B3.6 Flashcards
(431 cards)
What are the hominoids?
Chimps, gorillas, orang-utans and humans and thier ancestors
What are the hominids?
Chimps, gorillas, humans and their ancestors
What are hominins?
Humans and their ancestors
What are primates?
New world monkeys, old world monkeys, apes and humans
What are the closets relatives to primates?
Insectivores, eg mole, hedgehogs etc.
How much genetic code is shared between humans and chimpazines?
99%
What are many adaptations for primates focused on?
Tree dwelling
What are some adaptations primates have for tree dwelling?
Well developed collar bone (clavicle), 5 digit hands and feet, walking on the soles of feet (plantigrade foot posture), long nimble limbs
What are the 2 types of locomotion primates perform, define them
Arboreal locomotion - moving through the treesGround locomotion - moving on the ground
What are the 3 types of arboreal locomotion? explain and give examples of species that do this
Quadrupedalism - arms and legs are of equal length and importance, eg lemursModified quadrupedalism - Leaping an climbing, trunk is vertical before and after leaps+plus in resting eg tarsiersBrachiation - use of the arms to swing through trees and arms become longer, eg gibbons
What are the 3 types of ground locomotion? explain and give examples of species that do this
Terrestrial Quadrupedalism - using all four limbs all the time and all 4 limbs of similar length, eg baboonsKnuckle walking quadrupedalism- walking on all four limbs but on the front two limbs, on their knuckles and on the back two on the surface of their feet and front 2 limbs longer than back 2, eg chimpanzeeBipedalism - walking on two legs and the hands are not used for motion at all, legs longer than arms eg humans
What is a skeletal change to the CHEST to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Structure: HUMANS - rib cage flattened so centre of gravity is as little far forward as possible minimising tendency to fall forward APES - chest is flattened to the sides helping to lower centre of gravity
What are the skeletal change to the SPINE to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Shape: HUMANS - S shaped curve to provide support and balance for upright position of torso and places weight directly above joint between spine and pelvis APES - C shaped spine promotes quadrupedal locomotion Neural spines: HUMANS - short neural spines (points bits on spine FYI) are short as little muscle required to hold head up APES - long neural spines as need for large surface for muscle attachment to support large head in horizontal position
What are the skeletal and muscular changes to the PELVIS to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Shape: HUMANS - bowl shaped (broader+shorter) support upright torso by increased stability, weight transmitted directly to legs APES - longer+narrower for greater attachment of gluteus medius muscles=helps quadrupedalism movement and better support to torso organsMovement: HUMANS - gluteus maximus muscle located at rear of hips to help pull femur back when walking APES - smaller gluteus maximus that lies on outside of hip to raise legs sideways
What is the skeletal change to the LEGS to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Structure: HUMANS - legs are longer than arms as legs solely used for movement unlike arms, femur is longer=larger stride, thinner bone=lighter for more efficient movement (can be thinner as better weight distribution) APES - arms longer than legs as arms used more for weight distribution
What are the skeletal change to the KNEE to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Valgus angle: HUMANS - femur slants downwards and inwards+angled at knee joint, this puts the weight of the body directly underneath the spinal cord (increased valgus angle) = better balancing when walking APES - femur goes vertically from pelvis (no valgus angle)Lateral condyles: HUMANS - increased buttressing of the bone at the base of the femur preventing sideways movement of leg when walking APES - no increased buttressing
What are the skeletal change to the FEET to enable bipedalism compared to apes? explain how it helps for both quadrupedalism and bipedalism
Carrying angle: HUMANS - feet place directly under spine to prevent swaying when walking APES - feet on outside of pelvis Shape: HUMANS - there is a convex arch of foot that acts like a spring allowing for better transfer of weight down foot to big toe APES - no arch (flat footed)Big toe: HUMANS - aligned with other toes to provide final thrust against ground for forward propulsion APES - divergent (slightly opposed) to allow for grasping action
What are the skeletal change to the SKULL to enable bipedalism compared to apes? explain how it helps for human and ape behaviour/habits
Shape: HUMANS - rounded for increased brain capacity APES - flatter as doesn’t need larger brain capacityCranium capacity: HUMAN - enlarged skull (1350cc)(particularly frontal lobe) to accommodate for larger prefrontal cortex=better abstract+thinking capacity APE - smaller skull (500cc) as no need large prefrontal cortexStructure: HUMANS - weight concentrated in cranium+reduced attachment sites for chewing muscles (cooking makes it easier to chew) and facial muscles (no need for aggressive faces), weight concentrated in jaw for attachment of muscles (tough diet=more strenght)Foramen magnum: HUMANS - in centre of underside of skull so its is placed directly on top of spine=better balance APES - back of skull for horizontal position of headOccipital condyles (for attachment of first vertebrate): HUMANS - far forward helps bipedalism APES - far back helps quadrupedalism
What are the skeletal change to the JAW/ARRANGEMENT to enable bipedalism compared to apes? explain how it helps for human and ape behaviour/habits
Size: HUMANS - small in size as teeth are smaller APE - large as teeth are largeTeeth arrangement: HUMANS - teeth are arranged in ‘v’ arch shape+no diastema APES - are arranged in ‘u’ with parallel sides+diastema
What are the skeletal change to the TEETH to enable bipedalism compared to apes? explain how it helps for human and ape behaviour/habits
Shape: HUMANS - smaller and more uniformed size suited for omnivorous diet+softer cooking APES - larger specialised teeth for grinding and chewing, large canines for defenceStructure: HUMANS - smaller molars+premolars and thinner enamel as less chewing/grinding=less wear and don’t need to expend energy on making larger teeth/moving larger jaw=energy conserved APES - large molar+premolars and thick enamel as lots of chewing/grinding=more wear
What are the differences in BEHAVIOURAL ADAPTATIONS between humans and apes? how does this help their lifestyle?
Food: HUMANS - hunted/gathered then transported back to home/base and prepared APES - eaten where foundManipulation of objects: HUMANS - can perform fine careful movements APES - can only grab objects with rough/power grip
What are the differences in PHYSIOLOGICAL ADAPTATION between humans and apes? how does this help their lifestyle?
Ovulation: HUMANS - concealed as alpha male has complete dominance over mates through ordered and respected social structure APES - advertised as males don’t have complete dominance and social structure not rigid Sweat: HUMANS - produce a lot of sweat for efficient cooling APES - produce little sweat as little cooling requiredHair: HUMANS - relatively hairless for better cooling APES - very hair to keep warm in cool shade of forests
How has the structure of the HAND different in humans and apes? how does this help for their life style?
HUMAN - finger bones straight and thumb is long+fully opposable=very good grip on objects enabling complex tool making APES - finger bones curved and thumb short and not fully opposable=use of crude tools only and suits brachiation
How are humans generally adapted differently to apes?
Vertical centre of gravity - alignment of skull, trunk, legs and feetimproved bipedalism - valgus angle, arched feet, pelvic shape + vertical centre of gravityBrain structure - larger volume for larger prefrontal cortex etc. foramen magnum location, muscle attachment etc.Jaws/teeth - smaller teeth, more uniform size/shape and less muscle as food easier to chew [cooking] and less specialised