Timeline of human evolution

Source: Wikipedia, the free encyclopedia.

Haeckel's Paleontological Tree of Vertebrates (c. 1879). The evolutionary history of species has been described as a "tree" with many branches arising from a single trunk. While Haeckel's tree is outdated, it illustrates clearly the principles that more complex and accurate modern reconstructions can obscure.

The timeline of human evolution outlines the major events in the evolutionary lineage of the

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

Homo sapiens
(with age estimates for each rank) is shown below.

Rank Name Common name Millions of years ago (commencement)
Life 4,200
Archaea 3,700
Domain Eukaryota Eukaryotes 2,100
Podiata Excludes Plants and their relatives 1,540
Amorphea
Obazoa Excludes Amoebozoa (Amoebas)
Opisthokonts Holozoa +
Fungi
)
1,300
Holozoa Excludes Holomycota 1,100
Filozoa Choanozoa + Filasterea
Choanozoa Choanoflagellates + Animals 900
Kingdom Animalia Animals 610
Subkingdom
Eumetazoa Excludes
Porifera
(Sponges)
Parahoxozoa Excludes Ctenophora (Comb Jellies)
Bilateria Triploblasts / Worms 560
Nephrozoa
Deuterostomes Division from Protostomes
Phylum Chordata Chordates (Vertebrates and closely related invertebrates) 530
Olfactores Excludes
cephalochordates
(Lancelets)
Subphylum Vertebrata Fish / Vertebrates 505
Infraphylum
Gnathostomata Jawed fish 460
Teleostomi Bony fish 420
Sarcopterygii Lobe finned fish
Superclass
Tetrapoda Tetrapods (animals with four limbs) 395
Amniota Amniotes (fully terrestrial tetrapods whose eggs are "equipped with an amnion") 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 (i.e., non-egg-laying) 160
Infraclass
Eutheria Placental mammals (i.e., non-marsupials) 125
Magnorder
Boreoeutheria Supraprimates, (most) hoofed mammals, (most) carnivorous mammals, cetaceans, and bats 124–101
Superorder
Euarchontoglires Supraprimates: primates, colugos, tree shrews, rodents, and rabbits 100
Grandorder
Euarchonta
tree shrews
99–80
Mirorder
Primatomorpha Primates and colugos 79.6
Order Primates Primates / Plesiadapiformes 66
Suborder
Haplorrhini
"Dry-nosed" (literally, "simple-nosed") primates:
monkeys
(incl. apes)
63
Infraorder
Simiiformes monkeys (incl. apes) 40
Parvorder
Catarrhini "Downward-nosed" primates: apes and old-world monkeys 30
Superfamily
Hominoidea
lesser apes (gibbons
)
22-20
Family Hominidae
hominids
20–15
Subfamily Homininae Humans, chimpanzees, and gorillas (the African apes)[1] 14–12
Tribe Hominini Includes both Homo, Pan (chimpanzees), but not Gorilla. 10–8
Subtribe
Hominina
Genus Homo and close human relatives and ancestors after
hominins
8–4[2]
(Genus) Ardipithecus s.l. 6-4
(Genus) Australopithecus 3
Genus Homo (H. habilis) Humans 2.5
(Species) H. erectus s.l.
(Species) H. heidelbergensis s.l.
Species
Homo sapiens s.s.
Anatomically modern humans
0.8–0.3[3]

Timeline

Unicellular life

Date Event
4.3-4.1 Ga
The earliest life appears, possibly as protocells. Their genetic material was probably composed of RNA, capable of both self replication and enzymatic activity; their membranes were composed of lipids. The genes were separate strands, translated into proteins and often exchanged between the protocells.
4.0-3.8 Ga
Prokaryotic cells appear; their genetic materials are composed of the more stable DNA and they use proteins for various reasons, primarily for aiding DNA to replicate itself by proteinaceous enzymes (RNA now acts as an intermediary in this central dogma of genetic information flow of cellular life); genes are now linked in sequences so all information passes to offsprings. They had cell walls & outer membranes and were probably initially thermophiles
.
3.5 Ga This marks the first appearance of cyanobacteria and their method of oxygenic photosynthesis and therefore the first occurrence of atmospheric oxygen on Earth.

