Biological Anthropology Pt. 3

Homo floresiensis

- "hobbits" - Fores, Indonesia. No land bridge connected Flores island to mainland Asia during the Plio-Pleistocene. Need a boat to get there. -100-60,000 years ago - Stone artifacts from 190-50,000 years ago - Australopith like brain size but more vertical profile of face -About 3.5 feet tall - Australopith like wrists - Short lower limbs - Flat feet and long, curved toes - Simple flake stone tools (similar to Oldowan) - Evidence of butchery, hunting, and fire.

Dmanisi skulls, Georgia. Caucasus.

- 1.8 mya - Don't know what species to determine these as (H. ergaster, H. erectus, or H. georgicus) - Small bodies and brains - Oldowan technology - Perhaps synchronic population who took care of old and/or sick individuals

Java, Indonesia

- 1.8 mya - Homo erectus from Java: Mojokerto (1.8) and Sangiran (1.65) - Questions about provenance and dating; land bridge between Java and mainland Asia - No stone tools

Brains are expensive organs. They consume..

- 16x more energy than the same amount of muscle tissue - 20% of BMR devoted to brain (8-10 in other primates and 3-5 in most other mammals) - Even more costly to grow

Gusher Benot Ya'aqov, Israel

- 790,000 years ago - Charcoal, burned flints, hearths, burned grass seeds, and grains which possibly suggest cooking.

Areas that appear to lack neanderthal DNA - examples of certain genes:

- Activated in the testes - Located on the Y chromosome

Parts of a biological profile

- Age at death - Sex - Ancestry - Height and weight - Premortem (before death) injury and disease - Perimortem (during time of death) and postmortem trauma

What is the most supported model for AMHS origins?

- Assimilation model: genetic data are most consistent with assimilation (or partial replacement) - African origin of modern humans - Greatest amount of genetic diversity in Africa - AMHS first appear in the fossil record of Africa - But varying degrees of interbreeding with populations they found as they migrated

Sima del Elefante

- Atapuerca, Spain - 1.3 mya - Homo sp., first Europeans - Oldowan artifacts - Hominin remains - Species assignment not clear

Sima de los Huesos

- Atapuerca, Spain - 400,000 ya - "pit of the bones" - clear relationship with Neanderthals - Carnivores and humans; at least 28 individuals - Causes of the accumulation are not clear (perhaps intentional) - Homo heidelbergensis Not all express Neanderthal traits to the same degree; quite bit of diversity

Gran Dolina

- Atapuerca, Spain - 850-950,000 ya - Homo antecessor - Oldowan tools - Cut marks on human bones: oldest evidence of cannibalism and human bones processed in the same way as other fauna.

Evidence for fishing from Katanda, DR Congo (82-70 kya)

- Bone tools, including barbed points, appropriate tools for fishing - Two species of catfish, especially a larger species - Ability to develop new technologies allowed early modern humans to expand their subsistence base

Evidence for big game hunting in archaic Homo sapiens

- Bones of large animals associated with Acheulean tools - Humans may have stampeded large animals over the edge of this cliff and butched the caracasses )La Cote de St. Brelade, France) - Collaborative hunting effort and complex social patterns - Wooden spears, Schoeningen (400,000 ya): archaic middle pleistocene hominins hunted large animals and possessed specialized toolkits for doing so - Bodo cranium, Ethiopia (600,000 ya): marks on cranium that could indicate cannibalism

Tool industries in Homo erectus

- Both stone industries - East asian populations have migrated out of Africa before the Acheulean industry developed - East Asian populations may have lost the Acheulean industry because they didn't find suitable materials

Possibility for an intermediate proto-language used by hominins?

- Cannot rule out the possibility that an intermediate proto language was used by hominins before language evolved - This protolanguage may have been vocal, musical, or gestural - Transition to spoken language must have provided advantages

Evolutionary origins of modern human life history

- Comparative studies of modern great apes and humans - Studies of the fossil evidence of human evolution

Absolute and relative brain size of humans

- Comparatively under-developed at birth (humans only have about 27% of adult brain mass at birth, while chimpanzees have 36%) - Humans grow a larger proportion of their adult brain size during postnatal life. - Human brain growth rates are especially fast in the first 18 months of postnatal life

Time since death

- Decomposition experiments - Phases of decomposition studies - Predictable patterns of decomposition, as well as patterns of insect/arthropod presence

Atapuerca, Spain

- Different sites corresponding to different periods of human evolution

Other behavioral correlates

- Early weaning of dependent offspring → provisioning (nutritional supplementation) - Short interbirth intervals → human mothers may support multiple dependent offspring at a time.

