ANTH103 Exam 3

hominin criteria

bipedality/striding gait

pelvis

foramen magnum

foramen magnum

large opening at base of skull where spinal cord connects to brain. shift to the front allows for better posture and better locomotion

pelvis and hominin criteria

pelvis of bipedal hominins is wider and shorter than quadrupedal primates. provides greater support and stability for upper body when walking

oldest hypothesis of hominin evolution

one hominoid adapting and evolving into one hominin

decrease in tropical forest and increase in savannah

more bipedalism

Darwin and hominin evolution

focus on hunting for meat. bipedalism freed hands for weapons. language and more complex brain for manufacturing tools and language. but brain development happened much later. cooperative behavior

advantages of bipedality

free hands for carrying, making, and use tools

wider view of environment

efficient way to cover long distances, not good for fast travel

early hominins

pre-australopiths

australophiths

early homo sapiens

pre Australopiths

mixture of primitive and derived features.

late miocene and early Pliocene epochs (7mya -6/4/4mya)

pre Australopiths species

sahelanthropus tchadensis

orrorin tugensis

ardipithecus kadabba

ardipithecus ramidus

sahelanthropus tchadensis

found in Chad (west Africa) in forest environment

thought to live 7-6 mya but no absolute dating

one nearly complete cranium, jaw, and teeth fragments, but distorted

no post-cranial remains but a foramen magnum intermediate between apes and modern humans, suggesting more upright posture and possibility of bipedalism

compare sahelanthropus tchadensis skull to pongids and hominin

pongid like: small, but massive skull. large brow ridges, saggital and nuchal crests which are good for heavier chewing and upright posture

hominin like: upper canines reduced, vertical face

vertical face

allows for more efficient chewing, more force on molars, contrast to horizontally protruding face of primates

orrorin tugensis

approximately 6 mya

mostly teeth found

forest environment

no skull found

curved fingers: could be partially arboreal

some post cranial remains found: could be bipedal

what does teeth of orrorin tugensis reveal

large and thickly enameled teeth meaning they ate tough and fibrous foods like seeds, nuts, plants

consistent with idea that bipedalism evolved with changes in diet and/or feeding strategies

ardipithecus kadabba

Ethiopia

found by yohannes who is now a curator at natural history museum in CLE

5\.8-5.2 mya

forest environment

foot bone found suggests bipedality

ardipthecus ramidus

Ethiopia

4\.4 mya

found parts of at least 50 different individuals, but biggest finding was Ardi

findings of Ardi

small brain size: 200-250 cm3, but not necessarily complexity of brain

4 ft, 110 pounds

centrally located foramen magnum

pelvis and foot support bipedality but no striding gait

pelvis was more primitive

diverging big toe (like apes): retained adaptations for climbing trees

austrolopiths species and time

4\.2-1.2 mya

australopithecus

Paranthropus

bipedal but probably not striding gait

australopiths characteristics

small brain size, bipedalism, ape-like dentition

australopithecus anamensis

kanapoi and allia bay

thick enamel on molars

large canines

primitive jaw with sectorial lower first premolars: good for slicing and shear food during chewing

leg bones consistent with, but not proving bipedality

likely ancestor of Australopithecus afarensis

Australopithecus afarensis

found at Hadar, Ethiopia and Laetoli, Tanzania

60-100 individuals remains found

3\.9-3.0 mya

famous findings of A. afarensis

Lucy, first family, dikika infant, kadanuumuu

kadanuumuu

big man, much larger than Lucy

3\.6 mya

not clear if striding gait

was A. afarensis bipedal and striding gait

skull, pelvis, leg bones, and foot bones initially suggested erect, bipedal, and modern striding gait, but they could still be arboreal

