midterm

gorilla vs h erectus vs homo sapien skull

note: the gorilla skull should be larger, this is not drawn to scale Characteristic of homo sapiens!! Maximum length of the skull is -- in homoerectus -- the place of attachment of the neck muscles (nuchal muscles) ⇒ can tell bc there's a little peak The base of the brain case stays about the same, ballooning out from there→ expansion of frontal and occipital, and upper parietal lobes Same w african homo erectus specimens Shelf of bones extending over the eyes: in homo erectus, the shelf also goes over the bridge of the nose → like a built-in umbrella! Biggest brows in human evolution!! Goes straight over the bridge of the nose In evolution: Start to see reduction in the brow: projection above the nose→ brow ridges are 2 indep cups→ thinking of brow on the lateral margin → ability to see a puckering associated w the brow in modern humans, concentrated in area above eyes; more likely seen in morphological males

allele & significance

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome Significance: evolution depends on changes in genetic variability and changes in allele frequencies over time--mutations are the source of new alleles in the gene pool

zhoukoudian homo erectus

originally: 'Sinanthropus pekininsis': the Chinese man of Peking (older name of Beijing), now part of h erectus general features like thsoe of H. erectus from Java and Africa, including large brow ridges w low sloping foreheads and projecting faces without a chin brain sizes varied from 900-1200 ml, the latter w/in the range of living humans little evidence of sexual dimorphism in this sample, but it is more obvious in the African members of H. erectus

Oldowan pebble tool

pebble tool of the lower paleolithic through experimental archaeology, we can mimic technology used by our ancestors and see how it actually works, how long the process takes could smash antelope forelimb bones -> exposing the marrow defleshing the bone; shows scratch marks from an Oldowan tool

evolution of hominids and african apes since the gorilla/chimp+human (GLCA) and chimp/human (CLCA) last common ancestors

pedestals on the left = separate lineages leading to the extant apes (gorilla, and chimp and bonobo) text = key diffs among adaptive plateaus occupied by the 3 hominid genear

Collision of africa w the eurasian plate

picture: the dist of the continents at 50 million years ago vs today. early in earth history, there was a continuation bw the Med Sea and the Indian Ocean, which closed w the collision of Africa with the Eurasian Plate, around 20 million years ago -> Profound effects on climate of e africa, and resulted in formation of Rift Valley geological features that preserve many of the earliest signs of our ancestors the development of the Rift Valley can be seen along the E African third of the continent rim of mountains in SW Asia, where the African Plate made contact w the Eurasian Plate

chimps' eating habits

preferred foods: ripe fruits and leaves omnivorous -> commonality w chimps is part of our evolutionary lineage diverse in the ways that that they go after and extract diff food types pliability, long blades of grass -> remove outside leaves if it's a trig -> regular branch of the tree put a twig into a termite hole, then scrapes off the food

darwin's theory of evolution

presented it, and the considerable evidence he had amassed to support it, in On The Origin of Species, 1859 avoided all mention of humans, except for a cryptic sentence on the last page: "Much light will be thrown on the origin of man and his history" refused to publish it until he received an essay from Alfred Wallace

vestigial organs

as evolution progresses, some structures get side-lined as they are no longer of use ex: coccyx: much reduced version of an ancestral tail, which was formerly adapted to aid balance and climbing ex: appendix definition: an organ that is not functional in an organism, but was functional at some period in its evolutionary history significance: represents evolutionary change, for example the coccyx (a vestigial tail) was formerly adapted to aid balance and climbing in our ancestors. Now it holds the base of the abdomen

first australopithecine to be found

australopithecus africanus early human ancestor, lived in Southern Africa larger brain, smaller teeth, and a more rounded cranium than A. afarensis Still had ape-like features, like long arms and a pronounced jaw Similar to A. afarensis because both had a pelvis, femur, and foot bones that represented bipedalism but also showed signs of tree climbing. Lived about 3.3 to 2.1 million years ago ***gracile australopithecine

antibiotic resistence

bacteria can become resistant to antibiotics this is an example of natural selection in action!! antibiotic acts as an environmental pressure-> weeds out those bacteria w low resistene and only those w high resistence survive to reproduce!

early homo: first findings

best guess is that the first members of the genus Homo evolved from an australopithecine, probably a gracile australopith, sometime around 2.-2.5 myr But, the first documented appearance of members of our genus is just after 2.0 million years ago There are fragmentary fossil bones from slightly earlier, about 2.3-2.4 million years ago, but bc of their incomplete nature, they are v difficult to interpret These earliest well-documented fossils have all been found at sites east of Lake Turkana, in N Kenya. Somewhat later (after 2.0 myr) are fossils from Olduvai Gorge, Tanzania

biological anthro as an evolutionary science: importance

biological anthropology, like other life sciences, is foudned on the mechanisms and operation of evolution without an appreciation of how evolution operates, it is difficult to understand how humans developed and appreciate the diversity of modern human biology

adaptation & significance

biological mechanism by which organisms adjust to new environments or to changes in their current environment significance: the idea of natural selection is that traits that can be passed down allow organisms to adapt to the environment better than other organisms of the same species

criticisms of darwinian evolution toward end of his life/ immediately after?

by the time of Darwins's death in 1882, The origin of species had gone through 6 editions, in which Darwin had attempted to answer the most serious criticisms of his theory in spite of this, by 1900, Darwinian evolution was no longer seriously considered by most biologists ironically, the most important criticisms, those dealing w the ways by which hereditary material is transmitted across generations, and the origins of new traits, were being answered by discoveries in the emerging field of genetics

chimps vs modern humans: bipedalism

chimps have a spine that connects at the back of the skull and keeps the head at an angle. Humans have a spine that connects underneath the skull and keeps it completely upright.Chimps have a short connection between the femur and the pelvis, and hip muscles cannot contract to support upright walking/running. Humans have a longer connection and have muscles to withstand long distance walking and running. Humans have a much stronger knee joint to support long distance walking/runningUnfortunately, bipedalism can lead to back pain, slipped disks, and arthritis in hips and knees

bone marrow definition and significance

definition: a soft tissue inside the bone that produces blood cells, a good source of fat and protein for early human ancestors significance: cracked/broken bones have been found, representing that scavengers used stone tools (oldowan tools) to crack open bones in search of bone marrow, a food fatty food source. Other animals would not have been able to access this food source

chimps and humans as social critters

relationship-tied social group-tied layered social interactions: humans add layers to these social interactions

Transitional fossil

definition: fossils that provide patterns of evolutionary change from the early ancestors to modern life forms. significance: the Archaeopteryx was found in Germany and shares many characteristics with both dinosaurs and birds, showing that birds arose from dinosaur ancestors. In human evolution, species of Australopithecines can be viewed as important transitional fossils between our early ancestors and members of the Homo genus

rift valley

how the bones of an ancestor end up in a geological deposit where they can be found for study in this example, the Rift Valley and its geology play a v important role in the preservation of an animal's bones after the creature dies and their eventual discovery -> try to reconstruct the fossils that are found volcanic eruptions were very common-> resulted in accumulation of sometimes enormous amts of volcanic ashes. these ashes are very fine, silt-like materials, and they played a central role in the preservation of footprints at Laetoli, in N Tanzania, from about 3.7 million years ago

mosaic environment

juxtaposition of a lot of eco-zones in relatively small geographic space Ex: in Kenya Has within its confines 63 languages! Associated w many of these groups of folks Average Kenyan speaks the language of the people in which they are a part, as well as language of closest neighbors, and national (swahili) and official language (english)

australopithecine behavior

little specific info available abt what these creatures ate, and the possible diffs in diet bw the various kinds assumed that robust australopithecines ate a diet of coarse, gritty veggie foods (huge molar teeth) gracile ones like Lucy also possessed v large teeth for their body size, and both kinds of australopithecines had thick enamic on their teeth and also v heavy dental wear little known about specific aspects of adaptation and behavior stone tools found earliest at ~2.5 myr ago, but unassociated w any fossils. S african robusts are found w stone tools but it's unclear whether they, or a more advanced hominid, made the tools some evidence that by ~2.0 myr, early members of our own genus, Homo, had appeared; these may have been the toolmakers?

