HE - neanderthals

Date: 0.25 - 0.04 Ma
Site: Eurasia

Large posterior teeth
Supraorbital torus (brow ridge)
Large nose
No chin
Midfacial prognathism
Taurodontism (below gumline: small, stubby roots with large tooth. Point where roots of teeth fuse together much lower than other species)
Suprainiac fossa (depression)
Occipital bun (bulge)

Conical ribcage
Short trunk
Robust hand bones
Thick cortical bone
Wide pelvis
Large articular facet (type of joint)
Short distal limbs

Potential Neanderthal ancesstor
Fossils:
Primitive - no chin, robust mandible
Derived - modern human-like dental proportions
New species or already discovered species?

Suggests Neanderthals evolved in partial/complete genetic isolation from the rest of humanity through the gradual accumulation of distinctive morphological traits in European populations
Used to explain potential relationship between Homo heidelbergensis and Neanderthals

Scenario 1:
Homo heidelbergensis ancestor to Neanderthals and Denisovans, but not modern humans
Accretion model

Scenario 2:
Homo heidelbergensis ancestor to Neanderthal, Denisovans and modern humans
Homo heidelbergensis not more closely related to Neanderthals than to modern humans as seen in scenario 1

Site: Portugal
Mix of Neanderthal and modern human features - suggests closely related
Later confirmed that Neanderthals and modern humans are closely related using molecular analysis

Phylogeny created by combining nuclear and mitochondrial DNA
Neanderthals more closely related to Denisovans than modern humans
Evidence of introgression - some exchanges between Neanderthals and modern humans

Major glaciation during Middle Pleistocene
Led to population expansion and isolation
Found in south Europe (north = too cold) to survive and find food
Groups potentially more isolated

Large nasal aperture - warms and humidifies inspired air
Body poportions adapted to cold conditions following Bergmann's and Allen's rules
Short limbs
Short stature

Bergmann's rule - organisms at higher latitudes should be larger and thicker than those closer to the equator to better conserve heat so smaller SA:V
Allen's rule - shorter and thicker limbs at higher latitudes

Large and elongated brain
Expanded visual cortex - potentially helped with hunting
Distinct evolutionary trajectory (different from modern humans)
No globular phase of development (modern humans = rounded brain)
High brain growth rate

Faster dental maturation
Presence of adolescent growth spurt

Lithic industries (groups of stone tools)
Mousterian (type of tool found during Middle Paleolithic) - Levallois reduction method and retouched flakes (start with core and then retouch)
Chatelperronian (Upper Paleolithic) - produced by Neanderthal, modern humans or mixing of archaeological artefacts

Herbivore meat - woolly rhinos, mammoths
Good hunters, used tools, strategies

Ornaments
Music
Symbols

Paintings
Constructions

Burial
Cannibalism
Healthcare
Genetics suggest female migration between communities

Climate - highly variable, fragmentation of habitats
Competition with modern humans - indirect (limited resources during critical time intervals, disease), direct (interpersonal violence)
Demographics - small groups, lower birth rates, higher mortality rates, lower fertility rates, longer interbirth spacing, less complex social networks
Assimilation - Neanderthals assimilated into populations of modern humans