What characteristics define a hominin? Discuss which aspects of your definition can be assessed in the fossil record. Discuss the fossil finds at Dmanisi in terms of their morphology and

CHAPTER 10

Premodern Humans

The Pleistocene

• The Pleistocene, often called the Ice Age, was marked by

advances and retreats of massive continental

glaciations.

• At least 15 major and 50 minor glacial advances have been

documented in Europe.

• All life on the planet was impacted by changing weather patterns

• Hominins were impacted as the climate, flora, and animal life

shifted.

Pleistocene Stages

• Middle Pleistocene • The portion of the Pleistocene epoch beginning 780,000 ya and

ending 125,000 ya.

• Late Pleistocene • The portion of the Pleistocene epoch beginning 125,000 ya and

ending approximately 10,000 ya.

Glaciations

• Climatic intervals when continental ice sheets cover much

of the northern continents.

• Glaciations equate to colder temperatures in northern

latitudes and more arid conditions in southern latitudes,

most notably in Africa.

Interglacials

• Climatic intervals when continental ice sheets are

retreating, eventually becoming much reduced in size.

• Interglacials in northern latitudes are associated with

warmer temperatures, while in southern latitudes the

climate becomes wetter.

Changing Pleistocene Environments in Africa

Changing Pleistocene Environments in Eurasia

• Changing migration routes.

Homo heidelbergensis • Widely distributed, Middle Pleistocene, premodern human

• Found in Africa, Asia and Europe (first time Europe is permanently occupied)

• Replacing earlier hominins in their previous habitats (or coexisting as in Southeast Asia)

• Most likely the evolutionary ancestor to Homo sapiens and Neandertals

• Exhibit several H. erectus characteristics: • Large face, projected brows, low forehead, and thick cranial vault

• New Features: • Increased brain size, rounded braincase, vertical nose, and reduced occipital

African Homo heidelbergensis finds

• The Kabwe (Broken Hill)

skull from Zambia. • Clear mix of primitive and

derived traits

• Note the robust browridges.

• Bodo Cranium • The earliest evidence of Homo

heidelbergensis in Africa.

• Possibly defleshed with stone

tools.

Europe

• Gran Dolina finds in northern Spain may represent the ealiest H.

heidelbergensis, possibly dating to 850,000 ya

• Atapuerca site of Sima de los Huesos remains of at least 28

individuals date to 600,000-530,000 ya

• This is 80% of all Middle Pleistocene hominin remains found in the world,

crucial site for further study

• May be the earliest site of intentional disposal of the dead

Asia • Dali fossils display H. erectus and H. sapiens traits, cranial

capacity of 1120 cm3

• Jinniushan, northeast China, 200,000 ya individual with modern

features and cranial capacity appx 1260 cm3

• Many Chinese researchers have argued evidence suggests

separate evolutionary linage of Chinese specimens to modern

humans

• Debate remains if these specimins should be classified as H.

heidelbergensis or H. sapien

Middle Pleistocene Culture

• The Acheulian technology of H. erectus carried into

the Middle Pleistocene with little change until near

the end of the period, when it became slightly more

sophisticated.

• Some later premodern humans in Africa and Europe

invented the Levallois for controlling flake size and

shape.

• This suggests increased cognitive abilities in later

premodern populations.

The Levallois Technique

Middle Pleistocene Culture

• Premodern human populations built temporary shelters

evidenced by concentrations of bones, stones, and artifacts

• May have increased their use of caves as seen by large

deposits of bone and cultural remains in many areas.

• Chinese archaeologists insist that many Middle Pleistocene

sites in China contain evidence of human-controlled fire. Some

evidence from France, Germany and Hungary may also

support this.

Middle Pleistocene Culture • Evidence shows different food sources were exploited, fruits, vegetables, fish, seeds, nuts, and bird eggs, seasonally.

• Also marine life, new innovation in human evolution.

• There has been little evidence supporting widely practiced

advanced hunting at this time.

• However, in 1995 wood spears were found at the

Schöningen site in Germany provisionally dated to 400,000

to 300,000 ya • These were most likely used as throwing spears to hunt large animals.

• The bones of numerous horses were also recovered at Schöningen.

Neandertals of the Late Pleistocene

• Neandertals are premodern humans that are increasingly placed by researchers into the classification of a subspeices of H. Sapien, • Homo sapiens neanderthalensis with modern humans split of as

H. sapiens sapiens

• Many disagree with seperating them form the H. sapien species due to new genetic findings

Homo neanderthalensis

• Brain Size: Larger than H. sapiens today (1520 cm3 compared

to 1300-1400 cm3 (perhaps adapted to cold climate).