male vs female activity in family

males hunt relationship of moms to offspring: Life-long relationships Long growth and development periods At least 10 years of decent dependency; constant interactions w their moms and siblings -> Birth spacing in humans? 4-5 years; Darwinian reflex: if you rub their hands, they will grip onto you-> After 3/4 weeks, the reflex goes away bc they don't cling to their moms -> In chimps? ~6 years Years before baby chimp feels safe enough to go out of view of the mom Baby rides mom's back until around 3/4 years old Mom trying diff foods → baby will eat these foods Patiently allow the baby animal to continue trying after they fail (bc they can't communicate like humans do) Chimps often play with their offspring: throw in air, spend a lot of quality time w them

male aggression

secondary associations w a larger social group Necessary component Take what we think we know→ apply it in some measure to the past

sexual dimorphism

the diff in body size bw males and females of the same species in primates, if sexual dimorphism is present, the males are always larger than the females there appears to be marked dimorphism in all australopithecine species in primates, dimorphism is associated w male dominance; there are no dimorphic primate species w pair bonding, which is the basis for human family organization ex: sexual dimorphism in A. afarensis: sizes of the 2 lower jaws (top), both adults and the 2 upper jaws (below). large diff in the size of the teeth and overall size of the jaw bones while most anthropologists believe this is evidence for sexual diffs in body size, some suggest that there might be 2 diff species represented here

Nariokotome

west side of Lake Turkana where the most complete skeleton of an early hominid was found, "The boy from Nariokatome"

Biological anthropology as an evolutionary science

-Biological anthropology, like other life sciences, is founded on the mechanisms and operation of evolution -w/o an appreciation of how evolution operates, it is difficult to understand how humans developed and appreciate the diversity of modern human biology -Microevolutionary processes→ processes of change -Processes of change lead to BIG change, bc in our context this is speciation -Extended evolutionary synthesis

hunter-gatherer models

-living people are not fossils -"marginal" environments -hunter-gatherers today live in a world of non-hunter-gatherers -effects of western resources/values

transitional fossils

-many fossils show a clear transition from one species or group to another -Archaeopteryx: Found in Germany in 1861 Shares many characteristics w both dinosaurs and birds ⇒ good evidence that birds arose from dinosaur ancestors Key thing was that on land, the animals have a disarticulation bw the cranial bone and the shoulder complex → can raise head indep of front end of their torso

What is the basis of Evolution by Natural Selection? 3 key concepts

1) Adaptation: -animals possess biological attributes that permit them to follow a specific way of life -animal species differ in the sorts of biological features they possess, and not all mammals, for ex, have the same kinds of teeth -these specific biological features permit animals to be adapted to the way of life they follow -genotype is the underlying framework; environment molds and channels genotype into the phenotype -in humans, culture and the resultant complex behavior are a unique basis for the environment to influence and shape final phenotype 2) Reproduction and Mortality 3) Variation Adaptation arises via variations; some variations are more capable of producing specific traits; these will reproduce more, and their offspring will be more and more adapted to that particular context⇒ shift in variation, shift in behaviors

2 types of chimps

1) Common chimpanzee/ Pan Troglodytes More male-dominated groups Much more aggressive Territorial-based behaviors 2) Pygmy chimps/ bonobos: bigger than the common chimp Body type is more linear: limbs are more slender The "love bunnies" of chimps More matra-focused Less excitable and aggressive toward each other Common ancestor in the not very distant past (~1 million years) Both types of chimps are about the same distance from humans

the biology of early homo: In comparison to the australopithecines, the early members of the genus Homo possess...

1) molars and premolars are smaller in the bucco-lingual (side-to-side) dimension than those of the australopithecines 2) mandible and maxilla are less massive w muscle attachment areas smaller and reduced in robustness 3) brain volumes vary (from 510-800ml) but are, in general, larger and housed in a brain case w a higher, more rounded shape

australopithecine evolution: 2 views

1) time-ordered evolutionary lineage: earliest evolving into later forms; ultimately, into early members of the genus Homo, who will eventaully evolve into modern humans 2) early in australopith evolution, they spread into diff environments, and underwent divergence, evolving into a number of diff species, each w somewhat diff biological features, yet all possessing the ancestral traits. in time, only one species evolved into Homo

Evolution now (since 1949)

1949: American scientist G. G. Simpson published The Meaning of Evolution, which presented the Synthetic Theory of Evolution to a wide audience 1953: J.D. Watson and F. Crick documented a model of the structure of the genetic material: DNA→ provided basis for emerging understanding of the molec basis for genetic processes Genetic research continues to provide more info about mechanisms underlying evolutionary change

fossil samples in NE Africa

2 living hominins showing the discoveries from the Afar region of northest Africa. Although the fossils of this species has been recently increased, this provides a good idea of the nature of a fossil sample

Robust Australopithecines

3 currently recognized species of robust australopithecines as a group, these species differ from the grcile species in having: 1) huge back chewing teeth 2) larger jaws and jaw muscles, sometimes w a crest on the top of the skull for additional surface area for the major chewing muscle compared to modern humans, the front teeth are not significantly diff. but ENORMOUS diff in the size of the back teeth

who spread out of africa?

Between 1.8 and 1.7 myr, currently the most reasonable times when the hominids leave Africa, is also a period when there are perhaps 5 species contemporary with each other in Africa (H. habilis, H. rudolfensis, H. erectus, Australopithecus boisei and A. robustus) Were all of these species able to cross into Eurasia (disappearance of a barrier preventing animal movements across the Suez), or did only one species make it (some specific biological or behavior attributes that were present in only one of these species)? For the moment, this question remains unanswerable.

Alfred Wallace

Darwin refused to publish his book until he received an essay from Wallace Fellow naturalist independently developed the same theory that species changed over time bc of their struggle for existence after 25 years, someone else had come to the same conclusions from their observations of nature when Darwin read Wallace's essay, he knew he had to publish his findings

genetics and evolution: current view

Darwin's notion of gradual evolutionary change over time, via the mechanism of natural selection, is the dominant model in modern bio to explain the origins and development of life on the planet, as well as the modern human variation and adaptation

brain volume in H. sapiens, Australopithecus, chimpanzees

Definition: H. sapiens--1100-1300 cmˆ3australopithecines: 400-550 cmˆ3chimpanzees: 300-500 cmˆ3

Laetoli

Definition: location in Tanzania where footprints left in volcanic ash provide direct evidence of bipedal locomotion about 3.7 million years ago Significance: provided evidence of bipedal locomotion and foot size suggests a body size of less than 4 feet

Homologous structure

Definition: structures that may differ in form or function but derived from interior limb of vertebrates significance: homologous structures represent common ancestry

Taung Child

Definition: the Taung Child was found by Raymond Dart in the 1920s in South Africa. He was small brained and therefore appeared ape-like but his foramen magnum where the spinal cord leaves the skull was located more forward on the skull, representing that the head was held upright. Significance: this represented early evidence of bipedalism. was Australopithecus africanus. Raymond Dart described it as a new species after he discovered it

gradualism

Definition: the evolutionary model (Darwin's model) that proposes that change occurs gradually over time in a step-like manner. Basically, species change in small increments. Significance: was a new way of thinking about evolution as well as geological change (challenged catastrophism)

Lucy

E Africa: Hadar (Ethiopia) 3.2-2.9myr the partial skeleton of an adult female (w/o skull) who was ~1.1m tall and 27 kg. (3'6" and 59 lbs) her skeleton: -found without her skull but w her lower jaw and many parts of her skeleton -pelvis = very similar to that of living humans, demonstrates her bipedality -body proportions were prob diff from us -foot bones indicate that she was able to flex her toes in a much stronger manner than we are capable of, suggesting that she may have spent some time in trees -> this is confirmed by the footprints discovered at Laetoli some people think she could have actually been male Lucy is more similar in body size to chimps her shoulders point upwards -> indication of tree swinging, ours point directly laterally

looking at s vs e africa: which has more valuable fossils (with regard to dating)