For another billion years, prokaryotes would continue to diversify undisturbed.

2.5-2.2 Ga First organisms to use oxygen. By 2400 Ma, in what is referred to as the Great Oxidation Event, (GOE), most of the pre-oxygen anaerobic forms of life were wiped out by the oxygen producers.
2.2-1.8 Ga Origin of the
endosymbiosis
. Early eukaryotes lost their cell walls and outer membranes.
1.2 Ga Sexual reproduction evolves (mitosis and meiosis) by this time at least, leading to faster evolution[4] where genes are mixed in every generation enabling greater variation for subsequent selection.
1.2-0.8 Ga
Choanoflagellate

The

choanoflagellates.[5][6]

Proterospongia (members of the Choanoflagellata) are the best living examples of what the ancestor of all animals may have looked like. They live in colonies, and show a primitive level of cellular specialization for different tasks.

Animalia

Date Event
800–650
Ma
Dickinsonia costata from the Ediacaran biota, 635–542 Ma, a possible early member of Animalia.

Urmetazoan: The first fossils that might represent

Porifera (sponges
) lineage.
Diploblast: separation from the Ctenophora
("comb jellies") lineage. Planulozoa/ParaHoxozoa: separation from the Placozoa and Cnidaria lineages. All diploblasts possess
germ layers (ecto- and endoderm). Photoreceptive
eye-spots evolve.

650-600 Ma
Proporus sp., a xenacoelomorph.

Urbilaterian: the last common ancestor of xenacoelomorphs,

gonads connecting just before the posterior orifice. "Cup-eyes" and balance organs evolve (the function of hearing added later as the more complex inner ear evolves in vertebrates). The nephrozoan through-gut had a wider portion in the front, called the pharynx. The integument or skin consists of an epithelial layer (epidermis
) and a connective layer.

600-540 Ma
A sea cucumber (Actinopyga echinites), displaying its feeding tentacles and tube feet.

Most known animal phyla appeared in the fossil record as marine species during the

sea cucumbers, etc.), probably had both ventral and dorsal nerve cords
like modern acorn worms.

An archaic survivor from this stage is the

filter feeding
like in hemi- and proto-chordates.

Chordata

Date Event
540-520 Ma
Pikaia

The increased amount of oxygen causes many eukaryotes, including most animals, to become obligate aerobes.

The Chordata ancestor gave rise to the

closed circulatory system
, with highly branched blood vessels.

Olfactores, last common ancestor of tunicates and vertebrates in which olfaction (smell) evolved. Since lancelets lack a heart, it possibly emerged in this ancestor (previously the blood vessels themselves were contractile) though it could have been lost in lancelets after evolving in early deuterostomes (hemichordates and echinoderms have hearts).

520-480 Ma
Agnatha

The first

thrombocytes.[16]

460-430 Ma
A placoderm

The

the first jawed fishes (Gnathostomata); their jaws evolved from the first gill/pharyngeal arch and they largely replaced their endoskeletal cartilage with bone and evolved pectoral and pelvic fins. Bones of the first gill arch became the upper and lower jaw, while those from the second arch became the hyomandibula, ceratohyal and basihyal; this closed two of the seven pairs of gills. The gap between the first and second arches just below the braincase (fused with upper jaw) created a pair of spiracles
, which opened in the skin and led to the pharynx (water passed through them and left through gills). Placoderms had competition with the previous dominant animals, the
adaptive immunity (the latter two occurred independently in the lampreys and hagfish). Jawed fish also have a third, lateral semicircular canal and their otoliths are divided between a saccule and utricle
.

430-410 Ma
lungs, fin bones, two pairs of rib bones, and opercular bones, and diverge into the actinopterygii (with ray fins) and the sarcopterygii (with fleshy, lower fins);[17]
the latter transitioned from marine to freshwater habitats. Jawed fish also possess dorsal and anal fins.

Tetrapoda

Date Event
390 Ma
Panderichthys

Some freshwater lobe-finned fish (sarcopterygii) develop limbs and give rise to the

habitats
, where they evolved large eyes and spiracles.

