Biological Anthropology Delezene Exam 3 UARK

During the Miocene, where are hominoids found geographically?

Africa and Southeast Asia

When did hominoid diversity decline?

During the midmiocene, global cooling occurred, restricting forested environments. As the forests decreased, so did the diversity of ape species

Describe the locomotor diversity of Miocene hominoids.

Cautious climbers, terrestrial quadrupeds, arboreal quadrupeds, and suspensory.

Describe the dietary diversity of Miocene hominoids.

Fruits, Leaves, Insects, Meat, Seeds, etc.

Describe the body size diversity of Miocene hominoids.

13-385 pounds

What were Africa and Asian primate communities like in the Miocene?

All Diurnal

What about today?

They vary by species

What are two factors that are hypothesized to explain the loss of hominoid diversity in the Late Miocene?

Global Cooling, Loss of forest space

How do humans differ from other apes?

We are bipedal, larger brain size, smaller teeth, chins, broad dietary niches—a lot of meat, long life. Nonsynchronous physical and sexual maturity, postmenopausal period, short interbirth intervals

What are the morphological correlates of bipedalism?

Foramen magnum position. Foramen magnum position and orientation, lumbar and cervical lordosis, vertebral wedging, valgus knee, broad short ilium (pelvis shape), lesser gluteal muscles, nondivergent hallux, arch in feet, reduced canine height, nondimorphic canines, no canine honing

How does the foramen magnum position influence the location of the spine in relation to the cranium?

Hard to explain in words but you know this already

Curvature of the spine.

Contrast a quadruped and a biped. 1 curve in a quadruped, 3 curves in a biped. Cervical lordosis Thoracic kyphosis Lumbar lordosis

In what direction does a lordotic curve bend? Why does the biped have these curves?

Think about it in terms of balance. To be able to stand up without falling over.

Without these curves, which way would a biped tend to fall over?

Depends on the curve, both counteract eachother, creating a balance.

Why do chimps stand and walk bipedally with a bent hip, bent knee posture?

Their pelvis and spine are not positioned to be bipeds all the time. It makes for an awkward way of walking. They lack a valgus knee

Pelvis

Shape, size, and orientation of iliac blades in bipeds and quadrupeds.

Be able to describe the pelvis of a biped and quadruped using anatomical directional terms.

Bipeds: short broad illium, rotated into sagittal plane. Quadruped: narrow and tall illium, lying in coronal plane

Function of the gluteus medius and minimus in bipeds and quadrupeds.

Bipeds: hip abductors and stabilizers, Quadrupeds: extenders.

How does changing the shape of the ilium change the function of the gluteal muscles?

It changes the orientation

In a biped, the gluteal muscles prevent us from falling in which direction relative to the unsupported foot?

Our gluteal prevent us from falling directly over

Valgus vs. Straight knee.

Presence of a bicondylar angle = valgus knee

How does the valgus angle reflect the position of the knees in relation to the midline of the body?

Valgus knees bring the knee into the body, towards the midline

Why is a valgus knee advantageous for a biped?

Think about balancing on one foot. It helps us balance on one foot while walking

Big toe

(hallux).

In line with other toes or divergent?

Biped: In line, Quadruped: divergent

How does it differ between a biped and quadruped in terms of its anatomy and function?

Biped need this to help push them off when walking, and to help with balance. Quadrupeds use their divergent hallux to grab things

What is the canine honing complex?

The sharpening of the canine by the premolar.

What is the sectorial/honing premolar?

It is the premolar directly behind the canine. What does it do? It sharpens the canine

Which three teeth comprise the canine honing complex in extant apes?

Mandibular canine, maxillary canine and premolar

We have big brains.

We have a broad dietary niche that includes meat protein.

We acquire and process a lot of our food using tools.

