Timeline of human evolution
The timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, Homo sapiens,
throughout the history of life, beginning some 4 billion years ago down to recent evolution within H. sapiens during and since the Last Glacial Period.
It includes brief explanations of the various taxonomic ranks in the human lineage. The timeline reflects the mainstream views in modern taxonomy, based on the principle of phylogenetic nomenclature;
in cases of open questions with no clear consensus, the main competing possibilities are briefly outlined.
Overview of taxonomic ranks
A tabular overview of the taxonomic ranking of Homo sapiens is shown below.| Rank | Name | Common name | Millions of years ago | - |
| Life | 4,100 | - | ||
| Archaea | - | |||
| Domain | Eukaryota | Eukaryotes | 2,100 | - |
| Podiata | - | |||
| Unikonts | - | |||
| Obazoa | - | |||
| Opisthokonts | Holozoa + Fungi s.l. | 1,300 | - | |
| Holozoa | 1,100 | - | ||
| Filozoa | Choanozoa + Filasterea | - | ||
| Choanozoa | Choanoflagelates + Animals | 900 | - | |
| Kingdom | Animalia | Animals | 610 | - |
| Subkingdom | Eumetazoa | - | ||
| Parahoxozoa | - | |||
| Bilateria | Triploblasts / Worms | 560 | ||
| Nephrozoa | - | |||
| Deuterstomes | - | |||
| Phylum | Chordata | Chordates | 530 | - |
| Olfactores | - | |||
| Subphylum | Vertebrata | Fish / Vertebrates | 505 | - |
| Infraphylum | Gnathostomata | Jawed fish | 460 | - |
| Teleostomi | Bony fish | 420 | ||
| Sarcopterygii | Lobe finned fish | - | ||
| Superclass | Tetrapoda | Tetrapods | 395 | - |
| Amniota | Amniotes | 340 | - | |
| Synapsida | Proto-Mammals | 308 | - | |
| Therapsid | Limbs beneath the body and other mammalian traits | 280 | - | |
| Class | Mammalia | Mammals | 220 | - |
| Subclass | Theria | Mammals that give birth to live young | 160 | - |
| Infraclass | Eutheria | Placental mammals | 125 | - |
| Magnorder | Boreoeutheria | Supraprimates, hoofed mammals, carnivorous mammals, whales, and bats | 124–101 | - |
| Superorder | Euarchontoglires | Supraprimates: primates, colugos, tree shrews, rodents, and rabbits | 100 | - |
| Grandorder | Euarchonta | Primates, colugos, and tree shrews | 99–80 | - |
| Mirorder | Primatomorpha | Primates and colugos | 79.6 | - |
| Order | Primates | Primates / Plesiadapiformes | 75 | - |
| Suborder | Haplorrhini | "Dry-nosed" primates: tarsiers and monkeys | 63 | - |
| Infraorder | Simiiformes | monkeys | 40 | - |
| Parvorder | Catarrhini | "Downward-nosed" primates: apes and old-world monkeys | 30 | - |
| Superfamily | Hominoidea | Apes: great apes and lesser apes | 28 | - |
| Family | Hominidae | Great apes: humans, chimpanzees, gorillas, and orangutans—the hominids | 20–15 | - |
| Subfamily | Homininae | Humans, chimpanzees, and gorillas | 14–12 | - |
| Tribe | Hominini | Includes both Homo, Pan, but not Gorilla. | 10–8 | - |
| Subtribe | Hominina | Genus Homo and close human relatives and ancestors after splitting from Pan—the hominins | 8–4 | - |
| Ardipithecus s.l. | 6-4 | - | ||
| Australopithecus | 3 | - | ||
| Genus | Homo | Humans | 2.5 | - |
| H. Erectus s.l. | - | |||
| H. heidelbergensis s.l. | - | |||
| Species | Homo sapiens | Anatomically modern humans | 0.8–0.3 | - |
Timeline
Unicellular life
Animals or Animalia
Chordates
Tetrapods
| Date | Event |
| 390 Ma | Some fresh water lobe-finned fish develop legs and give rise to the Tetrapoda. The first tetrapods evolved in shallow and swampy freshwater habitats. Primitive tetrapods developed from a lobe-finned fish, with a two-lobed brain in a flattened skull, a wide mouth and a short snout, whose upward-facing eyes show that it was a bottom-dweller, and which had already developed adaptations of fins with fleshy bases and bones. Tetrapod fishes used their fins as paddles in shallow-water habitats choked with plants and detritus. The universal tetrapod characteristics of front limbs that bend backward at the elbow and hind limbs that bend forward at the knee can plausibly be traced to early tetrapods living in shallow water. Panderichthys is a 90–130 cm long fish from the Late Devonian period. It has a large tetrapod-like head. Panderichthys exhibits features transitional between lobe-finned fishes and early tetrapods. Trackway impressions made by something that resembles Ichthyostega's limbs were formed 390 Ma in Polish marine tidal sediments. This suggests tetrapod evolution is older than the dated fossils of Panderichthys through to Ichthyostega. Lungfishes retain some characteristics of the early Tetrapoda. One example is the Queensland lungfish. |
| 375 Ma | Tiktaalik is a genus of sarcopterygian fishes from the late Devonian with many tetrapod-like features. It shows a clear link between Panderichthys and Acanthostega. |