Neanderthals (H. neanderthalensis)

- Europe and Western Asia, around 150-40,000 ya - Systematic use of the mouth as a "third hand" (extremely worn teeth) - Mousterian stone tool industry: prepared core technology

Handaxe proportions

- Follow a mental template (unlike Oldowan tools) - Very regular proportions - These hold for Africa, Near East, and Europe - Requires more complex cognitive abilities

Cranial anatomy of Homo erectus

- Football shape to cranium (long and elongated) - Enlarged brain (more elongated, not tall) - Occipital torus (ridged areas) - Sagittal keel - Bar-like supraorbital torus - Pentagon shaped back of skull; greatest breadth low - Cranial capacity of 980; much less than humans but far greater than other species

Evidence of Neanderthal behavioral modernity

- Fossil eagle talons that were worn as jewelry by Neanderthals 130,000 years ago, found in a cave in Croatia. - personal ornamentation, rock art, burials, and care of elderly individuals. They were not producing these as systematically as modern humans do.

Evolutionary explanations for the modern human life cycle

- Growth of a large brain and the simultaneous dependency of multiple offspring generates high energetic demands on parents during their reproductive lives. Also, extractive foraging niche dependent on skills that take time to develop - Human life history traits that may have been key to reducing the energetic burden and increasing fertility: sloth growth during childhood, help from older non-reproductive adults

Neanderthal subsistence: hafted weapons

- Hafted weapons (stone tool on end of stick) = competent hunting - Animal remains at Neanderthal sites are often characterized by an abundance of one or two prey species (specialization) - Healthy adults are abundant in the animal remains - Cut-marked bones, first access - Also plants included in diet

Pre-Mortem injury and disease

- Healed fractures - Dental procedures

Main jobs of a forensic anthropologist

- Help in making a positive ID - Help determine cause of death (in cases where tissue is gone)

Turkana Boy (KNM-WT 15000)

- Homo ergaster - From Africa - Adolescent skeleton, estimated at around 8 years of age based on dental development - Estimated statue of 5'3 (about 6' as an adult), indicating a significant increase in overall body size compared to Australopithecus - Similar body proportions to modern humans

Determining height and weight

- How tall is skeleton, statistical ways of finding height with certain bones - Weight related to joint side and width of pelvis

Human kid dependency

- Human kids are still nutritionally dependent at weaning - Humans wean their infants earlier than expected for their body size - Unlike other great apes, humans continue to rely on supplemental nutrition support from others after weaning (provisioning)

Features of Homo naledi (South Africa)

- Human-esque skull: general shape advanced, though braincase is less than half of a modern human's - Versatile hands: suggests tool use - Long legs: Nearly indistinguishable from modern human, except slightly curved toes. Suggest efficient long-distance stride. - Primitive shoulders: would have helped with climbing and hanging - Flared pelvis: flare outward; shorter front to back than modern humans - Curved fingers: useful for climbing trees - Similar in body size to modern humans

Neanderthals (H. neanderthalensis) cranial traits

- Inflated cheeks - occipital bun - retromolar space - no chin - double-arched eyebrows - large nose - prognathism - large cranial capacity.

Modern human advantages

- Innovative: new, more elaborate technologies, projective weapons, clothing, shelters, and other innovations in material culture - Cognitive: personal adornment and symbolic behavior, art and music, ritual - Social: larger social networks, exchange networks, buffered risk of starvation

What impact did inbreeding have on who modern humans are today?

- Keratin (protein in hair, skin and nails) - Skin color - Risk factors for certain diseases - Cell surface immune receptors

Features of anatomically modern Homo sapiens

- Large cranial capacity - Limited development of occipital torus or bun - Prominent mastoid process - Small teeth and jaws - Chin - Canine Fossa - Limited development of brow ridges - Small face

Middle pleistocene hominins derived characteristics

- Larger cranial capacity (1200-1300 cc) - Higher forehead - Arched, double brow ridges - increase in molar size

Compared to other mammals of similar size, primates develop slowly and heavily in offspring. Primates have:

- Long gestation lengths - Large neonates - Low reproductive rates - Long developmental periods and late ages at maturity - Long lifespans - Large brains

