UARK BIOANTHRO EXAM 3 Delezene

What evolutionary scenario was envisioned by early thinkers that linked brain size, canine size, diet, locomotion, and tool use?

They believed humans have a larger brain therefore they need more calories. Meat has more calories so they have sharper canines. Apes had to use tools to acquire meat.

Which feature was expected to appear first and drive the evolution of the remaining features?

Big brains

Historically speaking, which species of extinct hominin was first discovered in Europe? When?

Neandertals, 1829

How was Homo neandethalensis reconstructed by Marceline Boule?

As caveman like

How did this affect interpretations of Neandertals and potential human ancestors?

Not based on hard science but slanting the data to fit preconceived notions of how early man was supposed to look so they would accept that's where humans came from

Why are so many fossils found in limestone caves in Europe?

Neandertal bones and artifacts were well preserved in these caves

What is taphonomy?

the study of fossils

How did Piltdown fit into the expectations of early evolutionary thinkers?

Large brains like humans, "missing link", intelligence evolved first

Who was involved in the hoax?

Charles Dawson

What anatomical elements were mixed into the Piltdown specimen?

Large human like brain case and an ape mandible ( and large chimp canines)

What's the historical context for the Piltdown "discovery"

Can be an example of scientific racism

What real hominin fossils were known at the time of Piltdown's discovery?

Homo Erectus, Homo neanderthalensis

Where were these other fossils found?

neanderthal: Germany, Erectus: Indonesia

What was the human fossil record like in England at that time?

In England, there were none

What role did Piltdown play in the acceptance of the Taung child as a fossil hominin?

It played on scientific racism as Piltdown had been "discovered" only 4 years before and scientists argued on if it was a young gorilla or a hominin because they preferred our ancestors be found in europe instead of africa

What evolutionary scenario did the Taung child imply that conflicted with the Piltdown remains?

Canine reduction before brain expansion, Bipedalixm before brain expansion, brain size is not the defining feature of hominins, it is either canine size or bipedalism

Which species does the Taung Child belong to?

Australopithecus africanus

Who, where, and when was it found?

Raymond Dart, South Africa, 1925,

What social/political factors played into the acceptance/rejection of the Taung child as a fossil hominin?

Scientific Racism and the scientists at the time wanting a european ancestor to be found instead of in africa

Kenya

Ethipoia

South Africa

Tanzania

Chad

African Rift Valley

(It's in Kenya)

Hadar

(It's in Ethiopia)

Laetoli

(It's in Tanzania)

What is the African Rift Valley?

Crack in earth's crust from Lebanon to Mozambique, Divides Kenya into 2 sections, rich in fossils that allow study of human evolution

What's going on geologically

The rapidly eroding highlands have filled the valley with sediments, a favorable environment for the preservation of remains. The bones of several hominid ancestors of modern humans have been found here.

Afar Triangle

Taung

(It's in South Africa)

Sterkfontein, Swartkrans, Kromdraii

(It's in South Africa)

Djurab Desert

(It's in Chad)

Lake Turkana

(It's in Kenya)

A. afarensis and A. africanus Cranial morphology

Ape like

A. afarensis and A. africanus Brain size

small

Sahelanthropus tchadensis

Geographical area of discovery
Southern Chad
Geological age
7 MYA
The person(s) who discovered it
Michel Burnett
What does the name mean?
Sahel = sahara, anthropus = human, tchad= Chad, ensis = originating from
Why it may be a hominin
Foramen magnum may be forwardly placed, small unsharp canine
Why it may not be a hominin
Small cranial capacity (360cc),thick superorbital torus, thin enamel on post canine teeth. Large brow ridge

Orrorin tugenensis

Geographical area of discovery
Kenya
Geological age
6 MYA
The person(s) who discovered it
Martin Pickford and Brigette Senut
What the name means (nicknamed millemium man)
Orrorin = 1st human in Tugen, tugenesis = originating from Tugen Hills in Kenya
Why it may be a hominin
Shape of the femur head, canine not large and not honed, postcanine are argued to be thickly enameled
Why it may not be a hominin.
Femoral neck is argued to be human like but no good picture,

Ardipithecus ramidus

Geographical area of discovery
Afar triangle of Ethiopia
Geological age
4.4 MYA
The person(s) who discovered it
Tim White
What the name means (nickname Ardi)
Ardi = ground, Pithecus = ape, kadabba = oldest ancestor in Afar language
Why it may be a hominin
Anterior foramen magnum, less facial prognathism, no knucklewalking, biped pelvis, small canines, cranial capacity 300-350 cc., smaller face than chimps
Why it may not be a hominin.
Nose sticks out, curved arched fingers (suspensory),
Focus on the foot, the big toe (hallux) especially
Grasping feet with divergent hallux

Australopithecus afarensis

Geographical area of discovery
Hadar, Ethiopia, and Laetoli, Tanzania
Geological age
2.9-3.7 MYA
The person(s) who discovered
Don Johansen and Mary Leakey
What the name means
AUSTRALOPITHECUS = austral - southern, pithecus-ape, afar = triangle, ensis = from
AFARENSIS: afar - triangle, ensis - from

Australopithecus africanus

Geographical area of discovery
Taung, Sterkfontein, Makapansgat
Geological age
3.2-2.2 MYA
The person(s) who discovered
Raymond Dart
What the name means
AUSTRALOPITHECUS = austral - southern, pithecus-ape, afar = triangle, ensis = from
AFRICANUS: of Africa