• Cranium: Large, long, low, and bulging at the sides, occipital

bun, with large brow ridge.

Homo neanderthalensis

• Structure: Robust, barrel-chested, and powerfully muscled with

shorter limbs than modern H. sapiens.

Important Neanderthal Finds

• La Chapelle-aux-Saints Skull • Outlier individual, especially robust

• Interpritation led to early views of

Neanderthal

• Krapina Cranium

• Possibly oldest fully Neanderthal

specimins

• Oldest burial on record

• St. Césaire

• St. Césaire, among the “last” Neandertals

Shanidar Cave

• In Shanidar cave, in the Zagros Mountains of northeastern Iraq, fieldworkers found partial skeletons of nine individuals, four of them deliberately buried.

• Shanidar 1 is a skeleton of a male who lived to be 30 to 45 years old, a very old age for prehistoric human.

• His height is estimated at 5 feet 7 inches, and his cranial capacity is 1,600 cm3.

• He had injuries that made it impossible to perform normal activities leading researches to believe he must have been helped by others.

Shanidar 1

• Could he represent

Neandertal

compassion for the

disabled?

Culture of Neandertals

• Neandertals improved previous techniques by inventing a new variation, Mousterian.

• They trimmed a flint nodule around the edges to form a disk-shaped core.

• Each time they struck the edge, they produced a flake, continuing until the core became too small and was discarded.

• They then trimmed the flakes into various forms, such as scrapers, points, and knives.

Subsistence

• Remains of animal bones demonstrate that

Neandertals were successful hunters.

• Used close-proximity spears for hunting (spear

thrower and bow and arrow weren't invented until the

Upper Paleolithic).

• Patterns of trauma in Neandertal remains match

those of contemporary rodeo performers, indicating

close proximity to prey.

Speech and Symbolic Behavior

• Prevailing consensus has been that Neandertals were

capable of articulate speech.

• Same hyoid bone and FOXP2 gene

• Even if Neandertals did speak, they did not have the

same language capabilities of modern Homo sapiens.

Burials

• Neanderthals buried their dead.

• Their burials included grave goods like animal bones and

stone tools.

• They placed the bodies of their dead in a flexed position.

Upper Paleolithic

• A cultural period usually associated with modern humans,

but also found with some Neandertals, and distinguished

by technological innovation in various stone tool

industries.

• Best known from western Europe, similar industries are

also known from central and eastern Europe and Africa.

Chatelperronian

• Pertaining to an Upper Paleolithic industry found in France and

Spain, containing blade tools and associated with Neandertals.

• Suggestive of some cultural hybridization

The 3rd Upper Paleolithic Hominin

• Denisova Cave, southern Siberia

• Finger bone and tooth dated to 50,000-30,000 ya

• Mitochondrial DNA shows significant genetic distance

from both Homo sapiens and Neandertals

• This means a third Hominin existed contemporaneously

with Neandertals and modern humans!

Molecular Connections: The Genetic Evidence

• Tremendous advances in past 15 years in sequencing

Neandertal mitochondrial and nuclear DNA

• Modern human populations outside of Africa possess1-

4% of distinctive Neandertal DNA

• Melanesian populations contain 4-5% of distinctive

Denisovan DNA

• Suggests interbreeding of premodern and modern

populations

CHAPTER 8 Primate and Hominin Origins

Dating Methods • Relative dating methods tell you that something is older or

younger than something else

• Stratigraphy- based on the law of superposition, which states that a lower layer is older than a higher one

• Biostratigraphy: Using comparative fossils, mainly predictable dentition, that have been dated at one site to date another

• Paleomagnetism: Using magnetically charged particles in deposits to determine the earths magnetic poles at time of deposit • This method is used primarily as a double check in conjunction

with other methods

Dating Methods

• Chronometric (Absolute) dating methods are based on

calendar years

• K/Ar, or potassium argon method used to date materials

in the 5-1 mya range

• Carbon-14 method used to date organic material extending

back to 75,000 years

• Uranium series dating

• Thermoluminescence

• Electron spin resonance (ESR)

Early Primate Evolution

• The beginnings of the primate order date to the

initial placental mammal radiation at least 65 mya.

• The earliest primates date to the Paleocene (65-56

mya) and diverge from quite early primitive

placental mammals, called plesiadapiforms.

