H. sapiens Flashcards
H. sapiens cranial anatomy
Chin - mental eminence Small teeth Small nose More vertical forehead Parietal bossing Very small browridge Rounded occipital Small face Depressed infraorbital region Globular vault Supracilliary eminance Fine nasals Non-prognathic face Dental reduction M1>M2>M3
Archaic vs anatomically modern H. sapiens
Archaic H. sapiens still retained some primitive features - H. rhodesiensis
‘Anatomically modern humans’ -> full suite of H. sapiens features
Early and recent H. sapiens still show clear differences
Substantial reduction in brain size from early to recent H. sapiens
H. sapiens post-cranial anatomy
Lower body mass
Longer lower and upper limb bones
Narrowing of thoracic region
Narrowing of pelvic region
Self-domestication in H. sapiens
Domesticated animal traits shared by H. sapiens: Smaller crania and bodies More gracile Facial retrognathism Smaller teeth Reduced sexual dimorphism Reduced agression
Domestic animal traits possibly shared by H. sapiens: Variation in hair/coat Increased fat storage Greater breeding seasons Increased lactation
Domestic animal traits not shared by H. sapiens:
Greater litter size
Mechanisms:
Inherited genetic changes - artificial or natural selection
Niche construction - created environments to suit our needs - CHANGED environments - modified selection pressures
Human cultural niche construction has essentially domesticated us?
Specimens postdating the likely divergence between Neanderthals and H. sapiens
Cannot be ancestral to both. African groups are more likely to be related to H. sapiens (based on biogeography) - or part of sister group
Ndutu, Tanzania - 350-400kya - gracile, small face, thin eyebrows
Kabwe,Zambia - 300kya - strong browridges, receding forehead, occipital torus
Eliye Springs, Kenya - 200-300kya - vertical frontal, rounded occipital
Bodo, Ethiopia - 600kya - large brain, projecting nose, parietal bossing
First known H. sapiens
Jebel Irhoud, Morocco, 315kya
Derived H. sapiens traits: Reduced browridge Inflexed infraorbital region Dental morphology Presence of chin
Primitive traits:
Non-globular braincase
Associated with brain and behavioural differences between early and recent H. sapiens?
Early H. sapiens specimens
Jebel Irhoud, Morocco - 315kya
Misliya, Isarael - 190kya
Herto, Ethiopia - 160kya
Omo, Ethiopia - 190kya
Omo and Herto are the oldest hominins showing clear H. sapiens affinities
Omo 1 and Omo 2
Ethiopia, 195kya
Omo 1: H. sapiens derived traits - rounded occiptal, reduced browridge, chin
Omo 2: Bigger browridge, retreating frontal, thicker vault - more archaic
Different species/date? Variation?
Herto
Ethiopia, 160-180kya
Largest cranium - 1450cc
Primitive: occipital and supraorbital ridges
Derived: globular neurocranium, retracted face
Ritual mortuary practice?
Cutmarks, polish on child’s skull
Different treatment to fauna
Earliest evidence outside Africa
Misliya, Israel
Maxillary bone with teeth dated to 190kya
Small, modern-looking teeth
As old as (or even older than) Omo and Herto specimens
Age remains controversial - could be no more than 60-70kya
Levantine modern humans
Qafzeh, Israel - 100kya
Skhūl, Israel - 120kya
Presence of both H. sapiens and Neanderthals
Possible location of interbreeding event(s)
Mousterian artefacts in sites of both species
Contact zone between Eurasia and Africa - dependent on climatic conditions
Skhūl/Qafzeh - short-lived expansion north or ancestors of eventual dispersal towards Australia?
Skhūl
Israel, 120kya
10 individuals - male, female and juvenile
Mixture of primitive and derived traits
Primitive - large browridges and prognathism
Deliberate burials -> good preservation
Reconstructions argued to obscure morphology
Qafzeh
~100kya, 14 individuals
Some elaborate (ritual?) burials
Qafzeh 11 child - skull and antlers of red deer
Qafzeh 9 - 6yo child across feet
Very unlike Neanderthals from same time period
Tall (170-180cm)
Derived traits: short crania, reduced browridges, high forehead, chin -different to Skhūl
‘Failed’ dispersal?
