exam 3

23 and me

African Americans are genetically extremely diverse and have a significant component of their genes from European ancestry. Overwhelmingly, the European ancestry comes from males. Rape during slavery. The people in the middle, who have 34-36% of their ancestry as African Americans, about ½ of them identify as African Americans and ½ identify as European Americans. They have basically the same genetics. Race is a social construct.

Homo Naledi

Found only in Rising Star (cave complex) in South Africa. Another side group Found very deep in the limestone. There is a series of channels and chambers. There are two tubes that go in different directions. Insane cave system that you have to climb through. In the first month, they got 1,500 fossils, all of which were human. That doesn't make sense. They were all recovered in a cube that was 1mx1mx80cm. You usually have animals in the cave - animal brought human into the cave, humans were eating animals, etc. Intentional disposal of the dead? Was this chamber a dump for dead people? Symbolic behavior? But it's SO hard to get into and it is dark. If it were easier to get into back then, why aren't there animals in there? Also small people, but not as small as Homo Floresiensis. Brains are only about 550cc. *KEY FACTS* - another small bodied descendant of homo erectus - small brain (550cc) - face is H. erectus-like - possible intentional disposal of dead, indicating potential complex behavior

homo habilis

* "handy man" * find them at olduvai gorge * turkana basin - particularly boobi fora * southern africa * sterkfontain * swarkprans * early homo spread across entire continent of africa — potentially indicataes behavioral flexibility , adaptablily * olduvai gorge * see pictures * 1930s and 40s dominant hypothesis explainining why humans evolved was darwin's tool hypothesis * mary and lewis leakey discovered : see pictures * hand and finger bones indicate dexterity, more human like than ape like * two halves of the parietal bone * argued that this was the first evidence dof brain size expansions, fit perfectly with the tool hypothesis * mandible of homo habilis * much bigger than modern human * teeth * highest points of the cupsos are on the outside of the teeth * the sides are more vertical * look different from robust austrlopiths * brain might be larger than australopithecines, but can't really tell from two parietal bones It was argued that this was the earliest evidence of early homo. But a lot of people in the discipline said that it was a gracile australopith. But they got more evidence: Homo Habilis specimen from Koobi Fora Flat face Much more complete cranium (brain size = 750cc) No doubt that brains were getting bigger. People were more willing to accept that the specimens found at Olduvai Gorge were homo. New methods for radiocarbon dating were developed in the 60s. The deposits in Olduvai Gorge were dated for the first time to be 1.9mya, which was much older than anyone thought. This indicated that the sequence of human evolution extended much further back than anyone had thought. Ledi-Geraru, right next to Hadar This is where one specimen of the earliest Homo was found. Actually 2.8mya. It is only a mandible. The teeth aren't like australopithecines because the cusps aren't centrally positions and the highest parts are on the outside of the teeth. Early Homo Even at 2.8 mya. Or at least the lineage leading to early Homo. * their son discovered homo habilis from koobi fora * human like flat face * much more complete neurocranium Paleoenvironment in Turkana Basin (Koobi Fora, Omo, West Turkana, Ledi-Geraru) C4 plant eaters (grasses) are present but not dominant before 3 mya. Mosaic of habitats. After 3 mya, grassland species becomes much more pronounced. There appears to be a transition from mosaic to dry habitats. Australopithecus are more adapted to fruits and things. Paranthropus and Homo are more adapted to open lands. D Eastern Africa: this transition was around 3-2.5 mya Southern Africa, this transition was around 2.5 - mya. Humerus, radius, ulna Upper limb length was kind of long, which we usually associated with some arboreal behaviors. Not yet fully committed to moving around on the ground. Wide diversity of cranial shapes and brain size and brow-ridge shape. *IMPORTANT INFO - Smaller molars and premolars compared to australopiths, but still very large. (may represent the beginning of the reversal in a trend). - Smaller chewing muscles (no sagittal crest, flatter face). - The brain is larger than in australopiths (500cc-750cc) - Longer upper limbs. - Precision grip.

overview early homo

* 2.8-1.4 mya * overlaps in time almost perfectly with robust australopiths in (western or eastern africa, p boisei) * eastern and southern africa * lived in mosaic but somewhat more open habitats as environments became cooler and drier * precision grip (synapomorphy with later Homo), presumed tool makers * ability to manipulate objects very finely with their hands * brain size larger than gracile and robust australopiths (synapomorphy with later homo) * *first time brains expanded was when gracile australopiths had 20% larger brain than apes* * *but now brain size is larger again* * large molar and premolar teeth with blunt cusps and somewhat thick enamel , but SMALLER than australopiths (synapomorphy with later Homo. * divergence in evolutionary strategies as robust australopithecines go all out with eating , other adaptations made by different species to get smaller teeth, tool use etc. flatter face (synapomorphy with later homo)

evolution of anatomically modern humans

* anagenesis * steady slow accumulation of modern like traits * anatomically modern at the top right picture * they've crossed some threshold into being anatomically modern homosapiens * we all evolved from african ancestors

venus figurines

* female figurines with pronounced breasts, buttox and genitalia * all resting their arms on top of their breasts

climate change now

* graphs * over the cenozoic * tmperature peaked mid eocene , 50 mya * cooling , dropoff in temp at antarctic glaciation — gap opened between antarctica and SA and .. * oscillations, but over past 20 mya, moving towards cooler, dryer temperatures * pliocene and pleistocene graph * amplitude of change over relatively short time periods has become increasingly greater as we've moved to the more recent time periods * last half million years (500k) * glacial maxima, very cold periods, * then rapid deglaciation, warm peaks , then cooling again to another glacial maxima, etc. * temp today, last time it was this hot 127,000 years ago * 20,000 it was the last glacial maximum —one of the coldest periods it has been in the last 65 million years * then rapid deglaciation up until holocene period, it has been quite warm * these graphs look at the same data, but on different time scales * these are all evolutionary time scales * time scales during which evolution can take place, populations can adapt to environmental changes (adapt, go exctinct, new species arise, etc.) * the hockey stick graph * most important scientific figure that you will see in your life!!! * see slides * 1998 * has been refined and extended since then * blue— oscillations in temperature that have been reconstructd from tree rings, corals, historical records, etc. white line being average. * 1,000 years * 0 represents average temp from .. * beginnning around 1850, temperatures make almost 90 deg turn * trend is almost straight with some oscillations * since 1850, temperatures have just skyrocketed * the temperature anomaly * huge deviaiton from regular variation over the past 1,000 years. * respected berkley physicisist, found better data, he was a skeptic, but then his reserach confirmed that this trend is real * double the increase in the last 150 years * what is causing this increase? * 1850 industrial revolution really taking off * CO2 levels over the last 10,000 years * high levels correspond with warming of envt temperature * see graphic * people have looked very hard for non-human related explanation for this pattern * there is none * the only explanation is that human activity * cutting down trees + pumping a lot of fossil fuel refuse into the atmosphere * graphic: carbon pollution set to end era of stable climate * holocene slow rise , then slow decline, over ~ 10,000 years * repreents about a deg F * represents the very peak of the warm period, then we should've been entering cold period * over last 10,000 temp has changed 1deg F...over last 100 years, temp has increased 1.8deg F * ' * \\ * see graphic * 20,000 years ago, coldest the planet has been for 65 million years * deglaciation, temps warming, about 3 deg celcius increase in temp, from coldest it's practically ever been, to the warmest it's been in the last 127,000 years * the projected increase over the 250 years from industrial revolution to 2100 (3 deg increase) is the same as from last glacial maximum to the end of that glacial period - 8,000 year period * CO2 over the last x years * third graph * shows increase over 12,000 years * shows 2millenia * this chane in climate is not on an evolutionary time scale (sea level chart) * organisms cannot evovle that quickly to adapt to the environment * distributions of organisms around the planet will change * changing patterns in the flora * affect how species interact with each other — moving around, coming into contact with new species, new conflict, some will succeed, others will go extinct * some new species will interbreed * polar bears * they have no chance * they're going to go extinct * their genes will flow into brown bears in canada, but as a species they're dooomed, they're going to die * organisms living at extreme poles in most danger * sea levels * 2ft to 4 ft difference increase * coastal communities are oging to be in trouble * so many people live near the coasts!!

multiregional evolution model

The hypothesis that modern humans evolved throughout the Old World as a single species after the first dispersion of Homo erectus out of Africa * base of the stem, some type of ancestral human * ancient ancient african population * hypothesizedx that 1.8-1.5 million years ago when erectines leave africa a division takes place * there's european, asian, and african population of erectines, linked together by gene flow * genes flow between adjacent populations * gene flow limits speciation, limits the ability of populations to diverge form each other * all over the world, archaic poplulations turn into modern populations, all over the world, because as these modern features are developpning, there is gene flow between adajacent populations * one lineage evolving, one species evolving

core

aka chopper

long thumb

anatomical indicator of precision grip -most apes don't have long thumb (they need thumb that is strong to grip, but having really long thumb would be problematic, could be bent, dislocated while moving from branch to branch. -humans have proportionally long thumbs (larger than that of chimp or gorilla) -having long thumb allows you to touch your fingertip to your thumb tip with enough movement left to move and finely manipulate your movements. ex. chimp could not pick up a pen betweeen it's thumb and second digit.