Primitive tetrapods ("fishapods") developed from tetrapodomorphs with a two-lobed

lobe-finned fish without these shallow-water adaptations.) 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.[18]

Mya
). 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.

375-350 Ma
Tiktaalik

Tiktaalik is a genus of sarcopterygian (lobe-finned) fishes from the late Devonian with many tetrapod-like features. It shows a clear link between Panderichthys and Acanthostega.

Acanthostega
Ichthyostega

Acanthostega is an extinct tetrapod, 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. The dorsal pair of ribs form a rib cage to support the lungs, while the ventral pair disappears.

hyoid. These "fishapods" had more ossified and stronger bones to support themselves on land (especially skull and limb bones
). Jaw bones fuse together while gill and opercular bones disappear.

350-330 Ma
Pederpes

bladders, and completely removed their gills by adulthood. The glottis evolves to prevent food going into the respiratory tract. Lungs and thin, moist skin allowed them to breathe; water was also needed to give birth to shell-less eggs
and for early development. Dorsal, anal and tail fins all disappeared.

caecilians
have none).

330-300 Ma
Hylonomus

From amphibians came the first reptiles:

scales evolved in amniotes (complete loss of gills as well).[20]

Evolution of the amniotic egg gives rise to the amniotes, tetrapods that can reproduce on land and lay

glands
.

Amniotes have advanced nervous systems, with twelve pairs of cranial nerves, unlike lower vertebrates. They also evolved true sternums but lost their eardrums and otic notches (hearing only by columella bone conduction).

Mammals

Date Event
300-260 Ma Shortly after the appearance of the first reptiles, two branches split off. One branch is the
Sauropsida, 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 (a branch of Sauropsida) had two. An early, inefficient version of diaphragm
may have evolved in synapsids.

The earliest "mammal-like reptiles" are the

mammals
.

The therapsids had temporal fenestrae larger and more mammal-like than pelycosaurs, their teeth showed more serial differentiation, their gait was semi-erect 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.[21] They had lost gastralia and, possibly, scales.

260-230 Ma
Cynognathus

One subgroup of therapsids, the cynodonts, lose

alveoli. Erythrocytes and thrombocytes lose their nuclei while lymphatic systems and advanced immunity emerge. They may have also had thicker dermis
like mammals today.

The jaws of cynodonts resembled modern mammal jaws; the anterior portion, the dentary, held differentiated teeth. This group of animals likely contains a species which is the ancestor of all modern mammals. Their temporal fenestrae merged with their orbits. Their hindlimbs became erect and their posterior bones of the jaw progressively shrunk to the region of the columella.[22]

230-170 Ma
Repenomamus

From

molars; mammals become diphyodont and possess developed diaphragms and males have internal penises. All mammals have four chambered hearts
(with two atria and two ventricles) and lack cervical ribs (now mammals only have thoracic ribs).

epipubic bones
, which serve to hold the pouch in modern marsupials (in both sexes).

170-120 Ma
Juramaia sinensis

Evolution of live birth (

marsupials. Nipples stemmed out of the therian milk lines. The posterior orifice
separates into anal and urogenital openings; males possess an external penis.

Monotremes and therians independently detach the

pinna and erect forelimbs. Female placentalian mammals do not have pouches and epipubic bones but instead have a developed placenta which penetrates the uterus walls (unlike marsupials), allowing a longer gestation; they also have separated urinary and genital openings.[23]

100-90 Ma
shrews and humans (base of the clade Boreoeutheria; males now have external testicles
).

Primates

Date Event
90–66 Ma
Plesiadapis
Carpolestes simpsoni

A group of small, nocturnal, arboreal, insect-eating mammals called

flying lemurs. They reduced the number of mammaries to only two pairs (on the chest). 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.[24] 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.[25][26]

One of the last Plesiadapiformes is Carpolestes simpsoni, having grasping digits but not forward-facing eyes.

