Lecture 20 - Pleistocene Homo Flashcards
pleistocene climate oscillation
- colder and more variable climate, especially by 1.8 ma
- interval marked by repeated glacial cycles, known as the Ice Age
- huge volumes of water in continental ice sheets (about 30% of earth’s surface) - lower sea level
- exposed land bridges connecting continents as a result of lower sea level
- highly unpredictable or variable climate, with as many as 2-dozen major glacial advances during the Pleistocene
H. ergaster cranial
- cranial capacity ~880 cm3
(significant jump in brain size) - long, low, flat skull
- no sagittal crest but had sagittal keel
- thick brow ridge
H. ergaster - Turkana Boy
most of what is known comes from Turkana Boy
* juvenile, presumably male, nearly complete skeleton
H. ergaster postcranial
- estimated stature of 5’3” (6’1”) as an adult, indicates a significant increase in overall body size compared to Aus.
- similar body proportions to modern humans - long & linear build (like modern tropical savanna habitants)
- heavily muscled - robustly built skeleton
- capable of walking and running large distances
- lacks arboreality
H. ergaster & H. erectus
- first hominin species known outside of Africa
- Africa, 1.9-1.0 Ma
- H. erectus - Asia, ~1.8 Ma - 30 Ka (discovered first)
Acheulean Tool Industry
- 1.6 Ma - 200 Ka
- more sophisticated tech than Oldowan
- symmetrical, biface tools,
toolmaker works tool symmetrically on both sides - retouching, soft hammer percussion –> made rough draft, then refined it with subtle flaking
- requires mental template and forward thinking - not immediately obvious from raw materials –> harder to replicate as compared to Oldowan replication
Out of Africa by 1.8 Ma
- varied environments, from tropical Africa into more seasonal colder regions in Eurasia and the Far East
- H. erectus likely hominins migrated out of Africa very shortly after their first appearance
- as soon as we see appearance out of Africa, only took 100k ish years to get to Java, Indonesia
- considering no intent to get there, and across multiple generations, really quick dispersal to get halfway across the globe
- encountered wildly different environments (more seasonal, colder)
Dmanisi skulls, Georgia, Caucasus, 1.8 Ma
- H. ergaster?, H. erectus?, H. georgicus?
- small bodies and brains
- Oldowan technology
- perhaps synchronic populationm who took care of old and/or sick individuals –> based on reabsoprtion of the jaw (dental anatomy)
Java, Indonesia, 1.8 Ma
- H. erectus from Java: Mojokerto (1.8), Sangiran (1.65)
- questions about provenance and dating; land bridge between Java and mainland Asia
- no stone tools
Why out of Africa by 1.8 Ma
- drier climate and more open landscapes would have expored land connections allowing for migration
- tools and increase cognitive capabilities allowed early hominins to colonize new environments
- obligate long-range bipedalism –> running after large game?
- Fire?
- OR expansion was earlier but only visible at 1.8 mya?
Trends in H. ergaster/erectus
- reduction in size of cheek teeth (similar to modern humans)
- increased body size and modern human-like limb proportions; long range bipedalism adaptations
- absolute brain size increases
- associated with Oldowan & Acheulean tools, evidence of fire
- wide geographic distribution outside of Africa
Archaic H. sapiens
transitional nature of these groups between H. erectus -like hominins and later species
Archaic H. sapiens
H. heidelbergensis
- Europe, 600-200ka
- large number of specimens coming from differen regions of Europe
- some of them show clear similarities with Neanderthals, but some other don’t
- probably direct ancestors of Neanderthals - direct evidence
middle stone age/middle paleolithic
- ~300-50Ka
- Mousterian industry
- Middle Pleistocene hominins and Neanderthals
- Levallois technique - required even more planning than Acheulean tools
–> more cutting edge, more efficient
–> very difficult, requires a lot of skill and needed to be taught rather than self-learn (entering realm of cumulative culture)
evidence for big game hunting
- bones of large animals associated with Acheulean tools
- humans may have stampeded large animals over edge of cliff (La Cotte de St. Brelade, France) and butchered the carcasses
- collaborative hunting effort, complex social patterns
neanderthal vs modern humans - cranial differences
neanderthal:
* inflated cheeks
* occipital bun
* retromolar space
* no chin
* double-arched browridges
* large noses
* prognathism
humans:
* small teeth & jaws
* no occipital bun
* chin
* limited development of browridges
* canine fossa
neanderthals vs humans - postcranial differences
neanderthals:
* robist, heavily muscled body - adaptation to conserve heat in their glacial environment
* barrel-shaped rib cage
* thick leg bones
* shortern than modern Europeans
Neanderthal subsistence
- hafted weapons, competent hunting
- animal remains at the Neanderthal sites are often characterized by an abundance of 1 or 2 prey species (specialization)
- healthy animal adults are abundant in animal remains at Neanderthal sites
- cut-marked bones, first access
- also plants included in diet
