Human Animal Final (with bones)

Skull

The bony structure that forms the head and protects the brain.

Clavicle

The collarbone that connects the arm to the body.

Scapula

The shoulder blade that connects the humerus with the clavicle.

Humerus

The long bone of the upper arm or forelimb.

Radius

The lateral bone of the forearm, on the same side as the thumb.

Ulna

The medial bone of the forearm, opposite the radius.

Carpals

The eight small bones that make up the wrist.

Metacarpals

The five bones of the hand located between the carpals and the phalanges.

Phalanges

The bones of the fingers and toes.

Vertebrae

The individual bones that make up the spine.

Ribs

The bones that form the rib cage protecting the chest cavity.

Sternum

Also known as the breastbone, it connects the rib bones at the front of the rib cage.

Pelvis

The bone structure that supports the organs in the lower abdomen.

Femur

The thigh bone, the longest bone in the human body.

Patella

The kneecap that protects the knee joint.

Tibia

The larger and stronger of the two bones in the lower leg.

Fibula

The thinner and smaller bone of the lower leg, located alongside the tibia.

Tarsals

The seven bones that make up the ankle.

Metatarsals

The five long bones in the foot between the tarsals and the phalanges.

Coccyx

The small tailbone at the base of the vertebral column.

Sacrum

The triangular bone at the base of the spine formed from fused vertebrae.

Zygomatic Bone

Also known as the cheekbone, it forms the prominence of the cheeks.

Maxilla

The upper jaw bone that holds the teeth.

Mandible

The lower jawbone, the only movable bone of the skull.

Nasals

The two bones that form the bridge of the nose.

Sphenoid Bone

A bone that forms part of the base of the skull and parts of the orbits.

Cervical Vertebrae

The seven vertebrae in the neck region.

Thoracic Vertebrae

The twelve vertebrae in the upper back, to which the ribs attach.

Lumbar Vertebrae

The five vertebrae in the lower back.

Encephalization Index

measure of brain size (usually compared to weight)

The human brain is ______.

Lateralized

Cortex

outer layer of cerebrum

What does the cortex control?

Motor and sensory operations

What does the neocortex control? (neo = new, so think about newer processes)

higher reasoning skills, language, and problem solving

What are fossils / what is the fossilization process?

Minerals replacing organic materials

What are the best conditions for fossilization?

Rapid burial and low oxygen levels

What is ‘taphonomy’?

study of post-mortem processes affecting organisms

Paleospecies concept (Intraspecific variation/lumpers)

observations between members of the same species- coloration, sexual dimorphism, baseline genetic differences, ages

Relative dating

estimate the age of an object relative to others (older or younger)

Principle of superposition (stratigraphy)

lower sedimentary layers are older than higher layers

Strata

Level of rock or rock unit

Absolute (chronometric) dating

process of physics and chemistry to give a date to an object (with a range of error)

Radioactive disintegration rate

Unstable versions of atoms (isotopes) change/”decay”

Shedding of electrons and the changing of the element from one atom into another

Half life

length of time for the material present to decay by one half

Carbon-14 Dating (14C)

carbon-14 half life: 5,730 years

How old must samples be to use Carbon-14 dating?

under 50,000 yrs

What year is set as present when dating things?

1950

Potassium/Argon dating (K/Ar Dating)

measures of the decay of potassium-40 into argon-40

How old should samples be when using K/Ar dating?

over 100,000 years

Bone is affected by:

soft tissue, lifestyle, environment

Dental arcade

shape of an organism’s rows of teeth

What does enamel thickness correspond to in an organism?

diet

shearing complex

edges on teeth that allow for slicing

mandibular symphysis

chin

habitual bipedalism

usually walk bipedally; most efficient

obligate bipedalism

only walk bipedally

prognathism

projection of middle or lower face

post orbital constriction

narrowing of skull behind eye sockets

foramen magnum

where the spinal cord emerges from the brain (centered in humans)

Os Coxae

(in humans) basin shaped hip bone

(in humans) upper limbs are ____ than lower

shorter

Advantage of having longer thigh bones?