middle paleolithic tools

based on flakes core produces 5 or 6 flakes used by neanderthals

Carolis Linnaeus

beginning of scientific racism invented the system of classifying nature into hierarchichal groups systema naturae he includes discussion of humans, genus homo american, european, asiatic, african ideat that different "varieties" of humans had different characteristics -->governed by laws vs. governed by customs vs. governed by caprice, etc. although he defines categories, very reacist, he doesn't explicitly arrange them in a hierarchy; implied but not direct

pentagonal cranium

characteristic of H. sapeins

quadrupedal hip musculature

coronally (backwards) oriented illium lesser gluteal muscles pass *behind the hip joint* when they contract they extend the thigh (propel your leg backwards)

olduvai gorge

excavated 1929-present tanzania east african rift valley these things are not naturally occuring georocks, they were produced by humans, they were tools! people didn't believe the archaeologists insisted that they were tools...okay...so if they're tools, where are the humans that madethem? 1959: OH 5: Zinjanthropus boisei -complete cranium of one of these ape man type things -lewis and mary leekey -lewis orginally thought how could the australopithecus make tools? tools require cognitive function, complexity...well... OH 7: Homo habilis -- described in 1964 --larger brain than australopithecus --smaller teeth --human like finger bones -- indicates manual dexterity --rushed to publish this "the tool maker"

zhokoudian

excavated beetween 1923 and 1937 same anatomy as that discovered by dubois

definitely bipeds

gracile australopiths

australopithecus afarensis sites

hadar and dihika in ethiopia laetoli in tanzania

missing link

huxley's idea that (which type) of ape is the closest living ancestor to humans question driven research project, very reflective of modern science thought that if asian apes were closest relative to modern humans, then the "missing link" should be in indonesia somwhere reflection of thought that there was a gap in the fossil record maybe

vertical-climbing hypothesis

hypothesis on the evolution of bipedalism importance of hip muscles we walk ith extended lower limb-- knee joint is fully extended when we put pressure on it --really unusual in primates and other animals but, when priamtes are climbing up vertical supports, they have extended knee joints, -->as i propel myself upwards, using hip muscles, fully extending hip and knee joints to propel from one level to another ancestor that is fully arboreal, spending all their time in the trees, live in habitat with a lot of vertical supports, then essentially when the forest starts to dry out, and they have to traverse over land to get to other trees, they started using their limbs on land in the same ways they use them in the trees -- essentially they were preadapted to be able to walk on the two limbs becaue they'd been using those muscles in the way that we do testable hypothesis? prediction-- our ancestors were fully arboreal -- critical assumption for this hypothesis to be true *it's the most widely accepted hypothesis: but straight believes it to be false*: -our closest living relatives chimps and? -but they have terrestrial adaptations, they walk on the ground using knuckle walking (quadrupedal) --> hyperextend their wrist, support themselves on their knuckles -chimp wrist joint xray: radius has a ridge that projects distally towards the wrist-- the dorsal ridge of the radius-- as the chimps extend its hands, the bones lock up together, prevent the bones from going into extension, becomes very stable -->means that chimps and gorillas have limited extension of their wrists, they can't fully extend their wrists, they lock their wrists into partially extended position we don't have this joint locking thing--so the key questions is, what did our ancestors have? --early humans also have the distal ridge --had limited ability to extend their wrists --means that they descended from knuckle walking ancestor-- terrestrial ancestors, which means that this hypothesis is probably not true.

Lucy

key discovery in 1973 at Hadar australopithecus afarensis full-ish skeleton

concavity

on the core

australopithecus africanus site

taung, makapansgat, and sterkfontein* most important all in south africa

128,000 kya

things got really hot, modern humans disperse out of africa, found other hospitable environments

Ororrin Tugenensis

"from the tugen hills" "dawn person of the tugen hills" Kenya, first of the species discovered in the east african rift valley today, mixed brushy area there is volcanic ash, so we can use radiometric dating methods the dates we have are very exact almost nothing is known about this speciimen -2 femurs, distal humerus, mandible, broken teeth, canine tooth -->something very special in the femur! The round part is the head and inserts into the hip joint. The neck of the femur connects the head to the rest. You can take a CT scan of the neck of the femur. When we did that, the inside shows up as spaces inside. What we are looking at is the hard, thick part (cortical bone). The thickness is *thin on top and thick on the bottom* This is a characteristic that we have and no other primate does. All of our weight is born on our femur as we walk. Biomechanical forces that pass through the femur are different in humans than other apes. *Lower part of the neck of the femur is under high biomechanical stress, so to reduce that the cortical bone there is very thick.* THIS IS THE EARLIEST BEST EVIDENCE OF THE APPEARANCE OF BIPEDALISM IN FOSSIL HUMANS AND IS IN A FOSSIL THAT IS 6 MYO. THIS WAS DEFINITELY BIPEDAL. *imporatnt info* - Asymmetrical distribution of cortical bone in the femoral neck - excellent evidence of bipedalism. - Slightly reduced canine. - Small Molars - Think enamel.

robust australopiths

* 2.7-1.4 mya .. some overlap in time with ? but no conatct bc found on completey different parts of the continent * eastern and southern africa * lived in more open habitats, some wet, some dry * almost nothing is known about locomotion * brain size like gracile australopiths (all australopiiths basically have same brain size) * tiny canines (synapomorphy with later hominins like us * huge molar and premolar teeth with blunt cusps and hyper thick enamel * can withstand very high forces * wear down very slowly * diet probably included resistant foods that were mechanically challenging to eat * 2 species paranthropus boisei and paranthropus robustus

anagenesis

* ancestral population with certain form, over time transforms into new population, etc. * at the end of the lineage, the youngest population might look quite different from the ancestral population * this is what is taking place in europe * see slides * populations could get isolated due to weather, develop different traits, come back together, broader sharing of novel characteristics? * face, brain size * this is probably the best documented evidence of an evolutionary process taking place in the human fossil record * anagenesis supported by vast evidence in the fossil record, very undisputed , very supported * h heidelbergensis morphology culminating in h. neanderthalis morphology * what's in between is a little bit arbitrary

the hockey stick graph

* beginnning around 1850, temperatures make almost 90 deg turn * trend is almost straight with some oscillations * since 1850, temperatures have just skyrocketed * the temperature anomaly * huge deviaiton from regular variation over the past 1,000 years. * respected berkley physicisist, found better data, he was a skeptic, but then his reserach confirmed that this trend is real * double the increase in the last 150 years * what is causing this increase? * 1850 industrial revolution really taking off * CO2 levels over the last 10,000 years * high levels correspond with warming of envt temperature * see graphic * people have looked very hard for non-human related explanation for this pattern * there is none * the only explanation is that human activity * cutting down trees + pumping a lot of fossil fuel refuse into the atmosphere

therianthropes

* figureinesthat are half animal half person * lots of these * very common shared motif accross thousands of miles and years

lascaux

* france * cave complex * all the walls are painted * 27,000 years ago * desceptively complex: * half drawn horse— you and i and the people who dres this know that it's a horse even tho only half of it is drawn on the wall * these drawings have perspective — you can tell which limb of the animal is closer to us * the deer have the proper number of antlers

colonization of europe by homo sapiens

* homo sapiens arrives in europe 40,000 years ago before and during the last glacial maximum (the coldest time) * LGM around 20,000 years ago * humans are moving into europe as it gets increasingly cold * *modern humans lack the cold weather adaptations of neanderthals* * the first europeans were migrants from Africa * they were of african descent, they had lived in very very warm habitats * *we lack cold weather adaptations that neanderthals had!!* * we are tall and lanky * we radiate heat * we don't have stocky build or special noses * we have high (something) ratio * we are not confiugred to live in very cold environments * and yet, neanderthals go extinct soon after the arrival of modern humans * neadnerthals disappear and modern humans survive * *represents a triumph of culture over climate* * more advanced tool technology * blades * broader use of resources * not just hhunting big game * utilizing plant foods * marine resources, like fish * using their environment in a broader way * more complex social behavior * as indicated by all of the evidence of symbolic behavior associated with art, music, etc. * make them *behaviorally more flexible* * allows them to be successful under very harsh environmental conditions, even when the biologically adapted neanderthals went extinct

evidence of symbolic behavior

* lascaux * france * cave complex * all the walls are painted * 27,000 years ago * desceptively complex: * half drawn horse— you and i and the people who dres this know that it's a horse even tho only half of it is drawn on the wall * these drawings have perspective — you can tell which limb of the animal is closer to us * the deer have the proper number of antlers * lots of carvings, animal figurines * 35,000 years ago * therianthropes * figureinesthat are half animal half person * lots of these * very common shared motif accross thousands of miles and years * venus figurines * female figurines with pronounced breasts, buttox and genitalia * all resting their arms on top of their breasts * * depictions of clothing? * venus figurine with design on head could be braids, but also potentially depictions of clothing * living in germany during the ice ages, needed some sort of headgear to stay warm probably * figurine from russia, clearly showing stitching of clothing * these folks had the same themes, same designs for 25,000 years (whereas our designs change every 10 years or so with trends) * music * phalanges of some animal, which hole bored out of them — they're whistles * raddii of birds * very hollow light bones so they can fly * holes born into them at regular intervals * flutes! * 39,000 years ago

paranthropus boisei

* map * olduvai gorge * louis and mary leakey * massive muscles on the topfrontside ofthe head * ribeyes on the side of the head * lake turkana * turkana basin * omo river * fossil deposit sites on east west and north sides of the lake * east side — koobi fora * west side— west turkana * north— omo * these are the most important sites of human evolution , best preserved human paleontology * ... * paleoenvironment in the turkana basin * koobi fora, omo, west turkana * isotopes indicating diets * .... * pressure son gracile australopiths, some disappear, others evolve, become robust australopiths * teeth slide * huge molar and premolar teeth * inflation of the gygomatic bone pulling the musclel forward * massive muscles on the side of the head, to generate enormous force *KEY FACTS* * saggital crest, inflated zygomatic bones = massive chewing muscles * huge motors and premolar teeth * tiny canines and incisors * hyperthick tooth enamel * small brain, but larger than ape * diet of hard or tough foods * non projecting face