66-56 Ma
temporal fossae as sight regains its position as the primary sense; eyes became forward-facing. Strepsirrhini contain most prosimians; modern examples include lemurs and lorises. The haplorrhines include the two living groups: prosimian tarsiers, and simian monkeys, including apes. The Haplorrhini metabolism lost the ability to produce vitamin C, forcing all descendants to include vitamin C-containing fruit in their diet. Early primates only had claws in their second digits; the rest were turned into nails
.
50-35 Ma
Aegyptopithecus

Simians split into infraorders Platyrrhini and Catarrhini. They fully transitioned to diurnality and lacked any claw and tapetum lucidum (which evolved many times in various vertebrates). They possibly evolved at least some of the paranasal sinuses, and transitioned from estrous cycle to menstrual cycle. The number of mammaries is now reduced to only one thoracic pair. 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 (the hypothesis now favored[27]). Catarrhines mostly stayed in Africa as the two continents drifted apart. Possible early ancestors of catarrhines include Aegyptopithecus and Saadanius
.

35-20 Ma
Proconsul

trichromatic
color vision had its genetic origins in this period. Catarrhines lost the vomeronasal organ (or possibly reduced it to vestigial status).

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

Date Event
20-15 Ma
uricase enzyme (present in most organisms).[28]
16-12 Ma Homininae ancestors speciate from the ancestors of the orangutan between c. 18 to 14 Ma.[29]

common ancestor of humans and the other great apes, or at least a species that brings us closer to a common ancestor than any previous fossil discovery. It had the special adaptations for tree climbing as do present-day humans and other great apes: a wide, flat rib cage, a stiff lower spine, flexible wrists, and shoulder blades
that lie along its back.

12 Ma
bipedalism
)—whereas, among present-day hominids, humans are better adapted for the latter and the others for the former. Danuvius thus had a method of locomotion unlike any previously known ape called "extended limb clambering", walking directly along tree branches as well as using arms for suspending itself. The last common ancestor between humans and other apes possibly had a similar method of locomotion.
12-8 Ma The clade currently represented by humans and the genus Pan (chimpanzees and bonobos) splits from the ancestors of the gorillas between c. 12 to 8 Ma.[31]
8-6 Ma
Sahelanthropus tchadensis

Hominini: The latest common ancestor of humans and chimpanzees is estimated to have lived between roughly 10 to 5 million years ago. Both chimpanzees and humans have a larynx that repositions during the first two years of life to a spot between the pharynx and the lungs, indicating that the common ancestors have this feature, a precondition for vocalized speech in humans. Speciation may have begun shortly after 10 Ma, but late admixture between the lineages may have taken place until after 5 Ma. Candidates of

Hominina or Homininae
species which lived in this time period include Ouranopithecus (c. 8 Ma), Graecopithecus (c. 7 Ma),
Sahelanthropus tchadensis
(c. 7 Ma),
Orrorin tugenensis
(c. 6 Ma).

Hominina). Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago[32] during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago[33] (late Miocene). A. ramidus had a small brain, measuring between 300 and 350 cm3. This is about the same size as the modern bonobo and female chimpanzee brain; it is somewhat smaller than the brain of australopithecines like Lucy
(400 to 550 cm3) and slightly over a fifth the size of the modern Homo sapiens brain.

Ardipithecus was arboreal, meaning it lived largely in the forest where it competed with other forest animals for food, no doubt including the contemporary ancestor of the chimpanzees. Ardipithecus was probably

bipedal as evidenced by its bowl shaped pelvis, the angle of its foramen magnum
and its thinner wrist bones, though its feet were still adapted for grasping rather than walking for long distances.

4-3.5 Ma
Reconstruction of "Lucy"

A member of the

hominins
—those species that developed and comprised the lineage of Homo and Homo's closest relatives after the split from the line of the chimpanzees.

It is thought that A. afarensis was ancestral to both the genus Australopithecus and the genus Homo. Compared to the modern and extinct great apes, A. afarensis had reduced canines and molars, although they were still relatively larger than in modern humans. A. afarensis also has a relatively small brain size (380–430 cm³) and a prognathic (anterior-projecting) face.

Australopithecines have been found in savannah environments; they probably developed their diet to include scavenged meat. Analyses of

vertebrae
suggests that these bones changed in females to support bipedalism even during pregnancy.

