human origins midterm 2

aroboreally

animals living in trees

bipedalism

ability to walk upright on 2 legs

(curved spine, widened pelvis, lengthened lower limbs)

nocturnal eyesize

animals active at night

more rods in eyes

dinural

acitve during day

more cones in eyes

k-selection

long-life span

produce few offspring at a time

r-selection

rapid reproduction

quantity over quality

superfamily homindea

part of the ape superfamily

1. molecular evidence

2. primitive cranio-dental charecteritstics

3. derived locomotor traits

4. slower life-pattern

cranial traits of hominodea

Pan, gorilla, pongo = Long skulls high faces

Homo= short faces round cranium

sexual dimorphism

observeable diffefences in behavioral and physical charecteristics of males/females

kin-selection

Individuals relatives survival and reproduction is prioritized

Inclusive fitness

a individuals overall contribution to survival and reproduction of their own genes

group selection

natural selection on a group that leads to benefits for the group

taphononmy

a branch of paleotonology that deals with fossils

canine sectorial complex

canines and pre-molars fit together and sharpen together

Biostratigraphy

Uses fossils to determine the relative age of rock layers

(Based off faunal sucsession)

foramen magnum position

foramen magnum= large opening at base of skull where spinal cord passes through

*forward position

*key for bipedal adaptation

primate charecteristics

emerged early 55-65 MYA

aboreal (tree dwelling), hghly social niche, binocular vision, color and depth perception, reduced olfaction

Anthropoids

monkeys, apes, humans

Anthropoid behavior

Increased parental care (k-selected)

More mutual grooming

varied locomotion/diets

anthropoid anatomy

No rhinarium (reduced smell)

forward facing eyes/color vison, fully enclosed eye/orbit, fused manidble at mid-line

Teeth = 2123

Longer gestation period

Hominoids

Apes/humans

Loss of tail

Hominioid charecteristics

Greater cognitive ability/behavior, hughly k-selected, territorial, natal groups,

Aegyptopithecus

- oligocene epoch
- 35 mya
- Modern day Egypt ( Fayum region)
-Prognathic snout
- 2.1.2.3. dental pattern
- increased sexual dimorphism
- thought to be a basal ancestor group to apes & old world monkeys

Sivapithecus

- 12.2 mya
- miocene epoch
- Indian subcontinent
- possible ancestor of orangutang
- Southern Asia
- narrow interorbital distance
- wide face with flaring zygomatics
- looks closer to orangutang

Gigantopithecus

- ancestor of the ape
- largest known ape to ever live
- 2 mya
- Pliocence
- terrestrial
- huge bodies (low quality diets)
- likely sister group of sivapithecus and pongo

Proconsul

- 23 to 25 mya
- Miocene epoch
- Eastern Africa ( Kenya & Uganda)
- arboreal quadruped
- shared similar traits with old world monkeys & apes
- lacks tail
- 2.1.2.3 dental pattern
- long arms, hands, and fingers

Dryopithecus

- Miocene epoch
- 12-10 mya
- Europe/Asia
- Y5 molar pattern
- arboreal

Y-5 lower molar cusp pattern

- Molar that has five cusps with grooves running between them, forming a Y shape
- Characteristic of Hominoids

anataomy evidence of bipedalism

- foramen magnum position
- spinal curvatures
- pelvic iliac blade orientation
- femur biondylar orientation
- femur neck bone distribution
- Foot: pattern of weight transmission
- Large calcaneus (heel) bone in foot

Australopithecus anamensis

- 3-4.2 mya
- East Africa(kenya)
- Ape- like dyastema
- Chimpanzee sized brain
considered the earliest most primitive Australopithecines

-Found in rift valley

-confirmed hominin

Australopithecus africanus

- 4.2- 3.8 mya
- South Africa (sterkfotien cave)
- Reduced Dyastema
- Intermediate convergent big toe = moving toward obligate bipedalism

-relaitively human dentition

-pelvis is more hominin

-central foramen magnum position

Australopithecus afarensis

- 3(?)- 2 mya PILOCENE
- afar region of Ethiopia (east africa)
- Pelvis is more adapted to bipedality

-increasing encephalization

still retained climbing, high sexual dimorphism

Speciation

- The process by which a new spices evolves from an earlier species. Speciation is the most basic process of macroevolution.

Order of Epoch

Paleocene
Eocene
Oligocene
Miocene
Pliocene

Pleistocene
Holocene

Prosocial behaviors

- Actions that benefit other individuals & or a society as a whole

Sahelanthropus tchadensis

- 7-6 mya
- Central / North Africa in Chad africa
- Possible biped, intermediate foramen magnum

-no sectorial complex

-more ape-like then human

Orrorin tugenensis

-6 mya
- East Africa (kenya)
- First clear evidence of bipedalism
- Femoral neck morphology
- Retained arboreal locomotion

*best canidate for pre-austrilopthecene

Ardipithecus ramidus

- 5.8- 4.4 mya
- East Africa, Middle Awash Ethiopia (rift valley tim white)
- Possible biped
- Divergent big toe
- small brained
- Teeth like chimps

-opposable thumbs/toes

Scenarios for the evolution of bipedalism

- carrying objects, tools, weapons
- hunting
- seed and nut gathering
- feeding from bushes
- thermoregulation cooling
- visual surveilance
- long distance walking
- malre provisioning

Plate tectonics

A theory that explains how major landforms were created through the movement of earths plates

Continental drift

suggests plates were once before uniformed “pangea” and have moved and drifted since

Pangea

The supercontient that existed during the late paleozolic/mesozoic era

Miocene hominoid charecteristics

Large-enameled molars, robust mandibles, small canines.