kebarra

* neanderthals are the first people to bury their dead * they intentionally bury their dead — very easy to tell, no doubt about this * so they're better preserved than others * partial skeleton from a modern site in israel * shallow grave, body was enterred (?) * lower limb missing because part of the grave eroded out, water washing it away * skeleton was discovered lying down, mandible was sitting on top of its chest like head resting on the chest, but the cranium was missing., preserved the highwig (?) bone, shows that the mandible was not preserved * led to speculation that the body was burried, and that people returned to it later and removed the head — just speculation * nothing in the burials themselves that point to obvious symbolic behavior (grave goods, presence of art, animal parts, etc.) * but there are bodies, clearly burried with intent * we do not know if the burial process meant the same symbolic nature that it does to us * time was spent in the cave to dig the whoell and put the body in it * is it bc the dead start to smell, decompose, or because it had meaning to the alive peopoel — we don't know

neanderthal sophistication

* neanderthals are using mousterian tools (middle paleolitihc tools) * just as sophisticated as hominins living at the same time in other parts of the world * flake based toools * really hard to master * knowlegde has to be transmitted, probably orally * quite sophisticated behavior (at least in technology) * hunters , a lot of meat in their diets * completely unfair that we use the term neanderthal as a pejorative * as being brutish, dumb, etc. * cave men * becaue they were very sophisticated and intelligent

west turkana

* new study 3 or 4 years ago west turkana * evidence that stone tool use dates back even further than 2.6mya * stream drainages on the west side of the lake * recently discovered pliocene deposits — 3.3 mya * stratigraphy in the cross section * top — recent material that has rolled, everyrhitng is out of place * in the pliocene beds, 3.3 mya * about 100 stone tools found in the * many found without context * but some are in context * lomekwian tools (smashing two rocks together) * might just look like broken rockcs but there is evidence to suggest otherwise * some broken rocks fit together, suggest they were broken purposefully, with force, locally, in a setting that has not led them to be disperesed again * perhaps humans provided force and broke these rocks — tools * if they fractured naturally in a stream, they would be found very far away * using one rock to file down the other one, make it sharper * archaelogists have reconstructed how these rocks were broken: * smashing one rock on top of another — very early stone tools might've been made this way , takes little cognitive effort to figure out that smashing two rocks together would make them break * cut marks/fracture patterns * one person tries to twist the bone, while the other smashes it with a rock * creates special fracture spiral patterns * takes sophisticated thought process to discover that this works * bones fractured by animals, the predators will eat the bone, ; so bones left in the archaelogical record that were fractured surely were fractured by human intention and force * might want to cut things with sharp bones * little indentations in the bone — specific scratches, indicating that it was scratched with a stone tool; people using stone tools to cut meat off of the animal bones

bipedal hip musculature

* paddle portion of the illium aligned in the *sagital plane* (sideways) * the faces of the paddles face to the side * the *lesser gluteal muscles arise off the outer surface of the illium now cross directly *over* the hip joint* * *when these muscles contract, they cause the side to side motion of the hip joint — abduction*

music

* phalanges of some animal, which hole bored out of them — they're whistles * raddii of birds * very hollow light bones so they can fly * holes born into them at regular intervals * flutes! * 39,000 years ago

highlights climate change report

* see quote ..." this period is now the warmest in the history of modern civilization" * "assessment concludes that based on extensive evidence, that it is extremely likely that *human activities, espeically emissions of greenhouse gases, are th edominant cause of the observed warming in the mid-20th centyurey*.... * "...primarily in response to human activities" * "rise of at least 8 ft. by 2100 cannot be ruled out" * "heavy rainfall is increasing in intensity and frequency across the us and globally and is expected to continue to increase." * ..."over the next few decades, annual average temps are expected to rise by about 2.5 deg F for the US, relative to the recent pas...." * "incidence of large forest fires in the western United states and alaska has increased since ...." * "the magnitude of climate change beyond the next few decades will depend primarily on the amount of greenohouse gases..." * "..unantiicpated changes and impacts, some of which are potentially large and irreversible. * we will not go extinct, but our lifestyles will change drastically * when warming was happening 127,000 ya, much slower, people shifted their lifestyles slowly moving away from the coast, seeking other resoruces * we have cultural systems in place that people can't move, people can't just up and move * chaos in economic markets * issues with resources * in our lifetimes and our children, our lifestyles are going to change drastically!!! * we must think to the future, demand better from our children

paranthropus robustus

* sites: * swartkrans * kromdraai * drimolen * south african paleoecology * different types of antelopes have different types of ecological settings, so you can see how many fossils you have of each kinds and see what the environment was like * mak 3 really old * st 4 au africanus - dry adapted species becoming more common * over time proportional representation of dry adapted anteloupe is increasing * "robust" australopithecines: paranthropus robustus * south african veresino of paranthropus boisei *KEY FACTS* **** southern version of paranthropus boisei, so very similar features * small brain (500cc— australopithecine size brain) * saggital crest, inflated zygomatics —>indicating huge chewing muscles * flat face (orthognathic face?) * massive premolar and molar teeth with very thick enamel — very strong, sturdy, just like p. boisei * thick mandible * small incisors, canines (not taking small bites?) * designed to eat a lot of things difficult to process with jaws and teeth

homo neanderthalensis

* specimens; * gibralter * la ferassie * france * amud * israel * characteristics * double arch brow ridges * enormous nasal cavities * mid part of the face has been pulled out a bit * projecting middle of the face * projecting molar gap * size of the brain and shape of the brain case * neandertals are the species of human with on average the largest brains (they're brains are on average a bit larger than our (modern human) brains) * 1250-1700 cc — neanderthal brain size * brain has gotten really big * brain case is more rounded (OVAL SHAPED) -- H.erectus has tent shaped brain case, with saggital keel * Anagenesis * ancestral population with certain form, over time transforms into new population, etc. * at the end of the lineage, the youngest population might look quite different from the ancestral population * this is what is taking place in europe * see slides * populations could get isolated due to weather, develop different traits, come back together, broader sharing of novel characteristics? * face, brain size * this is probably the best documented evidence of an evolutionary process taking place in the human fossil record * anagenesis supported by vast evidence in the fossil record, very undisputed , very supported * h h eidel bergensis morphology culminating in h. neanderthalis morphology * what's in between is a little bit arbitrary * Kebarra * neanderthals are the first people to bury their dead * they intentionally bury their dead — very easy to tell, no doubt about this * so they're better preserved than others * partial skeleton from a modern site in israel * shallow grave, body was enterred (?) * lower limb missing because part of the grave eroded out, water washing it away * skeleton was discovered lying down, mandible was sitting on top of its chest like head resting on the chest, but the cranium was missing., preserved the highwig (?) bone, shows that the mandible was not preserved * led to speculation that the body was burried, and that people returned to it later and removed the head — just speculation * nothing in the burials themselves that point to obvious symbolic behavior (grave goods, presence of art, animal parts, etc.) * but there are bodies, clearly burried with intent * we do not know if the burial process meant the same symbolic nature that it does to us * time was spent in the cave to dig the whoell and put the body in it * is it bc the dead start to smell, decompose, or because it had meaning to the alive peopoel — we don't know * they were not especially tall compared to us * average height in our species is 5.9 , * neandertals tend to range average of 5.6 * yet despite the fact that they wre shorter, they were not lessa mssive, because they had a different body shape * modern humans on average tend to be tall with long limbs — because every pereson living today is desended from populations evolved in africa few hundred thousand years ago with tall and narrow body shapes * neanderthals tend to be shorter and bulkier * very muscular different chest shape * more expanded, something shaped chest * lower (?) limbs relatively shorter (lower limb below the knee and forarm below the elbow) * makes walking less efficient * advantage— * heat conducts out of your body into the outside world if the outside temperature is colder, then you get cold, core temperature decreases * you lose heat from your skin * very complex folded 2D structure * the rate at which you loose heat is a function of the general surface area of your skin * mass of your body (retention of heat) is better with high body mass * high surface area to volume ratio in tall, slender people * allows you to get rid of heat * but this body type would lloose lots of heat in a cold area * populations will evolve locally in cold areas * to have stocky body shape * neanderthals are stocky , not especially tall, have shortened distal limb elements, probably as a physical adaptation to the cold weahter * allowing them to retain heat. * enormous nose * less established idea * large soft tissue folds inside the nose, when you breathe in air, lots of surface area for the air to be warmed on the skin before it gets inhaled and into your lungs * large naval cavity is a thermal regulatory adaptation to retain heat in cold environments (i.e. europe during the ice ages). * neanderthals were living in caves and occupying them * controled use of fire!! definitely had this adaptation * kabarra cave in israel * they lived in a place that was so cold during the winter, they must've made clothes of some kind, because it was too cold to survive otherwise * neanderthals are using mousterian tools (middle paleolitihc tools) * just as sophisticated as hominins living at the same time in other parts of the world * flake based toools * really hard to master * knowlegde has to be transmitted, probably orally * quite sophisticated behavior (at least in technology) * hunters , a lot of meat in their diets * completely unfair that we use the term neanderthal as a pejorative * as being brutish, dumb, etc. * cave men * becaue they were very sophisticated and intelligent * almost certainly a historical accident * la chapelle aux saints , in france * one of the first specimens discovered * teeth fallen out, arthritis, walked with a hunch etc. * when it was discovered in early 20th century, it became a sensation, images of it, nenaderthals being brutish people * the fact that someone with this many injuries could live so liong is actually a token to the sophisticated social system * the reason perceptions come to be is based on what is discovered first use mousterian tools *KEY FACTS* * related to thermoregulation: * Huge nose * projecting mid face * retromolar gap * probably accident related to pulling the face forward * double-arched brow ridges * help us identify specimens as being neanderthals * large brain * 1250-1700cc * largest of any fossil hominin * rounded, oval shaped brain case * stocky people, muscular build * descended from H. Heidelbergensis * middle paleolithic tools * burried their dead * distinctive behavior * first peopel to actually do that * not sure if that was symbolic or not * controlled use of fire * they interbred with modern humans a little bit

depictions of clothing

* venus figurine with design on head could be braids, but also potentially depictions of clothing * living in germany during the ice ages, needed some sort of headgear to stay warm probably * figurine from russia, clearly showing stitching of clothing * these folks all around the world had the same themes, same designs for 25,000 years (whereas our designs change every 10 years or so with trends)