We process food extensively outside of our mouth (extraorally)

Human life History Stages:

Pregnancy/ Birth - Infancy - Childhood - Juvenility -- Adolescence

Life History Milestones

Menarche -- first occurrence of menstruation, Menopause - ceasing of menstration, Weaning - infant becomes accustom to food other than it's mother's milk, Sexual Maturity—when an orgasm can biologically reproduce, Puberty - when adolescents reach sexual maturity, Physical Maturity—when an individual has reached full level of development

Senescence

deterioration with age

Lactational Ammenorhea

- temporary postnatal infertility that occurs when a woman is not menstruating and fully breatsfeeding

Interbirth Interval -

Time between births

We live a long time, take a long time to mature physically, have nonsynchronous physical and sexual maturity, have a menopausal period, and have short interbirth intervals

Why would the earliest hominin have looked very ape-like?

Because the first hominins were being derived from apes. The changes would have been subtle and over time. So they would still look like apes, but with slight human like changes

What is allopatric speciation?

Geographic barriers lead to the fragmentation of species—populations become isolated from each other

What role does gene flow play in speciation?

Gene flow is typically limited, or cut off. Thus creating the speciation

Be able to locate on a map: Kenya Ethiopia South Africa Tanzania Chad African Rift Valley. Hadar Laetoli Afar Triangle Taung Djurab Desert Lake Turkana

Sahelanthropus tchadensis

Geographical area of discovery: Chad Sahara

Geological age: 7 mya

The person(s) who discovered it: Michel Brunet

What does the name mean? Sahara human chad originating form

Why it may be a hominin: Foramen magnum forwardly placed, small unhoned canine, orientation of foramen magnum

Why it may not be a hominin: Small cranial capacity, thick suborbital torus, thin enamel on postcanine teeth, no post cranium

Orrorin tugenensis

Geographical area of discovery: Tugen Hills, Kenya

Geological age: 6 mya

The person(s) who discovered it: Martin Pickfort and Brigitte Senut

What the name means: First human, Tugen Hills, originating form

Why it may be a hominin: femoral shape, unhoned canine and smaller than apes, thickly enameled post canines

Why it may not be a hominin. No distal end of femur, limited sample size, no craniodental fossils,

Ardipithecus ramidus

Geographical area of discovery: Middle Awash, Ethiopia

Geological age:1994

The person(s) who discovered it: Tim White

What the name means: ground ape root

Why it may be a hominin: Fowardly placed foramen magnum, small non-honed canines, reduced iliac height, sagittaly-rotated ilium

Why it may not be a hominin: Heavily reconstructed pelvis, ischium is long, divergent big toe, no arch in foot

Australopithecus afarensis

Geographical area of discovery: Hadar, Ethiopia; Laetoli, Tanzania

Geological age :2.9-4.1 mya

The person(s) who discovered each species: Don Johanson and Mary Leaky

What their names mean: Southern ape afar triangle originating form

Cranial morphology: weak cranial cresting, 450 cc, strong subnasal prognathism, weak midface prognathis,

Brain size: 450 cc

Canine Size: reduced (small)

Are the canines honed like in extant apes? No Postcanine Tooth Size: Large Facial prognathism/orthognathism: strong subnasally, weak in midface Cranial Cresting: weak or absent Postcranial morphology: Pelvis: broad and short ilium like humans, laterally faced Knee shape: Valgus knee Arch presence/absence Hallux morphology: non divergent hallux, arch in foot, medial foot used to toe off

What does the Laetoli footprint trail tell us about A. afarensis locomotion?

They were bipedal, they also had a non divergent hallux

A. africanus

Geographical area of discovery: South Africa Geological age: 3.2-2.2 mya The person(s) who discovered each species: Raymond Dart What their names mean: Southern ape of africa Very similar to A. afarensis

Paranthropus robustus and P. boisei

Geographical areas of discovery: South Africa, Olduvai, Lake Turkana Region, Omo, Konso Geological ages: 2.0-1.5 mya, 2.3- 1.2 mya The person(s) who discovered them: Robert Broom Mary LeakeyWhat their names mean: parallel to humans large, parallel to humans funded expedition signifies persons name Cranial morphology: Brain size: 500-550 cc 450-550 cc Canine Size: Tiny canines Incisor Size: Tiny incisors Postcanine Tooth Size:huge Postcanine hypermegadontia: freaking huge post canines Premolar molarization: Foramen Magnum position: Facial prognathism/orthognathism: extreme, reduced in comparison Flaring Zygomatics

Why are the zygomatics so flared in Paranthropus?