E africa: we have a lot of info bc of dating from volcano activity. In e africa, many hominin sites are associated w the Rift Valley. Here, the presence of volcanic activity has permitted the use of radiometric dating techniques: potassium/argon (K/AR) whereas in S africa, australopithecines are found in cave deposits, but we can't say that the deeper you go, the older they are. sometimes we have whole individuals, but their parts aren't near each other.

homo erectus in Java

Eugene Dubois made first discovery: went to Java to find the "missing link" after initial discoveries by Dubois, many additional Homo erectus fossils have been found at a number of sites when H erectus lived on Java, the island was part of mainland asia, connected bc of the drop in sea levels brought abt by glacial activity in N Hemis (no longer connected to the mainland)

the earliest known hominin

Found july 2001, this fossil has been dated to 6-7 myr ago. There is some dispute about this fossil: some suggest it may have greater affinities w the apes Found in desert region in northern Chad (central northern part of africa)

The Baron Georges Cuvier (1769-1832)

Founder of comparative anatomy Developed the theory of Catastrophism: explained the existence of the remains of extinct animals The bones of an extinct giant salamander which was thought to be the bones of a human of biblical times. Cuvier was able to correctly identify the animal

Darwin's Voyage of the Beagle (1831-1836)

He was a FAILURE!! his last chance was a naturalist on the Beagle joined the crew as an unpaid naturalist (ate with the captain so the captain wouldn't go crazy → Captain couldn't eat meals w the crew) Jimmy button → learns english and becomes a translator bw the english and a south american tribe Hard time determining longitude→ used chronometer Sailers get close to coast→ drop cups in to the sea, and scoop them up → quantity composition of the materials in the cups so they'd know exactly where they were in the future if need be Metals were prone to corrosion→ anticipated that if one of them survived, that would be a feat for them When they arrived back in england, they were actually only off by a few mins! Aboard the "Beagle," Darwin spent five weeks exploring the galapagos islands Collected like 9 species (kills them) → takes to a bird specialist at the british museum

Orrorin tugenensis

In early 2000s, fossils discovered by a French team led by Brigitte Senut and Martin Pickford at 4 focalities in Tugen Hills of Baringo district of Western Kenya These sediments have been well dated to around 6 million years For the moment, Orrorin is known only from some skeletal bones and no skull or jaw remains have been discovered In an article published in late 2004 in journal Science, analysis of the internal structure of the upper part of thigh bone (femur) demonstrates that it was organized to support bipedal locomotion definition: predicted to be an early hominin species dated to about 6 million years ago significance: femurs show signs of bipedal locomotion, proving its significance in very early human evolution, potential early ancestor

earliest Homo erectus?

KNM-ER 373 1.8myr east of Lake Turkana 800 ml brain size smaller back chewing teeth this is probably an adult female?

Critiques of gatherer-hunters in modern world

Living in marginalized environments Usually gatherer-hunters don't have a lifestyle that puts them permanently in one place Some gatherer-hunters that sustain themselves on fishing products: fishing yields fresh fish, techniques of storing and drying those fish sustains them in activity times when there were no active fish to exploit→ don't move around in their environment

hominoid family tree

Most amount of genetic info is shared bw humans and chimps than any other critter out there Living primate genetic studies Equidistant from gorillas, but we often think that gorillas and chimps are more similar So much gorilla and chimp behavior is more similar than it is with humans Because they're both hairy! BUT density matters! Our hair total amount of hair is similar Body structure Knuckle walking Longer arms in relation to their legs Swinging around in trees Genetic studies: used to tally amount of difference, but also put a timeline on that Depending on genetic system used, it can be anywhere from 3 million years ago to 7 million years ago Precision of giving a date to the divergence using molecular studies is based on: Gene system and Way things are modeled -> doesn't give us a huge precision ⇒ We rely upon the fossil record to get a sense of divergence time Appears almost solidly that it is at least 6 million / 7 million years ago Earliest fossil record: human lineage Show derived characteristics Development of unique creatures associated w humans → associated w fossils dated in that date range We either don't recognize or don't have any fossils of chimps ever We have a tendency to say that if they're showing derived characteristics of human lineage, then they are in the human lineage But we can't say this! We can only do our best interpretations on this We don't have any fossil record of gorillas, but a massive fossil record of orangutans and gibbins Orangutans: amazing stasis in evolution Nedentition → consumption of more difficult to chew food stuffs Parsimony in contracting these evolutionary trees

Mary Leakey

Olduvai Gorge discoveries 1974: in addition to fossil bones, she found 3 footprint trails in hardened volcanic ash deposits in rift valley: -footprints are very similar to those made by modern humans and document a pattern of modern-like walking almost 4 milion years ago -major diffs: prints are much smaller than those of living humans, & the foot falls much closer -> suggest a body size of ~3.75-4ft in height (if made by adults, which the fossil evidence supports)

Hunter-gatherer myths

Products of a long and timeless past Products of extreme isolation Retain aspects of a distant past that illuminates the evolutionary history of all people

the first out of africa expansion by human ancestors

Some possible explanations: 1) increase in cultural complexity 2) breakdown of a barrier at the Suez bottleneck => crucial consequences. An important theory of modern human origins: that there was a later, 2nd expansion out of Africa associated with anatomically modern humans

19th century: The planet is not fixed!

The earth and all critters were created by god, and recently so! The story of Noah's flood was an important aspect of the way europeans tried to explain the planet Darwin: Hesitant bc he understood that this would conflict w religious beliefs; His wife feared for him!

speed of the hominid expansion out of africa

The expansion out of Africa was a very important event in human evolution. How long this expansion of range took has been the subject of some investigations. Calculations by Joe Birdsell (1957) of the time it took for humans to expand throughout the Australian continent from the first landing by hominids in northern Australia (perhaps 60,000 years ago) -> may have taken about 23,000 years for hominids to expand the 7,000 miles from Africa to Java (this is super short in evolution)

the paleolithic

The stone age or paleolithic divided into 3 stages: lower, middle, and upper Correspond to developments in tool making skills and complexity Lower: hand axes, pebble tools, first stone tools Middle: flake tools based on levallois technique Upper: plastic and cave art; tools made from blades, increasing presence of bone tools

humans in the evolutionary world

Thomas Henry Huxley: Evidence as to Man's Place in Nature, 1863 Darwin: The Descent of Man, 1871

earliest sites in eurasia after expansion out of africa

Ubeidiya: on jordan river in Israel, on a natural corridor out of africa. no hominid fossils, but stone tools similar to those from E Africa (Oldowan) and many African mammal bones. dated to ~1.5-1.6myr Dmanisi: in the republic of Georgia, the fossils are dated to ~1/5-1.8myr Perning: earliest of a series of sites on the island of Java (indonesia). a child's skull is dated to 1.6-1.8myr

evolutionary timeline

Wallace independently came up w idea of evolution

the earliest-in-time hominins

We would expect the earliest members of the human lineage to possess derived (specialized) feautres that would enable us to identify these guys and distinguish them from apes Unfortunately, this is not so easy bc the further back we go, the fewer derived features will be present What should we be looking for?? At the moment, opinion suggests the following: signs of bipedalism, perhaps smaller canines and thick enamel on chewing surfaces of back teeth (associated w a dietary change)

homo habilis

When established in 1964, considered to represent evolutionary transition from australopithecines to Homo Name means "handy person" Fossils are dated to 1.7-1.8 myr. Initially from olduvai and now from E. Turkana brain size: bw 580-650 ml, larger than those of the australopithecines, but smaller than other species of early Homo less broad molar and premolar cheek teeth than australopithecines

pentadactyl limb

a limb with five digits, such as a human hand or foot, which is found in many amphibia, reptiles, birds, and animals, which can allow us to deduce that all species in these categories derived from one common ancestor ancestral to all vertebrates... but modified for diff uses!!