3.3

--- mya oldest stone tools found recovered in pliocene deposits in west turkana

2.6

---- mya new type of tool seen in the fossil record oldowan tools

cut marks

----- or fracture patterns one person tries to twist the bone, while the other smashes it with a rock creates special fracture spiral patterns takes sophisticaed thought process to discoverthat this works bones fractured by animals , the predator would eat the bone; so animal bones left in the archaeological redcrod that were fractured surely were fractured by human intention and force

archaic homo

----- refers to some aspect of the anatomy interesting and important group of hominins that include the species that are our direct ancestors / very close cousins; species very closely related to us they collectively represent early humans that are our closest relatives they have a lot of the same adpations we have *homo erectus, homo heidelbergensis, homo floresiensis, homo naledi* *overview* * 1.9 million years ago (mya) to ~40 thousand years ago (ayr) * might've shared the landscape with homo habilis based on time frame? * lived for very long period of time * found all over the old world: asia, europe, africa * *first hominins out of africa* * they represent the first hominin populations to disperse out of africa * that means that they also colonized a wide range of habitats —> ecologically flexible * perhaps less tied to particular environments than the hominins that preceeded them * probably reflects behavioral flexiblity * something sophistaicated about them that allows them to colonize areaws they hadn't predviusly been * committed terrestrial bipedalism (synapomorphy with Homo sapiens) * post cranial skeleton almost modern (almost the same as ours) * really designed to walk and run on the ground * more closely related to modern humans than to other taxids * temporal trend towards increasing brain size (synapomorphy with homo sapiens) * *during their entire existence, brain size getting larger and larger* * even the earlier ones have some increased brain size relative to australopiths, but then it becomes dramatic over time * reduced molars, premolars, and mandibles (synapomorphy with homo sapiens) * reversed the trend * flat face, (synapomorphy with homo sapiens), but wide with pronounced brow ridges * wider faces than us * enormous brow ridges * sometimes enormous nosses/naval cavities * faces not identical to us, but don't project like apes or australopiths * larger, human-like body size (synapomorphy with homo sapiens) * australopiths were chimpanzee size maybe a bit larger * (how big are chimps??) * increasingly sohpisticated technolgoy * in terms of tool use and creation * culminate in *some use of symbolic behavior probably at the end of this group*

ten facts about human variation

1. human groups distinguish themselves principally culturally --we have distinguished ourselves into groups that we think are based biologically, but those are actually culturally constructed 2. human biological variation is continuous not discrete --* there are gradation of human variation in characteristics or genetics as you move from population to population accross geographical space * there are not firm markers you can use to separate groups genetically 3. because of this above point, clustering popluations is arbitrary 4. populations are biologically real, not races --within a popluation, evolutionary forces can act -- population is a viable unit in which to study evolution 5. but, even those populations have a constructed component -->even then, often there is gene flow between popluations; they're not completely isolated/separated,. 6. there is much more variation within groups (polymorphism) than between groups (polytypy) --* much more genetic variation within populations than between populations * more genetic variation within so called races than between so called races as conventionally defined * variation within groups so much larger than variation between groups - humans are very tightly connected group 7. people are similar to those nearby and different form those far away --* potentialy cultural mechanisms that prevent them from interbreeding a lot, but still people do reproduce with nearby peopled * gene flow between these adjacent populatiosn (geographically) 8. racial classification is historical and political, and does not affect natural biological patterns --* genocide due to racial differences * bosnian serbs vs. bosnian muslims * rwanda * tutsi, and hutu * populations that have been living in proximity with each other for hundreds of thousands of years ... definitely some interbreeding has taken place * think of each other as being really different, but biologically they're barely different at all 9. humans over all have very little genetic variation (our species is at most 300,000 years old) 10. racial issues are socio-political-economic, and not biological

pestera cu oase

40 kya modern humans make it from the levant to asia

late acheulean tools

400-450kya wooden throwing spears hunting! long sticks where the ends have been burnt to make them hard and then sharpened thicker at one end -->they are thought to be javelins -->if most of the weight is in front, it will propel forward --->probably throwing weapons.

koobi fora

HNM-ER 1470: homo habilis discovered here in 1972 by lewis and mary leakey's son

tools

Lomekwian Stone Tools - unsophisticated; made by slamming one rock against another to get a sharp edge Oldowan Tools - you get the concoidal fractures and choppers; soft-ball like things - you hit the core with another rock at a certain position and at a certain angle that you've thought of before Acheulian Tools - hand ax - involve the cognitive step of sculpting - sharp edges Late Acheulian Tools - throwing spears - 400-450kya Mousterian/Levallois Tools - based on flakes - Middle Stone Age tools - 250kya Upper Paleolithic Tools - blades

homo erectus timeline

Longest persisting species in the fossil record. 1.7 million years We've only been around for 200-300 kya They were doing something right. First discovered on the Island of Java, but that's not the oldest evidence. It is in Africa, about 1.9mya. Then almost immediately, you start to see evidence of it in different places. Asia: 1.7 mya China: 1.6 mya Indonesia: 1.5 mya Europe: 1.2 mya (Human evolution has been taking place in Africa since 7 mya, and now suddenly it rapidly spread out.)

south african paleoecology

Lots of Animal Fossils Examining the different types of antelopes: In the graph, we see the proportion of bovid fossils that belong to a certain group that are adapted to live in dry environments. On the x-axis is the sites where these things are found. And we can also see what hominins were around that area. We can see that the *climate is getting dryer as humans evolve.* *Because the proportion of dry adapted antelopes is increasing.*

tooth trend

Over the first ⅔ of human evolution, molar and premolars and enamel get bigger and thicker. With these early homo, they start getting smaller. Divergence in subsistence strategy. Exploring other teeth was probably made possible because of other adaptations.

Homo floresiensis

Side branch from Homo Erectus. In Indonesia, Homo erectus persists while on the mainland it evolves It's possible that while the sea levels were changing homo erectus became isolated. On islands and far away from competing human species, they didn't have to compete and may have been able to persist until 200kya. From the island of Flores, they have discovered an archaic human that has some facial characteristics of homo erectus. But they are really tiny! Like 3.5 feet tall. This was discovered in 2004, which is around the time that Lord of the Rings was coming out. They were nicknamed the hobbits. It may represent a dwarf population of homo erectus. When vertebrates get stuck on an island, they have limited resources. Really large animals on islands have a hard time because they exhaust all of the food. So natural selection favors a smaller body size. Insular Dwarfism There was also a dwarf elephant on this island. Not only is body size smaller, but has a really tiny brain. Like australopithecus size. *KEY FACTS* small stature -->likely to be a dwarf species descended from H.erectus face similar to H erectus, but a much smaller brain (<400cc)

replacement model

The theory that modern people evolved first in Africa and then spread out to inhabit virtually all the world, outcompeting or destroying other human populations in the process. * erectines living in africa, at a certain point they leave africa , dispersing to europe and asia * the asian and european populations of erectines don't evolve into modern humans * there is a transformation of the african lineage into modern humans, then again disperse to europe and asia * they represent different species that do not interbreed with the archaic humans already living in those areas, and do not interbreed

broad apical tuffs

anatomical indicator of precision grip -rounded things on the top of the fingers -broad flattened area of bone -the tip of the bone spreads out -- your broad, flat, fleshy touchpad finger tips -->chimps have narrow apical tuffs -->because we have broad fleshy touchpads, we can move things between our fingertips, manipulate them finely.

flexor pollicus longus

anatomical indicator of precision grip -sends tendon all the way down your arm to insert on the base of the distal phalanx of the thumb -muscle that flexes the thumb -->chimps have a muscle that goes to the same place but it is not independent of the muscles that control other fingers -->muscle that inserts on the base of the thumb, but same muscle that inserts on the distal phalanges of all of the fingers. -->when the chimp flexes the thumb it flexes all of the fingers. -*our muscle here allows us to move our thumb independently of our other 4 digits* -this ability is important to our ability to precisely manipulate objects.

first hominins out of africa

archaic homo

Homo heidelbergensis

archaic homo * H heidelbergensis petralona * derived from h. erectus maybe? * forhead does not recede quite as strongly * the brain is bigger * overlapping with the bottom range of modern human brain * H. erectus zhoukoudian * very thick brow ridges * thickessconstant all the way accross * H. heidelbergensis petralona * face wider * brow ridge thickn over center of the eyes, thinner on the sides laterally * homo heidelbergensis shows up around the world on different continents at the same time * europe petralona * asia dali * africa kabwe * crania all a bit more rounded * foreheads higher than homo erectus * wider faces * evolution has definitely taken place between these species * homo erectus populations appear to have transformed around the world in ways that are very similar * in a sense they're our most immediate direct ancestor *KEY FACTS* - founrd all over the world - brain case larger than H. Erectus, overlapping with modern humans - 1150-1250cc - more rounded cranium - wide face - thick brow ridges that thin laterally - *important because it is a short placeholder and the probable ancestor of us and another lineage!*

gracile australopiths

australopithecus afarensis and africanus * --------- = slender * but they're really heavily built, just not as heavily built as a next group * 4.2-1.9 MYA * eastern, southern, and central africa * lived in *mosaic habitats*, with closed habitats available * some tree cover, some open grasslands, some water in streams or lakes * unclear whether they used all these habitats, but they did live in mosaic habitat * *strong evidence of bipedality (synapomorphy with later hominins) , but also evidence of arboreality* * they're *definitely hominins*, they walk on two legs, but not exactly how we did, and they spent some time in the trees * further reduced canines (synapomorphy with later hominins) * *slightly larger brains* (synapomorphy with later hominins) * modest increase * first hint of increase in brain size * *large molar and premolar teeth with blunt cusps and thick enamel * surfaces get rounded, molar and premolars get large, enamel gets thick* * change in the feeding aparatus * diet was a very important adaption in these species * diet appears to be the second human adaptation (to bipedalism) * *diet probably included resistant foods that were mechanically challenging to eat*

brain size growth

australopithecus brains 20% larger than ape brains but they don't grow over the time of its existence homo habilis slightly larger homo erectus larger than homo habilis -- and continues to grow larger during its existence over time.