Forwardly placed zygomatics and "dished" midface.

What muscle of mastication attaches to the sagittal crest?

temporalis

What muscle of mastication attaches to the broad zygomatic bones?

massetor

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.

1: nonhoning canines, 2: obligate bipedalism, 3: large brains, 4: stone tools

Lucy

A. Afarensis

Selam

A. Afarensis

Taung Child

A. Africanus

Who left the laetoli footprint trail

A. Afarensis

Ardi

(the Ar. ramidus partial skeleton)

Toumai

Sahelanthropus tchadensis

Twiggy

Homo Habilis

Core:

any part of material that has had flakes removed from it

Hammerstone:

Stone used to remove flakes from core

Flake:

section of stone knocked off the core during knapping; often used as a tool

The Killer Ape Hypothesis:

Propsed that hunting was what drove human evolution

Who did Dart think was the killer ape?

A. Africanus

Osteodontokeratic Tool Culture

Stone, teeth and horn tools were collected by A. Africanus and used as weapons to hunt

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

Probably hyenas, Australopithecus was more likely prey than predator

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

There is evidence of scratching on carcasses

What are cutmarks on bones?

The tools were used to cut bones in order to extract bone marrow

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

Evidence of these purposefully broken bones have been found

Homo habilis

Geographical area of discovery Geological age: Olduvai, Lake Turkana area, Hadar, 2.3-1.6 mya The person(s) who discovered it: Mary and Louis Leakey What the name means: "Handy Human" Cranial morphology: no sagittal crest, more prominent forehead, projecting suborbital torus, smaller face, small post canine detition Brain size: 750 cc Canine Size: smaller Postcanine Tooth Size: smaller post canine detention Dental Arcade Shape: curved Foramen Magnum position: not listed Facial prognathism/orthognathism: prominent forehead, projecting suborbital torus, small face, Cranial Cresting: no

Which hominin is the likely stone tool maker at Olduvai?

Probably homo habilis or homo rudolfensis

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

Australopithecus?

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

?

Which plants follow a C3 photosynthetic pathway?

Trees

Which plants follow a C4 photosynthetic pathway?

Grasses

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

Typically a mixed diet of C3 and C4 but mostly C3

Which hominin has a nearly pure C4 signal?

Pananthropus Boisei

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

Forested areas

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

Sweating and hair loss, need for different locomotion due to lesser trees

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

Neanderthalensis

What evidence do we have that Homo Erectus exploited savannah habitats?

Stone tools,

Where are fossils of Homo erectus/ergaster found?

Throughout Africa, Europe, mainland asia, and indonesia

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

1.8mya -250kya

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

1.9mya

Is H. ergaster/erectus the geologically oldest hominin that we find outside of Africa?

yes

What tool technology is associated with the first H. erectus/ergaster out of Africa?

Acheulean stone tools (tear drop hand axes)

What was the diet of H. erectus/ergaster?

Large dietary niche, dependent on meat

How did its diet differ from earlier hominins?

It hunted and killed animals for food

If H. erectus/ergaster was a hunter, how might it have killed animals?

The endurance running method, then killing it with wood spears

H. erectus/ergaster gave rise to numerous populations of Homo throughout the Old World.

Where is Sima de los Huesos?

Spain

Why does the Sima sample appear to be an intentional collection of individuals?

They seem to be positioned specifically

What's the Neandertal time range?

Around 800K- 28kya.

Where are Neandertals found geographically?

All around Europe, the middle east and western asia

What is an autapomorphy?

Traits specific to the species

Know the following Neanderthal autapomorphies and what each autapomorphy looks like anatomically:

Occipital bun round bun thing in back of head Receding Zygomatics a dished looking face, or far back cheek bones Retromolar gap gap behind last tooth Taurodont molars large rectangular roots in molarLarge nasal opening Beveled incisor wear (not truly an anatomical autapomorphy, but probably reflective of a behavioral autapomorphy).

Why are Neandertal autapomorphies used to argue against their being ancestral to modern humans?

Because there are multiple very specific automorphies that are not shared in any other hominin ancestor

What is the Neandertal body shape like in comparison to most modern humans?

Smaller, shorter, short limbs and barrel chested