Human evolutionHuman evolution

Waikato university siteWaikato university sitehttp://sci.waikato.ac.nz/evolution/http://sci.waikato.ac.nz/evolution/

HumanEvolution.shtmlHumanEvolution.shtml

Main pointsMain pointsRapid changes as new fossils are found and Rapid changes as new fossils are found and re-evaluated every yearre-evaluated every yearHuman and chimp diverged about 7mya in Human and chimp diverged about 7mya in AfricaAfricaPut lineage is ‘bushy’, with many different Put lineage is ‘bushy’, with many different species in existence at the same timespecies in existence at the same timeAncestors of modern humans evolved in Ancestors of modern humans evolved in AfricaAfricaHomo erectusHomo erectus populations left Africa about populations left Africa about 1.5 mya and moved rapidly across Europe 1.5 mya and moved rapidly across Europe and Asia (out of Africa theory)and Asia (out of Africa theory)

Early (Miocene) apesEarly (Miocene) apes

Apes evolved in Africa 20 mya (Apes evolved in Africa 20 mya (proconsulproconsul) ) Monkey-like traits – backbone, pelvis and forelimbMonkey-like traits – backbone, pelvis and forelimb17mya land bridges to Eurasia allow migration 17mya land bridges to Eurasia allow migration out of Africa and divered into at least eight out of Africa and divered into at least eight groupsgroups13 mya – major climate change in Eurasia. 13 mya – major climate change in Eurasia. Apes that survived – in SE Asia (ancestors of Apes that survived – in SE Asia (ancestors of Urang-utan) and in Africa (ancestors of African Urang-utan) and in Africa (ancestors of African apes)apes)human evolution\human_odyssey.pdf

proconsulproconsul

Earliest hominins – already Earliest hominins – already ‘bushy’ lineage‘bushy’ lineage

Orrorin tugenensisOrrorin tugenensis – 6mya, Kenya, – 6mya, Kenya, bipedal, ape-like caninesbipedal, ape-like canines

Sahelanthropus tchadensisSahelanthropus tchadensis – 6-7 – 6-7 mya, Chad, might not be bipedal, mya, Chad, might not be bipedal, ape-like skull and dentition, forest ape-like skull and dentition, forest environmentenvironment

Ardipithecus ramidusArdipithecus ramidus – Ethiopia, 4.4- – Ethiopia, 4.4-5.8 mya, forest environment, 5.8 mya, forest environment,

Orrorin Orrorin femur-femur-headhead

6 mya6 mya

Sahelanthropus Sahelanthropus tchadensistchadensis

AustralopithecinesAustralopithecines - gracile - gracile

A. anamensisA. anamensis – 4.2-3.9 mya. Probably bipedal, – 4.2-3.9 mya. Probably bipedal, ape jaw and teethape jaw and teeth

A afarensisA afarensis (Lucy, foot prints) – 3.9-3 mya, (Lucy, foot prints) – 3.9-3 mya, fully bipedal, intermediate human-ape fully bipedal, intermediate human-ape dentition, face and cranium ape like, cranial dentition, face and cranium ape like, cranial capacity 375-550cccapacity 375-550cc

A garhiA garhi – 2.5 mya, Ethiopia, 450cc cranial – 2.5 mya, Ethiopia, 450cc cranial capacity, capacity,

A. AfricanusA. Africanus – 3.2-2 mya, bipedal, 420-500cc – 3.2-2 mya, bipedal, 420-500cc cranium,cranium,

A. anamensisA. anamensis

Lucy Lucy

Laetoli footprints Laetoli footprints

AustralopithecinesAustralopithecines – robust – robust ((ParanthropusParanthropus))

All have sagittal crest, large jaw, heavy All have sagittal crest, large jaw, heavy skull, thick enamel on molarsskull, thick enamel on molars

P. robustus – 2-1.5 mya, 530cc cranium, P. robustus – 2-1.5 mya, 530cc cranium, tough, coarse food, might have used toolstough, coarse food, might have used tools

P.aethiopicus – 2.6-2.4 mya, heavy face, P.aethiopicus – 2.6-2.4 mya, heavy face, large crest, 410cc cranium, large crest, 410cc cranium,

P. boisei – huge molars, massive built face P. boisei – huge molars, massive built face and jaw, highly specialised hard food dietand jaw, highly specialised hard food diet

Cut marks on bones –evidence Cut marks on bones –evidence for animal butchering using a for animal butchering using a

tooltool

Trends in human evolutionTrends in human evolution

Cranial capacityCranial capacity

BipedalismBipedalism

Skull – Skull – dental arcade dental arcade

facial anglefacial angle

Sexual dimorphismSexual dimorphism

Rib cageRib cage

BipedalismBipedalism

Appears very early- (Maybe up to 7mya)Appears very early- (Maybe up to 7mya)

Gradual change (walking, followed by Gradual change (walking, followed by running)running)

Earlier genus – position of foramen magnumEarlier genus – position of foramen magnum

Evidence from pelvic structure, knee and foot Evidence from pelvic structure, knee and foot structure structure

