ARC 1010: What it Means to be Human

• 25mya - 3.3mya

• Origins of the great ape lineage

• Divergence from our closest living relatives

• Becoming bipedal

• 3.3mya - 300kya

• First lithic tools

• First expansion of hominins outside of Africa

• Emergence of cooperative hunting and meat-focused diets

• Control of fire

• Emergence of Neanderthals in Europe

• 300kya - 48kya

• New lithic technology; first hafted tools

• Emergence of Homo sapiens in Africa

• 48kya - 12kya
• New lithic technology;
• Modern humans radiate from Africa

• No tail (= hanging, not balancing)

• Wider degree of freedom at the shoulder joint

• Only around 15 species left

• Other than humans, not very successful group; largely replaced by monkeys in Africa and Asia during past 10 million years

• Smaller/lighter than great apes (5-15 kg)

• Less sexually dimorphic and don’t build nests

• Arboreal and bipedal

• Smaller social groups than great apes

• Large body size

• Must be careful in the trees!

• Shorter arms and legs than lesser apes

• Short thumbs

• Mainly fruit eaters, some meat

• Humans are 98.7% similar to a chimpanzee (closest relative) and 95-97% similar to a gorilla 

• Chimp-human divergence 5-10 mya

• Gorilla-human divergence 8-19 mya

• humans more homogenous w/ similar genetics, chimps way more genetically diverse (2 chimps + diff than 2 humans on planet)

Hominins – our oldest ancestors – are incredibly rare

The evidence for them is mainly teeth and bone fragments

Between 2 and 6 Ma ago, all the evidence comes from Africa

Chad: Sahelanthropus tchadensis

Ethiopia: Aramis, Ardipithecus ramidus

Kenya/Tanzania: Kanapoi, Orrorin tugenensis

Key area in Tanzania for paleoanthropological stufy, invaluable in furthering our understanding of early human evolution. About 48 km (30 mi) long, located in the eastern Serengeti Plains in the Arusha Region not far, about 45 kilometres (28 miles), from Laetoli, another important archaeological site of early human occupation.

Homo habilis, probably the first early human species, occupied Olduvai Gorge approximately 1.9 million years ago (mya); then came a contemporary australopithecine, Paranthropus boisei, 1.8 mya, then Homo erectus, 1.2 mya. Homo sapiens is dated to have occupied the site 17,000 years ago.

The site is significant in showing the increasing developmental and social complexities in the earliest humans, or hominins, revealed in the production and use of stone tools and meat based dieting 

• -  20-25 hominins species

• -  Bush not tree

• -  Bipedalism comes first

• Often considered one of the defining characteristics of the hominin lineage

• the trait that defines our ancestral niche in the primate family
• who was bipedal? 

Chimpanzee

• Skull attaches posteriorly 
• Spine slightly curved
• arms longer than legs and used for walking]
• long, narrow pelvis
• femur angled out

Australopithecine

• skull attaches inferiorly 
• spine s-shaped
• arms shorter than legs and not used for walking
• bowl-shaped pelvis
• femur angled in

• Six fragmented bones, including a complete cranium (Toumai) and lower jaws

• Found (unexpectedly) in Chad, central Africa

• Dated to 7-6mya

• Features: – Bipedal

– Brow ridges

– No forehead

– Sloping face (prognathism)

• Nicknamed ‘Ardi’

• C 4.5 – 4.3mya

• At least 17 individuals, mainly teeth but including...

• A remarkably complete skeleton (c.45% preserved)

• Features

     – Fully bipedal, but also adapted for life in trees

     – Long arms relative to body – Grasping toes

Australopithecines

• 7 species e.g. Australopithecus afarensis
• Gracile”
• Probably the first tool users
• Brain size slightly larger than chimps
• leafy diet

Paranthropines

• 3 species e.g. Paranthropus boisei
• More robust, big chewing muscles
• meaty diet -> cranial ridge to accommodate chewing muscles

• c4-3mya
• East Africa (Tanzania, Ethiopia, Kenya)
• One of the best-known early hominins: large sample of different specimens

Lucy: AL288-1

The ‘first family’ AL 333

• 216 specimens, at least 17 individuals including 9 adults, 3 adolescents and 5 young children
• Mainly jaws and teeth but some humeri and femora

Dikika baby:

• Almost entire skull and torso and most parts of limbs
• ~3yrs old?