Derived features of human life history

- Long post-reproductive lifespan - Late age at first birth - Long gestation length: human gestation length 267 days whereas chimpanzees about 228 days. - Large neonates: newborn human infant weights about 6% of maternal bodyweight, whereas chimpanzees weigh about 3% of maternal body weight. - Early age at weaning - Short inter birth interval

Evidence from mitochondrial DNA

- Maternal inheritance - Rapid mutation - "Molecular clock": if mutations accumulate at a constant rate, one can calculate an estimated date for the most recent common ancestor between two lineages. - How much diversity within different groups: Africans have the most genetic diversity, which is what you would expect if people have been evolving in Africa longer African origin supported by mitochondrial DNA, Y chromosome and other nuclear DNA markers. - Divergence dates of African and non-African AMGS lineages are more recent than predicted by the multiregional model.

Evidence from Archaeology (stone tools)

- Middle stone age/middle paleolithic: Mousterian (mode 3) and prepared core - Late stone age/upper paleolithic: Aurignacian (mode 4) and blade-based

How do we know early records for fire were done by hominins and was not natural?

- More intense and longer lasting (burned at higher temps) - Spatially localized and discontinuous - Small, localized, fully oxidized, magnetically altered sediment patches at Koobi Fora (Kenya, 1.65-1.4 mya) and Chesowanja. Not everyone agrees this is definitely controlled fire. - Burned bones from Swartkrans (cave) in South Africa, from probably around 1.5-1.0 mya.

Archaic homo and Neandertal craniums

- More prominent brow ridge - less basketball shaped

Why are projectiles important?

- More success - Less risk: don't have to get as close to large game - Survivorship increases - Competitive advantage

Out of Africa Dispersal: Who, When, and Why?

- Varied environments: from tropical Africa into more seasonal and colder regions in Eurasia and Far East. - Homo erectus-like hominins migrated out of Africa very shortly after their first appearance in Africa

Gyrification of human skull

- Very gyrified - A way to fit more cortex into the skull - Effective brain size can increase without an associated increase of the skull

Characteristics of human language

- Voluntary and socially learned: planned use of words rather than reactive. - Semantic: arbitrary symbols convey meaning; phonemic - Syntax: order in which you put things matters - Recursive: phrases within phrases; hierarchical structure; can keep tacking on clauses to modify something - Displacement: ability to speak of things/events that are not physically present

Music

- archeological evidence for music predates evidence for cave art. - Expression and comprehension of social and emotional information - Flutes made from animal bones - Debate about Neanderthals having musical traditions or not - Clear that modern humans had them

Life history in the fossil record:

- brain size and development - body size and development - dental development.

Human specialization (cerebral cortex

- cerebral cortex surface is larger than expected for a primate of human brain size - Non uniform expansion of the cerebral cortex - Prefrontal, parietal, and temporal areas have undergone the greatest expansion.

Behavioral innovations of the middle stone age in Africa (280-20 kya)

- complex modern behaviors happened over a gradual period of time - Behavioral modernity wasn't associated with abrupt change - No single cognitive explosion that lead to the modern human mind - Gradual acquisition of typically modern human behaviors, starting in Africa

Homo antecessor

- initially described as the last common ancestor of Neanderthals and modern humans - Facial traits similar to H. sapiens - Dental traits similar to Neanderthals - Possible dead evolutionary end; evolutionary relationships are not clear

Modern human cranium

- large, basketball shaped brain case - Not very robust in features (limited development of occipital torus or bun) - Small face

applications of forensic anthropology

- legal context: IDs and cause of death - Mass fatalities: 9/11 - War dead: Defense POW/MIA Accounting Agency; task force in DOD tasked with identifying all POW and MIA soldiers from all wars. - War crimes and genocide

Middle pleistocene hominins primitive characteristics (similar to H. erectus)

- long, low skull and thick cranial bones - Very large brow ridges - No canine fossa - No chin - Postcranial skeleton more robust than modern humans

Out of Africa model (Models for AMHS origins)

AMGS originated in Africa and later dispersed to occupy the Old World. No gene flow/interbreeding, but replacement of existing hominins. Explains why there is relatively little genetic variation in modern humans.

What were tools used for?

Access the carcasses of animals to obtain meat, break bones to obtain marrow, secondary uses such as plant processing and woodworking.

Assimilation model (Models for AMHS origins)

African origins of AMHS. Varying degrees of interbreeding with existing populations. Hybrid of the other two models. Best supported by fossil record.

When do Neanderthalscome come back from Near East?