3.5–3.0 Ma
Kenyanthropus platyops, a possible ancestor of Homo, emerges from the Australopithecus. Stone tools are deliberately constructed.[34]
3 Ma The bipedal
Hominina) evolve in the savannas of Africa being hunted by Megantereon. Loss of body hair occurs from 3 to 2 Ma, in parallel with the development of full bipedalism and slight enlargement of the brain.[35]

Homo

Date Event
2.5–2.0 Ma

Early Homo appears in East Africa, speciating from australopithecine ancestors. The Lower Paleolithic is defined by the beginning of use of stone tools. Australopithecus garhi was using stone tools at about 2.5 Ma. Homo habilis is the oldest species given the designation Homo, by Leakey et al in 1964. H. habilis is intermediate between Australopithecus afarensis and H. erectus, and there have been suggestions to re-classify it within genus Australopithecus, as Australopithecus habilis.

Stone tools found at the Shangchen site in China and dated to 2.12 million years ago are considered the earliest known evidence of hominins outside Africa, surpassing Dmanisi in Georgia by 300,000 years.[36]

1.9–0.8 Ma
Reconstruction of a female H. erectus

Homo erectus derives from early Homo or late Australopithecus.

Homo habilis, although significantly different of anatomy and physiology, is thought to be the ancestor of Homo ergaster, or African Homo erectus; but it is also known to have coexisted with H. erectus for almost half a million years (until about 1.5 Ma). From its earliest appearance at about 1.9 Ma, H. erectus is distributed in East Africa and Southwest Asia (

Homo georgicus
). H. erectus is the first known species to develop control of fire, by about 1.5 Ma.

H. erectus later migrates

throughout Eurasia
, reaching Southeast Asia by 0.7 Ma. It is described in a number of
subspecies.[37]
Early humans were social and initially scavenged, before becoming active hunters. The need to communicate and hunt prey efficiently in a new, fluctuating environment (where the locations of resources need to be memorized and told) may have driven the expansion of the brain from 2 to 0.8 Ma.

Homo antecessor may be a common ancestor of humans and Neanderthals.[39][40] At present estimate, humans have approximately 20,000–25,000 genes and share 99% of their DNA with the now extinct Neanderthal[41] and 95–99% of their DNA with their closest living evolutionary relative, the chimpanzees.[42][43] The human variant of the FOXP2 gene (linked to the control of speech) has been found to be identical in Neanderthals.[44]

0.8–0.3 Ma
Reconstruction of Homo heidelbergensis

Divergence of Neanderthal and Denisovan lineages from a common ancestor.[45] Homo heidelbergensis (in Africa also known as Homo rhodesiensis) had long been thought to be a likely candidate for the last common ancestor of the Neanderthal and modern human lineages. However, genetic evidence from the

Sima de los Huesos fossils published in 2016 seems to suggest that H. heidelbergensis in its entirety should be included in the Neanderthal lineage, as "pre-Neanderthal" or "early Neanderthal", while the divergence time between the Neanderthal and modern lineages has been pushed back to before the emergence of H. heidelbergensis, to about 600,000 to 800,000 years ago, the approximate age of Homo antecessor.[46][47] Brain expansion (enlargement) between 0.8 and 0.2 Ma may have occurred due to the extinction of most African megafauna (which made humans feed from smaller prey and plants, which required greater intelligence due to greater speed of the former and uncertainty about whether the latter were poisonous or not), extreme climate variability after Mid-Pleistocene Transition (which intensified the situation, and resulted in frequent migrations), and in general selection for more social life (and intelligence) for greater chance of survival, reproductivity, and care for mothers. Solidified footprints dated to about 350 ka and associated with H. heidelbergensis were found in southern Italy in 2003.[48]

H. sapiens lost the brow ridges from their hominid ancestors as well as the snout completely, though their noses evolve to be protruding (possibly from the time of H. erectus). By 200 ka, humans had stopped their brain expansion.

