Lecture 14 - Homo Erectus

african H. erectus (H. ergaster)

1.9mya-500kya in east and south africa

cranial capacity 700-1000cc (avg = 800cc)

homo erectus triats

ancestral

• some post orbital constriction

• receding forehead

• no chin

derived traits

• less prognathism

• taller skull

• smaller jaw and post C teeth

H erectus face

external nose, thick cranium, large brow ridge

h erectus body

humanlike limb proportions, humanlike gait

increase in body size, shortened arms relative to legs from early homo to h erectus

born to run

some argue adaptation for endurance running is key to genus homo, suggested by:

• achilles tendon attachment

• arch in foot

• large gluteus muscles

• less robust shoulder muscles

• anti-bobbing head

• loss of body hair: adaptation for sweating?

H. erectus: turkana boy?

1.6mya in lake turkana, kenya

age of boy is 9-12, 5’4 and maybe almost 6’ if lived to be adult

age determination: dentition

study of growth rings of enamel suggest younger age while physiological development suggests older

childhoods were still shorter in H erectus than H sapiens

bone epiphyses, growth plate, metaphysis, diaphysis (what does this mean)

turkana boy body

• tall, lean (allows for heat dissipation)

• physically active probably even during heat of day

• lived on savanna fulltime, no arboreal activities like predecessors

african h erectus fire use

likely had controlled use of fire

• based on biological characteristics

• study of bones and rocks from kenya using FTIR spectroscopy 1.5mya is consistent with thermal alterations

• artifacts at this site and others also cluster in circles = hearths?

african h erectus/h ergaster

new tool technology → better processing of carcasses and sporadic hunting

fire benefits:

• warmth

• protection

• cooking: detoxify and tenderize meats and marginal plant foods

humans are obligate cooks

• our jaws and guts are too small to process raw food

• large brains demand lots of energy, require foods with some level of processing especially cooked meat could allow for this trade off from large guts to large brains

• when did this start? most now agree it was sometime around H erectus

H. habilis /. rudolfensis (late australopiths; paranthropus)

• oldowan tools

african H. erectus

acheulean tools

acheulean tools

first appear around 1.75mya

some argue they are too large to be functional

hominins continue making oldowan tools

new tool technology → better processing of carcasses and sporadic hunting?

african H. erectus is first hominin to move out of africa

older idea: these cultural advances led to migration to new lands

newer idea: an earlier form (proto-erectus) migrated out of africa

hominins from republic of georgia

did pre h erectus hominin leave africa first?

are georgia fossils intermediary to h habilis and erectus?

some have more ancestral features (smaller brain sizes, momre prognathic faces, shoulders less adapted to bipedalism)

dispersal out of africa

• climate change: grasslands shifted northwards

• game followed the grasses

  • hominins followed the game

  • OR sought more favorable climate conditions for another reason?

H. erectus or proto erectus moves out of africa ~1.8mya and keeps going east?: originally identified in indonesia, extensively documented in china

Is African H. erectus a distinct species from Asian H. erectus?

African H. erectus Asian H. erectus “H. ergaster

• 1.8mya-500kya

• thick cranium, large brow ridge

• 900-1000cc cranial capacity

Asian H. erectus

• 1.7mya – 300kya

• Thick cranium, larger brow ridge than H. ergaster

• 1000-1250cc

no acheulean tools in east asia

homo erectus in east asia continued only oldowan tradition

boundary = movius line. why?

use of perishable tools?

lower population density = less competition?

earlier form of homo ancestral to east asian h erectus?

h erectus in china

significant site for our understanding: zhoukoudian cave (800-400kya)

overall, Homo erectus had more modern human lifestyle (fire, advanced tools, greater geographic distirbution)

Zhoukoudian cave

Fossils from Zhoukoudian known as “Peking Man”

MNI = 51

hundreds of stone tools

faunal bone burned while fresh; cutmarks

deposits are ~40m deep

homo erectus lifeways

new tool technology (excluding indonesia) to process carcasses and hunt(?)

ate varied diet of plants and meat

controlled use of fire

social groups living and working together

indonesian h erectus

goes extinct ~300kya, but did it give rise to other forms in indonesia?

H. erectus from Indonesia, “java man”

H. floresiensis from Indonesia: “Hobbit Hominin”