long strides

running long distances

a pendulum swinging gait = _____

most efficient

sagittal crest

ridge on top of skull that forms an attachment point for chewing muscles

What are some disadvantages to bipedalism and/or human evolution?

slipped disks

lower back pain

exposed abdomen

weak knees

fallen arches

What are some reasons humans might have evolved to be bipedal?

carrying tools, young, or food

seeing over grasses

energy efficiency

reduced sun exposure

Early Hominins (era, __ mya, and features)

Late Miocene - early Pliocene

7mya - 1.8mya

ape-like features

Miocence - Pliocene transition characteristics (5mya)

cooling climate / climate changes

megadontia

large molar surface area

zygomatic arches

cheek bones

Who is “Ardi”?

 Ardipithecus ramidus

Ethiopia

4.4mya

upright bipedal

lived in a wooded area, challenging the savanna theory that humans evolved in grasslands

Australopithecines

A. afarensis & anamensis

gracile & robust

Lucy

Laetoli Footprints

3.9mya

possible upright hominins

non-divergent big toe

Genus Homo (___mya & characteristics)

appears 2.5 mya

smaller teeth and face

larger brains (among Homo & Australopithecus)

culture & tools

Homo habilis “handy man”

Earliest Homo species, ancestor to H. erectus, showed first substantial increase in brain size, and is the first species to definitively be associated with stone tool use. ~2mya

Oldowan tools

named after Olduvai Gorge

early - A. garhi; later - H. habilis

stone tools used by early hominins, characterized by simple flaked designs.

Homo erectus compared to earlier hominins

cranium larger

less prognathic

molars/premolars reduced

Homo erectus compared to humans

greatest breadth is lower

supraorbital torus (”brow ridge”)

Nuchal torus

No chin

Acheulian tools

Bifaces, handaxes, cleavers

Archaic humans = ___kya

350 - 30 kya

Modern humans = ___kya

300 kya

Neandertals (characteristics & timeframe)

125 - 30 kya

muscular

large nasal apertures

dental wear

1500cc brain

trauma patterns resembling rodeo riders

“Levallois” technique

A prehistoric stone tool production method used by early humans, characterized by the preparation of a flake from a striking platform to create sharp, symmetrical tools.

2 hypotheses for extinction of Neandertals

modern humans “outbred” Neandertals (gene flow)

modern humans “outcompeted” Neandertals (Homo sapiens are smarter)

characteristics seen in anatomically modern humans (AMH)

13-1400cc brain size

rounded & high skull

vertical forehead

Out of Africa theory

Origin of modern humans as a new species in AFRICA

Movement from Africa throughout the Old World after 100 kya

Replace hominids in Africa, Asia, and Europe —> change to hominin

Humans outcompete Neandertals

Genetic diversity is greatest in Africa bc of genetic drift

Y chromosome & mtDNA sequencing

Multiregional Theory

Homo erectus leaves Africa and keeps evolving

continuity between regions

significant archaic contributions to modern genome

we descend thru Neandertals

Assimilation theory

First AMH evolve in Africa, but NOT as separate species

AMH leave Africa and interbreed with Archaic humans in Europe and Asia

Assimilation of non-African populations rather than replacement

Evidence for gee flow between Archaic and anatomically modern humans

Modern humans “outbred” Neandertals

Homo erectus culture

enlargement of brain —> more sophisticated tools

scavenging, hunting, gathering

Acheulian tools

Hominin behaviors

obligate bipedalism & nonhoning chewing (grinding, not slicing)

Homo erectus (~1.8mya)

Likely descendant of H. habilis; the first hominin to move out of Africa and into Asia/Europe

Homo habilis vs rudolfensis

rudolfensis is larger than habilis, but both overall have bigger brains and small faces

Homo naledi

a morphologically primitive hominin found in cave deposits in South Africa (~335,000–236,000 yBP)

Homo floresiensis

possible new species of Homo found in Indonesia, notable for its small size

Occipital bun / nuchal torus

A rounded “bun” at the back of a skull

Supraorbital torus

brow ridge

Denisovans

An extinct hominin, likely of the genus Homo. Genetic evidence suggests they’re related to Neandertals & modern Homo sapiens