characteristics of ardipithecus ramidus
relatively small brain, prognathic, more forwardly placed foramen magnum, reduced canine size and loss of honing, minimal sexual dimorphism, foot retains a divergent big toe. lacked some features for suspension/vertical climbing and knuckle walking found in apes.
Two types of bipedal ancestors with large teeth and small brains from south africa
australopithecus (gracile) and paranthropus (robust)
derived traits of australopithecus anamensis (compared to apes)
reduced canines, larger molars, thick enamel, undisputed evidence of bipedalism
what was the cranial capacity of Australopithecus afarensis?
only 420 cubic centimeters, compared to gorilla (506), chimpanzee (395) and human (1325)
What evidence of bipedalism can we see from the footprints found at laetoli, tanzania (3.6 ma), left by Australopithecus afarensis?
adducted big toe, development of arches, deep depression of the heel; evidence of bipedalism
What are some retained arboreal features of Australopithecus afarensis?
relatively long and curved hand bones, higher mobile shoulder joints and upwardly-oriented shoulder blade, short lower (lumbar) vertebrae, relatively long upper limbs compared to short lower limbs
In terms of limb proportions, is A. africanus or A. afarensis more similar to Homo sapiens?
Name some evolutionary trends from Australopithecus to Homo
increase in brain size and capacity for tool making, decrease in prognathism, postcanine tooth size, increase in body size
Name some evolutionary trends from Australopithecus to Paranthropus
hypermasticatory complex, increase in cheek tooth size, decrease in prognathism
What are some characteristics of the teeth of Paranthropus?
enlarged cheek teeth with thick molar enamel; frontal dental reduction and crowding
What anatomical traits can be found in Robust Australopithecus that are related to diet?
presence of saggital crest, enlarged cheek teeth with thick enamel
What are some major trends seen in the australopiths in terms of dentition?
reduced canine size; larger cheek teeth; thicker enamel, paranthropus chewing adaptation, postcanine megadontia
What are some major trends seen in the australopiths in terms of locomotion/posture?
adaptations for bipedalism
What are some major trends seen in the australopiths in terms of relative brain size?
not substantially enlarged compared to apes
What are some major trends seen in the australopiths in terms of body size?
smaller than modern humans, with more sexual dimorphism
Where and when were the first remains of Homo habilis found?
Olduvai Gorge, Tanzania by the Leakeys in 1964
Where have early Homo fossils been located?
a number of sites in East and South Africa, including Malawi
What are some distinguishing features of early Homo?
larger cranial capacity and rounded cranial vault; small or no supraorbital torus, slight reduction in size of the cheek teeth, thinner enamel; more parabolic dental arcade, reduced prognathism, more gracile cranium; less developed cresting; reduced jaw muslces, but similar in body size to australopiths, associated with stone tools
What is the time frame of the Oldowan tool industry?
early stone age/lower paleolithic 2.6 million years ago-200 Ka
What are indicators/evidence that something was used as a tool?
stone tool cut marks (with parallel striations), found with animal remains
What was found in a site in Dikika, Ethiopia?
3.39 million years old bones that were cutmarked (evidence of potential flesh removal, marrow access), not found in association with hominins or tools-recovered a young Australopithecus afarensis. Provides evidence for stone tool assisted meat consumption before Homo.
What types of tool use was unique to the first tool makers/hominins (as opposed to the use of tools associated with chimps)?
Stone transport more than 10km, stone tool manufacture, using tools to make tools (woodworking), plant processing, large game acquisition, carcass processing
When looking at the first Homos, associated with the oldowan industry, what is there NOT yet evidence for?
manufactured hunting weapons, competent big game hunting, fire and cooking, camps, composite tools and hafting, pigments, ornaments etc.
Where and when did Homo erectus exist?
aka H. ergaster. found in africa, europe, georgia, asia, java. 1.8 million years ago - ca. 30 ka.
What was the first East African find?
robust Paranthropus boisei found in 1959 by the Leakeys at Olduvai Gorge, Tanzania
What are some traits of Homo erectus?
long, low brain case, larger nose, bigger brain, occipital torus, more gracile mandible, smaller premolars and molars, pentagonal shape to the skull, bar-like supraorbital torus, no chin
What was the "Turkana Boy"?
Homo erectus, found in Africa. thought to be an adolescent skeleton (8 years old based on dental development), estimated stature of 5'3," significant increase in overall body size compared to Australopithecus, similar body proportions to modern humans, heavily muscled, reduction of sexual dimorphism
Homo erectus is thought by some to actually be 2 species based on geographical variation, what is the division?
