 mya

The Cisuralian epoch ends; the Guadalupian epoch begins

259.1 mya

The Guadalupian epoch ends; the Lopingian epoch begins

252 mya

Permian-Triassic extinction event

251.9 mya

The Paleozoic era, Permian period and Lopingian epoch end; the Mesozoic era, Triassic period and Early Triassic begin

248 - 208 mya

First small mammals and dinosaurs evolved.

247.2 mya

The Early Triassic ends; the Middle Triassic begins

237 mya

The Middle Triassic ends; the Late Triassic begins

208 - 65 mya

Large dinosaurs flourished.

201.4 mya

The Triassic period and Late Triassic end; the Jurassic period and Early Jurassic begin

201.3 mya

Triassic–Jurassic extinction event

174.1 mya

The Early Jurassic ends; the Middle Jurassic begins

163.5 mya

The Middle Jurassic ends; the Late Jurassic begins

143.1 mya

The Jurassic period and Late Jurassic end; the Cretaceous period and Early Cretaceous begin

114 mya

Placental mammals evolve.

100.5 mya

The Early Cretaceous ends; the Late Cretaceous begins

85 mya

First primates evolve.

66 mya

The Mesozoic era, Cretaceous period and Late Cretaceous end; the Cenozoic era, Paleogene period and Paleocene epoch begin
Cretaceous–Paleogene extinction event

65 mya

Dinosaurs go extinct, mammals then increase in size and diversity.

56 mya

The Paleocene epoch ends; the Eocene epoch begins

35 mya

First apes evolve.

33.9 mya

The Eocene epoch ends; the Oligocene epoch begins

23.04 mya

The Paleogene period and Oligocene epoch end; the Neogene period and Miocene epoch begin

10 - 7 mya

Africa’s major tectonic event that led to the Formation of the Great Rift Valley.

8 - 6 mya

The divergence of our hominid ancestors from the Great Apes.

5.333 mya

The Miocene epoch ends; the Pliocene epoch begins

4.4 mya

Emergence of Bipedalism to avoid competition with monkeys(Australopithecus anamensis, Australopithecus afarensis - aka Lucy)
- Upright posture and full eye contact provided room for the emergence of the first gestural signals.
- The forearms can then be used to hold tools and weapons.
- The move to Bipedalism opened up major cognitive challenges in terms of the control of the hands.

4 mya

Major reorganization of Parietal cortex.
- Reduction of primary visual striate cortex
- The enlargement of Extrastriate parietal cortex, Angular gyrus, and Supramarginal gyrus
Such changes in the Parietal cortex support three basic cognitive functions.
- Processing in the dorsal stream (see Two-streams hypothesis) of the visual field is important for representing actions of the other in terms of one’s own body image.
- The association area of parietal maintain a map of the environment for navigation in the new bipedal mode.
- The Supramarginal gyrus is involved in Face perception. Expansion of this area would facilitate the development of social patterns and memory for social relations. -> It played a large role during the next period of evolution (social cohesion).

3.5 mya

The hominids in East Africa went through an expansion of their range and a proliferation of species.
- Tight competition with range contraction leads a set of targeted neural-behavioral adaptations. - the subordination of vocal system to cortical control.
- Side-effect of the cortical control over vocalization: local forms of communication like those of song-birds.
How about the Great apes in West Africa?
- The different requirements on group size in their arboreal habitat
- No bipedal gait and its resultant improvements in face-to-face communication.

3 mya

The Australopithecus evolve in savannas of Africa.
A gradual tripling of brain size.
- Massive changes in the interconnectedness of the Frontal lobes.
- Changes in the linkage of vocal production to motor and emotional areas.
- Linkages of the visual areas to motor areas.
- Expansion of many older areas, including the Cerebellum, Basal ganglion, and Thalamus.
- (these changes are basis for an ability to produce actions through movement and sounds throught vocalization)

2.58 mya

The Neogene period and Pliocene epoch end; the Quaternary period and Pleistocene epoch begin. The Quaternary is the final period of the Cenozoic era and continues to the present.

2.5 mya

Earliest stone tools - Oldowan (found in Ethiopia and Kenya, Africa); used to butcher carcasses for meat and to extract marrow from bones; linked with Homo habilis.

2 mya

The remarkable expansion of habitat to all of Africa and Eurasia by Homo erectus.
Brain expansion ran up against the Bipedalism, forcing a series of adaptations in female anatomy, parturition, and child rearing.
New forms of symbolic communication system - the spontaneous interaction of vocalizations, postures, and gestures in specific social and pragmatic contexts.
- Vocalizations had not yet been systematized. Gestural and postural patterns probably played a more central role.
- But their iconic and situated nature may have seved as a barrier to abstract systematization.

1.8 mya (the end of the Pliocene epoch, and the beginning of the Ealry Pleistocene epoch)

Homo erectus had achieved dominance over its hominid competitors.
The onset of the glaciations of the Pleistocene epoch.
Homo erectus spread beyond African Homo erectus. The first migration from Africa.

1.6 mya

First evidence; likely hearths; linked with African Homo erectus.

1.5 mya

Invention of Acheulean hand axe; linked with Homo ergaster - tall stature, long limbs.

1.2 mya

Brain expansion in homo line begins.

1 mya

Hominids spread to Europe.

800,000 ya

Crude stone tool kit - found in Spain, linked with Homo antecessor.

780,000 ya (middle Pleistocene epoch begins)

600,000 - 400,000 ya

Long crafted wooden spears and early hearths; linked with Homo heidelbergensis found in Germany.

500,000 - 100,000 ya

Period of most rapid brain expansion in Homo line.

300,000 - 50,000 ya

Gradual evolution of new system that supports a set of phonological contrasts.
- A major expansion of the parts of the vertebrae that carry nerves for the intercostal muscles. (p384)
- Loss of the canines.
- Adaptation of the arytenoids.
- Bending of the vocal tract.
- shaping of the musculature of the tongue.

200,000 ya

The emergence of Homo sapiens and Mitochondrial Eve.

200,000 - 30,000 ya

Neanderthals flourish in Europe and western Asia.

126,000 ya

Late Pleistocene epoch begins.

100,000 - 50,000 ya

Exodus from Africa - second major migration. See also Out of Africa theory

70,000 ya

Near extinction that brought the number of our direct ancestors down to only 10,000 individuals worldwide.

40,000 ya

Explosion of diverse stone tools, bone tools, blade tools, well-designed fireplaces, elaborate art; found only among Homo sapiens, not among Neanderthals.

40,000 - 35,000 ya

Homo sapiens (Cro-Magnon) arrive in Europe.

30,000 ya

Neanderthals go extinct.

27,000 ya

Homo sapiens colonize entire planet; all other hominid species are now extinct.

11,700 ya

The Pleistocene epoch ends; the Holocene epoch begins
Holocene extinction

Articles

2025-03-18 - Genetic study reveals hidden chapter in human evolution | University of Cambridge
- Modern humans descended from not one, but at least 2 ancestral populations that drifted apart and later reconnected, long before modern humans spread across the globe.
2024-07-12 - Princeton geneticists are rewriting the narrative of Neanderthals and other ancient humans

Major events

Articles

See also