| 365 Ma | Acanthostega is an extinct amphibian, among the first animals to have recognizable limbs. It is a candidate for being one of the first vertebrates to be capable of coming onto land. It lacked wrists, and was generally poorly adapted for life on land. The limbs could not support the animal's weight. Acanthostega had both lungs and gills, also indicating it was a link between lobe-finned fish and terrestrial vertebrates. Ichthyostega is an early tetrapod. Being one of the first animals with legs, arms, and finger bones, Ichthyostega is seen as a hybrid between a fish and an amphibian. Ichthyostega had legs but its limbs probably were not used for walking. They may have spent very brief periods out of water and would have used their legs to paw their way through the mud. Amphibia were the first four-legged animals to develop lungs which may have evolved from Hynerpeton 360 Mya. Amphibians living today still retain many characteristics of the early tetrapods. |
| 300 Ma | From amphibians came the first reptiles: Hylonomus'' is the earliest known reptile. It was 20 cm long and probably would have looked rather similar to modern lizards. It had small sharp teeth and probably ate millipedes and early insects. It is a precursor of later Amniotes and mammal-like reptiles. Αlpha keratin first evolves here. It is used in the claws of modern lizards and birds, and hair in mammals. Evolution of the amniotic egg gives rise to the Amniota, reptiles that can reproduce on land and lay eggs on dry land. They did not need to return to water for reproduction. This adaptation gave them the capability to colonize the uplands for the first time. Reptiles have advanced nervous systems, compared to amphibians, with twelve pairs of cranial nerves. |
Mammals
| Date | Event |
| 256 Ma | , an early Therapsid Shortly after the appearance of the first reptiles, two branches split off. One branch is the Sauropsids, from which come the modern reptiles and birds. The other branch is Synapsida, from which come modern mammals. Both had temporal fenestrae, a pair of holes in their skulls behind the eyes, which were used to increase the space for jaw muscles. Synapsids had one opening on each side, while diapsids had two. The earliest mammal-like reptiles are the pelycosaurs. The pelycosaurs were the first animals to have temporal fenestrae. Pelycosaurs are not therapsids but soon they gave rise to them. The Therapsida were the direct ancestor of mammals. The therapsids have temporal fenestrae larger and more mammal-like than pelycosaurs, their teeth show more serial differentiation, and later forms had evolved a secondary palate. A secondary palate enables the animal to eat and breathe at the same time and is a sign of a more active, perhaps warm-blooded, way of life. |
| 220 Ma | One sub-group of therapsids, the cynodonts, evolved more mammal-like characteristics. The jaws of cynodonts resemble modern mammal jaws. This group of animals likely contains a species which is the direct ancestor of all modern mammals. |
| 220 Ma | From Eucynodontia came the first mammals. Most early mammals were small shrew-like animals that fed on insects. Although there is no evidence in the fossil record, it is likely that these animals had a constant body temperature and milk glands for their young. The neocortex region of the brain first evolved in mammals and thus is unique to them. Monotremes are an egg-laying group of mammals represented amongst modern animals by the platypus and echidna. Recent genome sequencing of the platypus indicates that its sex genes are closer to those of birds than to those of the therian mammals. Comparing this to other mammals, it can be inferred that the first mammals to gain sexual differentiation through the existence or lack of SRY gene evolved after the monotreme lineage split off. |
| 160 Ma | Juramaia sinensis'' is the earliest known eutherian mammal fossil. |
| 100 Ma | Last common ancestor of mice and humans. |
Primates
| Date | Event |
| 85–66 Ma | A group of small, nocturnal, arboreal, insect-eating mammals called Euarchonta begins a speciation that will lead to the orders of primates, treeshrews and flying lemurs. Primatomorpha is a subdivision of Euarchonta including primates and their ancestral stem-primates Plesiadapiformes. An early stem-primate, Plesiadapis, still had claws and eyes on the side of the head, making it faster on the ground than in the trees, but it began to spend long times on lower branches, feeding on fruits and leaves. The Plesiadapiformes very likely contain the ancestor species of all primates. They first appeared in the fossil record around 66 million years ago, soon after the Cretaceous–Paleogene extinction event that eliminated about three-quarters of plant and animal species on Earth, including most dinosaurs. One of the last Plesiadapiformes is Carpolestes simpsoni, having grasping digits but not forward-facing eyes. |
