Bio Anthro (Anth 252 WVU) Final Exam

fossil

the traces or remains of an organism preserved in rock

fossilization

the process of fossil formation that occurs under certain conditions

1. suitable remains

2. quick burial

3. mineralizing context (petrifaction)

adapiform

one of a group of early primates that lived between 56 and 34 mya

relative dating

based on "Principle of Superposition" where the oldest layer at the bottom and youngest layer at the top

chronometric dating (absolute dating)

any dating method that provides a numerical age estimate for the dated material

radiocarbon dating

a radiometric dating method that relies on carbon-14, an isotope with a half-life of 5,730 years

radiometric dating

any dating method that uses the principles of radioactive isotope decay to determine numerical age

potassium-argon dating

a radiometric dating method that relies on radioactive potassium isotopes with a half-life of about 1.3 billion years

argon-argon dating

a radiometric dating method that relies on the ratio of two argon isotopes and has a date range similar to that of potassium-argon dating

nonradiometric dating

any chronometric dating method that is not based on the principles of radioactive isotope decay

paleomagnetic dating

a nonradiometric dating method based on changes in Earth's magnetic polarity

law of superposition

a law stating that material from lower geological layers must be older than material from higher geological layers

isotope

a variation of a chemical element that has a different number of neutrons in its nucleus than other variations of the same element

half-life

the length of time it takes for one-half of an amount of a radioactive isotope to decay

hominin

the classification group (tribe) containing humans and our extinct relatives since the split from other apes

omomyoid

one of a group of early primates that lived between 56 and 34 mya

miocene

- 23.8 mya to 5.3 mya

- ape/hominid divergence

- sahelanthropus tchadensis (7-6 mya)

- orrorin tugenensis (6 mya)

Pliocene

- 5.3-1.8 mya

- mixture of forest and grasslands for most

- first discovery: Raymond's Dart Australopithecus africanus

Australopithecus afarensis

- 3.2-2.9 mya

- early australopithecine from East Africa that had a brain size equivalent to a modern chimpanzee's and is thought to be a direct human ancestor

- Lucy

- eastern

Ardipithecus ramidus

- miocene

- 4.4 mya

- reasonably complete skeleton

- bipedal but opposable big toe/no arch

- teeth

- forested habitat

Early Homo

- late pliocene 2.0-1.8 mya

- bigger brain 650 cc (vs. 450 cc)

- reduced prognathism & browridge (still present)

- teeth smaller than Australopithecus

- some finger curvature

- smoother bipedal gait

- Oldowan culture

Homo habilis

- Homo habilis sensustricto (500-650 cc brain)

- Homo rudolfensis (600-800 cc brain)

Homo erectus

- early pleistocene (more grasslands)

- early as 1.8 mya to as late as 250,000 ya in Asia

- Eastern African origins

- first hominid to leave Africa

- Turkana Boy

- Earliest tools: Oldowan like

- later Acheulean

- bifacial handaxes and clevers

- foraged foods and possibly hunt

Homo erectus (cont.)

- prominent browridge

- larger brain 700 cc - 1200 cc (average 900 cc)

- sagittal keel

- no chin

- somewhat prognathic

- shovel shaped incisors

- post cranial: nearly modern body

Homo floresiensis

- Flores Indonesia

- Acheulean type tools rom 840,000 ya

- fragmentary bones 18,000 ya

- somewhat Homo erectus but shorter (3ft tall)

- result of insular dwarfism ?

Homo hiedelbergensis

- Middle Pleistocene (900,000 - 150,000 ya)

- rapid climatic changes

- Africa, Europe (earlier), Asia (very late)

- evolved in Africa from Homo ergastor/Homo erectus

- larger brain 1,000 cc - 1,400 cc

- heavy arching brow ridges

- thick skulls

- prognathic

- relatively modern post-cranial skeleton

Homo heidelbergensis (cont.)

- Levallois technology 300,000-200,000 ya

- more cutting edge per stone

- more stone tool types

- 1st wood tools

- large game hunting

- fire

Homo neanderthalensis

- occipital bun

- no chin

- large browridge

- large nose

- large molars

- body shorter but robust

- cold adapted

- some shared genes w/ modern humans: FOXP2 (language)

Homo neanderthalensis (cont.)