After about 90,000 ya in the Near East Neanderthals come back when the weather gets colder (ca. 70-40 kya)

Distinctive features of the human life cycle

Childhood: between infancy and juvenile period - occurs after weaning, when children are still dependent on others for food - Period of learning technical and social skills (language) - Ends with the attainment of adult brain size. Adolescence: between juvenile and adulthood - Begins with the onset of sexual maturity Allows for an extended period of social learning, and continued brain maturation - Marked acceleration of body growth - Ends with attainment of adult height

Macro and microscopic comparisons of extant species

Comparative method between modern species

Trends 2.5 MYA

Cooling and drying. Expansion of open grassland at the expense of closed forests.

Middle pleistocene hominins

Different populations with different evolutionary relationships. (H. heidelbergensis, H. rhodesiensis, and H. intercessor). - H. rhodesiensis: Africa - H antecessor: Spain - H heidelbergensis: Europe

Early evidence of tool use: Sdwartkrans, South Africa

Digging tools made of bones and horn cores (USOs and breaking into termite mounds), evidence for selectivity, but we don't know if Paranthropus or Homo were using these tools.

Why this pattern of brain growth? Metabolic constraints

Due to metabolic constraints of gestation. Fetal metabolic requirements outpace maternal supply at around the time when the baby is born

When did language capacity evolve? - evidence in Homo erectus

Evidence for asymmetric Broca's area in Homo erectus: implies some sort of language capacity in Homo erectus. (still up for debate due to rough evidence of brain)

Perimortem trauma

Evidence of non-healed injuries offer important clues to cause of death.

Ileret, Kenya

Footprints from 1.5 mya. - indistinguishable from modern humans, indicating a human-ice form of bipedal locomotion

Adaptations for language evolved...

Gradually over time. - Brain adaptation necessary for language evolved gradually during hominin evolution - Vocal adaptations likely evolved later

H. heidelbergensis

Large number of specimens coming from different regions of Europe. Some of them show clear similarities with Neanderthals but some others don't. They are probably direct ancestors of Neanderthals.

Extractive foraging

Natural selection has favored enhanced cognitive capacities in primates that rely heavily on extracted foods, which require complex processing techniques to access. - Capuchins open oysters with rocks - Chimps obtain termites and ants hidden in mounds - Chimps crack nuts with hammers - Baboons dig to expose corms hidden underground - For humans: coordinated hunting, marine resources, etc.

Evidence from Neanderthal DNA

Neandertal lineage is distinct from modern humans and there was interbreeding between Neanderthals and modern humans.

Neanderthal subsistence: Shelters

No clear evidence of permanent shelters: they did not stay in one area for long periods of time; instead used rock shelters

Cores

Oldowan tool industry (early stone age/lower paleolithic; 2.6 mya-200,000 ya); lumps of stone from which pieces are removed

Flakes

Oldowan tool industry (early stone age/lower paleolithic; 2.6 mya-200,000 ya); mall fragments of stones removed from cores

Hammerstones

Oldowan tool industry (early stone age/lower paleolithic; 2.6 mya-200,000 ya); rounded stone used to remove the flakes.

Why this pattern of brain growth? Selective advantages

Selective advantages of extended neural development - Key maturation changes in the brain continue through adolescence - Brain maturation occurs under massive environmental and social influences in our species - Neural circuits responsible for behavior are shaped by experiences in the local environment

Movies line

Separates H. erectus populations that developed Acheulean tools and those that did not

Brainstem

Stem at the base of the brain. Regulates many basic body functions. (Reptilian brain)

Encephalization

The proportional size of the brain relative to body size

What are "language areas" doing in nonhuman primates?

They are involved with non-vocal communication.

Portable art: figurines example

Venus figurines: Gravettian ca. 25,000 ya

Distribution of Middle pleistocene hominins

Very widespread. A variety of different tack lumped together

Endocranial cast

When the skull fills with sediment and is preserved, it leaves a fossil that provides a general representation of brain size and shape.