75 foot trail of fossilized footsteps in volcanic ash similar to human striding gait

however, more recent analyses suggest not yet striding gait

partially arboreal: long arms, slightly curved fingers

more finds of early hominins in forest environment and scapula of young show more pongid-like characteristics so no striding gait

short fingers: not as nimble as humans

fully opposable thumb

appear to be more pongid-like than human

size of A. afarensis

small: 3.5-4 ft to 5 ft

65-150lbs

sexual dimorphism

small, but strong: markings on long bones reveal lots of muscle

still small cranial capacity: 375-500cc

compare brain size and body size

primates have more excessive brain, steeper slope

characteristics of primitive skull

sagittal and nuchal crests

suggesting large jaw muscles, good distinction from other hominin species

A.afarensis had smaller crests and Homo sapiens had no crests

dentition of a. afarensis

somewhat pointed canines with small diastema (gaps in teeth) in lower jaw

large canine size in males and smaller in females (sexual dimorphism)

semi-sectorial premolar: can cut and crush

variation in dental arcade from parallel to v-shaped (intermediate to the U shape we have )

sectorial premolar

single sharp, blade-like edge to slice through tough or fibrous food material. much later evolution

mosaic evolution

not all parts of the body evolve at the same rate

a. afarensis had ape-like face and dentition, but more human like pelvis and lower limbs for bipedal walking

cultural remains of a. afarensis

not much, little tool evidence, hard to tell if it is a tool

australopithecus africanus

lived in south africa

3\.0/2.5-2.0 mya but hard to know for sure because absolute dating is not possible in limestone caverns with no volcanic events

finding of Australopithecus africanus

found in limestone excavation site at Tuang: skull of 3-4 year old

findings from Tuang Child

large molars, no projecting canines, no diastema, so no opposing jaw, parabolic dental pattern

centrally located foramen magnum so bipedal

cranial capacity at 400cc, prolly higher if lived to adulthood

criticisms of Tuang child

some argued that Tuang child did not display neoteny(retention of infantile traits and development) rather it was adaptations to diet of hard and brittle foods

some also argued that it did not fit the accepted theory of the time that the driving force behind human evolution is the increase in size and complexity of the brain

eoanthropus dawsoni

turned out to be a hoax

combined human skull with orangutan jawbone

paranthropus: robust australopithecines species and time period

2\.5-1.0 mya

P. aethopicus

P. robustus

P. boisei

characteristics of paranthropus

larger and more powerful jaws than homo sapiens

large molars and premolars

Robert Broom

scottish doc who found first specimens of p. robustus in south africa

found partial skull and jawbone of adult

confirmed existence of robust australopithecines in human phylogeny

Robert and Mary Leakey

husband and wife paleontologist duo who conducted research in olduvai gorge

found stone tools, first fossils of P. Boisei but argued that the tools were not used by Zing (name of P.Boisei fossil), laeotoli footprints

Rift Valley

able to do absolute dating because of volcanic ash deposited in strata

P. Aeothiopicus

black skull found in Kenya

large, think brow ridges, sagittal crest, flat and wide face

410 cc (cranial capacity)

intermediate between A. Afarensis and P. boisei

P. Boisei and P. robustus

2\.2-1.0 mya

500-520 cc

no stone tools or cultural remains

all robust austrolopithecines (paranthropus) went extinct

Homo habilis

2\.3-1.6 mya in south and east africa

found in olduvai gorge in the same strata as a. boisei

tool user

same size as australopithecines, but smaller jaw, smaller teeth, larger skull (610 cc), long arms, 3.5 feet tall

probably no language

omnivore and scavenged for meat

competitive exclusion

theory that two species can not occupy the same ecological niche as they will be competing with resources and over time, the better adapted species will outcompete the other. possible explanation for why p. boisei and homo Habilis were found in the same strata

homo rudolfensis

could have possibly existed at the same time as homo habilis

tools of homo habilis

oldowan tradition, pebble tools or choppers.

made of quartz, chert, flint

core, flake

oldowan tradition

earliest tool making tradition of early humans

flaking off small pieces of rock to create sharp edges- choppers

homo ergaster vs homo erectus

thought to be two different species in africa and Asia, but not true

homo erectus

evolved in south and east africa by phyletic evolution from homo habilis about 1.8mya to 300,000BP

migrated to Asia and Europe after evolving

major and minor cold periods

led to changing sea levels so land bridges formed allowing early humans to colonize new territories and adapt to new environments

