lecture 9 Flashcards
what characteristics of primates allow them to spend a great deal of time in trees? (3)
- flexible shoulder and hip joints
- grasping hands
- excellent depth perception
which characteristics are common to all primates? 4
- erect (upright) or nearly erect posture
- grasping hands and feet
- Diurnal (active during the day)
- complex social behaviour
what is the lowest taxonomic group that includes monkeys, apes, and humans?
Anthropoidea
what is the lowest taxonomic group that includes only apes and humans?
Hominoidea
how has walking patterns of Hominoidea change from the most primitive to the most derived? 5
- Gibbons and siamangs move by swinging from branches (brachiations)
- orangutan and bonobos- hands and feet
- Gorillas- knuckle walking
- chimpanzees- knuckle walking and bipedal swaggering
- Homo sapiens (humans)- upright posture and bipedal locomotion
which homonin 3 characteristics changed with the evolution from early to modern humans?
- smaller build
- less-protruding brow ridges
- more prominent chin
what evidence suggests that modern humans originated in Africa?
independent genetic studies of mitochondrial DNA and Y chromosome indicate that all human populations are descended from a common ancestor that originated in Africa and then migrated to various regions on Earth
which ape species spend the most time on ground (3)
Gorillas, chimpanzees, and bonobos
what trait allows researchers to distinguish between apes and humans
bipedal locomotion. Humans are bipedal, apes are not.
what evidence suggests that Neanderthals and modern humans represent 2 distinct species
mtDNA sequence data: the differences between gene sequences of Neanderthals and humans are much greater than the differences between any 2 modern humans
Primate character: erect (upright) or nearly erect posture=
= flexible hip and and shoulder joints
Primate character: grasping hands and feet=(3)
=1.opposable thumb (and/or big toe),
- nails not claws,
- fingertips with many sensory nerves
Primate character: Diurnal (active during the day) (2)
- forward facing eyes with overlapping fields of vision
2. rely more on vision than smell
Primate character: complex social behaviour (2)
- large, complex brains- great capacity to learn
2. small broods(1 hatching or birth)- extended parental care
how has the social structure of Hominoidea change from the most primitive to the most derived? 5
- Gibbons and siamangs - family groups/ solitary
- orangutan- solitary/family groups
- Gorillas- 2 to 65 per group
- chimpanzees and bonobos-20 to 130 per group
- Homo sapiens (humans)-doesnt say but i think large communities
def of primates
lineage that includes humans, apes, monkeys, and their close relatives
4 key derived traits of primates
- erect / nearly erect posture
- grasping hands (or feet)
- diurnal (active during the day)
- complex social behaviour
adaptations needed for 1. erect / nearly erect posture (1)
-flexible hip and shoulder joints
adaptations needed for 2. grasping hands (or feet) (3)
- opposable thumbs (and/or big toe)
- nails not claws
- fingertips with many sensory nerves
adaptations needed for 3. diurnal (active during the day) (1)
- forward facing eyes with overlapping fields of vision (rely more on vision than smell)
adaptations needed for 4. complex social behaviour
- large complex brains (great capacity to learn)
- small amount of offspring - extended parental care
4 characteristics of New World Monkeys (example = spider monkey)
- weigh less than old world monkeys
- arboreal (lives in trees)
- diurnal
- prehensile (grasping) tail as a 5th limb
3 characteristic Old world monkey (example baboon, vervet monkey)
- heavier than New World monkey
- arboreal/walk
- no prehensile tails
Hominoidea apes have 4 characteristics
- lack a tail
- much larger than monkeys
- vertebral column more stable
- complex behaviour
locomotion of gibbons and siamangs
brachiation-moves swinging from branches
locomotion of orangutan
hands & feet
locomotion of gorillas
knuckle-walking
locomotion of chimpanzees
knuckle walking and bipedal swaggering
locomotion of humans (homo sapians)
have adaptations that allow an upright posture and bipedal locomotion
hominins=
modern humans and our bipedal ancestors
hominin differ from apes by
upright posture and bipedal locomotion
bipedal locomotion freed hands to become …
specialised for other activities e.g. tool use
5 adaptations for bipedal locomotion
- lower spine becomes curved, shorter & more stable- absorbs shock
- hip bones became shorter and wider
- strong knees & ankle joints- more support for the weight of the body
- length of thigh bone increased stride
- angle at which spine connects with skull increases stability of head while walking
Ardipithecus (4.4 mya) (2)
- brain size of chimp
- less protruding face
- smaller canines - Probably walked bipedally
- but still had long curved fingers & opposable big toes
Australopithecus (East, central & South Africa)
4 species
- A. anamensis (4mya)
- A. afarensis (3.5mya)
- A. africanus (3 mya)
- A. sediba (2 mya)
Early humans: homo habilis who is their most likely ancestor
Australopithecus
Homo erectus (1.8 mya) 6 characters
- taller
- larger brain
- thicker skull
- protruding brow ridges
- made fairly sophisticated tool (incl. hand axes)
- groups moved out of East Africa about 1.5 mya
Archaic humans (<0.5 mya)
- descents of
- include a species
- descents of homo erectus
- Included Neanderthals:built shelters, made complex tools, may have used speech and some buried their dead
H. naledi (300-200kya) share characteristics shared with other Homo (3)
- lower limbs (locomotor traits)
- long lower limb, strong insertions for gluteus maximus , human-like foot and ankle - Hands (manipulation)
- morphology of wrist, thumb and palm -enhanced object manipulation - Jaws (chewing)
- small teeth
Modern humans: homo sapiens (3)
1- smaller build
2- less protruding brow ridges
3-more prominent chin
Out of Africa when and what 2 studies support this
modern humans migrated out of Africa and into Europe and Asia about 200 000 to 100000 years ago
- mtDNA sequences suggest an African ancestry for all modern humans
- Y chromosomes studies confirm that all modern humans are descendant of a single migration out of Africa
Australopithecus (East, central & South Africa):
Ape-like characters (3)
Human-like characters (2)
Ape-like characters
- protruding jaws
- pointed canines
- small skull & brain
Human-like characters
- enamel and teeth
- partly or fully bipedal
Early humans: homo habilis, earliest humans (2.3 to 1.7 mya) occupied woodlands and savannas of eastern and southern Africa. 3 characters
- mostly vegetarians, scavengers
- Co-occurred with species of Paranthropus
- Had bigger brains than Australopithecus and Paranthropus - probably 1st homonin to use tools
H. naledi (300-200kya) share characteristics shared with Australopithecus
brain & pelvis structure
H. naledi (300-200kya) share characteristics shared with humans
body structure and size
who drove archaic humans to extinction
homo sapiens because they competed for resources
recent data suggests modern humans interbred with..
archaic humans, including Neanderthals, outside of Africa as recently as 35 000 ya