75-130kya - warm interglacial period.
Skhūl/Qafzeh fossils correspond to a first wave of migration
60-75kya - cold glacial period.
Modern humans retreated during the following cold period.
25-60kya - warm interglacial period.
Successful later modern human migration.
12-25kya - cold glacial period
Asian modern humans
Until recently, H. sapiens presence outside Africa before 60kya was not accepted
- Lacked clear chronostratigraphic context
- Taxonomic assignment to H. sapiens was not clear
Increasing evidence for early H. sapiens in Asia
- Some sites potentially >100kya
- Chronologies and/or affinities are still disputed
Zhirendong
China
>100kya
Debated
- Robust mandible but incipient chin
- H. sapiens or gracile H. erectus?
Daoxian
Fuyan Cave, China
47 human teeth
80-120kya
Extremely modern-looking
Cavities
Al Wusta
Saudi Arabia, 85-95kya
Oldest directly dated fossil outside Africa or Levant
Modern human manual phalanx
Samples obtained from the fossil using laser ablation
Australia
Separated from SE Asia by ocean - sea levels sometimes lower, exposing Sunda and Sahul shelf
Ocean-going craft required - explains why not colonised until H. sapiens
Rapid eastern and western routes that reached southern Australia by 45kya
Related to later Australian aboriginal populations
First Australians are very variable in morphology
Madjedbebe, Devil’s Lair, Lake Mungo
Madjedbebe
Northern Australia, 65kya
Distinctive stone tool assemblage
Grinding stones, ground ochres, etc.
Clarkson et al 2017
Lake Mungo
SE Australia, 30-50kya
Ochre
Relatively gracile fossils
Devil’s Lair
SW Australia, 40kya
Artefacts - bone points, bone beads
Animal and plant remains
Manot Cave
Israel, 55kya
Closer to Upper Palaeolithic Europeans than Levantine early modern humans
Relationship with European UP modern humans?
Hershkovitz et al 2015
Grotta del Cavallo
Southern Italy, 43-45kya
Deciduous molars, originally classified as Neanderthals
New quantitative analysis show clear modern human affinity
Benazzi et al 2011
Grotta di Fumane
Northern Italy, 41kya
Deciduous incisor
Modern human mtDNA
Benazzi et al 2014
Kent’s Cavern
Devon, Britain, 42-44kya
Shares more dental traits with modern humans than with Neanderthals
Badly worn - many dental traits cannot be assessed
Higham et al 2011
Cro Magnon
SW France, 28kya
Cro Magnon 1 - old man (died in middle age)
Skull surface eroded
Evidence of pathology - fungal infection
Cro Magnon 2 - younger female
Not representative of Upper Palaeolithic H. sapiens
- More gracile and ‘modern’ - more like extant humans
Possible migration routes to the Americas
- Overland and through an ice-free corridor
- Siberia inhabited by 39kya
- Ice-free corridor closed between 20 and 13ya
- Either 40-20kya or after 13kya - Bering island/coastal route
- Across the Pacific Ocean
- Across the frozen North Atlantic via Greenland
Meadowcroft Rock Shelter
Pennsylvania, USA, 17ya
Only lithic remains
Age suggests that humans got to North America before the closure of the ice free corridor from 20-13kya
Early North American fossils
Kennewick man - Washington state, USA, 9.4kya - Rasmussen et al. showed DNA relationship closer to east Siberia than Europe/south Pacific
Spirit Cave - Nevada, USA
10.6kya
Monte Verde
Chile, 14.8kya
Hut structures, evidence of complex subsistence strategy
1800 years before Bering Strait would have been passable - supports coastal route of pre-20kya migration
Models for the origin of H. sapiens
Replacement theory/recent African origin model (no hybridisation)
- Modern humans evolved in Africa and replaced existing populations as they dispersed
- Classic model based on analysis of mtDNA/mitochondrial Eve
- Nuclear DNA disproves stirct interpretation
Hybridisation model
- African origin, hybridisation and replacement
- Similar to RAO
- More interbreeding between migrating early H. sapiens and indigenous hominins outside of Africa
- Migration of African populations a key factor in emergence of modern Eurasians
Assimilation (with replacement) model
- African origin of modern H. sapiens
- Significant interbreeding with other indigenous hominins
- Limited impact on morphology
- Differences with hybridisation model are subtle
Multiregional evolution theory (most hybridisation)
- Modern humans evolved concurrently from existing archaic populations all over the Old World
- Neanderthals in Europe
- H. erectus and H. heidelbergensis in Asia
- H. rhodesiensis in Africa
- Maintained species integrity because of constant gene flow
- Large/visible impact on morphology
Current model: OOA with assimilation/hybridisation
Hybridisation
Hybridisation did not have a limited impact - played a crucial role in driving behavioural and morphological modenity
Morphology: creates novelty and increases variation
Rapid morphological adaption to new environments
Behavioural: drives innovation
Mixing of different hominin cultures led to behavioural modernity
Used to be a taboo topic but hot topic today - fossil recrd, experimental models, aDNA analysis, GWAS studies
Modern contemporary humans
Single species that evolved in Africa and spread across the globe BUT different extant human groups carry small amounts of genetic material from multiple extinct hominin groups due to past interbreeding.