• A vast number of fossil primates from the Eocene

(56–33 mya) have been discovered and now total

more than 200 recognized species.

Eocene Primates • Fossil primates from the Eocene display distinctive primate features.

• North Africa fossils dating from the early Eocene (50 mya) and Egypt (37 mya)

• Some may have been ancestral to the lemurs and lorises, or the tarsiers, evidenced by a dental comb

• Most do not appear to be ancestral to any living primate

• When the Eocene primates in their entirety are examined, it is certain that they were:

1. primates,

2. widely distributed, and

3. mostly extinct by the end of the Eocene

• Darwinius, from the

Messel site in

Germany, discovered in

2009 and dates to 47

mya. Though initial

claims to connection to

living primates were

made, they have yet to

be confirmed and are

hotly debated

Oligocene Primates

 The Oligocene (33–23 mya) has yielded fossil

remains of several species of early anthropoids.

 By the early Oligocene, continental drift had separated

the New World from the Old World.

 The earliest anthropoids may have reached South

America by “rafting” over from where they emerged in

Africa.

 The ancestry of New and Old World monkeys was

separate after 35 mya.

Oligocene Primates from Fayum

• Apidium: Early primate genus found in the Fayum, a region

in Egypt

• Primitive dental arrangement suggests near or before

evolutionary divergence of Old and New World anthropoids

• Small, squirrel-like fruit and seed eating, adept at leaping and

springing

Oligocene Primates from Fayum

• Aegyptopithecus

• Largest of Fayum anthropoids, roughly the size

of a modern howler monkey (13-18 lbs)

• Short-limbed, slow-moving

• Bridges the gap between

Eocene fossils and succeeding

Miocene hominoids

Miocene Fossil Hominoids

• Existed for the entirety of the Miocene, 23 to 6mya

• Thousands of fossils have been discovered, many of

which only tenuous or disputed conclusions have

been drawn

• Geographically widespread with fossils discovered

across Africa, parts of Europe and Asia

Miocene Fossil Hominoids

African forms (23–14 mya)

 Found primarily in Western Kenya, these have many

primitive characteristics.

 Proconsul

 Apelike derived teeth, but postcranially resembles a

monkey

Miocene Fossil Hominoids Asian forms (16–7 mya)

• The largest and most varied group found from Turkey through India/Pakistan and east to southern China, most are highly derived.

• Sivapithecus

• Found in Turkey and Pakistan

• Facial features similar to the modern orangutan, suggesting a fairly close evolutionary link.

Sivapithecus Compared

• Comparison of a modern chimpanzee (right), Sivapithecus (middle), and a modern orangutan (left).

• Both Sivapithecus and the orangutan exhibit a dished face, broad cheekbones, and projecting upper jaw and incisors.

Miocene Hominoid Fossils Conclusions

• Mostly large-bodied hominoids, similar to

orangutans, gorillas, chimpanzees, and humans not

siamangs and gibbons.

• Most forms discovered are so derived that they are

probably not ancestral to any living form. (except

Sivapithacus)

• Definite hominins from the Miocene has not been

indisputably confirmed. Some finds suggest that

hominins diverged sometime in the latter Miocene.

Who are the Hominins?

• Name for all members of the tribe Hominini

• Includes all bipedal hominoids back to the divergence with

African great apes.

• Refers to all great apes (orangutans, gorillas, chimpanzees,

and bonobos) and humans

• Defined by dental features, bipedal locomotion, large brain

size, and tool making behavior

• Characteristics that developed at different rates, called

mosaic evolution

Mosaic Evolution

• A pattern of evolution in which the rate of evolution in one

functional system varies from that in other systems.

• In hominin evolution, bipedal locomotion is a defining

characteristic; other features such as brain development

and behavior become significant in later stages

• In other words the traits that make us human did not all

evolve at the same time, and different species evolved at

different rates with different traits

Traditional Classification of Hominoids

Revised Classification of Hominoids

Paleoanthropology

• Paleoanthropology is defined as the study of early

humans.

• Paleoanthropologists reconstruct the anatomy,

behavior, and ecology of our ancestors:

• It is a diverse multidisciplinary pursuit seeking to

reconstruct every bit of information possible

concerning the dating, anatomy, behavior, and

ecology of our hominin ancestors.

• Locate early hominin sites, collect faunal remains

and artifacts

Early Hominin Tools

• Earliest tools likely made of perishable materials

• Hominin bipedalism would have made tools easier to

transport

• Oldowan-Earliest recognized stone tool culture, including

very simple tools, mostly small flakes

Hominin Bipedalism

• Habitual bipedalism, efficient and standard bipedal locomotion is seen only in hominins.