Eugene Dubois

found first fossil remains of homo Erectus in Indonesia

not immediately accepted because they thought it was an unusual ape

Dubois finding in Indonesia

skull cap, femur, and other smaller fragments

originally named pithecanthropus Erectus but later named homo erectus

1\.6 mya to 300,000BP but most fossils from 800,000 to 300,000BP

Findings in China by Davidson Black

in Zhoukoudian limestone caverns, found a molar belonging to the Peking Man (Sinanthropus pekinensis)

Weidenreich’s findings in Zhoukoudian

found remains of about 40 individuals, including 6 complete or nearly complete skulls

780,000-400,000BP

also found remains of giant hyenas, possibly scavenging on remains of early humans

Dmansi site in Georgia

1\.75 mya

shape of body and skull similar to African homo erectus but projecting lower face, large upper canine, short stature, small cc (550 cc) so similar to australopithecines

use of stone tools

migration evidence in Dmansi

likely the first hominins to migrate out of east and south africa

fissioning: splitting the group into smaller groups

occupied the expanded areas

adapted to seasonal climates

movement facilitated by land bridges

postcranial characteristics of homo erectus

males: 5’6, 100lbs; females: 5’3

relatively short arms and legs compared to homo habilis

modern striding gait

very little difference between homo sapiens

main difference between homo erectus and homo sapiens

approximate mean of 970cm3 brain size and differences in dentition

increase in brain size and most likely complexity

some variation due to sexual dimorphism but most due to increasing brain size

shape of skull of homo erectus

brain case long and low, receding forehead

pronounced supraorbital torus

projecting nasal passage in some

sagittal keel and nuchal torus in some

smaller jaw and teeth than homo habilis but larger than in homo sapiens

maximum breadth at the base of the skull

tools of homo erectus

evolved oldowan style to acheulian tradition by 1.5 mya

bifacial stone tools: hand axes, cleavers

soft hammer technique, great variety of tools

but remained unchanged for 1 million years

diet of homo erectus

scavenging

primarily wild plants, tubers, fruit, occasional meat

homo heidelbergensis

archaic homo sapiens

300,00-130,000 BP

found in africa, Asia, europe

characteristics of homo heidelbergensis

modern pot cranial skeleton

increased cranial capacity: 1200 cc

skull is wider at top than bottom

smaller teeth than homo erectus, but larger than homo sapiens

fossils found in east africa and Germany

tool making of homo hidebergensis

Levallois technique: efficient and precise flakes

africa at about 200,000 BP

spread to Europe and Asia, prolly also china

cave and open air sites

possible systematic hunting of herd mammals by some groups

fire in homo heidelbergensis

possibly control fire, but not ability to make it

used as weapon to scare away animals, run buffalo off cliffs

cook food, so more nutrition

used for heat

used to harden wood and bone points, so less likely to break

possibly increase in work day

terra amata site

possible base site for homo heidelbergensis

found lots of hearths, stone tools, and animal bones

no skeletal material

acheulian (so more advanced tools)

11 habitation levels

thought to be seasonal camps occupied for few days by group of about 15 individuals during late spring and early summer

first evidence of sea resources

also use of red ochre

homo neanderthalensis vs. Homo sapiens neanderthalensis

debate between scientists if neanderthals are a separate species or a subspecies of Homo sapiens neanderthalensis

neanderthals location and time

possibly as early as 500,000 BP, but mostly found in Europe between 75,000-30,000 BP

also found in Europe and west Asia

Neanderthal DNA

both homo sapiens and homo sapiens neanderthalensis evolved from homo heidelbergensis populations

99\.8% gene similarity to modern humans

3\.0-3.8% of human genome of europeans and asians, on average comes from the mating of females neanderthals with male modern humans: mating happened after humans left africa

did male neanderthals mate with modern females?