Palynology

the study of pollen/spores

Raymond dart

Had the original austrolipithecus africanus

*Issue of nature

*Discovered taung child

Taung child

first early hominin found in africa and the first discovery of a human genus different from our own

*member of a. africanus

*small brain

Swartkans cave

Showed evidence for paranthopus robustus

-1.8 MYO

Laetoli footprints

Fossilized footprints found in Tanzania; said to be evidence of bipedalism in hominins

Louis leakely

Discovered remains of zijanthropus boisei/paranthropus boisei with mary

*Found in olduvai gorge in Tanzania

Genus australopithecus

genus of early hominins during the pilocene/early plestiocene

Traits of australopithecus

terrestrial bipeds, large chewing teeth, thick enamel, brain only slightly larger than apes

Paranthropus boisei

Robust skull, massive jaws, large cheek teeth, sagital crest for powerful chewing

*first user of stone tools

-Large cheek bones (zygomatics)

Australopithecus sediba

pliestocene epoch ; found in south africa

small brain, long arms, human like pelvis/hands

John Robinson

Discovered complete skull of Australopithecus africanus

mosaic evolution

features (morphological/behavioral) evolve at different rates

where were earliest hominins found

africa

Paleocene (65-55.8mya)

first archaic primates

Eocene (55.8-33mya)

first euprimates, early strepsirhinnes, halpolrhines

Oligocene(33-23 mya)

early cartarrhines,precursors to monkeys and apes

Miocene (23-5.3mya)

monkeys and apes, first human like taxa

Pliocene(5.3-2.6mya)

early hominin diversification

Pleistocene(2.6-0.105mya)

early homo and decendents

Holocene (0.105mya-present)

modern humans

Binocular vision

Overlapping visual fields

Forward facing orbits primates

helps locomotion through 3-dimensional aboreal world

helps indentify ripe fruit

Temporalis muscle

Separated by fully enclosed orbits

Orthograde posture

related to brachiation; under branch hanging/swinging

New world monkey dentition

2133

Old world monkey dentition

2123

also found in gorillas, chimps, orangutans, gibbons

Encephilization

Larger brains, become more complex and visually oritented

Cartahinni

all old-world monkeys, apes, humans

Strepsirhinni (wetnosed primates)

lemurs, lorieses

wet rhinarium (nosepad)

good vision, nocturnal, grooming claw.

Haplorhinni (dry-nosed primate)

no rhinarium; more emphasis on color vision

use hands for grooming, larger brains then strepsirhinni

NW monkey nostril

side-ways facing

3-premolars

grasping tail

OW monkey nostril

down-ward facing

2-premolars

Ischial callosites

non-human hominoids

body size 15-400lb

tropical-dry savanah

monogamy-harem

Pentalpedal

use front legs and scoot

*used by kangeroos

Brocas area

language production

Weirnickes area

language comprehension

Laurasia

part of pangea that split off (north hemisphere)

formed north america/eurasia

Where was afrarensis found?

In hadar

Thought to be the earliest hominins ever found

*Tim white/Don johnason

Lucy

shows clear evidence of bipedalism

*found in afar region of etheopia by donald johnason

species: afaransis

Dikka

“Lucys baby”

Found in ethopia

2.5 yr old

species afaransis

australopithecene height

tended to be shorter males at 4’11 females at 3’5

flourine-analysis

bones exposed to ground water (containing florine)

potassium-argon

half-life of 1.25 billion years to produce argon

argon-argon

more persice can date entire hominin record

radio-carbon

half-life of 5,730 years can be used with any organic material

absolute dating

generating the age of find based off the find itself, based on radio-isotope decay and half-life ratios

When a trait or adaptation arises for one purpose but becomes useful in a new enviroment or context that is called

Exaptation

postorbital closure

bar that protects eye

primates

members of the mammalian oder primates, which includes lemurs, lorises, tarsiers, monkeys, apes, and humans.

morphology

the form (shape/size) of a body structure

steroscopic vision

the condition whereby visual images are, to varying degrees, superimposed. This provides for depth perception, or viewing of the external environment in 3 dimensions. Stereoscopic vision is partly a function of structures in the brain.

cusps

the bumps on chewing sutface of molars/premolars

Strepsirrhini

the primate suborder that includes lemurs and lorises

Cercopithecidae

the taxonomic family that includes all Old World monkeys

polyandry

a mating system where a female associates with more than one male with whom she mates

sister groups

the relationship of new clades that result from the splitting of a single common lineage

dental comb

arrangement of teeth in lemuriforms so that they can groom themselves