Limited mtDNA variation compared to apes - suggests modern humans organised recently
Modern humans are genetically very similar - suggests significant gene flow
Genetically homogenous but phenotypically very diverse
African modern human genetic variation
No Neanderthal or Denisovan DNA in African populations
African populations genetically more diverse than non-Africans
African populations are closer to the modern human origin
‘Serial founder effect’
Serial founder effect
Explains the two defining features of human genetic variation
- Genomes in Africa have many unique variants
- Reduced genetic diversity outside of Africa
Modern human behaviour
Sophisticated stone, bone and wood tools
Hunting and gathering of a diverse set of animals (both marine and terrestrial) and plants
Symbolic behaviour including personal ornamentation, figurative art, and music
Living shelters, burials
Models of the evolution of behavioural modernity
- Gradual African origin (beginning 200kya)
- Punctuated late African origin (beginning 50kya)
- Gradual origins across multiple continents and multiple hominin species (beginning 200kya)
Aurignacian stone tools
Mode 4, H. sapiens
36-28kya
Succeeded by Gravettian (28-21kya), Solutrean (21-16.5kya) and Magdalenian (16.5-11kya)
Blade-based technology
Complex tools
Regional variation in fairly sophisticated bifacial tools (cultural differences)
Hunting strategies
Advantages of projectiles (later stone age)
- More success
- Less risk
- Survivorship increases
- Competitive advantage
Art and music
After 40kya, in Europe and Africa
Intensification and consistent presence of artistic behaviours
- Cave art (high concentration of sites in France and Spain e.g. El Castillo 40kya and Altamira 15kya, Spain + Chauvet 32kya and Lascaux 17kya, France)
- Portable art, including figurines
- Music
Cave art made using natural substances - red and yellow ochre, manganese, charcoal - create a variety of colours
Different instruments - horsehair, sticks, and fingers used to apply paint
Significance is unclear
Magic purpose - improve hunting success
Other ritualistic or symbolic purpose - naturalistic scenes, including animals that were not hunted
Venus figurines e.g. Brassempouy, France Dolní Věstonice, Czech Republic Venus of Willendorf, Austria Venus of Lespugue, France
Music: expression of social and emotional information
Flutes made from animal bones
Debate about Neanderthals having music traditions or not
Clear that modern humans had them
Personal ornamentation
Shell beads
Üçağızlı, Turkey, 40kya
South Africa, 70kya
Burials
Lake Mungo, Australia, 30-50kya
Sungir, Russia, 28kya
Ochre
Increased use of grave goods - beads etc.
Concept of live after death?
Shelter
Mezhirich, Ukraine, 16kya
Bones from at least 149 mammoths
Evidence of increased mobility and portable protection from the environment
Subsistence strategies
EXPANDED SUBSISTENCE BASE
More varied diet, which also included use of aquatic resources
SETTLEMENT PATTERNS
Sites occupied for longer periods and extensively modified
Evidence of more permanent shelters e.g. mammoth bone shelters