Homo sapiens

Date Event
300–130 ka
Reconstruction of early Homo sapiens from Jebel Irhoud, Morocco c. 315 000 years BP

Denisovans emerge from the northern Homo heidelbergensis lineage around 500-450 ka while sapients emerge from the southern lineage around 350-300 ka.[49]

Fossils attributed to H. sapiens, along with stone tools, dated to approximately 300,000 years ago, found at

Homo sapiens
. Modern human presence in
East Africa (Gademotta), at 276 kya.[51] In July 2019, anthropologists reported the discovery of 210,000 year old remains of a H. sapiens in Apidima Cave, Peloponnese, Greece.[52][53][54]

Patrilineal and matrilineal most recent common ancestors (MRCAs) of living humans roughly between 200 and 100 kya[55][56] with some estimates on the patrilineal MRCA somewhat higher, ranging up to 250 to 500 kya.[57]

160,000 years ago,

Homo sapiens idaltu in the Awash River Valley (near present-day Herto village, Ethiopia) practiced excarnation.[58]

130–80 ka
Eemian
).

Modern human presence in Southern Africa and West Africa.[59] Appearance of mitochondrial haplogroup (mt-haplogroup)

L2
.

80–50 ka
MIS 4, beginning of the Upper Paleolithic
.

Early evidence for behavioral modernity.[60] Appearance of mt-haplogroups

Denisovans in Oceania with trace amounts in Eastern Eurasia,[64] 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.[65][66][67][68]

50–25 ka
Reconstruction of Oase 2 (c. 40 ka)

"great leap forward" theory.[69]
Extinction of Homo floresiensis.[70]
M168
mutation (carried by all non-African males). Appearance of mt-haplogroups
U and K
.
Paleolithic art
.
hybrid
populations in Asia and Africa.) Appearance of Y-Haplogroup
R2; mt-haplogroups J and X
.

after 25 ka
Reconstruction of a Neolithic farmer from Europe, Science Museum in Trento

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.
ASIP), after 30 ka;[71]
Inuit adaptation to high-fat diet and cold climate, 20 ka.[72]

Extinction of late surviving archaic humans at the beginning of the Holocene (12 ka). 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,[73] or lactase persistence.[74][75] A slight decrease in brain size occurred a few thousand years ago.

