Our Fossil AncestorsOur Fossil Ancestors

How We Got to Be WeHow We Got to Be We

How We Became the Way We AreHow We Became the Way We Are

We’ve looked at our own anatomy and those of our We’ve looked at our own anatomy and those of our closest relatives, the chimpsclosest relatives, the chimps

With the evidence of our ancestors in scattered With the evidence of our ancestors in scattered pieces, we need to reassemble the existing partspieces, we need to reassemble the existing parts

We also need to infer the missing parts based on our We also need to infer the missing parts based on our knowledge of human anatomyknowledge of human anatomy

We start with the principles of natural selection and We start with the principles of natural selection and genetics, the two primary sources of human evolutiongenetics, the two primary sources of human evolution

Overview of Human EvolutionOverview of Human Evolution

Principles of evolution: Natural selection and Principles of evolution: Natural selection and geneticsgenetics

TaxonomyTaxonomy The behavior of our primate cousinsThe behavior of our primate cousins Our ancestry from Our ancestry from Australopithecus Australopithecus to to HomoHomo Tools as evidence of culture evolutionTools as evidence of culture evolution Capacity for Language—and thereby capacity Capacity for Language—and thereby capacity

for culturefor culture

Principles of Evolution: Natural Principles of Evolution: Natural SelectionSelection

Darwin’s Contribution: Darwin’s Contribution: On the Origins of SpeciesOn the Origins of Species Natural Selection: A twofold processNatural Selection: A twofold process First, there is a wide variety of species that come into First, there is a wide variety of species that come into

being. being. Second, environmental factors select those species Second, environmental factors select those species

that are better adapted to the conditions than othersthat are better adapted to the conditions than others Example: “Industrial melanism” among moths in Example: “Industrial melanism” among moths in

EnglandEngland

““Industrial Melanism”: An Example Industrial Melanism”: An Example of Natural Selectionof Natural Selection

Coal-burning steel plants spread soot all Coal-burning steel plants spread soot all over the city, such as Manchester, Englandover the city, such as Manchester, England

Birds picked off the light colored moths Birds picked off the light colored moths and left the dark colored onesand left the dark colored ones

Result: dark colored moths enjoyed a Result: dark colored moths enjoyed a selective advantage—can you see why in selective advantage—can you see why in this photo?this photo?

In rural areas, the light colored moth had In rural areas, the light colored moth had the selective advantage—no soot. the selective advantage—no soot.

This process is known as “industrial This process is known as “industrial melanism”—melanism means “being melanism”—melanism means “being dark”dark”

Principles of Evolution: Genetics IPrinciples of Evolution: Genetics I

If natural selection involves the If natural selection involves the varieties of species to be selected varieties of species to be selected from, then where do the varieties from, then where do the varieties originate in the first place?originate in the first place?

The The realreal origin of speciesorigin of species rests in rests in the genes of all life forms—plants, the genes of all life forms—plants, animals, fungianimals, fungi

Gregor Mendel, an Augustine monk, Gregor Mendel, an Augustine monk, experimented with peas to discover experimented with peas to discover the effects of combining different the effects of combining different strainsstrains

These efforts started the science of These efforts started the science of geneticsgenetics

Principles of Evolution: Genetics IIPrinciples of Evolution: Genetics II The The nucleusnucleus (center) of a (center) of a cell cell contains contains

all genetic material: genes, all genetic material: genes, chromosomes, and DNAchromosomes, and DNA

GenesGenes: Hereditary information : Hereditary information determining physical characteristicsdetermining physical characteristics

ChromosomesChromosomes: the chains containing : the chains containing chromosomeschromosomes

DNADNA (deoxyribonucleic acid): the (deoxyribonucleic acid): the molecules that make up most of the molecules that make up most of the chomosomeschomosomes

DNA contains 2 chains linked by the DNA contains 2 chains linked by the bases adenine (A), thymine (T), bases adenine (A), thymine (T), cytosine (C), and guanine (G)cytosine (C), and guanine (G)

A always matches with T, and C always A always matches with T, and C always matches with Gmatches with G

Principles of Evolution: Genetics IIIPrinciples of Evolution: Genetics III

Genotype:Genotype: the genetic makeup of a particular the genetic makeup of a particular characteristic (peas, eye color)characteristic (peas, eye color)

Phenotype:Phenotype: the physical characteristics the physical characteristics created by the genetic makeupcreated by the genetic makeup

GenesGenes are always paired: male contributes are always paired: male contributes half, female contributes halfhalf, female contributes half

AllelesAlleles: Variations of a genetic characteristic: Variations of a genetic characteristic These are chains of DNAThese are chains of DNA