Handaxe usage

- "Swiss army knife"; strip bark off branches, process hides, saw, etc. - Processing large animal carcasses (tip cuts through joints and meat) - Wood and plants - Cores (as flake dispensers): flakes have razor sharp edges which are useful for cutting meat, processing hides, processing plant foods, etc. - Non-utilitarian purposes: maybe they just liked making these sort of things

FOXP2 Gene

a gene involved in speech and language. Regulates the expression of other genes that influenced development of language circuits in the brain. A single base pair mutation is associated with heritable speech and language impairments - Gene is present and highly conserved in all vertebrates - The human version of FOXP2 from the chimpanzee version in 2 amino acid changes causing functional differences. - Strong positive selection and fixation of the modern human version of FOXP2

Homo rudolfensis

absolutely larger brain size, australopith like broad mid face, relatively larger molar teeth, well developed mandible for chewing muscles

Art and modern humans

after 40,000 years ago in Europe and Africa there was an Intensification and consistent presence of music, rock art, and portable art such as figurines

What evidence suggests Neanderthals had difficult lives

almost never lived beyond 40-45 years. Most of the older neanderthals suffered some sort of debilitating disease or injury.

Primary areas of brain

basic functions, motor control, and primary sensory processing; humans have a lot devoted to association cortex rather than primary inputs

Sulcus

crevices between wrinkle things on brain

Early evidence of tool use: Dikika, Ethiopia (3.39 mya)

cut-marked bones, not found in association with hominins or tools, but provides evidence for stone tool assisted meat consumption before Homo.

Early hominin fossil location

early homo fossils have been found at a number of sites in East and South Africa (Kenya, Southern Ethiopia, Tanzania, etc)

Early evidence of tool use: Lomekwi, Kenya (3.3 mya)

evidence of stone tools; Lomekwian tools. Well before earliest homo.

Did Paranthropus specializations evolve in parallel or from a common ancestor?

finish later

H. habilis

finish later

Paranthropus

hyper masticatory complex, increase in cheek tooth size, body similar to Australopithecus. robust australopithecine; chewing machines, "nutcracker man"; large, forwardly placed sagittal crest and increased size of zygomatic arch with a dish-shaped, broad face. Enlarged cheek teeth with thick molar enamel; frontal dental reduction and crowding

Language area asymmetry

in 95% of modern humans, language function is lateralized to the left hemisphere of the brain. (different for left-handed people than right-handed people)

Grandmothering hypothesis

inclusive fitness benefits are derived from older, non-reproductive adults who contribute to the care of their grandchildren. - By improving the survival and reproductive success of close relatives, this increases the probability that the genes you share with them will be passed down.

Homo

increase in brain size and capacity for tool making, decreased in prognathism, and postcanine tooth size, and increase in body size.

Parietal lobe

integrates sensory information from different modalities, important for tool use

What parts of the brain increased/decreased during human evolution?

large increase in association areas and olfactory region reduced.

Early homo anatomy

larger cranial capacity, slight reduction in size of the cheek teeth; more parabolic dental arcade; thinner enamel. Reduced prognathism, more gracile cranium. Similar in body size to australopiths; associated with stone tools.

Frontal lobe

many higher cognitive functions associated with intelligence

Expanded subsistence base in anatomically modern Homo sapiens

more varied diet, which also included use of aquatic resources.

Language processing areas in the human brain

mostly in left hemisphere

Tool use behavior similar to chimps

nut cracking, stone tool use, stone transport (<2 km), stone selectivity, small game hunting.

The genus Homo

out of Africa. (Homo erectus and Homo ergaster)

Association cortex of brain

portion of the cortex that does not fall within primary motor and sensory areas → processing and integrating primary inputs; humans put a lot into doing other stuff

Human menopause

post-reproductive period in the lives of females, characterized by the permanent cessation of ovulation and menstruation. Fertility decline has been documented in other primates but no not experience menopause in the same way humans do. - Reproductive termination occurs midway through the lifespan, well before advanced somatic aging. (slow somatic aging)

Temporal lobe

primary auditory cortex, visual object recognition, processing of semantics, long term memory.

Ancestry

racial or ethnic background of an individual. - Tricky to determine due to overlap - Morphologies common in certain populations - Large database on skulls and skeletons of known ancestry compare.

Extensive paternal care & cooperative breeding

reproductive strategy and social system in which nonparental members of a social group help to support offspring who are not their own.

Settlement patterns of modern Homo sapiens

sites occupied for longer periods and extensively modified. Evidence of more permanent shelters (mammoth bone shelters)

Tool use unique to hominins

stone transport (>10 km), stone tool manufacture, using tools to make tools (woodworking), plant processing, large game acquisition, carcass processing

Where does H. floresiensis fit into our lineage?

three hypotheses - Microcephalic H. sapiens (unlikely) - Dwarfed lineage of H. erectus probably due to habitat. (most likely explanation) - Descendent of H. habilis or australopith population.