Homo ergaster (Africa), Homo erectus (indonesia)
What characterizes the Acheulean tool industry?
symmetrical/bifacial tools, retouching, soft hammer percussion
What would you find in the Acheulean "tool kit?"
3 classes of core tools: handaxes, cleavers, picks; many formal flake tools: Denticulates, scrapers, burins, borers
How are Acheulean tools different from Oldowan tools?
handaxe proportions follow a mental template, tools have very regular proportions, standardized form (holds for Africa, Near East, Europe), requires more complex cognitive abilities
What typifies handaxe usage in the Acheulean?
"swiss army knife," for processing large animal carcasses (tip cuts through joints and meat), cores as flake dispensers
What is an important Acheulean site?
olorgesaille, kenya. Flakes that showed a Vitamin A deficiency (evidence of a meaty/animal based diet)
Why is fire important?
cooking, warmth, cave occupation, predator protection, hunting, transformation of materials, social functions
How do we know fires were manmade (vs natural brush fire)?
more intense and longer lasting (stronger magnetic signal, higher temperature), spatially localized and discontinuous
What was found at Gesher Benot Ya'aqov, Israel?
site from 790,000 years ago, israel, charcoal, burned flints, hearths, burned grass seeds, grains, discrete clusters, not distributed wholly throughout the site, provided evidence for the presence of hearths
What characterizes the remains found at Dmanisi, Georgia?
1.7 mya; still oldowan, small bodies and brains, Homo ergaster
What characterizes the remains found at Yuan Mou, China
1.7 mya (reversed polarity), 2 incisors show shovel shaped incisor, Homo erectus
What are some trends in Homo ergaster/erectus in terms of teeth?
reduction in size of cheek teeth (similar to modern humans)
What are some trends in Homo ergaster/erectus in terms of body size?
increased body size and modern human-like limb proportions; postcranial adaptations to long-range bipedalism
What are some trends in Homo ergaster/erectus in terms of tools?
associated with Oldowan and Acheulean stone tools. More evidence of hunting, fire
What are some trends in Homo ergaster/erectus in terms of geographic distribution?
wide geographic distribution outside of Africa, persisted for a long time
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, expansion was earlier but only visible at 1.8 mya
What are some characteristics of Homo floresiensis?
hobbit! Australopith-like brain size, but more vertical profile to the face, about 3.5 ft tall, Australopith-like wrists; short lower limbs, flat feet (with no longitudinal arch) and with long curved toes
What kind of tool use was associated with Homo florensiensis?
simple flake stone tools; evidence of butchery, hunting
Where does H. floresiensis "fit in?"
island dwarfism? but brain should be larger if derived from Homo sapiens...descendant of remnat H. habilis or australopith population
What type of hominin existed in the Middle Pleistocene? ca. 800-150,000 years ago?
Archaics (somewhere between modern H. sapiens and H. erectus)
What are some derived features of archaics that make them similar to H. sapiens?
larger cranial capacity (1200-1300 cc), higher forehead, rounder braincase, with more vertical sides (variably present), arched, double brow ridges, molar size is decreased
What are some primitive retentions of archaics that make them similar to H. erectus?
long, low skull; thick cranial bones, very large brow ridges, no canine fossa, no chin, post-cranial skeleton more robust than modern humans
what was found at Atapuerca, Spain and other nearby sites?
site with archaics, 1.2 mya - 350 ka, hominins, cave bears, single handaxe, homo ancestor, artifacts, cut-marked bones, cannibalism?, artifacts, hominin remains, elephant bones
In what time frame was the Levallois technique prevalent?
middle stone age/middle paleolithic ~300-50ka
What was found at a site in Ethiopia dating back to 600 Ka?
Bodo cranium, possible evidence of cannibalism? Toothmarks on cranium
Where and when did H. neanderthalensis exist?
ca. 150 - 27,000 years ago; upper pleistocene. around europe
Which "industry" is associated with the middle stone age/middle paleolithic?
mousterian industry, prepared core technology
What type of technology is associated with the late stone age/upper paleolithic?
What has been found at sites in europe dating back to 250-40 kya relating to neandertal hunting?
rare hafted weapons, evidence of competent hunting. Animal remains at neandertal sites are often characterized by an abundance of 1 or 2 prey species, healthy adults are abundant in the animal remains at neandertal sites, cut-marked bones, first access
What has been found at neandertal sites in europe dating back to 250-40 kya?
rare hafted weapons, competent hunting, interpersonal violence, cannibalism, long-term survival of sick or injured individuals, burial without grave goods, little evidence of long-distance networks, use of pigments.
what are the two models for the origins of anatomically modern Homo sapiens?
mutiregional and replacement
Consider the multiregional model for the origin of AMHS. Does the pleistocene hominin lineage evolve into anatomically modern H. sapiens or is it replaced?
pleistocene hominins represent a single evolving lineage across different regions, there is significant gene flow between regions (europe, africa, asia)
Consider the replacement (out of africa) model for the origin of AMHS. Does the pleistocene hominin lineage evolve into anatomically modern H. sapiens or is it replaced?