Principles of Evolution: Genetics IVPrinciples of Evolution: Genetics IV

When different alleles combine:When different alleles combine: Allele of one manifests as a phenotype Allele of one manifests as a phenotype

(Dominant; all peas are smooth in the (Dominant; all peas are smooth in the upper diagram)upper diagram)

The other does not (Recessive, wrinkled The other does not (Recessive, wrinkled peas)peas)

Only in the second generation do wrinkled Only in the second generation do wrinkled peas appear as phenotypes because two peas appear as phenotypes because two genes for wrinkled peas are combinedgenes for wrinkled peas are combined

Or both alleles may manifest as hybrid Or both alleles may manifest as hybrid (Codominant, color of flowers in lower (Codominant, color of flowers in lower left—red and white are combined to left—red and white are combined to produce pink)produce pink)

Principles of Evolution: Genetics VPrinciples of Evolution: Genetics V

The origin of species: The origin of species: mutation mutation or change in genetic or change in genetic makeupmakeup

DNA molecules may switch positions on the chain or DNA molecules may switch positions on the chain or cross over into the opposite chain to produce a new cross over into the opposite chain to produce a new characteristic or characteristic or traittrait..

Whether the new trait survives depends on how well Whether the new trait survives depends on how well it adapts to the environment—the it adapts to the environment—the natural selectionnatural selection processprocess

This is the natural history of our earliest hominin This is the natural history of our earliest hominin formsforms

Human and Prehuman Populations: Human and Prehuman Populations: Evolutionary ProcessesEvolutionary Processes

Early hominins are products of both mutation and Early hominins are products of both mutation and natural selection.natural selection.

To the biological we can add a third factor: culture.To the biological we can add a third factor: culture. Changes and natural selection can be modified to Changes and natural selection can be modified to

explain the selective advantages that culture hasexplain the selective advantages that culture has Culture involved adaptation to habitats: a cold habitat Culture involved adaptation to habitats: a cold habitat

proved advantageous to so-called Eskimos; a warm proved advantageous to so-called Eskimos; a warm habitat such as a tropical rainforest fit the Amazonian habitat such as a tropical rainforest fit the Amazonian native population wellnative population well

This section looks at both biological and cultural This section looks at both biological and cultural factors supporting the early factors supporting the early homininshominins

Major Developments in Early Major Developments in Early Hominins: Biology Hominins: Biology Australopithecus afarensis: Australopithecus afarensis: The first The first

evidence of hominin bipedalism; included evidence of hominin bipedalism; included “Lucy” and this couple in Laetoli who left “Lucy” and this couple in Laetoli who left footprints characteristic of human bipedsfootprints characteristic of human bipeds

Australopithecus africanus: Australopithecus africanus: Gracile Gracile (light-boned) hominins who probably were (light-boned) hominins who probably were among our ancestors; other varieties have among our ancestors; other varieties have been found and described.been found and described.

Paranthropus boisei Paranthropus boisei and and robustus: robustus: the the robust (heavy boned) hominins with robust (heavy boned) hominins with powerful jaws to chew tough vegetation—powerful jaws to chew tough vegetation—most likely died off without progenymost likely died off without progeny

Major Developments in Early Major Developments in Early Hominins: CultureHominins: Culture

Homo erectus: Homo erectus: The first maker of The first maker of handaxes (Acheulean tradition) and users handaxes (Acheulean tradition) and users of fire (upper right)of fire (upper right)

Homo habilis: Homo habilis: The first documented The first documented toolmaker, of choppers (Oldowan toolmaker, of choppers (Oldowan tradition, upper left)tradition, upper left)

Homo heidelbergensis: Homo heidelbergensis: The first maker of The first maker of flakes from prepared coresflakes from prepared cores

Homo neanderthalensis: Homo neanderthalensis: Maker of two Maker of two complex tool traditions: Mousterian and complex tool traditions: Mousterian and ChattelperronnianChattelperronnian

Lower left and right) Two very different Lower left and right) Two very different

artist conceptions of “neanderthalsartist conceptions of “neanderthals””

Trends of the Earliest Hominins: The Trends of the Earliest Hominins: The AustralopithecinesAustralopithecines

The next several diagrams will show the following:The next several diagrams will show the following: Bipedalism was fully established with Bipedalism was fully established with

Australopithecus afarensisAustralopithecus afarensis and and africanusafricanus Paranthropus boisei Paranthropus boisei and and robustus robustus were fully bipedalwere fully bipedal All australopithecines (including Paranthropus) had All australopithecines (including Paranthropus) had

apelike facial features; the robust also had a sagittal apelike facial features; the robust also had a sagittal crest for their chewing musclescrest for their chewing muscles

