Primates, Hominins and Bipedalism

Level 3 Biology Study - Human Evolution

________ are a group of mammals including humans, great apes, monkeys and others

primates

________ are a family of primates including humans and great ________

homonids, apes

________ ________ include orangutans, gorillas and chimpanzees

great apes

great apes use ________ as locomotion, knuckle walking or ________

brachiation, bipedalism

do great apes have tails?

no

great apes display sexual ________, with ________ (males / females) larger and stronger

dimorphism, males

great apes are mostly ________, with 4 limbs

quadripedal

great apes are ________ (herbivorous / carnivorous / omnivorous), and their ________ have 5 cusps

omnivorous, molars

are all great apes endangered?

yes

great apes have ________, or human-like, characteristics

anthropoid

________ are a subfamily of homonids, including all living and ________ species belonging to the ________ ________

hominins, fossil, human lineage

there are __ genera of hominins: ardipithecus, australopithecus and homo

3

of all hominin species, only ________ ________ are alive today

homo sapiens

________ are the closest living relatives to humans, with 98.6% of the same genetic material

chimpanzees

apes are ________,walking on 4 legs; while humans are ________, walking on 2 legs

quadrupedal, bipedal

apes have a __-shaped spinal chord; humans have a __-shaped spinal cord

c, s

apes have a femur ________ under the hip joint, which causes a “swagging” motion if walking bipedally; humans have a femur ________ under the pelvis, known as the ________ angle, so legs are positioned under the centre of ________ when walking upright

straight, angled, valgus, gravity

humans have bony projections on the base of the femur known as ________, which prevent the ________ tilting sideways when walking

buttresses, knee

________ have a longer femur, while ________ have a shorter, thicker femur

humans, apes

apes have ________ arms, allowing them to swing through trees (________) and walk on all fours; humans have ________ arms

longer, brachiation, shorter

the ________ ________ is the hole where the spinal cord exits the brain. in apes, it is located in the ________ of the skull, meaning that their skulls project farther forward. in humans, it is located in the ________ of the skull, to ________ the head more efficiently when upright

foramen magmum, back, centre, balance

do apes or human have thicker, stronger neck muscles to support the weight of their skull?

apes

apes have a __-shaped jaw; humans have a __-shaped jaw

u, v

apes have a more defined _______ _______ (at the base of the back of the skull) and _______ _______ (at the peak of the skull); in humans, these are reduced

nuchal crest, sagittal crest

apes have large _______ around the skull to support it, while humans save _______ by requiring reduced muscles, with the skull balanced better

muscles, energy

apes have a large _______ _______ (cheekbone), to chew tough vegetation; in humans, this is reduced in size

zygomatic arch

apes have a large _______ _______, which reduces chewing stress on the skull; in humans, this is reduced in size

brow ridge

apes have a _______ (shorter/longer) and _______ (narrower/wider) _______ _______, with large attachments for leg muscles; in humans, it is a _______ (shorter/longer) and _______ (narrower/wider), or “_______”-shaped

longer, narrower, pelvic girdle, shorter, wider, bowl

humans’ bowl-shaped _______ _______ reduces stress on the _______; aids muscles used for _______; supports internal _______; and allows _______ of large-skulled babies

pelvic girdle, hips, walking, organs, birth

apes have a rib cage which is flattened _______ (front to back / side to side), shaped like a _______ to support a herbivorous gut; humans have a rib cage which is flattened _______ (front to back / side to side), to move the _______ __ _______ towards the _______

side to side, funnel, front to back, centre of gravity, spine

apes have _______ feet with a/an _______ big toe and _______ toes to grip tree branches for climbing; humans have _______ feet used for shock absorption, with _______ toes and a _______-facing big toe over which we _______ with each step

flat, opposable, curved, arched, straight, forward, pivot

apes have a _______ face and a _______er brain; humans have a _______ face which allows for a _______er brain

sloped, small, flat, large

humans have a larger _______, the largest part of the brain, and more extensive folding of the outer layer of the brain, the _______ _______; important for _______ solving, _______-making, c_______, m_______, _______ perception and _______ thought

cerebrum, cerebral cortex, problem, decision, communication, memory, sensory, abstract

humans have a larger _______, which is important for _______ and precise _______ coordination

cerebellum, balance, muscular

humans have _______’s area, which is used for making speech; and _______’s area, which is used for interpreting speech

broca, wernicke

both apes and humans have the _______ grip, while only humans have the _______ grip

power, precision

apes have _______ phalanges while humans have _______ phalanges

curved, straight

humans have a longer, _______ thumb, with a _______ joint on the first m_______ and _______ muscles to flex the tip joint

opposable, saddle, metacarpal, flexor

male apes have larger _______ teeth (most likely for defending females and young), while there is no difference in those of humans

canine

the _______ grip allows for more controlled _______ movements

precision, grasping

apes have a shorter _______, and are unable to produce _______ sounds; in humans, this is longer, and there is the _______ (voice box) below this, allowing us to make complex sounds for _______

pharynx, complex, larynx, speech

do humans or apes have more sweat glands?

humans

an advantage of bipedalism is that it frees the _______, for carrying f_______, t_______ and b_______, and p_______ food

hands, food, tools, babies, picking

an advantage of bipedalism is that it provides greater _______, allowing humans to look _______ vegetation to find food/shelter, and also appear more _______

height, above, intimidating

an advantage of bipedalism is that it is _______ efficient for walking

energy

an advantage of bipedalism is that is allows hominins to keep _______ in the savannah, by increasing _______ around body, and decrease the _______ _______ of body in sunlight

cool, airflow, surface area

a disadvantage of bipedalism is that is causes hominins to move _______ than quadripedes

slower

a disadvantage of bipedalism is is requires a smaller _______, introducing difficulties with giving _______

pelvis, birth

a disadvantage of bipedalism is it is less _______, decreasing one’s ability to _______ when standing/walking. to minimise this, skeletal changes have been selected for to maintain a _______ __ _______ within the body

stable, balance, centre of gravity