AMHS evolves in africa and then spreads to Europe and Asia. There is no gene flow/interbreeding, but replacement of existing hominins.
How do you account for the difference in body size between neandertals and AMHS?
H. sapiens were much less robustly built b/c of evolutionary history in the warmer latitudes of Africa. Relying less on muscle strength and more on tool use to get things done.
What traits characterize the beginnings of modern human facial anatomy?
vertical forehead, vertical face, moderately convex scull, no protruding face, tucked in below the cranium. These start to show up in the fossil record around 270,000 ka (late middle Pleistocene in Africa
Where does the fossil record show distinctly modern human traits?
Omo Ethiopia, 200,000 years ago: rounded brain case, frontal bone, distinct chin, mastoid process. at Herto, Ethiopia (165,000 ka) vertical orientation of face
What evidence from the fossil record suggests that there were two expansions out of africa as opposed to one?
long hiatus in the fossil record
What are some especially important innovations of the African Middle Stone Age that we see in the fossil record by 60,000 years ago?
projectile technology, fishing, personal adornment, larger social networks, exchange networks (as evidenced by beads), belief systems (burial with grave goods)
Why are projectiles important?
more success in hunting, less duress, survivorship increases, competitive advantage
Around when and where did evidence in the fossil record indicate in increase in symbolic behavior and social intensification?
90,000 years ago, south africa, namibia, tanzania, ethiopia, senegal
Around when do anatomically modern Homo sapiens first appear in the fossil record?
ca. 40,000 years ago
When do we see venus figurines in the fossil record?
ca. 25,000 years ago (Lespugue, France, Willendorf, Austria, Dolni Vestonice, Yugoslavia)
What is distinct about the H. sapien ritual burial in contrast to Neanderthal burials?
Arene Candide, Italy; 20,000 year old burial shows mammoth ivory pendants and a flint blade buried alongside the body of a teenage boy. Upper Paleolithic graves commonly included artifacts, body adornments and sprinklings of red ochre.
What is associated with an expanded subsistence base as found in H. sapiens?
more varied diet, which also included use of aquatic resources
What is associated with settlement patterns of H. sapiens?
Sites occupied for longer periods and extensively modified. Evidence of more permanent shelters (e.g. mammoth bone shelters)
What innovative advantages did modern humans have?
new more elaborate technologies, projectile weapons, clothing, shelters, and other innovations in material culture.
What cognitive advantages did modern humans have?
personal adornments and symbolic behavior, art and music, ritual.
What social advantages did modern humans have?
larger social networks, exchange networks, buffered risk of starvation.
Why is useful to use mitochondrial DNA in tracking changes in the human lineage?
Maternal inheritance, no recombination of genetic material from the mother and father...so any difference that occurs over time is solely due to mutation, not genetic recombination), rapid mutations, short code, can calculate a "molecular clock" and estimate a date for the most recent common ancestor between the two lineages
In which populations does mitochondrial DNA show that is there consistently more diversity: sub saharan african populations or populations outside of africa?
sub saharan africa populations always show more diversity because they evolved for longer
What does evidence from neandertal mitochondrial DNA tell us?
neandertal lineage is distinct from modern humans
What is the coalescence time of human and Neanderthal reference sequences that we know from the genomic data?
ca. 706,000 years ago
When does genomic data indicate that there was a split between ancestral human and Neanderthal populations?
ca. 370,000 years ago
Did neandertals (or other 'Archaics') and modern humans interbreed?
At least a little. Evidence that adaptive allele of the brain size gene microcephalin (D variant) introgressed into Homo sapiens from an archaic Homo lineage (evidence from remains found at Lagar Velho, Portugal 24,500 ya)
What are some major evolutionary novelties of humans?
habitual upright walking (bipedalism), characteristics of dentition, elaboration of material culture, significant increase in brain size, long developmental period and long lifespan, mosaic evolution (different traits evolve at different points in time)
When did humans evolve their relatively large brains?
happens around when the genus Homo bursts (around 1.7 mya/between 1.5 and 2 mya)
What is the function of the cerebellum?
integrates sensory perception, coordination and motor control; learning new motor skills
what is the function of the cerebrum (neocortex)?
higher cognitive functions, such as sensory perception, generation of motor/action commands, spatial reasoning, memory, conscious thought, speech, language
What is the function of the frontal lobe?