They also had long arms, curved fingers, short tibia They also had long arms, curved fingers, short tibia (look up your diagram) and other apelike traits(look up your diagram) and other apelike traits

Their cranial capacities were small, not much larger Their cranial capacities were small, not much larger than apes (see next slide)than apes (see next slide)

Encephalization (a.k.a. Bigger Encephalization (a.k.a. Bigger Brains)Brains)

A. afarensis:A. afarensis: 390-500 cc; av. 440 cc 390-500 cc; av. 440 cc A. africanus: A. africanus: 435-530 cc; av. 450 cc435-530 cc; av. 450 cc A./P robustus: A./P robustus: 520 cc, one specimen520 cc, one specimen A.P. boisei: A.P. boisei: 500-530 cc; av. 515 cc.500-530 cc; av. 515 cc. H. habilis: H. habilis: 500-800 cc; av. 680 cc.500-800 cc; av. 680 cc. H. erectus: H. erectus: 750-1250 cc; av. 1000 cc750-1250 cc; av. 1000 cc Neanderthal: 1300-1750 cc. av: 1450Neanderthal: 1300-1750 cc. av: 1450 H. (s.) sapiens: H. (s.) sapiens: 900-2350 cc. av. 1400900-2350 cc. av. 1400

Lucy (Lucy (Australopithecus afarensisAustralopithecus afarensis) ) and Us (Homo sapiens)and Us (Homo sapiens)

Note the Following:Note the Following: Shorter (3’6”)Shorter (3’6”) Longer armsLonger arms Curved fingersCurved fingers Shorter lower legsShorter lower legs Greater prognathismGreater prognathism Sloped foreheadSloped forehead Smaller cranial capacitySmaller cranial capacity What are the Similarities?What are the Similarities? Hint: it’s all related to bipedalismHint: it’s all related to bipedalism

When We Became Bipedal When We Became Bipedal (According to Gary Larson)(According to Gary Larson)

““Hey! Look! No Hey! Look! No hands!”hands!”

(Does he look like Lucy (Does he look like Lucy to you. . .?)to you. . .?)

Gracile and Robust Gracile and Robust AustralopithecinesAustralopithecines

For For A. africanusA. africanus (top), note: (top), note: Somewhat rounder skullSomewhat rounder skull No Sagittal crestNo Sagittal crest Prognathous jawPrognathous jaw For Paranthropus boisei, note:For Paranthropus boisei, note: Sagittal crest (ate a lot of veggies)Sagittal crest (ate a lot of veggies) Massive lower jaw (mandible)Massive lower jaw (mandible) Flatter faceFlatter face Massive cheek bones (zygomatic arch)Massive cheek bones (zygomatic arch)

Genus Homo: Biological and Genus Homo: Biological and Cultural TrendsCultural Trends

With With Homo habilis, Homo habilis, some of the apelike traits some of the apelike traits begin to disappearbegin to disappear

Prognathism and heavy brow ridges begin to be Prognathism and heavy brow ridges begin to be reducedreduced

Arms are long in Arms are long in H. habilisH. habilis but shorter in but shorter in H. H. erectuserectus

Encephalization increases from 680 cc in Encephalization increases from 680 cc in H. H. habilishabilis to 1000 cc in to 1000 cc in H erectusH erectus and upward from and upward from there.there.

Tool design, manufacture, and use define the Tool design, manufacture, and use define the genus genus Homo Homo from the australopithecinesfrom the australopithecines

A Primer on Stone ToolsA Primer on Stone Tools Stone tools have to be made of Stone tools have to be made of

crystalline rockcrystalline rock: otherwise they : otherwise they won’t fracturewon’t fracture

Examples include obsidian and Examples include obsidian and flint, like these arrowheadsflint, like these arrowheads

The main types of stone tools are The main types of stone tools are corescores, the rock being worked on, , the rock being worked on, and flakes, the pieces chipped off and flakes, the pieces chipped off the core (lower left)the core (lower left)

Flakes include Flakes include bladesblades, which are at , which are at least twice as long as they are wide least twice as long as they are wide (lower right)(lower right)

A Primer on Stone Tool A Primer on Stone Tool ManufactureManufacture

A A hammerstone hammerstone is the stone used to is the stone used to flakeflake chips chips of stone from the of stone from the corecore in the toolmaking process in the toolmaking process (top)(top)

The The percussion technique percussion technique involves the use of involves the use of stone or softer material to strike the stone being stone or softer material to strike the stone being worked worked

The The hard hammer percussion technique hard hammer percussion technique involves striking the stone with the hammerstone, involves striking the stone with the hammerstone, mostly for rough work. (top)mostly for rough work. (top)

The The soft hammer percussion technique soft hammer percussion technique is the is the use of antler, bone, wood, or ivory for use of antler, bone, wood, or ivory for retouching retouching the work using percussion methodsthe work using percussion methods

The The pressure technique pressure technique involves pressing the involves pressing the work using soft material such as an antler for work using soft material such as an antler for retouching; here, the toolmaker is using bone to retouching; here, the toolmaker is using bone to refine an obsidian projectile point.refine an obsidian projectile point.