neanderthal body shape

avg 5'6 we're avg 5'9 they're not very talll compared to us they were shorter, but same mass; they had different body shape modern humans = tall with long limbs-- bc every person living today is descended from populations evolved in africa few hundred k years ago, who were tall and dnarrow ---- tend to be shorter and bulkier muscular chest shape, more expanded lower limbs relatively shorter -->makes walking less efficient *advantage* heat conducts out of your body into the outside world if the outside temperature is colder, then you get cold, core temperature decreases. you lose heat from your skin --very complex folded 2D structure --the rate at which you loose heat is a function of the general surface area of your skin -- mass of your body (retention of heat) is better with high body mass --high surface area to volume ratio in tall, slender people -- allows you to release heat, but this body type would loose lots of heat in cold area --populations will evolve locally in cold areas: to have stocky body shape not tall shortened distal limb elements probably as physical adaptation to the cold weather allowing them to retain heat *enormous nose* less established idea large soft tissue folds inside the nose, when you breathe in air, lots of surface area for the fair to be warmed on the skin before it gets inhaled and into your lungs large nasal cavity is a thermal regulatory adaptation to retain heat in cold environments (i.e. europe during the ice ages!)

first evolved human adaptation

bipedalism

early homo

brain getting bigger, teeth starting to shrink back

evolutionary trends in hominoids and cercopithecoids

changing environmental conditions often creates the selective pressures that lead to species evolving -Hominoids and cercopithecoids exhibit opposing trends in diversity. -Cercopithecoids are rare in the early Miocene, while hominoids are numerous. -But by the late Miocene, cercopithecoids are numerous and apes are rare. -Change in diversity in the two groups probably a consequence of climate change. * beginning in the *middle miocene*, trend towards *cooling temperatures* * cooler, dryer— * rainforest shrinking * ape (hominoid) populations under stress, some are dying out * ape habitats degrade, more and more species become extinct * old world monkeys (cercopithecoid) can chew leaves, adaptations for things other than soft fruit * able to thrive in the new environment

rounded cranium

characteristic of h. neanderthalensis

tent shaped cranium

characteristic of homo erectus

Acheulian tools

characterized by very large things (cleavers) that look like ax heads, or hand zxes sharp edges that go very long around the periphery ubiquitous found accross lots of sites cool thing about theese -- they're very difficult to make we can all learn to make other stone tools in 5 min, but theese are very difficult to learn how to make have to hae an idea of the tool in mind that you're going to make before you go about making it, need to put forethought into it --complex intellectual functioning. *show up around 1.8mya and persist until ~200,000 ya* These tools persist long after every other species (other than homo erectus) of human went extinct. There was a period of time when homo erectus was the only human species in the world. And these tools were being made them. We can't say that homo erectus was the only one to use these tools, but we do know that they made them.

tool use history

chimps also use and make tools straw to get termites stones to break open really really hard nuts --cognitively significant behavior reasonable to think that the earliest humans (australopiths and pre australopiths ) would've used tools as chimps did... however we don't have any fossil evidence of this fair to assume that early hominins might have used tools

brain stem

control actions not under your conscious control (involuntary actions)

piltdown

discovered 1912 in england in a quarry ape like jaw large braincase suggests that brain size is the first human characteristic that evolvved, defines us as a group given it's own name *Eoanthropus* ***this was a forgery!!!!! it's a skull of a modern human and the mandible of the orangutan no articulation between the jaw and the skull this discovery becomes discredited

Taung

discovered 1924 at the buxton quarry raymond dart-- australian probably 3-6 yr old person that died noticed immediately that this was not a monkey but much more like an ape, but no apes in south africa noticed it's human like --although the face projects, not as much as you would expect from juvenile ape --small canine --bottom of the skull, there's a little fragment of the forangum magnum-- hole thorugh which spinal cord connects to the vertebral column --> *noticed that the framing was pointing down, indicating bipedalism* although, it has a small brain *australopithecus africanus* australo = south pithecus= ape africanus= africa says, this thing is a human ancestor initial reaction from academia: this is ridiculous, you just discovered a chimp, this is not a human ancestor

Engis 2

discovered in 1829 at ---- cave first hominin fossil found -- nobody paid that much attention belgium braincase of an infant neanderthal

gibralter 1

discovered in 1848 at forbes quarry mine neadnerthal wasn't very recognized...ppl were just like hm, this is a weird person

feldhofer 1

discovered in 1856 in the neander valley quarry feldhofer first one that was actually recognized as human ancestor german word for valley = thal neanderthalers-- people of the neander valley at about the same time this fossil was discovered, darwin's on the origin of species about natural selection was being published this fossil is being discussed among academic circles of the time -- naturalists (not biologists) darwin himself did not actually talk about human evolution excpet: he could imagine one day light being shed on the evolution of human people reading his work at the time connect his ideas to human evolution, and he does eventually in 1871 publish the descent of man

pithecanthropus erectus

dubois's discovery of trinil 2 * pithe = ape * anthropous = man * erectus= erect * thought it was an upright walking man, but also ape like

Sahelanthropus Tchadensis

earliest hominins "the person of the --- from chad" the first evidence of human evolution found in a lake basin in chad in the djurab desert --site named Toros-Menalla site --water that would fall on the mountain ranges drained into a single watershed in the center of that basin -->today the country is incredibly dry, but there is a small lake called lake chad. mya the lake was bigger, the fossils are found along the margins of an ancient lake site Toros Menalla --much wetter 7 million years ago than it is today mosaic some grassland/woodland fauna and flora all around very few specimens of this species are known -cranium found encrusted in sediment called *TM 266* -- small brain, no larger than chimp --face projects, not as much as apes (reduced facial projection) --canine tooth is smaller than apes thin dental enamel (teeth are not very strong, they're ape like) --very thick brow ridge --*foramen magnum* on the bottom of the skull where the spinal cord exits the cranium and goes down into the vertebral column -- *FACES DOWN* --> implies that the head sat on top of an upright vertebral column instead of being in front of a horizontal one -->this is some evidence that this species MAY hvae been bipedal (we don' thave the rest of the skeleton ... *not definitely an early human ancestor, but it is plausible...if it is a biped, it was a hominin.*

Pre-australopiths

earliest known hominins east and central africa lived in mosaic habitats -->many types of sub habitats in easy access some evidence of bipedality (synapomorphy with later hominins) slightly reduced canines (synapomorphy with later hominins) small brains (symplesiomorphy with apes) the earliest: Sahelanthropus Tchadensis and Ororrin Tugenensis

lomekwian tools

early stone tools smashing two rocks together might just look like broken rocks,but there was evidence to suggest otherwise: -some broken rocks fit together, suggest that they were borken purposefully, with force, locally, in a setting that has not led them to be disperesed again -->perhaps humans provided force and broke these rocks-->> tools use one rock to file down the other, make it sharper how these rocks were broken: -smash one on top of the other -->takes little cognitive effort to figure out that smashing two rocks together would make them break

upper paleolithic tools

end of the pleistocene ~40kya-11.5kya blades flint blades are long and thin twices as long as they are wide sohpisticated technology use controlled pressure to break off long thin blades very efficient one core produces around 20 blades more tools for the same volume of raw material bone harpoons and needles they're becoming more flexible in their habits *used by homo sapiens*

precision grip

first seen ~ 2mya finger bones of OH &=7 (olduvai hominin 7) -fingers different from ape -able to hold objects more finely -2mya precision grip (and brain sizes start getting large) *long thumb* -most apes don't have long thumb (they need thumb that is strong to grip, but having really long thumb would be problematic, could be bent, dislocated while moving from branch to branch. -humans have proportionally long thumbs (larger than that of chimp or gorilla) -having long thumb allows you to touch your fingertip to your thumb tip with enough movement left to move and finely manipulate your movements. ex. chimp could not pick up a pen between it's thumb and second digit. *broad apical tuffs* -rounded things on the top of the fingers -broad flattened area of bone -the tip of the bone spreads out -- your broad, flat, fleshy touchpad finger tips -->chimps have narrow apical tuffs -->because we have broad fleshy touchpads, we can move things between our fingertips, manipulate them finely. *flexor pollicis longus* -sends tendon all the way down your arm to insert on the base of the distal phalanx of the thumb -muscle that flexes the thumb -->chimps have a muscle that goes to the same place but it is not independent of the muscles that control other fingers -->muscle that inserts on the base of the thumb, but same muscle that inserts on the distal phalanges of all of the fingers. -->when the chimp flexes the thumb it flexes all of the fingers. -*our muscle here allows us to move our thumb independently of our other 4 digits* -this ability is important to our ability to precisely manipulate objects.

thomas H huxley

founded the idea of a biology department he's the naturalist who most connected darwin's ideas to human evolution published essay about everyitng they knew about primates living at the time he started looking at primates and how similar they are to humans *1862 on man's place in nature* --beginnings of primatology and paleoanthropology --discovery of new facts is not the most important part of science...it's the development of new concepts (ex. darwin's evolutionary concepts allowed people to interpret thesee fossils and move forward...)

australopithecus africanus

gracile australopiths from south africa * map * south africa * three sites * taung * original * sterkfontain * giant whole in the ground now, * used to be a sinkhole lots of sediments and fossil bones * 3rd? * graphics * shows how sites were formed? * carbonate rock, dissolves in water * water level * ... * sometimes they're closed, not much can get in * sometimes they're open, sediments can get in, bones can fall in * some occasions animals come in use the cave, die therE? * .. * picture * relatively copmlete specimen * "little foot" * .. * 95% complete skeleton * found in chamber 20m underground, fell down shaft, died at the bottom, perfectly preserved * biped — not as efficient as us * prob spend some time in the trees * craniodental morphology in A. africanus * .. * zygomatic arch * moving muscles forward, yo have expanded the force of the muscle can contrac with * adds leverage * important part of adaptation, allowingn them to eat tougher foods *KEY FACTS* * first australopithe to be discovered (in 1925 by Raymond Dart) * postcranial skeleton like Au. Afarensis * bipedal, but with some arboreality, + less efficient when walking * large jaws, molars, and premolars, also large chewing muscles * adaptations for diet of hard or tough foods (something resistant that would require repetitive force or chewing to consume) * projecting face * brain is small, but larger than apes (500cc)

