The Living Primates/ primate evolution Flashcards
Why do we study non human primates?
- understand physical and behavioural diversity
- living models for interpreting hominid fossil remains
- conservation
What are the characteristics of chordata (vertebrate)
- has spinal cord, covered by vertebrae
- bilateral symmetry (left side same as right)
- share same skeletal design (arms, legs etc)
What are some characteristics of mammalian (mammals)
- 200 mya was first
- viviparous (births live offspring)
- many are placental (famales connected to fetus through placenta) (limited offspring)
- females possess mammary glands which provide food for offspring
- homoiotherms: regulate body temperature (fur, fluctuation of blood cell size)
- dentition (2 sets of teeth, different types of teeth)
- skeletal structure ( limbs tucked under body)
What is the dental formula for mammals
2 incisors
1 canine
2 premolars
3 molars
What are primate characteristics
- hands/feet (opposable thumbs, nails no claws (most), lots of nerves in tips of fingers)
- forward facing eyes/ stereoscopic vision
- long period of infant dependency and learning
- mainly tropical, arboreal, vegetarian
- found 30 degrees above or below equator
Describe prosimians
- found in Asia, Africa, Madagascar
- small medium sized
- nocturnal (mostly)
- vertical climbing and leaping
- quadrupedal
What’s the difference between old world and new world monkeys
Old world nostrils are downward pointing, new world are broad and flat. Old world have 2 premolars new world have 3. New world all live in trees, old world is trees and ground
Describe hominoids
- old world apes and humans
- absence of tails
- dentition
- differences in skeletal structure and shape
What is “the fossil record”
- “bone that have turned to stone”
- impressions of ancient life forms (footprints, endocasts)
Whats a holotype?
The best or most complete form of a fossil; standard for other fossil recoveries are compared
What is an analogy?
Similarities organisms share due to similar adaptation to similar selective pressure (convergent evolution)
What is homology
Similarities organisms share because of common ancestry; taxonomic significance
What is a primitive trait
Trait that has not changed from ancestral state
What is a derived trait
Trait that has changed from ancestral state
Describe the Paleocene?
- 65-53 mya
- primate origins : plesiadapiformes