A. afarensis and A. africanus canine size

tiny canines

A. afarensis and A. africanus incisor size

tiny incisors

A. afarensis and A. africanus Postcanine Tooth Size

Large flat

A. afarensis and A. africanus Postcanine hypermegadontia

Enlarged large molars and premolars

A. afarensis and A. africanus Premolar molarization

Molarization is evolution of less specialized teeth into molars

A. afarensis and A. africanus Foramen Magnum position

anterior

A. afarensis and A. africanus Facial prognathism/orthognathism

Prognathism ( reduced to Australopithecus)

A. afarensis and A. africanus Flaring Zygomatics

Big muscles of mastication

A. afarensis and A. africanus Forwardly placed zygomatics

Over premolars, "dished" midface

A. afarensis and A. africanus Cranial Cresting : What muscle of mastication attaches to the sagittal crest?

Temporalis

A. afarensis and A. africanus Cranial Cresting : What muscle of mastication attaches to the broad zygomatic bones?

masseter

Homo Habilis

Geographical area of discovery
Eastern Africa (Olduvai, Lake Turkana area, Hadar)

Geological age
2.3-1.6 MYA
The person(s) who discovered it
Mary and Louis Leaky
What the name means
Homo - human, habilis - handy (nickname is handyman or Twiggy)

Homo Habilis Cranial morphology

No sagittal crest, more prominent forehead, projecting supraorbital torus, smaller face, is in between human and ape

Homo Habilis Brain size

large

Homo Habilis canine size

small canines

Homo Habilis Postcanine Tooth Size

Large post canine teeth

Homo Habilis Dental Arcade Shape

Large premolars and molars, small canines and incisors, parabolic

Homo Habilis Foramen Magnum position

Anterior

Homo Habilis Facial prognathism/orthognathism

Orthognathic face

Homo Habilis Cranial Cresting

No cresting

Homo Habilis Postcranial morphology

Small brow ridge, deep, flat cheeks, orthognathic face

Homo Habilis foot morphology

more suitable for bipedalism

Homo Habilis hand morphology

tool user

Which came first during human evolution: obligate terrestrial bipedalism, reduced nonhoning canines, large brains, or stone tools? (Assume that Ar. ramidus is a good guide for what hominins that predate Australopithecus would have looked like

Large brains, diet, tool use, locomotion, small canines

Lucy

Australopithecus afarensis shows sexual dimorphism

Selam

Australopithecus afarenis, is almost complete and also a child

Taung Child

Australopithecus africanus, first and best example of early hominin brain evolution

Laetoli footprint trail

stralopithecus afarensis, made by some of the first upright-walking hominids

Ardi (the Ar. ramidus partial skeleton)

Ardipithecus ramidus, reflects a human-African ape common ancestor that was not chimpanzee-like.

Core

body of the tool

Hammerstone

stone tool used to chip away core

Toumai

Sahelanthropus tchadensis, possibly very close to the time of the chimpanzee-human divergence

Twiggy

Homo habilis, evidence for the validity of the Homo habilis species

Flake

flakes of stone that fall off core when hit with hammerstone

Oldowan Stone Tool Industry

Oldest recognized stone tool culture, including very simple tools

The Killer Ape Hypothesis

Proposed that hunting was what drove human evolution (the Osteodontokeratic tool culture was created by A. Africanus)

Who did Dart think was the killer ape?

A. Africanus

What are cutmarks on bones?

Scrapes in the bones

What evidence is there that marrow was extracted from bones using stone tools

Cutmarks

Osteodontokeratic Tool Culture What is it?

The use of bone (osteo), tooth (donto), horn (keratic) tools

If A. africanus didn't collect the bones in the caves, then who/what did?

Other agents such as the prey of the predators (example: hyenas are bone collectors)

What is the evidence that Oldowan stone tools were used to acquire meat?

There really aren't different types of tools in the Oldowan, the point is sharp edges to cut stuff

Which plants follow a C3 photosynthetic pathway?

Trees and fruit

Which plants follow a C4 photosynthetic pathway?

Grasses

Which hominin is the likely stone tool maker at Olduvai?

Homo because Paranthropus didn't have the brain size and was not a carnivore

Which hominin is associated with the 3.4 mya "cut-marked" bones from Dikika, Ethiopia?

Paranthropus

What kind of "tools" are hypothesized to have made the cut marks?

stone

What is the general trend for hominin diets in terms of the use of the C3 and C4 vegetation

Have different carbon isotope signatures

Which hominin has a nearly pure C4 signal?

Paranthropus boisei

What is the savannah hypothesis for the origins of bipedalism?

An idea that we shifted to bipedalism as a response to living in an open habitat like the savannah

What environments were occupied by the earliest bipeds (e.g., Ardipithecus and Australopithecus)?

wood and grass lands

In addition to H. ergaster/erectus, what other hominin lineage adapted to life on the savannah?

p. bosei

Why is the savannah hypothesis wrong when it comes to explaining the origins of bipedalism?

Savannah's didn't exist in early Pliocene and Miocene, early hominins lived in woodland habitats,

What evidence do we have that this lineage exploited savannah habitats

c4 rich diet

Why might adaptations to savannah life explain the anatomy and behavior of Homo erectus/ergaster?

A bipedal posture reduces exposure to the sun, they weren't pure carnivores, capable of running which permitted persistence hunting

Where are fossils of Homo erectus/ergaster found?

Turkan area

What is the age of the oldest fossils attributed to H. erectus/ergaster that are found outside of Africa?

1.8 MYA

Where are these fossils found?

Dmanisi, Georgia

When does H. erectus/ergaster appear in the fossil record?

1.8 MYA - 250 KYA