Ardipithecus ramidus

ground-dwelling ape that is potentially a root for other humans middle awash, ethiopia an amazing area all of the fossils in this area same age, volcanic event, 4.4 mya mosaic environment, more on the wooded side early hominins inhabiting somewhat wooded environments -- we did not evolve on the grassland reconstructed cranium: -Small brain, even a little smaller than chimps More projecting, ape-like face Smaller canines than in a chimp Reduction in incisor size (less reliance on fruits?) - more human-like? Still ape-like pattern of molar/premolar size Much less projecting canine, similar to later hominins. The foramen magnum was reconstructed as projecting down, but it's not great evidence. Some primitive characteristics, some more modern. We got parts of the rest of the skeleton too. It has been interpreted by those who discovered it as being a biped. Controversial * bipedal * valgus knee joint (femoral shaft approaches at an angle) * butthe knee joint is not actually prserved, we don't have any actual fossil evidence of this * illiac blade in pelvis oriented in sagittal * but, very damaged fossils * methods not very well described * take this human like pelvis with a serious grain of salt * big toe lost it's ability to grasp, in line with the other toes — aduccted * but here, it's not in line with the other digits * still has substantial ability to grasp, and points out to the side * much more chimapnzee like than human like * a lot of the evidence we have that this is a biped is weak, so then we have to question is it really a hominin...weak evidence * be cautious about concluding that artipithecus is atctualy bipedal and actually a hominin * makes sense for one of the early hominins, makes sense that it would be least human like *important info* * anteriorly placed foramen magnum = bipedalism? * canines not projecting * brain small (300-350 cubic cm) * small molars and premolars * thin dental enamel * possibly a direct ancestor of later hominins * but very little evidence that it was bipedal (take all evidence with a large grain of salt)

longest living hominin species

homo erectus

the strapping youth

homo erectus speicimen found in west turkana site bw 8-12 yrs old had it achieved fully adult height, it would have probably been between 5'8 or 5'10 beautifully preserved -what is missing is the hand bones and foot bones -died in a floodplain before it flooded -->everything was burried except fingers and toes and fish ate them away long lower limbs modern human like limb proportions would have walked on the ground pretyt much like us chest slightly more funnel-shaped than ours brain size = 800/900 cc -->twice as large as a chimp -->larger than a homo habilis --still smaller than ours (biggest ones at the end of this time was about 1100cc)

feeding posture

hyopthesis on the origin of bipedalism idea that bipedalism evolved not as a mode of locomotion, but as a subsistence adaptation raeching for fruit on a branch froms the gorund, stand on two legs, reach with arms perhpas some of the key musculoskeletal elements evolved when our ape ancestors were reaching out on the trees or on the ground during feeding once upright posture became adopted for feeding, then adaptations for improving the mode of locomotion would've evolved later very difficult to test: but isopotes sugegst that early ancestors ate a lot of fruits (this cold support this hypothesis)

thermoregulation

hypotehsis on the evolution of bipedalism trees disappearing, grasslands spreading, more time on the savannah, sun beating down on you , it can get hot, you don't want to overheat quadrupedal ape, a largea mount of ythe surface area of your body is really exposed to diredct sunlight standing on two legs, less surface area of your body exposed to very diredt sunlight, morel surface area exopsed to wind ability to sweat is a distinctly human characteristic unique idea that seeks to explain bipedalism and sweating testable prediction? -prediction that bipedalism actually did evolve in open habitats, the earliest bipeds did live in the savanah -->but a lot of the earliest hominins lived in forest habitats -->shade would've been available for these hominins -->removes the impetus for thinking that thermoregulation is the answer

tool-use

hypothesis of evolution of bipedalism darwin suggestion, 1871, book the descent of man when you stand on two legs, your upper two limgs are free to do other things, not related to locomotion - ex. like making tools start making and using tools, gosh it would be useful if your hands were really dexterous it would be really great if you were clever so you could devise new tools , create other ways if you start to develop tools you don't need teeth as weapoin anymore, so canines could be smaller you might want to communicate the use of tools to people in the community, so you develop language, complex thought, symbolism, etc. stand up straigjt... eloquent idea, explained evolution of all of the human characteristics very logical, made a lot of sense, but almost certainly not true what is the testable preducation of this hypothesis? --the preiicitno of this hypotelsiss is that there should be coordingation in the timelines of development of tool use and bipedalism --BUT, the earliest hominins (bipedalism) pre-date the earliest tools by 4.5 million years :(

carrying

hypothesis of evolution of bipedalism if you stand upright on two legs, frees your upper limbs for other things, here carrying your offspring with you maybe carrying food environment getting colder, dryer, maybe your resources are more dispersed, you need to be able to go to one region, break off some branches with fruit, carry them back to a home base provisioning behavior males would go out carry and gather food and bring back to females taking care of the offspring at the homebase carrying could be very imporant how would you test this hypothesis? --straight doesn't know --biggest problem with this hypothesis is that we don't know wwhat data we can collect in the fossil record to test this hypothesis --remains just an idea, untestable idea --this hypotheses are very difficult to test

locomotor efficiency

hypothesis on the origin of bipedalism rainforests drying up, forest patches separated by grasslands, need to be able to get from plaace to place with enough energyto collect food and stil go bak to where you came from turns out htthatt walking bipedally is a very enregeitcally efficient form of locomation traveling between food trees testable? bipedalism in the earliest hominins would have been inefficient...would it have been more or less efficient than alternative modes of locomotion? -->unclear if at the very origin of bipedalism it actually would have been an efficient form of locomtion.

functional morphology of bipedalism

important bc bipedalimsm was the first human characteristic if we find fossils with evidence of bipedalism, you know you've found a human ancestor bipedalism great indicator you've found a hominin limb length (we've talked about this before, refer to exam 2 notes on bipedalism and limb length) valgus knee joint hip musculature large, adducted hallux (big toe)

eugene dubois

in his 20s interested in evoution and the idea of the *missing link*--huxley's idea that (which type) of ape is the closest living ancestor to humans question driven research project, very reflective of modern science thought that if asian apes were closest relative to modern humans, then the "missing link" should be in indonesia somwhere 1891: discovers trinil 2 -on the banks of the solo river in indonesia -the brain is much smaller than what you see in humabns today, and in neanderthals -->about 1/3 to1/2 the size of the brain of a modern person -->but twice as large the size of an ape -odd shape -unusual anatomy -but, had femur indicating upright walking -Pithecanthropus erectus -->pithe= ape -->anthropus= man -->erectus= erect --> thought it was an upright walking man, but also ape like -leading naturalists of the time do not care about his discovery...tgey;re saying it's a diseased person or an orangutan -->no one believes him -->takes the skeletons he discovered, puts them in a box under his house, dies very bitter and unbelieved.

hip musculature

in relation to bipedalism positioning of the lesser gluteal muscles in relation to the hip joint gorilla gorilla * the *illium paddle portion faces backwards* * allign in *coronal plane* * muscles that arise of the posterior surface of the paddle like portion of the illium, they insert on the top of the femur but they *pass behind the hip joint* * these muscles known as the lesser gluteal muscles— they arise off the back end of your hip * because those muscles are behind the hip joint, when they contract they extend the thigh (propel your leg backwards) * homo sapiens * bones of the human pelvis have completely reconfigured themselves * paddle portion of the illium aligned in the *sagital plane* * the faces of the paddles face to the side * the *lesser gluteal muscles arise off the outer surface of the illium now cross directly over the hip joint* * *when these muscles contract, they cause the side to side motion of the hip joint — abduction* * super important for bipedal locomotion...why? * when you walk on two legs, you are walking on one leg at a time * the knee joint has to be positioned under the center of mass of the body * it is not possible for the hip joint to be under the center of mass of the body * when you shift your weight to one leg, the leg off the ground, that hip joint is unsupported , the pelvis would want to fall down, gravity wants to pull it down, but...the lesser gluteal muscles fire, pull your pelvis back up, stabilize you as you walk * the reorientation of the pelvis so that the *illium is saggital and the muscles are over the hip joint* * left = skeleton * right = muscles

large adducted hallux

indicator of bipedalism * homo sapiens * lost the ability to grasp with the big toe * why? * when we walk on two legs, when we propel ourselves forward, our weight shifts over our foot, and as we shift to the next foot, we push ourselves forward, most of the force goes through the big toe * if it was very mobile, it wouldn't be able to push effectively, handle that weight * if it was small, couldn't handle the weight either * pan troglodytes * grasping big toe *for walking in trees probably?

valgus knee joint

indicator of bipedalism * take the femur, the femur is the thigh bone, distal end of the femur is at the knee joint, take the femur and lay it on something flat, the shaft of the femur tilts to one side * australopithecus afarensis — you can see the tilt see slides * pan troglodytes — no angle * *your thigh bone is not oriented straight up and down*— consequence is that your *knee joints are closer together than your hip joints* * important because when you walk bipedally, you do not walk on two legs, you walk on one leg at a time, you spend a lot of time balancing on one leg (quadrupeds have four limbs on the gorund, don't fall over very often) * the only way to *balance is if the center of mass of your body is directly positioned over the supporting limb* * only your knee joint can be above the center of mass of your body? * every time you step you have to shift your body one side to the other in order to balance * if your knee joint was same distance apart as your hip joints, you would have to walk very oddly, * makes you stable when you walk, much more energetically efficient

qafzeh

israeli site basically fully modern human real genuine hcin

Paleoenvironment in the turkana basin

koobi fora, omo, west turkana, ledi-geraru C4 plant eaters (grasses) are present but not dominant before 3 mya. -->Mosaic of habitats. After 3 mya, grassland species becomes much more pronounced. There appears to be a transition from mosaic to dry habitats. -->Australopithecus are more adapted to fruits and things. -->Paranthropus and Homo are more adapted to open lands. Eastern Africa: this transition was around 3-2.5 mya Southern Africa, this transition was around 2.5 - mya.