Subterranean solution cavities in limestone

acidic→ melts minerals Stalagmites and stalactites → creates these caverns/holes People's remains would fall into these caverns bc they make a temporary shat to surface; an avenue for these materials to fall into Fossils found in s africa are tough to deal w → its like dribbling sand into a cone → the bones fall down -> Nothing that says that things deeper in the cave are older than those at the top -> Sometimes have whole indivs, but their parts aren't near each other These aren't very well-dated

human origins are where?

africa!

humans and gorillas: comparative anatomy

anatomical evidence suggest that they shared a recent common ancestor, but very diff from the more distantly related woodlouse... yet all have a common shared characteristic: bilateral symmetry

white eyes

characteristic of humans In humans, by having white surrounding a highly pigmented center, from a distance you can tell where that person's gaze is pointed It's a communication device→ tells our engagement

Australopithecines

common term for all members of the genus Australopithecus the best known of our early ancestors: now known from sites in E, S, and Central Africa dated from ~4.1 to ~1.5 million years ago first identified by Raymond Dart in 1925. the fossil was of a young child from the site of T'aung, a limestone quarry in the Cape Province of S Africa. Dart examined the fossil and found several features he believed identified this child as a human ancestor -> named the fossil Australopithecus africanus ('the southern ape of Africa') characteristics: combination of ape-like and human traits 1) bipeds -> must be in the human lineage 2) small, non-projecting canines, w variable development of the sectorial premolar 3) incisers not much bigger than in humans, but massive back chewing teeth (huge premolars and molars) 4) huge jaws and jaw muscles 5) small, ape-sized brains in a skull that was very ape-like: volumes range from 400-500ml (compared to modern humans: 1200-1400ml, chimps: 375ml, gorillas: 500ml) on the basis of diffs in features like size of the teeth, the brain and body, the australopithecines have been divided into 7 and perhaps more species, with 2 genera (plus of genus, lol) sometimes proposed we know virtually nothing aboout their adaptation, diet, social organization, or genearl behavior by ~2 million years ago, members of our own genus, Homo, appear on the scene, probably evolving from one of the later australopithecines. they had bigger brains and smaller back teeth, but were still quite diff from living humans first stone tools appear in the fossil record ~2 million years ago, as well as indications from scratch marks on animal bones that meat eating was occuring, but we don't know if from hunting or scavenging

Hadar

definition: archaeological site in Ethiopia where Lucy was discovered by Donald Johanson in 1974. This has been the site of many additional findings by Mary and Louis Leakey significance: all findings at this site, and Lucy in particular, have provided insight into human evolution. Lucy's skeleton (A. afarensis) is 40% complete and shows proof of bipedalism

artificial selection

dogs! selection can change the freq of alleles in a population dogs have been artificially selected for certain characteristics for many years, and diff breeds have diff alleles all breeds of dog belong to the same species, so this is an example of microevolution as no new species has resulted

humans and chimps are generalists

function in many diff kinds of environments

chimps as social critters: picture of chimp hitting other chimp w a stick

holding a stick: aggressive display victim of aggression is basically screaming what precipitated this action?? National geographic photographer: Provision the chimps w bananas Initially: throw bananas out→ chimp free-for-alls Now: put bananas in a box with a catch that they can pull to open the box → only provision them if 1 comes near the box, only done once a week ⇒ these chimps showed up when the box was never going to open, eventually this chimp "LOST IT" ⇒ after the interaction: aggressive chimp goes to other and hugs and kisses her (ameliorating the problem, etc)

homo erectus vs homo habilis

homo erectus: top homo habilis: bottom diff in size of brain cases, though both have reduced faces from the australopith condition as well as smaller back chewing teeth the possibility that the top is a male and the bottom is a female of the same species is lessened by the fact that there is another skull that is very similar to the top, but is more robust -> suggests that it is the male of this species

Lake Turkana

in N Kenya lake formed by the rift by the flow of the Omo river from the north dotted lines around the lake = ancient shore lines when the lake was higher in these lake sediments are found a treasure trove of early hominid fossils ex: on the east side of the lake is Koobi Fora, where Richard Leakey and his colleagues have found many fossils red lines = presence of the fault lines of the rift

Olduvai Gorge

in Northern Tanzania famous for the discovery by Mary Leakey in the sediments you see stacked like a layer cake at the bottom of the gorge Definition: fossil excavation site where Louis and Mary Leakey discovered many of their findings that contributed to knowledge of human evolution Significance: found fossils of P. boisei, H. habilis, and H. erectus, Oldowan tools,

evolutionary time scales

macroevolution: long time scale events that create and destroy species; if 2 populations of a species become isolated from one another for tens of thousands of years, genetic diff may become marked; if the 2 populations can no longer interbreed, new species are born ex: Galapagos finches microevolution: short time scale events (generation-to-generation) that change the genotypes and phenotypes of populations ex: directional selection ex: selective selection; dog breeds

australopithecus afarensis

many fossils, and other evidence, from 2 sites in E Africa: Hadar (Ethiopia) and Laetoli (Tanzania) dated bw 3.7-2.9 myr at Laetoli (3.7 myr), in addition to fossil bones, Mary Leakey found 3 footprint trails => completely bipedal At Hadar (3.2-2.9myr), many fossils have been found including the most complete australopithecine known: ~40% of a skeleton called 'Lucy' in the size and proportions of the skull, it had a unique combination of biological traits pelvis similar to modern humans ape-like facial structure, large canines, small brain size (like modern chimp's) probably significant body size diffs bw males and females ***gracile

descent with modification

passing traits from parent to offspring, heredity

genetics & evolution: types of genetic selection

provides the info that Darwin didn't possess on the underlying basis for variation and the introduction of new biological features genetic data answers fundamental questions about how hereditary material is transmitted across generations Double helix structure of DNA was discovered in 1953-> Showed how genetic info is transferred from one cell to another almost without error Directional selection: Effect of natural selection when indivs at one end of normal dist curve have higher fitness than indivs in middle or at other end Diversifying/ disruptive selection: effect of natural selection when indivs at the extreme ends of the normal dist curve have higher fitness than those near the center of the curve Stabilizing selection: Effect of natural selection when indivs near the center of a normal curve of distribution have higher fitness than those at the extremes; Selection against both extremes keeps curve narrow and in same place

Fossil record

shows a sequence from simple bacteria to more complicated organisms through time and provides the most compelling evidence for evolution

original locomotory pattern of hominoids

suspensory hanging!!! maximum flexibility of the forelimb ((circumduction of the shoulder, etc) Palms facing forward→ move inward (radius rolls over fixed point of the olna) → olna makes no bone connection in the wrist at all! The meniscus → huge flexibility of motion in the wrist of all hominoids

archaeology & significance

the study of human history and prehistory through the excavation of sites and the analysis of artifacts and other physical remains Significance: has led to the discovery of the fossils of our ancient human ancestors

human evolution on the shoreline?

this would all be submerged, so we don't know!! australia separated from southeast asia -> our ancestors had to boat

australopithecine adaptation

unclear whether the various species occupied diff environments, or whether, like chimps, they were capable of utilizing a variety of seasonally related habitats, including forests, woodlands, and open grasslands uncertain just how widely distributed these creatures were. did they live throughout africa? outside of africa?

bonobos' sexual encounters

used as a way of communicating and reducing tensions bw each other gender does not matter!!! this is a social device!! to diffuse negative interactions

Human gatherer-hunters

-Living humans subsist on the products of agriculture and animal domestication. very few follow a way of life based on gathering of wild vegetation, insects and small animals, and the hunting of larger animals -However, prior to the invention of agriculture, some 12,000 years ago, all humans were gatherer-hunters -Examining the life ways of the few living gatherer-hunters provides insight into the adaptations of our earlier ancestors We set the framework for what is considered to be domestication We've been conditioned to the ways we think about food: rice, beans, corn, etc People from the past aren't stupid about the things that are growing there: they know exactly what to do to manipulate those products Sedentary diseases are eliminated

evidence that our human origins are in africa

-Our closest living relatives, the african apes, the chimpanzee and gorilla, are both native to africa **BUT remember that there is only the most meager fossil evidence (one tooth) documenting the evolutionary history of either of these 2 primates -All of the earliest fossil evidence of our own evolutionary history is limited to africa, and it is only relatively late in human evolution that our ancestors are found in Eurasia -There are fossil deposits of this early time in europe and asia, and they show no trace of our early ancestors Dubois: mongolia→ found dinosaurs Moved his efforts to indonesia Early focus on asia as our origin ⇒ we have found early fossils in human lineage ONLY in africa (NOWHERE ELSE)

basic evolutionary statements

1) All life is related, via evolution, to the 1st life forms on earth. It is reasonable to believe that the earth and its physico-chemical makeup are responsible for all the origins and subsequent evolution of all earthly life 2) Evolution represents change; though there are many ways of characterizing this process, here it will be viewed as descent with modification 3) Although there's an abundance of evidence supporting the reality of evolution, there's still much debate about precise mechanisms responsible for evolutionary change, and relative importance of these mechanisms in explaining the diversity and patterning of earthly life