• 3.6 mya footprints in damp volcanic ash from Tanzania
• Includes footprints from three hominin individuals of different size;
• Smallest individual walked side by side on the left of the largest individual.
• Intermediate-sized individual superimposed its feet over those of the largest individual
• 14 footprints from two new hominins published in Dec 2016
• 150 metres away from other footprints
• Speed = less than 1 m/s

• Carrying: weapons and tools; vegetable foods, water, and infants
• Savannah-based theory; Travelling efficiency theory
• Postural feeding
• Provisioning family
• Thermoregulation
• Wading/Aquatic ape theory
• warning/ threat display
• Complex topography hypothesis

• General cooling trend from c. 3.3 mya
• In Africa, drier climates cause reduction in tree cover, expansion of grasslands.
• Changing distribution of food resources
• grasslands meant more meat
• Early hominins adapted to woodland margin environments

• 6-8 mya to ca. 3.5 mya

• Small, sexually-dimorphic hominins

• Small brains

• Bipedal

• No tool-making or evidence for eating large animals

1stly, 2 myths: man the tool-maker and man the hunter 

2ndly, 1st members of the genus Homo: 

• Homo habilis Hadar, Ethiopia, 2.4-1.4mya, brain size =500-650cm3
• Homo rudolfensis, 1.9mya, brain size =700-850cm3

Thought these were the first tool makers but they weren't 

Earliest stone tools: 

Lomekwian – 3.3 mya

• Lomekwi, Kenya 
• Very basic knapping skill, lots of failed strikes

Oldowan - 2.6mya

• Simple cores and flakes only
• Skill varies widely but includes some very accomplished knapping

or called 'core and flake' 

Means one modifies the world around us to solve problems 

Found in Kadar, Gona (Ethiopia, 2.6mya)

Lokalalei 2C, 2.34mya, Kenya

• Systematic knapping
• High level of control
• Few failed strikes

• Stone tools predate known Homo fossils
• Possibly associated with A. garhi, P. boisei/ robustus, A. africanus, H. habilis/rudolfensis
• Bone tools used for digging, termite fishing
• Many of our relatives use tools, sticks, etc. to eat and hit things
• other monkeys and primates use stone tools: e.g. 
• Capuchins use as hammer and anvil, and bearded capuchins use stones to dig for tubers and process plants like cactus 
• Macaques use stones to crack open molluscs and crabs

Famous example is Kanzi the 9y/o captive male bonobo, who was taught to knap

• Taught language to communicate, roughly equivalent to a 1.5 yr old human child
• Initially hand-held knapping technique, learned by imitation.
• Independently developed own flaking technique... (possibly indicative for how first Oldowan knappers began exploring raw material properties of stones?)

Famous example is Kanzi the 9y/o captive male bonobo, who was taught to knap

• Taught language to communicate, roughly equivalent to a 1.5 yr old human child
• Initially hand-held knapping technique, learned by imitation.
• Independently developed own flaking technique... (possibly indicative for how first Oldowan knappers began exploring raw material properties of stones?)

Many similarities in basic sensorimotor systems

BUT Hominins show:

• Greater degree of physical skill
• Better causal reasoning
• Greater temporal and spatial scale of tool use

so humans not tool makers, but apes and some monkeys can flake stone and use tools

the earliest evidence for stone tools is earlier than our own genus

Looking at relatives, eating a diet of plant foods, termites, faeces

Chimps hunt and share meat

Why?

• Not to do with nutritional shortfall (only observed in times of food abundance)
• Primarily appears to be a form of male social bonding;
• Occasional sex-for-meat, but not primary purpose (males did not appear to gain an advantage in this) 
• hierarchy of eating still
• but not only about caloric intake, e.g. 2017 news about chimps who murdered and ate their former tyrannical leader 

• Evidence for bone processing at Dikika, Ethiopia 3.39 mya marks on herbivore bones 
• Very similar in date to the first known stone tools (3.3 mya in Lomekwi, Kenya)
• Before the genus Homo

• Evidence for bone processing at Herto Bouri; 2.5 mya, stryations on bone
• hunting or scavenging? most likely scavenging as highly competitive and dangerous
• out of trees risking lions/birds of prey
• A handful of simple stone tools have been recovered from the vicinity but association with fossils uncertain

why meat? primates can be up to 200kg with small brains, we have big brains and small intestines

meat was necessary 

• We are an African ape
• Our earliest ancestors were walking long before they developed large brains or made stone tools
• We are not unique as a tool-maker, or even as a maker of stone tools The earliest stone tools pre-date Homo
• Other primates hunt and eat meat too; scavenging is usually easier; big-game hunting is probably very recent in evolutionary terms
• Bipedalism, tool use and increased carnivory provided the foundations for rapid brain expansion that characterises the Homo lineage