| 63 Ma | Primates diverge into suborders Strepsirrhini and Haplorrhini. Strepsirrhini contain most prosimians; modern examples include lemurs and lorises. The haplorrhines include the two living groups: prosimian tarsiers, and simian monkeys, including apes. One of the earliest haplorrhines is Teilhardina asiatica, a mouse-sized, diurnal creature with small eyes. The Haplorrhini metabolism lost the ability to produce vitamin C, forcing all descendants to include vitamin C-containing fruit in their diet. |
| 30 Ma | Haplorrhini splits into infraorders Platyrrhini and Catarrhini. Platyrrhines, New World monkeys, have prehensile tails and males are color blind. The individuals whose descendants would become Platyrrhini are conjectured to have migrated to South America either on a raft of vegetation or via a land bridge. Catarrhines mostly stayed in Africa as the two continents drifted apart. Possible early ancestors of catarrhines include Aegyptopithecus and Saadanius. |
| 25 Ma | Catarrhini splits into 2 superfamilies, Old World monkeys and apes. Our trichromatic color vision had its genetic origins in this period. Proconsul was an early genus of catarrhine primates. They had a mixture of Old World monkey and ape characteristics. Proconsul's monkey-like features include thin tooth enamel, a light build with a narrow chest and short forelimbs, and an arboreal quadrupedal lifestyle. Its ape-like features are its lack of a tail, ape-like elbows, and a slightly larger brain relative to body size. Proconsul africanus'' is a possible ancestor of both great and lesser apes, including humans. |
Hominidae
Homo
Homo sapiens
| Date | Event |
| 300–130 ka | Fossils attributed to H. sapiens, along with stone tools, dated to approximately 300,000 years ago, found at Jebel Irhoud, Morocco yield the earliest fossil evidence for anatomically modern Homo sapiens. Modern human presence in East Africa, at 276 kya. A 177,000-year-old jawbone fossil discovered in Israel in 2017 is the oldest human remains found outside Africa. However, in July 2019, anthropologists reported the discovery of 210,000 year old remains of a H. sapiens and 170,000 year old remains of a H. neanderthalensis in Apidima Cave, Peloponnese, Greece, more than 150,000 years older than previous H. sapiens finds in Europe. Neanderthals emerge from the Homo heidelbergensis lineage at about the same time. Patrilineal and matrilineal most recent common ancestors of living humans roughly between 200 and 100 ka with some estimates on the patrilineal MRCA somewhat higher, ranging up to 250 to 500 kya. 160,000 years ago, Homo sapiens idaltu in the Awash River Valley practiced excarnation. |
| 130–80 ka | Marine Isotope Stage 5. Modern human presence in Southern Africa and West Africa. Appearance of mitochondrial haplogroup L2. |
| 80–50 ka | MIS 4, beginning of the Upper Paleolithic. Early evidence for behavioral modernity. Appearance of mt-haplogroups M and N. Southern Dispersal migration out of Africa, Proto-Australoid peopling of Oceania. Archaic admixture from Neanderthals in Eurasia, from Denisovans in Oceania with trace amounts in Eastern Eurasia, and from an unspecified African lineage of archaic humans in Sub-Saharan Africa as well as an interbred species of Neanderthals and Denisovans in Asia and Oceania. |
| 50–25 ka | Behavioral modernity develops, according to the "great leap forward" theory. Extinction of Homo floresiensis. M168 mutation. Appearance of mt-haplogroups U and K. Peopling of Europe, peopling of the North Asian Mammoth steppe. Paleolithic art. Extinction of Neanderthals and other archaic human variants Appearance of Y-Haplogroup R2; mt-haplogroups J and X. |
| after 25 ka | Last Glacial Maximum; Epipaleolithic / Mesolithic / Holocene. Peopling of the Americas. Appearance of: Y-Haplogroup R1a; mt-haplogroups V and T. Various recent divergence associated with environmental pressures, e.g. light skin in Europeans and East Asians, after 30 ka; Inuit adaptation to high-fat diet and cold climate, 20 ka. Extinction of late surviving archaic humans at the beginning of the Holocene. Accelerated divergence due to selection pressures in populations participating in the Neolithic Revolution after 12 ka, e.g. East Asian types of ADH1B associated with rice domestication, or lactase persistence. |