Hunter-gatherer pitfalls

1) An ahistorical approach to anthropology (the changeless past) Looking for passage from atlantic to pacific → icebound for 3 years, don't decide to leave the boat until the 3rd year Passed groups of native american people as they're walking south, and they don't recognize them as being human ⇒ HOW IS THIS POSSIBLE? This pattern is repeated in many contexts, including well into the 20th century 2) Hunter-gatherers remained remote until anthropologists penetrated their lives 3) The "noble savage" approach romanticizing hunter/gatherer peoples' lives, popularized by the French philosopher Jean-Jacques Rousseau hunter/gatherers live in a state of grace from which the rest of humanity had fallen

diff bw homo erectus and H. ergaster, and is it valid?

1) H erectus was established in 1894 for fossils from Java. Later discoveries in Java and China have been placed w/in this category 2) fossil disoveries at Late Turkana -> initially suggested close affinity w Asian fossils. later, asserted that there was too much temporal and geographic distance bw the 2 samples to place them all in a single species. so, African fossils (e.g Nariokotome boy) moved to Homo ergaster 3) no morphological studies demonstrated specific diff bw the 2 samples 4) very recently discovered fossil skull from Bouri (Ethiopia) now demonstrates that there should be NO species distinction in this photo: H erectus from s china (left) and skull from Bouri Ethiopia (right)

Jean-Baptiste Lamarck (1744-1829)

A french natural historian who was an early proponent of the idea that evolution occurred and proceeded in accordance w natural laws Major idea: inheritance of acquired characters Cow examples: Diff varieties of cows are bred for diff characteristics → Economic feature of the guernsey cow is that it has a slightly higher fat content to milk than do other cow varieties Had a greenhouse, growing things based on characteristics Accumulates info related to adaptation via natural selection Lamarck's Giraffe -> This theory was later disproven (evolution by inheritance of acquired characteristics) Significance: he was responsible for developing some of the earliest ideas of evolution in organisms but his theories were ultimately disproved by Darwin's theories which hold today

Thomas Henry Huxley

British anatomist; professor of anatomy and staunch defender of Darwin's ideas 1863, published his famous defense of evolution: Evidence as to Man's Place in Nature documented the evidence for placing humans in an evolutionary world using the comparative gross anatomy of humans and the African apes (chimps and gorillas) plus the very few human fossils known at the time briefly described the anatomy of the fossil from the Neander Valley discovered in 1856 Definition: defended Darwin's theory of evolution and his book "The Origin of Species" even after it received criticism for going against the current belief in creationism Significance: he not only defended Darwin and his ideas, but also published his own defense of evolution in "Evidence as to Man's Place in Nature" (1863). He used comparative anatomy of humans and African apes as his evidence.

gene flow vs isolation

Debate concerning the level of isolation of small hominid populations after their spread out of africa were these populations... 1) able to exchange genes w neighboring groups 2) isolated -> underwent a series of speciation events this must be seen w/in the current fashion of constructing the human fossil record as one w many extinct species, a tree that is very "bushy" in contrast to a human evolutionary model w few extinct species Humans not as bounded as many other species that have a broad geographic distribution Ex: in australia, pops that have been found (in the skeletal sense) are hugely varied → trouble putting them in easy categories w each other Recently did genetic studies on these things → there were at least (maybe more) 20 migrations of separate human groups *These are just the ones that we have genetic evidence of Homo sapiens really doesn't have a definition!!!

species

Definition: A group of similar organisms that can breed and produce fertile offspring. Significance: anthropology and research of fossils in our ancestry have led to the discovery of multiple species within our lineage. As more fossils are found, species are either lumped together or split according to how significant their differences are

gene

Definition: A segment of DNA on a chromosome that codes for a specific trait Significance: discovered in 1866 by Gregor Mendel who proved the law of inheritance which showed how traits are passed down from one generation to the next, and thus helps to explain how evolution or natural selection could occur

uniformitarianism

Definition: Charles Lyell's idea that geologic processes have not changed throughout Earth's history (the processes that are sculpting the Earth now are the same processes that shaped the Earth throughout time) Significance: helps uphold the idea of gradualism because this is what we observe today, so it is what is most likely to have happened in the past as well. Charles Darwin and Alfred Russel Wallace used this theory to support their findings. discredited the theory of catastrophism

Watson and Crick

Definition: Developed the double helix model of DNA, discovered double helix in 1953 Significance: By determining the structure of DNA, they were able to determine that genes consist of base pairs which are replicated when a cell divides. This knowledge helped better understand mutations which ultimately lead to evolution.

louis leakey

Definition: English paleontologist whose account of fossil discoveries in Tanzania changed theories of human evolution (1903-1972) Significance: established excavation site and Olduvai gorge, discovered fossils of H. habillis, H. erectus, made huge contributions to knowledge of human evolution along with his wife Mary

Raymond Dart

Definition: South Africa, Found the skull of an infant male, Taung child Significance: the Taung child had a foramen magnum more forward in the skull than apes do which represents that the skull was likely held upright and the creature likely walked upright on two legs. Early sign of bipedalism

typology

Definition: a classification according to general type or group Significance: Linnaean taxonomy represents a type of biological typology which groups certain animal families and species together based on their characteristics and lineages. Helps explain the relationship between species

Homo sapiens

Definition: a hominid species who have larger brains, use language and advanced tools, modern humans Significance: modern humans

Mutation

Definition: a random error in gene replication that leads to a change Significance: mutation changes allele frequencies in an organism and then in a species. This is a key aspect of evolution, so without mutation evolution would likely not occur to the same degree

Neo-Darwinism/Modern Synthesis

Definition: an evolutionary theory proposing that mutations produce variations and that natural selection determines which variations will survive in order to produce biological evolution, combines Darwin's theory of natural selection with the knowledge of modern population genetics Significance: was the reigning theory of evolution in the 1930s but has since been replaced by EES which adds on an additional layer of the interplay of organisms and their environment/culture/extra genetic inheritance

phenotype

Definition: an organism's physical appearance, or visible traits. Result of interplay of genotype and environment Significance: in human, culture and the resultant complex behavior are a unique basis for the environment to influence and shape phenotype. Genotype determines phenotype

Paranthropus boisei

Definition: ancestor who lived in East Africa about 2.3-1.2 million years ago, had adaptations for heavy chewing, large chewing muscles and cheek teeth that are about 4x the size of those of modern humans, had even larger teeth than P. robustus, Mary Leaky found a skull at Olduvai Gorge that proved this was a new species.**Robust australopithecine

canine reduction definition

Definition: canines have greatly been reduced over time through the evolutionary process, along with jaw reduction. Chimps and gorillas have obvious sharp canines, males especially, showing sexual dimorphism. there is a decrease in this sexual dimorphism in the Homo genus

Charles Lyell & significance

Definition: effectively discredited the long-standing view that the earth's surface had been formed by short-lived cataclysms, such as biblical floods and earthquakes his principle = uniformitarianism: same geological processes that are at work today slowly formed the earth's surface over an immensely long time Significance: re-defined/re-explained how Earth's geology changed over time. The new theory of uniformitarianism was also used as support for Darwin and Wallace and their theory of gradualism. Darwin was inspired by uniformitarianism, saw evolution as a biological uniformitarianism

Environment (in the sense relevant to genetics)

Definition: environment combines with an organism's genotype to produce the phenotype. significance: according to the EES, the environment and organisms evolve together. So the environment has an effect on an organism's genetics which affect the phenotype so make the organism more suited to the environment, and the organisms also change the environment.