Ritual burial

upper Paleolithic graves commonly included artifacts, body adornments and sprinklings of red ochre - possibly suggesting the concept of life after death/religious beliefs

Blade based technology

variety of tool types made from stone, bone and antler.

Gyrus

wrinkle things in brain

Pleistocene

(1.8 mya-10,000 ya) Climate oscillation - Colder and more variable climate starting at 1.8 mya - Interval marked by repeated glacial cycles, known as the Ice Age. - Huge volumes of water in continental ice sheets - Exposed land bridges connecting continents

The first "type fossils" of Homo habilis

(1964) in East and South Africa (2.4-1.4 mya). OH 24 and OH 7. Important features including smaller cheek teeth, increased brain size. They were found alongside stone tools. Found at Olduvai Gorge, Tanzania.

Paranthropus boisei

(East Africa, 2.3-1.2 mya) Forwardly-placed sagittal crest, Forward-projecting cheek bones (zygomatic), Reduced prognathism, Thick enamel, anterior dental crowding; marked reduction in incisors and canines, enlargement of premolars and canines

Paranthropus aethiopicus

(East Africa, 2.7-2.5 mya) Well-developed sagittal and nuchal crests, Prognathism; "dish-shaped" face, Forward projecting cheek bones (zygomatic), Well-developed sagittal crest, Relatively small brain

Homo erectus sensu lato

(Homo erectus and Homo ergaster; 1.8 mya-30,000 ya) - Much larger brain with a modern-human-like stature and body plan - First species to leave Africa (Europe --> Georgia --> Asia --> Java)

Paranthropus robustus

(South Africa, 2.0-1.5 mya) only in south africa, Tough foods, especially during times of resource scarcity, Extremely close to P. boisei

Neanderthal-modern human interactions

- Neanderthals and modern humans co-inhabited in Europe for approximately 10,000 years - Both species hybridized (demonstrated by DNA analysis) - Did they interchange knowledge? Late Neanderthals associated with Chatelperronian tools, similar to modern human tools - Are these interactions related to the extinction of Neanderthals? Direct competition, ecological competition, genetic replacement, etc. - What impact did inbreeding have on who modern humans are today? - Keratin (protein in hair, skin and nails) - Skin color - Risk factors for certain dieases - Cell surface immune receptors

Do Neanderthals have the FOXP2 gene?

- Neanderthals share the derived version of FOXP2 with modern humans - The emergence of the derived version of FOXP2 predates the divergence of Neanderthals and humans. - Although gene flow may also have an effect (could have entered Neanderthal gene pool through interbreeding)

Cerebrum

- Neocortex. Outer surface of the brain. - Higher cognitive functions, such as: -sensory perception - generation of motor/action commands - spacial reasoning - memory - conscious thought - speech - language.

Some especially important innovations by 60,000 years ago in Africa

- Projective technology: thrusting spear - Fishing - Personal adornment, larger social networks, exchange networks, as evidenced by beads - Belief system? (Evidence of burial with grave goods)

Trends in Homo ergaster/erectus

- Reduction in size of cheek teeth (similar to modern humans) - Increased body size and modern human-like limb proportions; post cranial adaptations to long-range bipedalism - Absolute brain size increased - Associated with Oldowan and Acheulean stone tools. Evidence of fire. - Wide geographic distribution outside of Africa, persisted for a long time.

How can we study changes that may have lead to speech in the fossil record?

- Relaxation of the cranial base: more flat angle in chimps - Reconstructing the position of the larynx in fossils: modern humans have a much more flexed cranial base compared to other hominins.

Acheulean intelligence

- Requires more complex cognitive abilities than the Oldowan - Mental representation of a target image - Advanced planning to arrive at that product, and ability to modify technique to achieve that goal

Neanderthals (H. neanderthalensis) postcranial traits

- Robust, heavily muscled body - barrel-shaped rib cage - thick leg bones - Adaptation to different climates and ecological conditions (Allen's rule)

Modern humans in the Near East

- Skhul and Qafzeh, Israel (110-90,000 ya) - Preserved anatomically modern cranium - Didn't behave like modern humans: early AMHS had a Middle Stone Age toolkit

Clues for determining sex

- Skull: males have larger and more exaggerated features such as larger brows, zygomatic arch extension, and shape of chin. - Pelvis: females have an elongated public region as well as a wide subpubic angle

What traits create the "ape mind"?