• We are an African ape
• Our earliest ancestors were walking long before they developed large brains or made stone tools
• We are not unique as a tool-maker, or even as a maker of stone tools The earliest stone tools pre-date Homo
• Other primates hunt and eat meat too; scavenging is usually easier; big-game hunting is probably very recent in evolutionary terms
• Bipedalism, tool use and increased carnivory provided the foundations for rapid brain expansion that characterises the Homo lineage

when 1st Homo sapiens moved across the world 

• Lithic toolkits that contain bifaces (handaxes) as well as cores and flakes
• ~1.8mya - ~100,000ka
• More complex toolmaking: Preconceived form, More complex manufacturing process
• Links between meat eating and brain size increases
• Homo ergaster/erectus
• Functions: chopper, butchery knife, flake dispenser, scraper, throwing weapon, digging tool, or simply functional tool? 
• Then Homo antecessor; Homo heidelbergensis
• Inc brain size
• 1st occupation of N Europe (incl UK)
• Fire
• Coop hunting w hand-held thrusting spears
• 1st man-made shelters

330,000 - 40,000 BP 

• 2st hafted tools incl stone-tipped spears and projectiles 
• Homo neanderthalensis; anatomically modern Homo sapiens

from approx 250kya, skeletally modern H. sapiens, Omo Kibish (195kya) and Herto Bouri (160kya), Florisbad (250kya), Klasies River Mouth (>90kya) 

• Symbolism, abstract, only meaning to them
• use of symbols and grammatical language -> personal ornaments (perforated animals teeth), portable art (abstract symbols carved), static art (cave paintings)
• 1 sign, manty meanings unless context/social knowledge
• symbols - relationships, membership to groups (religion), flags

evidence for abstract symbols in African and the Levant appears 100kya onwards after skeletal modernity

e.g. Blombos Cave, Klasies River Mouth, Diepkloof rockshelter

Oldest abstract (symbolic) engraving in the world 

• Markings in red ochre fragments
• Marks not typical of incidental marks made by humans
• 307 pieces showed deliberate modification
• Primarily worked to generate powder, but some show more complex patterns
• Some show deliberate pattern, others don't
• Doodles, notation, personal ownership, abstract concept?
• Interp as geometric engraving possibly similar designs on body or cloth
• Excavators infer a tradition of geometric engraving, likely applied to other media e.g. human and animal skin, wood, and stone using the extracted ochre powder. Henshilwood et al. 2009

• At least 68 Nassarius kraussianus shell beads
• Usewear shows beads strung to hold them in alternate positions
• Possible bracelets, necklaces, collar or head bands
• shell beads deliberately perforated and polished and on strings as necklace/bracelet/ornament/clothing decoration

Deipkloof: geometric designs on ostrich eggshells, personalised drinking vessels

•  270 fragments of intentionally marked ostrich eggshell
• Eggshell containers
• Standardised abstract geometric patterns
• geometric designs on ostrich eggshells
• personalised drinking vessels

• Graves packed with engraved stuff
• shamanistic figurines
• cave art
• religion and ritualistic evidence

Fossils anatomically indistinguishable from modern humans in Africa from 250 kya
Archaeologically recognisable symbolic behaviour only apparent from 100 kya, WELL AFTER physical modernity

Image problem byword for inferiority

not too different to us today, matter of degree

Humans vs Neandethals: 

• braincase shape (bun shape) 
• forehead (none for neanderthal)
• browridge (nea big)
• nasal bone projection
• chin (none for nean)
• occipital contour

Nean have bigger brain than modern humans, but heavier set, so need more brain mass to control it 

• Neanderthals successfully colonised varied environments from the Near East to central Asia to norther Europe
• They adapted their diet to make use of locally available resources
• They were capable of hunting the largest prey
• live 4350ky , successful species
• used medicines
• care for sick/elderly (old bones w 0 teeth and injuries found Iraq, Shanidar
• buried their dead, 25 examples in shallow depressions, a little evidence of grave goods and ritual burial but debated
• +ev of symbolic thinking: claws feathers talons as deco, ritual use of caves ( in EU made circle of stalagmites, curation of pigments

• Often get a bad rep but were capable hunters and survived for several 100,000 years in Eurasia
• Doing many of the same things as Homo sapiens
• Symbolic capabilities are still debated today. For this reason, traditionally seen as inferior to modern humans.
• Extinct by 40,000 years ago

• Humans and Neanderthals interbred around 65-50 kya and all non sub-Saharan Africans still carry their DNA today (up to 2.1%)
• that 2.1% will be different for almost everyone
• Humans also interbred with another hominin species, the Denisovans (up to 6% in Melanesians)
• Neanderthals and Denisovans interbred with each other
• Clear evidence for interbreeding with a 4th ancient ancestor, not yet identified
• And yet, still no archaeological evidence that Neanderthals and modern humans ever met