Gregor Mendel & Genetics

Definition: father of modern genetics, discovered genes in 1866, determined the laws of inheritance Significance: through his studies of pea plants he determined the laws of inheritance and discovered that one set of genes comes from each parent. (Heredity), his findings filled in the gaps in knowledge that Darwin left behind. this provided genetic evidence for natural selection, as Darwin thought this theory was correct but did not understand why 1856-63: a monk called Gregor Mendel cultivated 29,000 pea plants to investigate how evolution worked (ie how characteristics were passed down the generations) figured out the basic principles of genetics: offspring received characteristics from both parents, but only the dominant characteristic trait was expressed his work only came to light in 1900, long after his death

James Hutton

Definition: father of modern geology along with Charles Lyell, created the first theory of uniformitarianism Significance: the theory of uniformitarianism was essential for developing modern theories of human evolution, supported Darwin's theory of gradualism. Darwin was inspired by uniformitarianism, saw evolution as a biological uniformitarianism

Genotype

Definition: genetic makeup of an organism Significance: the environment molds the genotype into the final form of the phenotype

Genetics and evolution: evolution in early 1900s

First 30 years of 20th century were marked by the accumulation of enormous amounts of info abt genetic processes it was recognized by a number of geneticists that this info provided the missing answers needed to support Darwinian evolution 1942: Julian Huxley (grandson of Thomas Henry Huxley) published Evolution, The Modern Synthesis ⇒ genetic research utilized w Darwinian natural selection to produce the Synthetic Theory of Evolution, or Neo-Darwinism

chimps vs humans vs australopithecus chart

Height: Gigantopithecus Biggest people recorded on earth today: in the Netherlands Smallest people: atori forest (adult height of 4 ft) Growth hormone factor #1 Locomotion: Humans = bipeds -Walk with a "stride" or "striding gate" -Pick one foot up and put the other down, we don't hop/shuffle/etc -Trunk balance: major musculature in our trunk, in the very top part of our legs ⇒ there for balance (Bipedal birds bop when they walk, move their body weight over their hind limbs) -Biggest locomotory part in humans: our butts! -Erect posture : have to use calf muscles, We fatigue doing nothing -The swing phase, the stance phase -Double support: 60% of the time, feet are on the floor -Double float: for runners, when no leg is on the ground; Pushing and pulling weight forward -We are not fast, but we have endurance Chimps = knuckle-walking -Can make that motion going up in trees -Sometimes referred to as "vertical climbers" ⇒ going up trunks of trees -Sleep in trees, go up in trees to find food We share with chimps, gorillas, and orangutans: Virtually entire structure of our upper torso

EES: Extended Evolutionary Synthesis

"Organisms are constructed in development, not simply 'programmed' to be developed by genes. Living organisms do not evolve to fit into pre-existing environments, but co-construct and coevolve w their environments, in the process changing the structure of ecosystems" "In our view, this 'gene-centric' focus fails to capture the full gamut of processes that direct evolution" definition: the idea that organisms are constructed in development, not simply programmed to develop by genes. Organisms do not evolve to fit into pre-existing environments but co-construct and coevolve with their environments in the process of changing the structure of ecosystems Significance: represents a different way of thinking of evolution, takes into consideration how environment shapes organisms' traits and how organisms modify environments. Human culture becomes a central focus, along with the idea that parents often reconstruct their environment for their offspring EES might better explain MACRO-evolutionary processes, as it integrates developmental bias, plasticity, niche construction, and extra-genetic inheritance integration of: 1) developmental bias (how physical development influences the generation of variation) 2) plasticity (how environment directly shapes organism) 3) niche construction (how organisms modify environments) 4) extra-genetic inheritance (how organisms transmit more than genes across generations) Human culture becomes a central focus rather than a special case (inheritance outside of genes) Parent-offspring similarities result in part from parents reconstructing their own developmental environments for offspring

attributes unique to living humans amongst the primates

1) bipedalism 2) hidden ovulation 3) pair bonding 4) rituals surrounding the consumption of food: Food is more than food for humans; Omnivores - eating broadly over broad range of foods 5) complex tool making 6) language and cognition 7) in relation to body size, a large, complex brain 8) layered social organization: Distinctions in social groups (ex. Prof on one side of desk and student on the other) takes away the structure of the layered organization that we have come to know--some people dont like it; Different forms of you (tu vs. ud.) 9) assisted birth 10) prolonged middle childhood: from an evolutionary perspective why do children stop growing? Increase in fat content of the brain through myelination--brain weight increases and kids become more social--physical parts of growth arent there but maturation in a social and cultural context sky rocket during this time 11) complex culture with a wide variety of societal norms of behavior ==> the question is when did these features evolve and how many of them relate to human modernity??

Charles Darwin: Natural Selection

1809-1882 British natural historian co-developer, w Alfred Russell Wallace, of a theory of evolution based on the concept of natural selection Voyage of the Beagle (1831-1836): Participated in a 5 year voyage of exploration during which he made observations of the natural world which led to his theory of evolution usually viewed as differential reproduction -a relative process -neither absolutely positive or negative, but works relatively w/in environmental circumstances. what may be adaptive in one environment at one time may be maladaptive at other times and places Definition: A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits, theory developed by Charles Darwin and Alfred Russel Wallace Significance: is still the reigning theory of evolution which can now be supported with genetic evidence and knowledge about the laws of inheritance. Those who are best adapted to their environments are most likely to reproduce and survive as a species

NE Africa: Neanderthal reconstructions

A reconstruction of some very dumb neanderthals indeed. They look glum and they probably are, waiting around for extinction. Please note that neanderthals never smile But if you dressed them up, you could take them anywhere! Hah hah

North Africa Fossils

Amud Cave, northern Israel Lived in caves -> whole indivs instead of fragments caves are always 55 degrees → easy temperatures, men can easily live in there The skeleton of the neandertal from a site in the southwest of France (la Chapelle-aux-Saints) Deliberate burial: allowed the bones to be safely interred and away from destructive agents in the environment. note that this male had lost virtually all of his teeth prior to death

chimps as humans in fur suits

Bc of their biological and behavioral similarities to humans, chimps are often used as models of what our earliest ancestors were like Major problem w this is that living chimps are the result of an evolutionary history as long as ours, and they may have changed as profoundly as we have There is not a single fossil bone documenting the evolutionary history of either chimps or gorillas

Chimpanzees

Considered by most anthropologists to be our closest living relative Most often used as models for the evolution of human behavior and adaptation Organized into social groups of non-paired males and females Basically herbivores, consume a wide variety of vegetable materials with a concentration on fruits Have been observed eating insects, sometimes using tools to get at them, hunt and eat at least 15 diff kinds of vertebrates, including monkeys Social behaviors: Recognize each other by diffs in the construction of their faces Recognize and greet indiv animals Gravitate to particular animals Have distinctive faces Have a highly structured pattern of muscles of facial expression: skeletal muscles that don't insert into bone, they insert into skin→ move the skin around on your face, depending on your emotion (also a human characteristic) Humans have the senile crease: appears around the age of 25 (from muslces of facial expression) Nonverbal and verbal communication are equally important Long growth and development period Long of time in infancy, childhood, late childhood, adolescence, adulthood Look at time frame for sexual maturation, ex: first birth in females In chimps: 16 y/o Don't have a good sense of this in humans, depends on the time (grandparents is diff than parents will be diff than us)

Where is evidence found for natural selection?