- Mousterian technology (Levallois based)

- variety of tools

- single media tools common

- shelters (temporary)

- fire and cooking; primarily meat, range of foraged foods

- many injuries, had infirmary type thing; cared for the old

- some art

- burial (caves)

Homo sapiens

- anatomically modern humans

- late Pleistocene (emerge); Holocene

- as early as 300,00 ya

- modern face but, archaic/elongated face & large teeth

- chin

- loss of prognothism

- small teeth/jaws

- gracile & relatively tall

Homo sapiens (cont.)

- Upper Paleolithic

- stone innovations; blades & microliths

- composite tools

- varied materials

- atlatl

- highly varied diet

- fire and shelters

Denisovans

- limited finds; i.e., partial phalange, toe, 3 teeth

- Denisova Cave in Altai Mountains (Siberia)

- interbreeding with local Neanderthal pop.

- interbreeding with modern human pop.

Homo luzonensis

- April 2019 Callao Cave, Philippines

- 67,000-50,000 ya

- 13 pieces found; teeth, hand/foot bones, & femur parts

- odd mix of Australopithecus/Homo erectus/Modern humans

bipedalism

a form of two-footed locomotion where movement occurs primarily through the use of the hind limbs

occasional bipedalism

bipedal locomotion that is practiced sometimes (or occasionally)

habitual bipedalism

bipedal locomotion that is practiced regularly (or habitually)

obligate bipedalism

bipedal locomotion that is practiced all the time

savanna hypothesis

an explanation for the evolution of bipedalism that argues bipedalism was selectively favored as open grassland environments expanded throughout Africa in the past

- humans stood because they lived in a grassy area and it gave them an advantage of bipedalism

savanna environment

open grassland interspersed with pockets of trees

patchy forest hypothesis

an explanation for the evolution of bipedalism that argues bipedalism was selectively favored because it was more energy efficient than quadrupedalism in the patchy forest environment of Africa

thermoregulation hypothesis

- bipedalism was selectively favored because it helped early hominins to stay cool during the hottest times of the day

provisioning hypothesis

- bipedalism was selectively favored because it helped males to provision females and improve reproductive success

postural feeding hypothesis

- argues bipedalism was selectively favored as a way to more efficiently reach hanging fruit in small trees

gracile

having thin, light musculature and bone

robust

having thick, dense, heavy musculature and bone

prognathic

having a projecting or protruding face

sexual dimorphism

the physical differences between adult males and adult females of a species

sagittal crest

a ridge of bone along the midline of the cranium that allows for the attachment of extra-large chewing muscles

Oldowan technology

- 2.5 mya

- the earliest stone tool technology, characterized by chopper and flake tools

- transported materials

- scavenging food, not hunting

chopper

- a large, heavy stone tool with a sharp edge where small pieces of rock have been removed

flake

- a small piece of rock that has been removed from a larger rock and can be used as is or further modified into a specialized tool

Acheulean technology

- the second and more widespread stone tool technology that was characterized by handaxes

biface

a stone tool that has had flakes of stone removed from two sides

handaxe

a biface tool that is shaped like a pear or teardrop

zygomatic arch

cheekbone area formed by numerous small bones, allowing a space for the jaw muscles that attach to the mandible below and the temporal bone above

orthognathic

having a flat face

brow ridge

a bony ridge located above the eye orbits

occipital torus

a ridge of bone along the occipital bone that forms a small point when seen from the side

Out of Africa I

the migration between 1.8 mya and 800 kya of Homo erectus out of Africa and into Asia and Europe

sagittal keel

a very slight ridge of bone along the midline of the cranium

Mousterian technology

- a stone tool technology that used the Levallois technique to produce a variety of specialized flake tools

Levallois technique

- a process used to produce regularly shaped flakes that can then be further modified into different tools

occipital bun

a large, round projection located on the occipital bone

Upper paleolithic technology

- a complex stone tool technology characterized by tools made from special stone flakes called blades

- blades and microliths

- composite tools

- varied materials; bone, shell, wood, ivory

blade

- a stone flake with a special elongated form

replacement model (Out of Africa II)

- an explanation for the evolution of humans that argues the species evolved in Africa and then expanded to other regions, replacing related species as it went

island (endemic) dwarfism

- a process where animals that are large on the mainland evolve to be smaller on an island as an adaptation for the limited amount of available resources

founder effect

- a type of genetic drift that occurs when a subset of a larger population founds the next generation due to substantial population loss or population movement