See also

References

  1. ^ Finarelli, J.A.; Clyde, W.C. (2004). "Reassessing hominoid phylogeny: Evaluating congruence in the morphological and temporal data". Paleobiology. 30 (4): 614.
  2. S2CID 2325560
    .
  3. ^ depending on the classification of the Homo heidelbergensis lineage; 0.8 if Neanderthals are classed as H. sapiens neanderthalensis, or if H. sapiens is defined cladistically from the divergence from H. neanderthalensis, 0.3 based on the available fossil evidence.
  4. ^ "'Experiments with sex have been very hard to conduct,' Goddard said. 'In an experiment, one needs to hold all else constant, apart from the aspect of interest. This means that no higher organisms can be used, since they have to have sex to reproduce and therefore provide no asexual control.'
    Goddard and colleagues instead turned to a single-celled organism, yeast, to test the idea that sex allows populations to adapt to new conditions more rapidly than asexual populations." Sex Speeds Up Evolution, Study Finds (URL accessed on January 9, 2005)
  5. ^ "Proterospongia is a rare freshwater protist, a colonial member of the Choanoflagellata." "Proterospongia itself is not the ancestor of sponges. However, it serves as a useful model for what the ancestor of sponges and other metazoans may have been like." http://www.ucmp.berkeley.edu/protista/proterospongia.html Berkeley University
  6. S2CID 13171894
    .
  7. ^ Monahan-Earley, R., Dvorak, A. M., & Aird, W. C. (2013). Evolutionary origins of the blood vascular system and endothelium. Journal of Thrombosis and Haemostasis, 11 (Suppl 1), 46–66.
  8. .
  9. .
  10. .
  11. .
  12. ^ Udroiu, I., & Sgura, A. (2017). The phylogeny of the spleen. The Quarterly Review of Biology, 92(4), 411–443. https://doi.org/10.1086/695327
  13. ^ Elliot D.G. (2011) Functional Morphology of the Integumentary System in Fishes. In: Farrell A.P., (ed.), Encyclopedia of Fish Physiology: From Genome to Environment, volume 1, pp. 476–488. San Diego: Academic Press
  14. ^ These first vertebrates lacked jaws, like the living hagfish and lampreys. Jawed vertebrates appeared 100 million years later, in the Silurian. http://www.ucmp.berkeley.edu/vertebrates/vertintro.html Berkeley University
  15. Victoria, Australia's East Gippsland, currently holds the record for oldest coelacanth; it was given the name Eoactinistia foreyi when it was published in September 2006. [1]
  16. ^ "Lungfish are believed to be the closest living relatives of the tetrapods, and share a number of important characteristics with them. Among these characters are tooth enamel, separation of pulmonary blood flow from body blood flow, arrangement of the skull bones, and the presence of four similarly sized limbs with the same position and structure as the four tetrapod legs." http://www.ucmp.berkeley.edu/vertebrates/sarco/dipnoi.html Berkeley University
  17. .
  18. ^ "In many respects, the pelycosaurs are intermediate between the reptiles and mammals" http://www.ucmp.berkeley.edu/synapsids/pelycosaurs.html Berkeley University
  19. ^ Werneburg, Ingmar; Spiekman, Stephan N F (2018). 4. Mammalian embryology and organogenesis. In: Zachos, Frank; Asher, Robert. Mammalian Evolution, Diversity and Systematics. Berlin: Walter de Gruyter, 59-116. DOI: https://doi.org/10.1515/9783110341553-004
  20. .
  21. ^ "Paleontologists discover most primitive primate skeleton", Phys.org (January 23, 2007).
  22. ^ Alan de Queiroz, The Monkey's Voyage, Basic Books, 2014.
  23. ^ "A new primate species at the root of the tree of extant hominoids". phys.org. Retrieved 2020-05-29.
  24. PMID 15737392
    .
  25. .
  26. .
  27. ^ Perlman, David (July 12, 2001). "Fossils From Ethiopia May Be Earliest Human Ancestor". National Geographic News. Archived from the original on July 15, 2001. Another co-author is Tim D. White, a paleoanthropologist at UC-Berkeley who in 1994 discovered a pre-human fossil, named Ardipithecus ramidus, that was then the oldest known, at 4.4 million years.
  28. S2CID 20189444
    .
  29. .
  30. .
  31. .
  32. ^ NOVA: Becoming Human Part 2 http://video.pbs.org/video/1319997127/
  33. S2CID 53481281
    .
  34. .
  35. .
  36. ^ "Rubin also said analysis so far suggests human and Neanderthal DNA are some 99.5 percent to nearly 99.9 percent identical." Neanderthal bone gives DNA clues (URL accessed on November 16, 2006)
  37. PMID 12368483
    .
  38. .
  39. .
  40. .
  41. .
  42. .
  43. .
  44. ^ Timmermann, A., Yun, KS., Raia, P. et al. Climate effects on archaic human habitats and species successions. Nature 604, 495–501 (2022). https://doi.org/10.1038/s41586-022-04600-9
  45. .
  46. .
  47. ^ Zimmer, Carl (10 July 2019). "A Skull Bone Discovered in Greece May Alter the Story of Human Prehistory - The bone, found in a cave, is the oldest modern human fossil ever discovered in Europe. It hints that humans began leaving Africa far earlier than once thought". The New York Times. Retrieved 11 July 2019.
  48. ^ Staff (10 July 2019). "'Oldest remains' outside Africa reset human migration clock". Phys.org. Retrieved 10 July 2019.
  49. S2CID 195873640
    .
  50. .
  51. .
  52. .
  53. .
  54. .
  55. ^ Henshilwood, C.S. and B. Dubreuil 2009. Reading the artifacts: gleaning language skills from the Middle Stone Age in southern Africa. In R. Botha and C. Knight (eds), The Cradle of Language. Oxford: Oxford University Press, pp. 41-61.
  56. S2CID 4365526
    .
  57. .
  58. ^ Rincon, Paul (2010-05-06). "Neanderthal genes 'survive in us'". BBC News. BBC. Retrieved 2010-05-07.
  59. PMID 27032491
    .
  60. .
  61. .
  62. .
  63. .
  64. .
  65. .
  66. .
  67. .
  68. .
  69. .
  70. .

External links