The Modern Primates (Monkeys, Apes, Humans)

The Modern Primates (Monkeys, Apes, Humans)

1. evidence is only very small picture

   • many branches of evolution

2. for any living organism survival is key - biological adaptation to changing environment

3. The Classification System

   • called Linnaean after 18th c. Swedish naturalist Carl Von Linne (Linnaeus)
     • looked at range of variations - grouped them into families
     • still used today in a way

4. The Primate Order

   • primates share a number of features with other mammals

5. Characteristics of Primates

   • large brain
   • sense organs: highly developed sight, touch but NOT sound
   • primate dentition - mammals chew, sideways movement
     • gaps in chimps (locking)
     • slight gap in early Australopithicines
     • no gaps in modern humans
   • primate skeleton (hand & feet): ability to climb - environment heavily forested
   • ADV.
     • safety (away from preditors)
     • usefulness of some changes for specific use can have other uses (e.g. hands: we no longer tree climb but out hands are still immensely useful)
     • access to resources
     • reproduction and care of young (grooming, kissing, communicating, learning)

6. Fossil Primates

   • fossil record tells us what environment was like at this time
     • forested, rain, lots of water
       • 23mya; Proconsul (species) - tree-dwelling fruit eating hominid

7. The Earliest Hominins

   • bipedalism key characteristic
     • ADV.
       • see higher
       • free's up hands
     • change ribcage shape
       • lung capacity increases
   • Ardipithecus Ramidus 4.4mya
     • discovered 1992-1994
     • vital statistics
       • most complete human skeleton in human lineage
     • 1.2m high, bipedal
     • foot anatomy - flat footed, grasping toes; typical of chimps and gorillas, perfect for climbing trees

8. The First Australopithicus/pithecines

   • A. afarensis to A. africanus
     • afarensis - light build compared to robusta w. heavy build
   • A. boisei to A. robusta
   • change in brain size - getting bigger
   • move towards flatter face
   • sexual dimorphism
   • molars more prominent
   • why bipedal?
     • adapting to changed environment from forest to savanna
     • carrying (weapons, water, infants)
     • feeding from bushes, travelling between food trees
     • KEY: environ. play large role

9. A. afarensis (Lucy)

   • small brain
   • heavy protruding jaw housed large molars
   • massive facial and cranial bones
     • long arms relative to legs
       • curved fingers and toes
   • small stature (c. 120cm height)