- Social learning and traditions: vern different behaviors from one another - Tool use: routinely use tools for termite fishing and nut cracking - Self-awareness and self recognition: tolerant of other members in social groups; important for development of social behaviors that we see in humans.

Symbolic behavior, social intensification after 90 kya

- South Africa, Namibia, Tanzania, Ethiopia, and Senegal - Asserting group identity: personal adornment; which tribe are they a part of

Why do babies have so much fat?

- Support energetic costs and provide important substrates for brain development. - Buffer against the cost of nutritional disruption and infection following weaning.

Gyrification index

- The degree of folding in the cortex. - Ratio of total cortical surface to outer cortical surface - Increased with brain size

Human specialization (visual cortex)

- The human visual cortex is reduced compared to chimpanzees. - Related to the expansion of the parietal association cortex, important in spatial sense, integrating visual information with information about body position > tool use

Why "out of Africa" at 1.8 mya?

- Tools and increased cognitive capabilities allowed early hominins to colonize new environments - Obligate long range bipedalism - Running after large game - Fire - Possible that expansion was early but only visible at 1.8 mya

Dental development in fossil record

- Tooth formation can be examined and compared against modern ape and human standards - Molar eruption shows a strong relationship with the timing of key events such as weaning. - First permanent molar eruption occurs 3 years earlier in chimpanzees than humans. Timing of tooth eruption differs in humans and apes. - Dental development as a proxy for life history: daily growth lines in teeth provide a method of estimating the absolute age of death of immature individuals.

Control of fire: why is it important?

- cooking: makes food more digestible, less food is needed to get the same amount of nutrients, some toxins can be neutralized. - Warmth: important in cold and seasonal environments out of Africa. Crucial to migrations to Asia and Europe. - Cave occupation: Allows the use of caves as shelters - Predator protection especially important for large groups; used together with stone tools and spears. - Social function: may have facilitated the formation of social bonds; emergence of different types of communication

Clues for age at death

- dental eruption: sequence offers clues for younger individuals - Epiphyses: pattern of fusion of bones - Public symphysis: Ridges and erosion on public symphysis - Cranial suture obliteration: cranial bones fuse together as an individual gets older

Human specialization (prefrontal)

- expanded in apes in comparison with other primates. Humans show a further expansion of this area compared to apes. - More complex neurons in humans (longer and more branches dendrites)

Late Middle Pleistocene in Africa

- hominins show no trace of Neanderthal features. Instead they share more features similar to modern humans. - Specimen from Jebel Irhoud, Morocco: non-protruding face, tucked in below the cranium with a moderately convex skull.

Why this pattern of brain growth? Obstetrical dilemma

Bipedalism requires a pelvis with a narrow birth canal so the brain cannot grow too large before birth

Acheulean tool industry

-1.6 mya-200,000 ya -More sophisticated technology - Symmetrical, biface tools - Retouching, soft hammer percussion

Language-like abilities of other primates

-There is evidence that primate vocal communication can be produced voluntarily, can be learned, and that their calls communicate symbolic information - Specific calls can represent different predators - But they have a limited mastery of syntax and ability to communicate about things outside their immediate experience.

Rock art

-examples from Europe after 40,000 ya - El Castillo, Spain 40 cya - Altamira, Spain 15 cya - Chauvet, France 32 cya - Lascaux, France 17 kya; Depicts two aurochs (extinct cattle) squaring off, small horse above, and small stags below - Variety of scenes, including animal figures, often rather realistically drawn - Human figures were less common - Abstract patterns - Natural substances: red and yellow ochre, manganese, charcoal to create a variety of colors - Different instruments: horsehair, sticks, and fingers Significance is unclear - Magic purpose, to improve hunting success - Other ritualistic or symbolic purpose (naturalistic scenes, including animals that were not hunted)

When did language capacity evolve? - anatomy of vocal tract

-larynx has a lower position compared to chimpanzees which allows humans to produce a larger variety of sounds - human tongue differs in shape and forms the back wall of the oropharynx which contributes to the production of different sounds - Human speech sounds are produced by moving the tongue, lips, and oral cavity. - By repositioning the larynx further down, this expands the supra laryngeal space and increases its capability to produce a greater variety of sounds

Lifestyles and behaviors of these archaic Homo sapiens

-similar to those Homo erectus was using. - Mousterian: prepared core technology - Middle Pleistocene hominins and Neanderthals - Required even more planning than Acheulean tools

Neanderthal burials

-some evidence that neanderthals buried their dead. However, it is not clear if these burials had a religious nature. - Shanidar 4 skeleton: "the flower burial". Large amount of pollen. Was this individual buried on flower beds?