• Hominins are also obligate bipeds, meaning they cannot locomote efficiently in any other form

• Advantages of bipedalism:

• Freed the hands for carrying and tool use

• Offers a wider view of surroundings.

• Bipedal walking is an efficient in covering long distances.

Obligate Bipedalism: Structural Alterations

• Foramen magnum positioned under the skull to balance

the skull and enable the head to be held upright

• Two distinctive curves in spine to keep weight centered

above pelvis

Obligate Bipedalism: Structural Alterations

• Pelvis is comparatively much shorter and broader and extends

around to the side, stabilizing the line of weight transmission

from lower back to hip joint, supporting internal organs in

upright posture

Obligate Bipedalism: Structural Alterations

• Foot as stable support instead of a grasping limb

• Elongated legs to increase the length of stride

• Full extension of knee and narrow stance to maintain center of

support directly under the body

Finding Early Hominin Fossils

• East Africa sites along the Great Rift Valley where more than

2,000 hominin fossils have been found

• South Africa sites with geological strata more complex than

along the East African Rift Valley

Possible Early Hominins

• These are grouped as the Pre-Australpiths

• They are classified as homimin, but it’s disputed by some

• Sahelanthropus tchadensis

• Small braincase and huge browridge

• Intermediate foramen magnum

• Vertical face, hominin like teeth

• No post-cranial remains to prove locomotion

• Ardipithecus

• Ardi, a female skeleton is 50% complete, earliest hominin to have

so many parts of the body preserved

• Pelvis and foot show both derived and ancestral characteristics

• Divergent big toe shows high climbing ability and life

adapted to the trees

Orrorin Tugenensis

• First hominid with preserved post cranial remains

• Best evidence among the Pre-Australiths for bipedalism

• Dated to 6mya

Australopiths (4.2–1.2 mya)

• The group of well studied, diverse and widely distributed of the early African hominins are called australopiths.

• This group of hominins is made up of two closely related genera: Australopithecus and Paranthropus.

• Existed over a 3 million year time range from approximately 4.2 mya until becoming extinct apparently close to 1 mya.

Australopiths (4.2–1.2 mya)

• Major features

1.They are all bipedal though not necessarily the

same as Homo

2.They all have relatively small brains at least as

compared to Homo.

3.They all have large teeth, particularly the back

teeth, with thick to very thick enamel on the

molars.

Australopithecus afarensis

• Found primarily at Hadar, Ethiopia and Latoli, Tanzania

• Primitive in relation to later Australopiths

• Very sexually dimorphic

• Obligate and habitual bipeds that were still capable of climbing

• Evolutionary bridge between early pre-Australopiths and the

later hominin species

Laetoli footprints

• Dated at between 3.5 and 3.7 mya.

• Fossilized hominin footprints were found in an ancient volcanic

bed in Laetoli, Tanzania.

• Despite agreement that these individuals were bipedal, some

researchers feel they were not bipedal in the same way as

modern humans.

Note the deep impression of the heel and the large toe in line (adducted) with the other toes.

Infant A. afarensis skeleton • A mostly complete female infant

A. afarensis skeleton was announced in 2006.

• The discovery was made at the Dikika locale in northeastern Ethiopia, near the Hadar sites.

• Dated to 3.3 mya.

• First immature hominin prior to 100,000 ya

• Key to developmental study

Later More Derived Australopiths (2.5–1.2 mya)

• Over time australopiths became adapted to varied niches, became more derived and showed physical changes making them distinct from their immediate ancestors.

• There were at least three separate lineages of hominins living between 2.5 and 1 mya.

• Australopithecus

• Paranthropus

• Homo

Paranthropus

• Very derived australopith

• Displays features characteristic of a varied and tough diet

• Massive teeth

• Large jaws and sexually dimorphic sagittal crest

• Small brain capacity

• Large, broad, flat face

• Two species:

• Paranthropus boisei: Very dentally

robust specimens from East Africa

• Paranthropus robustus: Less dentally

robust species from South Africa

Austrolpithicus africanus

• Dated to 3 and 2 mya

• Discovered in South Africa

• The Taung child, discovered in 1924

• Well preserved child's skull

• Small relative braincase

• Large teeth, but reduced from Paranthropus

• Clear markers for obligate bipedalism

Austrolpithicus sediba

• Considered by initial reports to be transitional between the

australopiths and early Homo, but contested by others

• Dated to less than 2mya

• Early Homo remains have been dated earlier leading to the

challenges to the A. sediba lineage claims

• Austrlopith charactristics;

• Small brain

• Long arms, curved fingers

• Primitive foot features

• Homo characteristics

• Very derived hand

• Possible brain changes

Early Homo (2.0+-1.4 mya)

• Evidence suggests at least one, possibly two species lived

in East Africa for at least a million years.