unique human adaptations

large brain -was not first -3-4 million years ago, slightly bigger than apes -2million years ago brain size really took off tool-use -tools are essential to our survival -tool use has been thought to be important to defining humans precision grip -we have modified the bones and muscles in our hands allowing us to manipulate objects in fine ways -ability to finely use our digits -most primates have a power grip-- able to grasp things, stay on the branch, suspension, support their body weight with hands language -ability to communicate lots of ideas , symbolic dieas, do so rapidly and with low error -we don't know when language evolved-- does not get preserved in the fossil recored -many mammals have communication systems , but ours is the most elaborate -there are areas of the brain correlated with speech, but otherwise its hard to detect language use on the fossil record *bipedalism* -human adaptation that evolved first -- 7 million years ago , evidence of bipedalism -all of the above adaptations were 2-2.5 mya -so, for the first while, humans were basically apes on two legs, and don't have any of these other adaptaions -learn about why bipedalism evolved in order to understand why humans evolved.

20 kya

last glacial maximum coldest it has been over the last 65 million years

mousterian tools

levallois tools, middle plaeolithic tools, middle stone age tools 250 kya based not on large cores, but on flakes the production of regularly flaked shapes retouch= taking tiny flakes off to make a round but sharp edge process; you have to use something that is softer than the rock as hammerstone; like an antler or something;

cerebrum

like a bike helmet sitting on top of a central stalk of the brain controls touch, vision, hearing speech reasoning emotion learning and fine control movement high order cognitive functions + functions under conscoius control (voluntary muscle movement)

hominins

living and extinct humans everything that is more closely related to humans

the descent of man

mid-19th century backdrop of darwin presenting natural selection and evolution 1871 he publishes the--- -- --- attempt to explain all of the diversity in terms of evolutionary theory physical anthrpology documenting anatomical characteristics of different people and relating back to classificatiosn of race (ex. brain size) trying to prop up ideas of race

ardipithecus ramidus sites

middle awash -- ethiopia

early brain growth

modern humans * we have accelerating browth and then prolonging the growth of brain sizes * chimps, after first year of life , there's leveling off after 2/3 years of life * humans, rapid acceleration of growth from birth until they reach ~ adult size brain at age 6 (but continues growing slightly until 21) * can't have brain grow to adult size in womb because childbirth would be too difficult * we've changed the way we develop to accommodate our large brain size

replacement with hybridization

most true explanation of the origin of modern humans * deep root of african population, begin to diversify genetically, at some point later in time 140,000 ya , leave arica dispers to the rest of the world * as they spread, they encournter these archaic populations in other parts of the world, and some interbreeding takes place, so you get some genetic diversity in europeans and asia * largely a replacement event but twith some continutity through hybridiziation with local populations

cerebellum

motor reflex and coordination muscle memory

race and genetics

much more variation between humans in one single population, than between two different populations overall less than 15% of all human genetic diversity is accounted for by differences between human groups

2 major hypotheses of origin of modern humans

multiregional evolution model replacement model ("out of africa model")

la chapelle aux saints

neanderthal site in france one of the first specimens discovered * teeth fallen out, arthritis, walked with a hunch etc. * when it was discovered in early 20th century, it became a sensation, images of it, nenaderthals being brutish people * the fact that someone with this many injuries could live so long is actually a token to the sophisticated social system * the reason perceptions come to be is based on what is discovered first

first people to bury their dead

neanderthals

kada gona

near awash river in ethipia 2.6 mya stone tools unequivocably made by humans concoidal fracture, concave scar on the chopper

oldowan tools

new type of tool seen in the fossil record 2.6 mya one rock is used to produce a tool out of another rock; these tools are both held in a separate hand, have to strike one with the other in a certain fashion to produce the desired outcome hammerstone (round rock) in one hand, another rock in the other hand -->need coordination between the two hands -->strike the hammerstone on the other rock in a particular section, needs to be a narrow area, you will detach a flake from the original raw material (the core) and the thing that will detach is called the flake -->both the flake and the core have sharp edges and could be tools evidence that these kinds of rocks are human made-- find multiple flakes that can fit back together ------ tools show *conchoidal fracture* -->* with this type of technology, holding core in one hand and hammerstone in the other hand, the nature of being able to produce this particular fracture and produce a flake, it produces a particular kind of fracture that is very identifiable and is characteristic of human activity—> conchoidal fracture * raw material hit with hammerstone, the fracture is not a flat, planar fracture, after the flake comes off there's a scar left behind on the core, thatscar has concavity associated with it, hit from above, flake move away, leaving concavity on the core * convexity on the flake (the bulb of percussion), corresponds to (leavves behind these concave scars) the concavity on the core * characteristic to human tool use

race

not biologically meaningful socially constructed as real because racism is real

paranthropus boisei sites

olduvai gorge - tanzania turkana basin koobi fora and west turkana -- kenya turkana basin omo-- ethiopia

homo habilis sites

omo, west turkana, koobi rora swartkrans, sterkfontein olduvai gorge

convexity

on the flake

lower paleolithic tools

one block of raw material, make one tool

feeding and carrying

only hypotheses of the evolution of bipedalism that we could not falsify likely contribute to the evolution of bipedalism however we cannot say for sure our knowledge has progressed through a process of elimination

chimpanzees

our most closely living relatives

homo erectus

overview: First specimen was discovered on Java by Eugene DuBois. It was found at Trinil. *Skull is very long and low.* Huge brow ridges with a gutter behind them. Supraorbital tori. The thickness is pretty much the same all the way across. Ridge of bone that runs up and down the sagittal plane of the skull. Angulation of the occipital bone and a torus (beam of bone) along the occipital bone. The cranial bone is massively thick. Double what you see in other species. *Mandible and face start to look modern.* *Dental reduction in size. Approaching human-like proportion in tooth size. Something is changing about the way that these animals are using their jaws and teeth. Probably not to process really highly resistant foods. Either softer foods or they are processing them more before they go into the mouth.* First discovered on the Island of Java, but that's not the oldest evidence. It is in Africa, about 1.9mya. Then almost immediately, you start to see evidence of it in different places. Asia: 1.7 mya China: 1.6 mya Indonesia: 1.5 mya Europe: 1.2 mya (Human evolution has been taking place in Africa since 7 mya, and now suddenly it rapidly spread out.) Specimen found in West Turkana Site ("The Strapping Youth") Between 8 and 12 years old. Had it achieved fully adult height, it would have prob been between 5'8 or 5'10. Beautifully preserved. What is missing is the hand bones and foot bones. Died in a floodplain before it flooded. Everything was buried except fingers and toes and fish ate them away. Long, lower limbs. Modern, human-like limb proportions. Would have walked on the ground pretty much like us. Chest slightly more funnel-shaped than ours. Brain size = 800/900cc Twice as large as a chimp. Larger than a homo habilis Still smaller than ours. The biggest ones at the end of this time was about 1100cc. Their appearance is correlated in time with the appearance of Acheulian tools. These tools persist long after every other species of human went extinct. There was a period of time when homo erectus was the only human species in the world. And these tools were being made them. We can't say that homo erectus was the only one to use these tools, but we do know that they made them. Social Organization There is a specimen from Diminisi. This individual had no teeth. The jaw looks like that of someone with denchers. He had lost all teeth but lived long enough for tooth sockets to resorb. Elderly individual. It is very likely that the individual could only have survived to live this long without teeth if it was being cared for by other members of the group. Probably actually costing the group something. Advanced social behaviors. Group care/group cohesion. Sounds like what we do. This behavior is almost 2 million years old. Longest persisting species in the fossil record. 1.7 million years We've only been around for 200-300 kya They were doing something right. *KEY FACTS* - A HUGE LEAP FORWARD IN RELATION TO THE HOMININS BEFORE THEM - THERE IS A REASON THEY COULD DISPERSE INTO SUCH DIVERSE HABITATS AND PERSIST FOR SO LONG; VERY ADAPTIVE AND FLEXIBLE - WE'VE CROSSED A THRESHOLD TO SOMETHING THAT IS BASICALLY HUMAN - - oldest living hominin species - *first hominin to leave Africa* - much larger brain, which increases over time from about 650-1100cc - tent-shaped cranium (as seen from the back); the top is the sagittal keel - occipital torus - sagittal keel - massive brow ridges - wide, flat face - small teeth and jaws -modern limb proportions. committed terrestrial biped. -human-like body mass - sophisticated acheulian tools - likely ancestor of all later hominins (bc there was nothing else alive... basically the rest of human evolution is tinkering with ---- ------)

johan blumenbach

person credited with coming up with the concept of race identified a hierarchy of 5 races europeans were central, this allwed symmetry, which reflects degeneration varieties must represent "degenerations" from the essential type degeneration = a means of explaining differentiation from the norm he made the white european the central form of human, and other forms represented degenerations eventually turns into the 4 races: caucasian, negro, mongolian, american indian

hammerstone

round rock used to make flake and core tools (oldowan tools)