no, y-chromosome of male neanderthals had mutations on 3 immune genes that apparently caused an immune response in female modern humans leading to fetal loss

effects of neanderthal DNA in modern humans

skin and hair color, immunity and susceptibility to certain diseases

coexisting of neanderthals and modern humans time period

in Europe: 45,000 to 30,000 BP

possibly in the Middle East as early as 80,000 BP

skull of neanderthals

1520 cm^3

long, low and bulging at the sides

occipital bun

large supraorbital tori and projecting face

some forehead

were neanderthals adapted to the cold

yes, broad nose that helped warm and humidify the cold

also short and stout

lived in caves and open-air sites, occupied harsh environments like the Ice Age

hunting for neanderthals

herd mammals like reindeer, wooly rhinos, mammoth

didn’t specialize on one type of game

hunting tools for neanderthals

had necessary weapons like knives and scrapers and spears, needles, fire-making tools

just lacked a thrusting spear

mousterian tradition

widespread used of Levallois technique and production of a range of stone tools like hand axes, scrapers, and points

more complexity in tools; 60 different tools

complexity in tool making example

while the early homo erectus handaxe was created with 25 blows in one step, increasing complexity in tool making led to the neanderthal knife that was made in 111 blows with 4 steps and the coo-magnon knife which was made with 247 blows and 9 steps

religious practices of neanderthals

may have believed in supernatural forces or deities, but really hard to be sure

burials of neanderthals

found intentional burial site at shanidar with remains of several individual, including one with cluster of flower pollen near the head. some included food and tools

neanderthal care of the elderly (2 examples)

la chappelle-aux-saints: old man with arthritis and 2 teeth

shanidar: 40 year old male with congenital deformity of right arm and shoulder

shows that the community cared for the old, sick, and disabled

did neanderthals have language

probably capable of language but likely not as language is symbolic and there is no art, so prolly no language

violence for neanderthals

at shanidar site, body found with spear puncture in rib

moula-guercy cave(France): 120,000-100,000 BP, some humans and non-human bones process in a similar way, maybe example of cannibalism

Denisovans location and time

300,000-50,000 BP in Denisova, Siberia

neanderthals and Denisovans diverged from line leading to modern humans about 500,000 BP

only some tools and few small fossil fragments found

homo florsiensis

found on Flores island

3 foot tall female with 380cm3 skull

7 adults found: 100,000-60,000 BP

long limbs, more similar to homo erectus than Homo sapiens

isolated island population, possibly form of modern human condition of dwarfism

went extinct

partial replacement model

theory that modern human evolved in africa and then migrated out, partially replacing the archaic Homo sapiens populations like neanderthals and Denisovans through interbreeding and competition

Homo sapiens evolution

evolved from homo heidelbergensis in africa by at least 200,000 BP

arrived in Asia by 100,000 BP and in Europe by 45,000 BP

there was some admixture

admixture

mixing of two or more genetically distinct populations

can have implications in prevalence and risk of genetic diseases and can vary across different populations

mitochondrial dna evidence for homo sapiens evolution

evidence was used to estimate that modern humans evolved in africa as early as 200,000 BP

use of y chromosome

passed down directly from father to son without recombination, showed, that first hominins evolved 150,000-200,000 BP

Eve hypothesis

africa has more genetic variation than everywhere else, suggesting a bottleneck effect in the rest of the world. as people moved out, they did not have nearly as much genetic variation as in africa

approx only 200-2000 females

Cro-Magnon

early modern humans that lived in Europe around 45,000-10,000 BP

increased behavioral adaptions

occupied all of the world except for the central pacific islands

full-blown hunters and gatherers

more weapons than just thrusting spear

bering strait land bridge

thought to have connected Asia and North America during periods of low sea level

possibly two migrations at 50,000-40,000 BP and 28,000-10,000 BP

earliest dates of human presence in Siberia

30,000 to 35,000 BP

earliest dates of human presence in Chile and how did they get there

monte verde, Chile: 14,800 BP

got there possibly through rafts, following the coast

inuit

arrived in 10,000 BP

last group to make it over to the americas

earliest human presence in Australia and how

no land bridge, so thought to have come by raft

paintings and artifacts from 65,000 BP and fossils from 30,000 BP

early human (after and during migration) tools advancements

more specialized and better made tools (100+)

improvement in Levallois technique to punch blade technique

also first two part tools like handles of blades

earliest needle at 20,000 BP

more selective in use of flint

heat treating of flint and bone

ability to make fire (iron pyrite)

punch blade technique

prepare a stone core by striking it with a hard hammerxtone to create a platform from which flakes can be removed. then, bone or antler punch is used to strike the core and make a sharp flake that can be shaped and refined into a blade