Darwin argued that living things have been evolving on earth for millions of years. evidence for this process could be found in: 1) fossil record: extinct vs living forms; fossils in diff layers of rock (sedimentary rocks strata) showed evidence of gradual change over time 2) geographical distribution of living species: diff animals on diff continents, but similar adaptations to shared environments => descent with modification 3) homologous structures of living organisms: scientists noticed animals w backbones (vertebrates) had similar bone structure; may differ in form/function; limb bones develop in similar patterns (arms, wings, legs, flippers) diff mature forms, but develop from the same embryonic tissues => strong evidence that all 4-limbed animals w backbones descended w modification, from a common ancestor 4) similarities in early development: similarities in embryonic development

Homo rudolfensis

Dated to about 1.8-1.9 myr Term comes from the original name (Lake Rudolf) for Lake Turkana in N kenya Fossils possess v large brain volumes (750-800ml), but also very large, australopithecine-size molar teeth Are the H. rudolfensis fossils the males, and the H. habilis fossils the females of a single, sexually dimorphic species?

gatherer-hunters

Definition: going after wild, non-domesticated plants and animals for food Significance: all humans were gatherer-hunters before the invention of agriculture and domestication. Evidence has found that our ancestors used poison tipped arrows for hunting that are sometimes more effective than modern technology. Our ancestors lived an active lifestyle that required walking an average of 10 miles a day, they were mobile, depended on resources and access to water, had few possessions, only the essentials for survival. Many ate roots and tubers (water storage devices) Diet: very associated w the processes of food production VERY diff than what we deal with today Animals, other vegetation products in environment Very good understanding of environments Flexible, detailed mapping of food sphere in their environment -> Is there such a thing as a good human / an evolutionary diet? Australopithecus → woodland environments Looking at tall vegetation, separated by more open spaces (grasslands) → choose among resources in their environment to fulfill nutritive needs Tree nuts, tree fruit Major component of diet in our lineages comes from fruit, nuts Social organization of these folks from the past Multiple females w offspring, multiple males Modeled off of living chimps (the common chimp) Social organization, access to food, etc Human-like? Ape-like?

The Great Chain of Being

Definition: hierarchical structure of all matter and life, thought to have originated from God. God is at the top of the hierarchy and all other life is ranked below him. Significance: represents an old way of thinking about creation and species in the world. Linnaeus and his taxonomic system which classified and ranked all living beings replaced this model and still holds today.

Lumping/Splitting

Definition: lumping is when two things are placed into the same category unless there is convincing evidence to divide them and splitting is when two things are placed in different categories unless there is convincing evidence to unite them. Ex: lumping Homo erectus and Homo ergaster

Sahelanthropus tchadensis

Definition: one of the oldest known ancestors in the human family tree, lived in West-Central Africa between 7 and 6 million years ago, had a combination of ape-like and human-like features. Had small brain, sloped face, prominent browridges, elongated skull but also small canine teeth and a spinal cord opening underneath the skull representing bipedality Significance: early ancestor in the human lineage, some early proof of the beginnings of bipedality

Linnaean Taxonomy

Definition: relating to the system of taxonomic classification and binomial nomenclature originated by Carl Linnaeus. In the Linnaean system, organisms are grouped according to shared characteristics into a hierarchical series of fixed categories ranging from subspecies at the bottom to kingdom at the top. Significance: This created a standard naming system for all animal species and created a clear organization and hierarchy of species. This system continues to operate today and helps to classify modern and extinct speciesl

Paranthropus robustus

Definition: robust australopithecine who lived in Southern Africa about 1.8-1.2 million years ago, had large back teeth and large cheek bones that allowed for large chewing muscles from the jaw, could eat tough, fibrous foods

challenges to current views of evolution: punctuated equilibrium

Definition: the evolutionary model proposed by Stephan Jay Gould and Niles Eldridge that states that species change little for millions of years and this is punctuated by a short burst of change that then creates a new species. Significance: represents a challenge to the current view of evolution, (Darwin's gradualism) and challenges the idea of natural selection. Instead they believed that natural selection occurs once a species is already existing and increases the survivability within a species Biologists such as S. J. Gould argue that the process of evolution is NOT slow and gradual, as Darwin had indicated, but operates by rapid bursts of evolutionary change punctuated by longer periods of stasis, when little or no change occurred Based on his examination of the fossil record of shell fish in geological deposits, Charles Lyell said the same thing to Charles Darwin in the 1840s when Darwin was working on his theory. Darwin considered Lyell's views but ultimately rejected the notion of rapid evolution change Punctuated equilibrium Natural selection → moves toward perfection? Species in the process of speciation? Selection on the next level Mechanism producing these incipient species?

radiometric dating

Definition: the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products Significance: very crucial for anthropological knowledge, helps put findings and remains into perspective, able to create a better timeline for human evolution

Paleontology

Definition: the scientific study of fossils Significance: contributes much knowledge to anthropology and human evolution. Without fossils we would have no way to know about our early ancestors and would have nearly no concept of any past/extinct species

stratigraphy

Definition: the study of rock layers and the sequence of events they reflect Significance: can help put fossils into a timeline of human evolution when certain fossils are found in different rock layers. form of relative dating (not absolute) **biostratigraphy is a branch of stratigraphy that uses the fossils found inside rock layers to determine the relative ages of rock layers

catastrophism definition and significance

Definition: the theory that changes in the earth's crust during geological history have resulted chiefly from sudden violent and unusual events. Significance: this theory was replaced by Lyell's theory of uniformitarianism and Darwin's and Wallace's theory of gradualism, representing new development and research into human evolution

natural theology

Definition: theology or knowledge of God based on observed facts and experiences apart from divine revelation. argues for the existence of God. believed until Darwin's controversial findings that supported evolution through natural selection. Significance: represented the old way of thinking about the world and about the species living in the world, and made Darwin's findings even more revolutionary because they were so controversial. It was an entirely new way of thinking

Fossilization

Definition: when living material is replaced with mineral substances in the remains of an organism significance: allows remains to be preserved, which allows archaeologists and anthropologists to collect bones and artifacts to draw conclusions about our lineage and human evolution

Zhoukoudian H. erectus site

Located in N China The most northerly of the early Homo sites (aka COLD during the winter), though it is unclear whether the hominids actually occupied the cave during the winter. If so, it would be the first indirect evidence for the use of clothing Along w fossil bones of about 45 indivs, there are animal bones w cut marks and burnt bones indicating the use of fire Evidence suggests a long term but intermittent occupation of the site bw 600-400,000 yr No evidence for burials site of Dragon bone hill hackberry seeds animal bones

homo erectus adaptations

Most evidence comes from the Zhoukoudian site: 1) Bones w cut marks → suggest hunting/ scavenging 2) Evidence of use of fire, perhaps clothing 3) No evidence for burial Stone tools are known from many sites all over africa and asia. They represent the acheulian industry of the lower paleolithic

Darwin summary & significance

Natural selection On the Origin of Species, 1859 -> presented Wallace's essay and some of his work at a scientific conference of the Linnaean Society in July of 1858, then he started to write his book (took 18 months to complete) The Descent of Man, 1871 significance: contributed significant and revolutionary knowledge about evolution and his ideas still stand today. He determined much about variation in a species and evolution by natural selection. He also placed humans in the evolutionary world along with Huxley

Harbored Kalahari

Studied group of people in the kalahari desert Health and disease; diet Richard lee: Marxist anthropologist family, social structure Egalitarian social structure? Due to his bias Eating Christmas in the Kalahari: story of being culturally inept purchases a cow from neighboring group→ throws feast Realizes during the feast that these folks are treating him like a member of the social group, but he internalizes it as being insulting of his party; insulting is actually common among these folks in order to level wealth differences "Insulting the meat": "Couldn't you afford to get us a better cow?" ⇒ went on for a number of years Produced large literature on this as the population increases, must move to a more agricultural mode bc limits in resources present in their current diet thin but very strong: bodies adjusted to lifestyle Movie: The Gods Must be Crazy: Culturally insensitive, Inappropriate iteration of their lives Humans have mutualism: relationships, structural component (ex: marriage); unity has a parsing out of duties/tasks (males have a tendency to engage in riskier food-getting behaviors than are associated with hunting; riskier means dangerous or also possibility of not ending up w food; females are in charge of gathering) Dietary composition? Paleolithic diet, huge diversity of foods (at least 200 diff kinds of foods coming from plant sources), seasonally: roots and tubers, at least 50 diff kinds of vertebrates ⇒ in general there is no bad food, there's only overconsumption of some bad food, so they can never eat bad food bc they have so much variety! Limiting factor: water Hunting: they make poisons out of beetles that is lethal → intricate knowledge of the environment

biogeography

Study of past and present distribution of organisms geographic spread of organisms tells of their past evolution marsupials occur in 2 populations today in the Americas and Australia => shows the group evolved before the continents drifted apart