H. erectus – very efficient movement – very H. erectus – very efficient movement – very narrow pelvic outlooknarrow pelvic outlook

Wider pelvic outlet (in Wider pelvic outlet (in SapiensSapiens) might be ) might be adaptation to larger infant head sizeadaptation to larger infant head size

Cranial capacityCranial capacity

Gradual increase in cranial capacityGradual increase in cranial capacity

Early Early AustralopithecinesAustralopithecines similar to similar to

modern chimp (Around 400cc)modern chimp (Around 400cc)

Later Later australopithecinesaustralopithecines about 550cc about 550cc

Homo erectus – 510-1225cc (within Homo erectus – 510-1225cc (within

modern range)modern range)

NeanderthalNeanderthal (1450cc) larger than (1450cc) larger than HomoHomo

(1350cc) reflect difference in body size.(1350cc) reflect difference in body size.

Skull morphologySkull morphology

Dental arcade from U (chimp) [with cheek Dental arcade from U (chimp) [with cheek teeth parallel] to V (human)teeth parallel] to V (human)

Decrease in size of teeth (molars ) Decrease in size of teeth (molars )

Decrease in crest and ridges (sagital – Decrease in crest and ridges (sagital – diet, nuchal – posture)diet, nuchal – posture)

Facial angle becoming flatter (to vertical in Facial angle becoming flatter (to vertical in Homo) Homo)

Other trendsOther trends

Reduce sexual dimorphismReduce sexual dimorphism

Rib cage size and shape:Rib cage size and shape:Funnel (Funnel (A. afarensisA. afarensis))

Barrel shape (Barrel shape (HomoHomo))

Funnel shape accommodates the large gut Funnel shape accommodates the large gut needed for a herbivore (eg – gorilla). Barrel needed for a herbivore (eg – gorilla). Barrel shape and hips – indication of meat in diet.shape and hips – indication of meat in diet.

Out of AfricaOut of Africa

Homo floresiensisHomo floresiensis

Discovered 2004, in IndonesiaDiscovered 2004, in Indonesia

18,000yo remains18,000yo remains

Tiny – adult female 1 m tall, cranial Tiny – adult female 1 m tall, cranial capacity 380cc,capacity 380cc,

Tool maker and userTool maker and user

Mix of traits:Mix of traits:Primitive – low cranium, brow ridges, bipedal Primitive – low cranium, brow ridges, bipedal

(narrow pelvis)(narrow pelvis)Advance - flat face, Advance - flat face,

Theory – a dwarf form of H. erectus, a case Theory – a dwarf form of H. erectus, a case of dwarfism on islandsof dwarfism on islands

Homo neanderthalensisHomo neanderthalensis

230,000-30,000 ya, ice age, in Europe and 230,000-30,000 ya, ice age, in Europe and middle eastmiddle east

Robust and heavily builtRobust and heavily built

Cranial capacity – 1450cc Cranial capacity – 1450cc

Skull – elongated, receding forehead, weak Skull – elongated, receding forehead, weak chin, large nasal cavitychin, large nasal cavity

Complex tools (Moustarian)Complex tools (Moustarian)

mDNA evidence – not closely related to mDNA evidence – not closely related to Homo sapiensHomo sapiens

Cultural evolutionCultural evolution

ToolsTools

FireFire

ShelterShelter

ClothingClothing

ArtArt

Cooperative behaviour (hunting)Cooperative behaviour (hunting)

Domestication of plants and animalsDomestication of plants and animals

Tools (I)Tools (I)

Only stone tools surviveOnly stone tools survive

Chimps – modified twigs and rocks, learnt Chimps – modified twigs and rocks, learnt behaviour, regional culture, pre-meditationbehaviour, regional culture, pre-meditation

A. gahri – 2.5 mya A. gahri – 2.5 mya

H. habilis - Oldowan culture [cobble H. habilis - Oldowan culture [cobble stones, one or more flakes knocked of one stones, one or more flakes knocked of one side]side]

H. erectus – Acheulean culture[sharper, H. erectus – Acheulean culture[sharper, straighter edges, smaller flakes removed, straighter edges, smaller flakes removed, worked from many sides, range of uses]worked from many sides, range of uses]

Oldowan toolsOldowan tools

Acheulian toolsAcheulian tools

Tools (II)Tools (II)

H. sapiens (archaic)H. sapiens (archaic) and and H. H. neanderthalensisneanderthalensis - Mousterian tools - Mousterian toolsStone core is shaped before flakes are Stone core is shaped before flakes are

removedremovedRange of usesRange of usesSome have tang at the end that suggests a Some have tang at the end that suggests a

wood or bone handlewood or bone handle

Mousterian toolsMousterian tools

Moustarian tool

Upper palaeolithic industryUpper palaeolithic industry

Modern Modern H sapiensH sapiens

Africa – 40,000 – 12,000yaAfrica – 40,000 – 12,000ya

Wider range of material, regional variationWider range of material, regional variation

Uses – fishhooks, harpoon points, needles Uses – fishhooks, harpoon points, needles ……

Neolithic spear headNeolithic spear head

Neanderthal cave drawingsNeanderthal cave drawings