Ledi Geraru, Ethiopia

2.8 mya. Found mandible that was likely part of the genus homo.

Australopithecus or homo? (How do we classify them)

Anatomically, they are more similar to Australopithecus, but classification as Homo has been classically supported by their ability to use and make stone tools (first tool-making species). Now, evidence that other non-Homo species may have used stone tools. Still debate for this.

Forensic anthropology

Applied biological anthropology in medico-legal context. - apply knowledge of osteology and human variation - collaborate with others (medical examiner, pathologists)

Cerebellum

Ball thing at the bottom of the brain. Integrates sensory perception, coordination, and motor control. Learning new motor skills.

Human brains are exceptionally big. This means they have...

Greater ability for cognitive function and mental acuity.

H. heidelbergensis (splitting taxonomy)

H. heidelbergensis, H. rhodensiensis, and H. antecessor all separate species.

H. heidelbergensis (lumping taxonomy)

H. heidelbergensis, H. rhodensiensis, and H. antecessor all together.

Were hominins hunters or scavengers?

Hominins probably practiced both hunting and scavenging; Opportunistic omnivores: incorporating a variety of plant foods, insects and meat

first evidence for a shift in the pace of dental development was in ....

Homo erectus

What was the first Homo species to have a significant increase in brain size

Homo erectus. Then Neanderthals and archaic Homo sapiens are virtually indistinguishable from modern Homo sapiens suggesting some sort of natural selection driving increase in brain size.

Homo erectus: one species or two?

Homo ergaster or Homo erectus: - Homo ergaster came out of Africa (1.9-1.0 mya) - Homo erectus came out of Asia (1.8-30,000 ya)

Homo rudolfensis vs H. habilis

Homo habilis (OH 24) have smaller brain with small face and small jaw with more human like teeth vs Homo rudolfensis (KNM ER 1470) have larger brains but more primitive facial structure and teeth. Sexual dimorphism?

Wernicke's area

Important for speech comprehension

Broca's area

Important for speech production

Why was H. floresiensis so small?

Insular dwarfism: reduction in size of large animals when they get isolated in small habitats (islands). In the absence of predators, being small is a selective advantage (less resources needed to survive). Ex: dwarf elephants in Flores

Later AMHS

Klasies River Mouth, South Africa (120-90,000 ya)

Homo erectus: arboreal or bipedal?

Lack many features that indicate arborealism, so they were likely fully committed to bipedalism - Can run efficiently over a long distance, similar to modern humans. This may be important for hunting.

Social intelligence hypothesis

Large brains and associated cognitive capacities allow primates to cope with and exploit increasingly more complex social relationships. (Dubar 1992: relative neocortex size correlates with social group size in primates)

Ecological intelligence hypothesis

Large brains evolved in response to selection for enhanced problem solving abilities in the ecological domain - navigating the environment, finding food, and processing food. - Mental maps: primates follow optimized routes to preferred fruit trees in their environment - Hamadryas baboons know the locations of water holes in their environment

First anatomically modern humans from Africa

Omo Ethiopia (195,000 ya) Herto, Ethiopia (165,000 ya)

Australopithecus became extinct and two new species arose. What were they?

Paranthropus OR Homo

Early evidence of tool use: Nouri, Ethiopia (2.5 mya)

Percussion and cut-marks on bones, no tools found, australopithecus garhi

Multiregional model (Models for AMHS origins)

Pleistocene hominins represent a single evolving lineage across different regions. AMHS evolved in the context of significant gene flow between regions. Out of touch with current evidence.

Primate life stages

Prenatal period: conception to birth Infancy: begins at birth. Dependent on mother for nutrition and protection. (lactation) Ends with weaning and eruptions of first permanent tooth. Juvenile: travel and forage independently.Learn important social skills. Ends with sexual maturation. Adulthood: reproductively mature. Behind at eruption of last permanent tooth.

Occipital lobe

Primary visual cortex

Unique features of the human body growth curve

Prolonged period of slow body growth during childhood then marked adolescent growth spurt, which is late in onset and high in magnitude - Slow body growth during human childhood coincides with peak demands of brain metabolism

Where does Homo naledi fit into the human lineage?

We don't know because we do not know how old it is.