Homo habilis: Homo habilis: The First Known The First Known ToolmakerToolmaker

Note the following:Note the following: Face is much flatterFace is much flatter Reduced brow ridge (supraorbital Reduced brow ridge (supraorbital

torus) torus) Larger cranial capacity (680 cc.)Larger cranial capacity (680 cc.) Toolmaking TechniqueToolmaking Technique HammerstoneHammerstone used to strike used to strike A A core core (lump of stone) to knap(lump of stone) to knap A fA flake lake (stone chip)(stone chip) Note: Note: Stone has to be crystalline (so it Stone has to be crystalline (so it

will fracture predictably)will fracture predictably) This is the Oldowan traditionThis is the Oldowan tradition

Homo erectus: Homo erectus: Cranial StructureCranial Structure

Note the Following:Note the Following: Cranial capacity: 1,000 ccCranial capacity: 1,000 cc Occipital bunOccipital bun Reduced brow ridgeReduced brow ridge Reduced sloping foreheadReduced sloping forehead Reduced prognathismReduced prognathism Artist’s conception of Artist’s conception of H. H.

erectuserectus

Homo ErectusHomo Erectus (H. ergaster to Some): (H. ergaster to Some): Postcranial SkeletonPostcranial Skeleton Note the following:Note the following: Fully bipedalFully bipedal Arms about length of Arms about length of Homo sapiensHomo sapiens Cranial capacity: 1000 cc (average)Cranial capacity: 1000 cc (average) Main apelike features: Main apelike features: Prognathous lower facePrognathous lower face Sloping forehead Sloping forehead

Tool Traditions: Lower PaleolithicTool Traditions: Lower Paleolithic

This is the longest period of tool making, This is the longest period of tool making, starting at about 1.5 million years ago with the starting at about 1.5 million years ago with the OldowanOldowan

The Acheulean makes its appearance about The Acheulean makes its appearance about one million years agoone million years ago

The handaxe style is not found east of Central The handaxe style is not found east of Central India; this boundary is the Movius Line, India; this boundary is the Movius Line, named after Hallam Movius, who first made named after Hallam Movius, who first made that observation. that observation.

Lower PaleolithicLower Paleolithic

Oldowan Tradition: Oldowan Tradition: Four or five strokesFour or five strokes Unspecialized: choppersUnspecialized: choppers Flakes also made and usedFlakes also made and used Acheulean Tradition: Acheulean Tradition: 50-75 strokes50-75 strokes Symmetrical design Symmetrical design Multiple uses: cutting, Multiple uses: cutting,

piercing, choppingpiercing, chopping

Homo heidelbergensisHomo heidelbergensis (a.k.a. (a.k.a. “Archaic” “Archaic” Homo sapiensHomo sapiens

Note the following:Note the following: Brow ridges much reducedBrow ridges much reduced Forehead is higher, though slopingForehead is higher, though sloping Reduced prognathiamReduced prognathiam Cranial capancity 1200 cc. Cranial capancity 1200 cc. Artist’s conception shows closer Artist’s conception shows closer

similarities to ourselves similarities to ourselves

Manufacturing Levallois Cores Manufacturing Levallois Cores and Flakesand Flakes

Knappers:Knappers: Selects the appropriate core, Selects the appropriate core,

up to a pound of stoneup to a pound of stone Strikes the edge of the coreStrikes the edge of the core Knaps the surface of the Knaps the surface of the

intended flakeintended flake Knocks off the flakeKnocks off the flake Retouches the flake to Retouches the flake to

desired shapedesired shape May knap four to five flakesMay knap four to five flakes

Homo neanderthalensisHomo neanderthalensis and and H. H. sapienssapiens skull skull

Note the following for “Classic” NeanderthalNote the following for “Classic” Neanderthal Greater prognathism; humans lower jaw is straightGreater prognathism; humans lower jaw is straight Absence of chin that human hasAbsence of chin that human has Presence of brow ridge; human has none, has higher foreheadPresence of brow ridge; human has none, has higher forehead Presence of occipital bunPresence of occipital bun Larger cranial capacity: 1450 cc vs. 1400 cc in humansLarger cranial capacity: 1450 cc vs. 1400 cc in humans Also note: Also note: Artist’s conception of Neanderthal childArtist’s conception of Neanderthal child