climate change history

see lecture 23 10/29 -- what's the point * what is causing the climate to change in the first place? * probably a few things happening in the collecative * but the overall trend from relatively warm to relatively cool, driven by climatic events: * see grpahic * related to plate techtonics * north america and europe stuck together, breaking apart, so they're moving towards each other in the pacific, on the other side of the world * neogene, paleogene, cretaceo * cretaceous, south america and africa are very close * all the continental land masses are cloase ... * why does this matter? * because as north america and europe are moving, * see slides — i don't understand this view * alask and russia almost touching each other — tiny channel between them * small place for the water to circulate from atlantic to the arctic...hared to circulate wate,r cold water getitns tuck at the north pole, can't be warmed, leads to global temperature cooling * plate techtonics and the closing off of the arctic ocean * 5.5 million years ago to presnt day * average decline * spikes getting much more violent, greater variability * squiggles represent fluctuations in global temperature * starting to see increases in amplitude, particularly in the pleistocene * fluctuation in the magnitude of temperature change is increaseing * climatic variability increasing dramtically in last 2.5 my * last half millionyears * very rapid changes in temperature * why? what is responsible for these fluctuations * malinkovitch cycles (see slides) * precession * obliquity * eccentricity * thes three culminate in solar forcing? * stages of glaciation * see graphic * cooling trend in the polio-pleistocene coincides with increased climatic variability * still does not explain why starting ~3 millinon years ago these amplitudes become greater , more extreme * the malinkovitch cycles explain the fact that there are oscillations in temperature, but they do not explain why those oscillations have become more intense (higher magnitudes) * hypothesis of why the magnitudes beocme more intense has to do with plate techtonics * temperature analysis related to oxygen isotope values * oxygen isotope stages * odd numbered stages are warm * even numbeered stages are cold * stage 2 is the "last glacial maximum" * last time it was super cold 20,000 years ago * stage 5 is the "last interglacial" * last time it was super super warm 128,000 * we live in warm stage, but about 20,000 years ago it was incredibly, incredibly cold * glacial maxima * ice covering parts of the northern hemisphere * the ice sheets ended at WAshU! mound, morraine * why did these glaciers form? * probably because of geological variable... * at one time , south america was an island continent, and then 3 million years ago, central america rises out of the sea, connects north and aouth america, cuts off the atlantic from the pacific * allows the mammals of south america to disperse into north america and visa versa (great american interchange) , fauna interspersing between the two continents * appearance of the land bridge * gulf stream exists because warm water circulates into the carribean, has nowehre to go, shoots up the atlantic, over to europe * .. * warm water brought to europe, evaporates more quickly, raining more in europe, snowing, more , temperature has just become cold enough for this water to freeze, packs up , forms glaciers * later, when the earth becomes warm again, the ice will melt again * cooling of temperatures allows other mechanisms to acontrol the glaciation? * confused... * variation of amplictudes * ocmbination of overall trend towards the earth getting colder, and the dpresence of malinkovitch cycles affeting amount of solar radiation, and a lot of precipation over a continent that can either freeze or run off. * outline of the continents changing * parts of thee world underwater become exposed, given opportunities for early humans to inhabit certian habitats, maybe that will evnetually become islands? * massive glacier * downstream effect of the climate of the entire world * lses humidity, more water trapped in the glaciers * graphic * temperature change inversely related to ice volume * post-glacial sea level rise * sea level change at various locations vs. time * 21,000 years ago last glacial maximum, very cold period, glaciers at their greatest extent * sea levels 125meters lower than they are today * over 350 lower than they are today at last glacial maximum * islands today, in the past connected to the mainland (southeast asia, indonesia, see slides maps) * temp, sea level, and vegetatation * iimportant for the ecology of early humans and the animals they lived with * see graphic * less forests inglacial periods * changes food availability * changes temperature uner which people are living, need adaptations for dealing with temperature (Ex. cold you need to deal witih that) * slides * beaver, wooly mamoths, etc. * during last glacial maximum, huge elk with huge antlers, go extinct bc they're well adapted for cold, steppe environments * slides * huge bear * twice the mass of living grizzly bears * cave bears * long term changes in the environment and long term change that start off modest and become quite extreme, humans and mammals need to be able to adapt to this or go extinct.

atapuerca

sima de los huesos (cave of bones) * 80% of all the human fossils of the middle pleistocene * almost all of teh fossil record of archaic humans come from this one cave * probably what happened, people would die, get thrown into this hole * unclear if this is symbolic behavior , like the intentional disposal of the dead * lots of well preserved fossils * 300,000 , after h h bergensis populations had been in europe for a while distinct features arise * two distinct brow ridges , not a continuous bar * distinct gap between the two eyes' brow ridges * large nasal cavity , large opening * the entire face, mid facial projection, has been pulled out a bit * same size brain * as the face has been pulled forward, the tooth row has also moved forward a bit * these are all also characteristics of Archaic HOmo: H. neanderthalensis. * these are not neanderthals tho

dikika

site in ethiopia next door to hadar, where australopithecus afarensis was found south of the awash river found one bone, with two parallel marks (fissures) on them indistinguishable from bones that have been cut with stone tols age of this bone with potential cut marks is 3.2 mya see slides about the same age of the evidence of smashing rocks to breka them to make tools (lomekwian tools) au af. living at this time...suggests that au. af couldl've been using stone tools stone tool manufacture use could've appeared in the record 3.2 mya

Trinil

site on the island of java where eugene dubois discovered first evidence of homo erectus

Ledi-geraru

site where one specimen of the earliest homo was found 2.8 mya it is only a mandible the teeth aren't like australopithecines because the cusps aren't centrally positioned and the highest parts are on the outside of the teeth. --early homo or at least the lineage leading to early homo

tool

something from your external surroundings/environment, that the focal organism takes and either adapts for a different purpose to serve some kind of function that facilitates the function, catalyzes the function, that the function could not happen wiithout the adapted use of that object

40 kya

something important happens in europe at this time * modern humans make it from the levant to asia * 40kyr something important happens in europe * neanderthals disappear and then modern humans appear * there is no evidence from any archaelogical site of neanderthals and modenr humans occupying the same area at the same time. * usually find one layer with neandethals, then sterile layer, then layers of modern humans * howeer, DNA has been extracting from both neanderthals and modern humans * pestera cu oase: * ~40,000 oldest fossil modern human in europe actually well preserved * no evidence of neanderthals in the cave * BUT DNA has been extracted, it's estimated that this individual had a neanderthal ancestor only 5 generations prior —> this indicates contact between populatiosn of neanderthals and modern humans * 40kyr neanderthals go extinct and modern humans replace them * doesn't mean they were directly competing and humans killed them off, just means that somehow modern humans were able to survive and thrive better in this environment than neanderthals * and maybe they were beter able to compete for resoruces * this specimen is modern human like in every sense (even tho it has neanderthal ancestor) * has pentagonal cranium, which is characteristic of H. sapiens

indentations in animal bone

specific scratches, indicating that it wa sscratched with a stone tool; peaople using stone tools to cut meat off of the animal bones

neanderthal cold weather adaptations

stocky body shape enormous nose controlled use of fire prob had clothes

predates

stone tool manufacturing (3.3 mya ---- the evolution of a precision grip (2 mya)

paranthropus robustus sites

swartkrans kromdraai drimolen

tool use

taking an object that already exists and using it

tool making

taking an object, modifying it to perform a function/create a tool

homo erectus social organization

there is a specimen from diminisi no teeth jaw looks like that of someone with dentures -->he had lost all teeth but lived long enough for tooth sockets to resorb...elderly individual it si very likely that the individual could only have survived to live this long without teeth if it was being cared for by other members of a group probably actually costing the group sometihng advanced social behavior --group care/cohesion sounds like us this behavior is almost 2 million years old.

false

tool use is uniquely human

hypotheses on the origin of bipedalism

tool-use carrying thermoregulation feeding posture locomotor efficiency vertical-climbing hypothesis

sachelanthropus tchadensis sites

toros menalla both in chad

ororrin tugenensis sites

tugen kills -- kenya

humerus radius ulna early homo

upper limb length was kind of long, which we usually associated with some arboreal behaviors not yet fully committed to moving around on the ground

human brains

we are larger animals than chimps , so we would be expected to have larger brains but we actually have proportionally larger brains as well

spheroids

weird rounded rocks get their round shape because they've bene used to mash/grind things, do it in such a way that results in the rounded shape of the rock

origin of modern humans

what is known? 1. *anatomically modern humans appear first in Africa — *consistent with both models* * the differences between the hypotheses had to do with the arrows and the directions of the arrows, not with the colors and locations (from last class graphics) * completely compatible with both models for humans to show up in one place first * *need to find evidence incompatible with one or the other model in order to reject it 2. modern humans reach the near east by 120-80 kya (but they do not reach europe). their presence in asia at this time is disputed..*consistent with both models*) 3. by 45-35 kya, modern humans colonize europe and asia, and other archaic humans(including neanderthals , disappear). *consistent with both models* 4. between 55 and 40 kya, neanderthals and modern humans interbreed in the near east and europe,. *consistent with multiregional evolution, inconsistent with replacement* -->replacement hypothesizes that there's no interbreeding bw species; that modern humans disperse out of africa and replace all other species 5. eurasian populations diverge from african populations ~45 kya. *consistent with replacement but inconsistent with multiregional evolution* -->modenr eurasians exhibit really low genetic diversity -->means they have not diverged from each other for very long--> share a pretty recent common ancestor -->multiregional model predicts people evolving over the world, diverging at the very beginning, deep ancestry -->clearly have diverged very recently, this fact disproves the theory of deep ancestry 6. genetic variability is much greater in african populations than in eurasian populations. *consistent with replacement but inconsistent with multiregional evolution* -->african population has very deep root, appeared earlier, has been diverging for a very long time 7. Thus, modern humans from africa appear to have replaced neanderthals and other archaic humans in Eurasia, but with some hybridization what's probably true? *replacement with hybridization*: * deep root of african population, begin to diversify genetically, at some point later in time 140,000 ya , leave arica dispers to the rest of the world * as they spread, they encournter these archaic populations in other parts of the world, and some interbreeding takes place, so you get some genetic diversity in europeans and asia * largely a replacement event but twith some continutity through hybridiziation with local populations