many higher cognitive functions, associated with intelligence
What is the function of the parietal lobe?
integrates sensory information from different modalities, important for tool using
What is the function of the temporal lobe?
primary auditory cortex, visual object recognition, processing of semantics, long-term memory
What unique evidence do we see of brain reorganization in humans?
the primary visual cortex and the lunate sulcus
Name the language processing areas in the human brain.
broca's area, wernicke's area, angular gyrus, sylvian fissure, arcuate fasciculus
Where is the language processing area in the human brain? (left or right)
in 95% of modern humans, language function is lateralized to the left hemisphere of the brain
What do cell architecture studies indicate about the left-side broca's area in the human brain?
it is significantly expanded
How can we reconstruct the position of the larynx in fossils?
by looking at the angle of the mandible
What is FOXP2?
a gene involved in speech and language. unique to humans (2 amino acid changes in the human form)
Compared to muscle tissue, how much energy does the brain consume?
16 times more energy per unit mass than muscle tissue
What is the percentage of BMR (basal metabolic rate) devoted to the brain in humans compared to other primates and mammals?
20% in humans, 8-10% in other primates, 3-5% in most other mammals
What is the social intelligence hypothesis?
brain expansion allowed primates to cope with more and exploit increasingly more complex social relationships
Increased size in which part of the brain is associated with group size and rates of tactical deception?
relative neocortex size
What is the ecological intelligence hypothesis?
brain expansion in primates evolved in response to selection for enhanced problem solving abilities in the ecological domain - navigating the environment, finding food, and processing food.
What do mental maps facilitate?
allows for primates to follow optimized routes to preferred fruit trees in their environment
What is extractive foraging?
natural selection has favored enhanced cognitive capacities in primates that rely on extracted foods, which require complex processing techniques to access
Give some examples of extractive foraging.
capuchins opening oysters with rocks, chimps obtaining termites and ants hidden in mounds, chimps cracking nuts with hammers, gorillas digging to obtain underground bamboo shoots, baboons digging to expose corms hidden underground
What is associated with the tendency of primates to develop slowly and invest heavily in offspring?
prolonged gestation, prolonged infancy and juvenile periods, long lifespan, give birth to single offspring, with some exceptions
What is the infancy period characterized by in primates?
begins at birth, dependent on mother for nutrition and protection, ends with wearing and eruption of first permanent tooth
What characterizes the juvenile period in primates?
travel and forage independently, learn important social skills, ends with sexual maturation
What is distinctive about the childhood stage of the modern human life cycle?
occurs 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
What is distinctive about the adolescence stage of the modern human life cycle?
occurs between juvenile and adulthood period, 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
What are some unique features of the human growth curve?
prolonged period of slow body growth during childhood and then marked adolescent growth spurt, which is late in onset and high in magnitude
What is distinctive about menopause and the post-reproductive life span in the human life cycle compared to other primates?
while other primates experience fertility decline with age, humans are unique in their extended post-reproductive life span
What is menopause?
the post-reproductive period in the lives of females, after the cessation of ovulation and menses
What is the 'grandmothering hypothesis?'
inclusive fitness benefits are derived from older, non-reproductive females (and males!) who contribute to the care of their grandchildren
How do humans off-set the costs of slow maturation?
relative early age at weaning, short birth interval, stacking of multiple dependent offspring
What are the human life history traits that may have been key to reducing the energetic burden and increasing fertility?
slow growth during childhood and help from older and non-reproductive adults
What does the growth of a large brain and the simultaneous dependency of multiple offspring generate?
high energetic demands on parents during their reproductive lives
How is dental development a useful proxy for life history?
teeth are abundant in the 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 life events such as weaning
What do we know from growth lines in teeth that helps to provide a proxy for life history?
growth lines are daily, and provide a method of estimating the absolute age of immature individuals
Which hominin species are known from East Africa?
Paranthropus boisei NOT (Australopithecus africanus and Homo neanderthalensis)
Which of the following statements is FALSE:
Several definite Homo habilis fossils have been discovered in Iraq
There is evidence that "Archaic" Middle Pleistocene hominins (referred to as
Homo heidelbergensis by some researchers) may have engaged in cannibalism, true or false?
Earlier Homo erectus populations had smaller cranial capacity than later populations of H. erectus. True or false?
There is much evidence that Neandertals engaged in ritualized and symbolic behaviors. True or false?
Which of the following is TRUE of the Replacement model of modern human origins:
Its proponents argue that modern humans had a single localized origin in Africa, Its proponents argue that modern human variation evolved recently
A lesion (i.e., injury) in Wernicke's area may result in all of the following:
Fluent but nonsensical speech, Substituting one word for another, Problems with speech comprehension