Homo neanderthalensisHomo neanderthalensis and and H. H. sapienssapiens: Postcranial Skeletons: Postcranial Skeletons

Note the following for Note the following for Neanderthals:Neanderthals:

Heavier brow ridge and sloping Heavier brow ridge and sloping foreheadforehead

Bones generally more robustBones generally more robust Larger rib cageLarger rib cage Broader pelvisBroader pelvis Shorter forearmShorter forearm Shorter tibiaShorter tibia Larger ankle jointLarger ankle joint

Middle PaleolithicMiddle Paleolithic

Tools begin to show greater specializationTools begin to show greater specialization With the Levalloisian tradition, flake tools are With the Levalloisian tradition, flake tools are

more important than core tools like the more important than core tools like the AcheuleanAcheulean

The Mousterian tradition, associated with The Mousterian tradition, associated with Neanderthals, become more specialized, Neanderthals, become more specialized, dominated by notches, scrapers, and pointsdominated by notches, scrapers, and points

Levalloisian TraditionLevalloisian Tradition

This tool involves a unique technique, as follows:This tool involves a unique technique, as follows:

Neanderthal Tools: Mousterian and Neanderthal Tools: Mousterian and Châtelperronian TraditionsChâtelperronian Traditions

Mousterian (top)Mousterian (top) Bordes: 63 typesBordes: 63 types Burins (engravers) Burins (engravers) Scrapers and knivesScrapers and knives Even a type of handaxeEven a type of handaxe Part of the Part of the MesolithicMesolithic Châtelperronian (bottom)Châtelperronian (bottom) First blades—by NeanderthalsFirst blades—by Neanderthals Definition: flakes twice as wide Definition: flakes twice as wide

as they are longas they are long Initiated the Initiated the Upper PaleolithicUpper Paleolithic

Upper PaleolithicUpper Paleolithic Except for the Chatelperronnian, tools of the Upper Except for the Chatelperronnian, tools of the Upper

Paleolithic are products of Paleolithic are products of Homo sapiensHomo sapiens This period begins about 35,000 BP and works up to This period begins about 35,000 BP and works up to

the near present; Aztecs still used obsidian tools at the near present; Aztecs still used obsidian tools at the time of Conquestthe time of Conquest

The tools increase in specialization, vary by region, The tools increase in specialization, vary by region, and become smaller and more refinedand become smaller and more refined

Artwork and ornamentation also become evidentArtwork and ornamentation also become evident

Upper Paleolithic: Modern Upper Paleolithic: Modern Human Tool TraditionsHuman Tool Traditions. .

Commonalities of Tools:Commonalities of Tools: Blades: Ever thinner and smallerBlades: Ever thinner and smaller Increased tool specializationIncreased tool specialization Other material: bone, ivory, antlerOther material: bone, ivory, antler Other DevelopmentsOther Developments Artwork (such as this mural at Artwork (such as this mural at

Altamira, Spain)Altamira, Spain) Ornamentation (Venus statuettes)Ornamentation (Venus statuettes) Except for the Chatelperronian, Except for the Chatelperronian,

the the

Review and ConclusionReview and Conclusion We have. . . We have. . . Looked at the biological bases of culture: for Looked at the biological bases of culture: for

language, toolmaking, and bipedalismlanguage, toolmaking, and bipedalism Compared our anatomy with chimps, our closest Compared our anatomy with chimps, our closest

relativesrelatives Discussed evolutionary change based on natural Discussed evolutionary change based on natural

selection and mutationselection and mutation Looked at our ancestors and the tools they made Looked at our ancestors and the tools they made

The Territory AheadThe Territory Ahead Nonhuman Primate Behavior: Nonhuman Primate Behavior: How close in behavior are How close in behavior are

our cousins’ to our own?our cousins’ to our own? Language: Language: The medium of cultureThe medium of culture Making a Living: Making a Living: Industrial societies are not the only cultures Industrial societies are not the only cultures

in the worldin the world Sex, Family, and Its Extensions: Sex, Family, and Its Extensions: The world’s first social The world’s first social

organizationsorganizations Economics: Economics: How goods and services are providedHow goods and services are provided Social Control: Social Control: Governance and lawGovernance and law Psychology: Psychology: Freud didn’t start it allFreud didn’t start it all The Supernatural: The Supernatural: Were there gods before God?Were there gods before God? Culture Change and Globalization: Culture Change and Globalization: Is there life outside Is there life outside

corporations?corporations?