James Hutton and Charles Lyell

considered to be the founders of modern geology developed the concept of uniformitarianism: changes in the topography of the earth's surface are the result of the slow and gradual, but constant operation of natural processes such as wind, rain, temperature change, volcanism, and other normal earthly processes Earthquakes wiping out coastlines in minutes These are still operating→ the planet is still in flux **Geologists are key in supporting Darwin's point of view fossil shell deposits on a mountain side: how did they get there? => letter from Darwin to Lyell discussing the geology of the Andes erosion-> new soils being made

what does it mean when a chimp has a curled up body and is grinning

curled up body = submissive posture grin = sign of being intimidated, nervous -> origin of the smile/laugh = nervous energy?

bipedalism: origin and functions

definition: movement on two legs in an upright position. Allowed in some hominids due to a broad pelvis and femurs angled towards the knees which help stabilize the body's center of gravity and aid in balance significance: features that represent bipedalism have been key to understanding human evolution. In a larger sense, bipedalism allowed humans to use their arms and hands for things like tool making instead locomotion. (chimps represent a similar idea, as they usually walk bipedally when carrying food) sugarcane: You have to really work to get the sugar out of the cane Go into bipedal posture a lot of the time ⇒ human bipedalism ? To CARRY THINGS Static posture → chimps are trunk-upright at least 90% of their waking hours, not too dissimilar from humans Positional behaviors: getting fruit from bushes, etc ***Darwin was the first person who proposed origin of bipedalism for carrying Thought they were carrying weapons But first stone tools were 3.3 million years before present So what ARE they carrying? -Helpless offspring -Food sources -Perishable objects in their environment function of bipedalism efficient way of navigating an environment Efficiency, speed, mobility, etc → our walks are like controlled falls Release calf muscles Peak efficiency : slow to medium jog We store glycogen in our muscles in a diff way than other animals

Hominid

definition: the group consisting of all modern and extinct Great Apes (that is, modern humans, chimpanzees, gorillas and orang-utans plus all their immediate ancestors) contrast with hominin: the group consisting of modern humans, extinct human species and all our immediate ancestors (including members of the genera Homo, Australopithecus, Paranthropus and Ardipithecus) significance: studying hominid ancestors has increased understanding of human evolution

The boy from Nariokatome

discovered in 1984 WT-15000 skeleton of an approx 11-12 y/o boy most complete skeleton of an early hominid found eroding out from under the roots of a tree, up until the origins of deliberate burials, around 100,000 years ago this is the most complete skeleton of our ancestors ever found skeleton doesn't reveal how this child died, but it possesses some very interesting biological features, including a v tall stature, a brain of 800+ ml, relatively small teeth, but robusticity that is greater than that of the presumed female

Homo erectus

earliest dated at E Turkana at 1.8-1.9myr, and contemporary w the other early Homo species name was originally given to later-in-time fossils found in the last century in Java possessed v large brains (800ml), like H. rudolfensis, but also reduced in size back chewing teeth, like H. habilis **the most reasonable of the early Homo species to be considered ancestor to later in time hominids (modern humans) not all anthropologists agree that this is the right, or only, name for the hominids of this time. some believe that homo erectus is a term to be used only for the fossils from Asia, and that the earliest species in Africa should be called Homo ergaster

evolutionary relationships of early homo

early homo evolved from one another australopithecine species there may be as many as 3 species of early homo living at the same time in east africa, w H. erectus the most probable ancestor of later hominids after 2.0myr, stone tools are common, often w animal bones w scratch marks -> suggests butchery or scavenging of dead animals unclear which early homo species made the tools (or if a robust australopithecine was responsible)

early homo: expansion out of africa

early members Homo are found in Africa bw 2-1.8 million years ago evidence of early humans on the island of Java (indonesia) and in the republic of Georgia, sometime after 1.8myrs ago -> at about this time, there is a spread out of africa and into Eurasia. no one knows why from this point on, the Old World is more or less populated by human ancestors after our ancestors spread out of Africa, there begins a time of human evolution which will culminate w the appearance of modern humans in varous parts of the world. how they evolved and the precise evolutionary pathways are in dispute

Ardipithecus ramidus, & why was the discovery of these fossils startling?

found in 2009 Fossils discovered in Rift Valley Sediments along the Awash river in Ethiopia Ardipithecus: Called into question ways by which bipedalism evolved and our relationships to chimps and gorillas 2 diff species: A kadabba and A. ramidus Dated to ~4.4 myr (A. ramidus) and to more than 5.6 million years ago (A. kadabba) A. ramidus appears to be a central species in our understanding of the early evolution of our lineage The anatomy of A. ramidus is a curious mix: 1) Anatomy of a biped but with an opposable big toe → used trees as part of its adaptation 2) Has none of the specialized anatomical traits in the wrists and hands of the knuckle walking african apes 3) Small non-projecting canines, typical of the members of the hominin lineage. size of back teeth significantly smaller than the huge chewing teeth of the later australopithecines 4) their brain size is within the range of chimps ~4 ft tall, 110 pounds little sexual dimorphism bw males and females all of these features represent that this species is within the human lineage, but represent that they also lived in trees

the origins of tool making

from observations of chimps in their natural habitat-> capable of making simple tools, like termiting sticks earliest members of the human line were at least as capable as living chimps of making simple, non-durable tools we will never find these objects in the fossil record first stone tools appear in fossil record in e africa ~2.5 myr: river pebbles w flakes chipped off to produce a cutting edge first tools = beginning of the Paleolithic debate about precise level of neurological abilities necessary to produce stone tools made to a pattern

chimps and gorillas vs human genes

genetic codes are almost identical!! if evolution is true then we might also expect that closely related organisms will be more similar to one another than more distantly related organisms comparison of the human genetic code w that of other organisms show that chimps are nearly genetically identical (differ by less than 1.2%) whereas the mouse differs by ~15%

Afar depression

geological depression near the Horn of Africa, also a part of the Great Rift Valley and is well known as one of the cradles of hominids

Robust vs. Gracile Australopithecines

similar brain case size (400-500ml) and projection of the face major diffs: size of temporal and masseter muscles and their attachment areas forward projection of the cheek region in the robust guys-> functional, bc of their huge back teeth

how to determine locotion style based on fossils

similarity of skull propotions and large, projecting faces bw lucy and chimps... BUT the diffs in pelvis related to bipedality in the australopithecine

australopithecus or paranthropus

some anthropologists believe there are too many diffs bw the robst and gracile australopithecines for them to be placed in a single genus, Australopithecus the robusts, with their huge chewing teeth and muscles, as very specialized creatures, who deserve a genus of their own, Paranthropus

traditional view of human-ape relationships & origins of bipedality vs the question raised by Ardipithecus

top: evolutionary diagram of human and african ape relationships, based on various genetic studies bottom: evolutionary diagram of human and african ape relationships, based on evidence from Ardipithecus question raised by Ardipithecus: are these knuckle-walking apes the result of common descent or parallel evolution??

gracile australopithecines

there are a number of australopithecine species that are together known as the lightly built or gracile australopithecines 3.2-2.9myr differ from 3 other australopithecines: 1) smaller back chewing teeth 2) smaller jaws and chewing muscles bc of the large size of these structures, these other 3 species are known as the robust australopithecines

species of early homo & where are they known from

these species have been proposed based on diffs in size of the brain case, as well as diffs in posterior tooth size 1) homo habilis: known from sites at Olduvai Gorge (Tanzania) and east of Lake Turkana (Kenya) 2) Homo rudolfensis: Lake Turkana 3) Homo erectus: Olduvai Gorge, Lake Turkana, S Africa

where and how do chimps sleep at night

they climb trees to make nests sleep patterns: 4 hour sleep cycles that grade into each other; apes retreat to tree nest at dusk and get up at dawn