• One lineage likely evolved in H. erectus, the other went

extinct

• Homo habalis remains have been discovered in Turkana

and Olduvai and are the best known early Homo species

• Early Homo show:

• Significantly increased brain size

• Associations with stone tools

• Skull shape unlike the australopiths

• Face shape and teeth still robust

Homo naledi • Dicovered in 2013

• Over 1500 fossils found in the Dinaledi Chamber in the Rising

Star cave system representing at least 15 individuals

• Largest collection of a single species ever found in Africa

• Full age range from infants to adults have been found

• Unique mix of australopith and Homo characteristics

• Small brain, trunk, pelvis and femur similar to australpiths

• Cranial shape, hands and feet close to Homo

• Remains may have been intentionally placed

• Not yet dated

Three Options for Dating H. naledi

What’s the Big Picture • Even with new finds all the time there will always be gaps in the

fossil record, it may always be incomplete

• There are patterns to be found:

• Early hominin species had restricted ranges, this can lead to rapid

speciation from population isolation

• Most species appear to have been at least partially tied to arboreal habitats

• Some (mainly Paranthropus) diets of coarse, fibrous plant foods, such as

roots may have routinely taken them farther away from the trees and led to

divergence

• Very little evidence for an evolutionary trend of increased body size or of

markedly greater encephalization except for some early Homo

• No association of any pre-australopith or australopith hominins with

patterned tool use

• All early African hominins show an accelerated developmental pattern like

the great apes, one quite different from Homo sapiens

CHAPTER 9 The Earliest Dispersal of the Genus Homo:

Homo erectus and Contemporaries

First Dispersal of the Hominins

• Close to 2 million years ago, hominins expanded out of Africa into other areas

of the Old World.

• Early hominin fossils have never been discovered out of Africa, leading

researchers to believe that the early hominins were isolated there for 5 million

years.

• After 2 mya, there’s less diversity in these hominins than in their pre-

australopith and australopith predecessors.

• There is some variation among the different geographical groups of these

hominins, and anthropologists still debate how to classify them.

• There is universal agreement that the hominins found outside of Africa are

members of genus Homo.

Homo erectus • The first hominin to expand into new regions of the Old

World.

• Homo erectus is the hominin species for which there is the

most evidence.

• As a species, H. erectus existed over 1 million years.

• More evolved behavioral/cultural practices and larger more

derived bodies aided their success

• East African finds have been dated to 1.7 m.y.a.

Lumping vs Splitting

• Depending on preference researchers tend to want to group individual fossil finds together into species (lumping) or split a genus into as many identifiable species as possible (spliting)

• Some researchers split Homo erectus into two species • African fossils into Homo ergaster.

• Asian fossils into Homo erectus

• Analyses show that H. erectus/ergaster are a closely related species and possibly geographical varieties of a single species

Morphology of Homo erectus

• There was much varition in the individual groups that are

included in H. erectus, but they share a set of features:

Body Size

• Adult weight >100 lbs, average adult height of ca. 5 feet 6

inches

• Sexually dimorphic, weight and height varied according to

sex

• Increased robusticity (heavily built body) that dominated

hominin evolution until anatomically modern H. sapiens

Brain Size

• Cranial capacities 700 cm3 to 1250 cm3

• Brain size closely linked with overall body size

• H. erectus is larger-bodied than early Homo sample but relative brain size is about the same

• Relative brain size of H. erectus is considerably less encephalized than later members of genus Homo

Cranial Shape • Thick cranial bone, large brow ridges (supraorbital tori), and projecting

nuchal torus

• A projection of bone in the back of the cranium where neck muscles attach;

used to hold up the head.

• Braincase long and low, with little forehead development

• Cranium wider at base, compared with earlier and later species

• Sagittal keel, a small ridge from front to back along the sagittal suture

African Origin of H. erectus • African origin supported by evidence of:

1. Earlier hominins prior to the appearance of H. erectus occurring in

Africa.

2. 1.7 mya fossils at East Turkana, in Kenya, where australopiths have

also been found,and not long after a

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