our primate relatives Flashcards
(155 cards)
why are primates studied
because it helps us learn about humans as models for anatomy, behavior, and shared adaptations
what are the four main categories of derived traits for PRIMATES
- post cranium
- cranium
- life history
- ecology & habitat
what does postcranium mean
anything that is not the head
list some post cranium adaptations of primates
-pentadactyly
-prehensile hands
-hallax
-nails
-finger/toe pads
-finger prints
-hind-limb dominated locomotion
-tendency toward vertical postures
-clavicle gives more shoulder motion
what is pentadactyly
having 5 fingers or 5 toes on each hand/foot
what is prehensile hands
adapted for grasping
what is the hallax and why do humans not have it
hallax is the opposable big toe
humans dont have and we have the derived trait of inline big toes
what are some cranium adaptations of primates
-decreased olfaction
-emphasized vision
-post orbital bar
-forward facing eyes
-stereoscopic vision
-increased visual processing
-less prognathic
-encephalization quotient
-function based dentition
what is decreased olfaction
less reliance on scent
what is the post orbital bar
the eye has a bone going around it that is completely closed if there is a post orbital bar, but if not there would be a hole or it wouldnt be present at all
what is stereoscopic vision
depth perception
what is less prognathic mean
less of a snout
what is the encephalization quotient
EQ is the brain:body size ratio
humans have large brain for a smaller body
what are the four types of teeth
what is human dentition formula
incisors, canine, premolars and molars
2 1 2 3
what does life history mean as an adaptation of primates
how the animal spreads growth & reproduction out over its lifetime
what is unique about primates life history vs other animals
primates LIVE SLOW LIVE LONG while most animals LIVE FAST DIE YOUNG
what are some characteristics of the adapted life history of primates
-long lives
-later reproduction
-single offspring at a time
-long interbirth intervals
-long gestation
-lots of investment of offspring
-long infant dependency
what are the ecological adaptations of primates
-tropical distribution
-relatively omnivorous
-diurnal
-social living
-behavior learning & flexibility
what are the names of the two theories for why primates have derived these traits from the last common ancestor
arboreal hypothesis
visual predation hypothesis
what is the arboreal hypothesis
primates have these derived traits because they adapted to living in a 3D arboreal environment (xyz axis)
what is the visual predation hypothesis
primates have the derived traits because it makes them more competitive as predators
convergence of traits with predators who rely on vision and grabbing to catch prey.
what are primates most closest relatives
bats, tree shrews, colugos
what is the typical environment that primates live in
tropical areas or forest bc arboreal
where are fossils of primates found vs where are they living today (exclude humans obv)
found in north america and europe, living in the americas, africa and asia