Hominoid Fossil Record Flashcards
who were two principle figures in earliest human evolution studies?
Thomas Huxley and Charles Darwin
summarize the principle characteristics of the social system of each of the four hominoids
1 Chimpanzees
-highly social and live in communities
-arms extend beyond knees, knucle walk
-opposable thumbs and big toes to grip branches
-diet: fruit and leaves
2 Bonobos
-peaceful and led by females
-knuckle-walkers
-big toes and opposable thumbs
-long limbs and narrower trunk
3 Gorillas
-can stand up but prefer to walk on knuckles
-broad chest and shoulders
-diet: herbivrous
-pronounced brow ridge
4 Orangutans
-very large and arboreal mammals that live in trees
-arms longer than legs
-solitary
-large jaws and flatten nose in concave face
-grasping hands and feet to move through branches
5 Gibbons and Siamangs (Lesser apes)
-small
-low sexual dimorphism
-less intelligent (smaller CC)
-arboreal, moves bt brachiation
-no tails
-fruits and plants mainly
distinguish between “short back” and “long back” scnarios of human evolution?
during the great bauplan shift, modern apes evolved to have few lumbar vertebra (3-4) to reduce stress placed on spine to suspend this meant they have a shorter back then when humans experience lumbar stabilization and have 5-6 lumbar columns that help us to bipedally walk
how do human and chimps/gorillas pelves differe with respect to their articulation with the lumbar column?
in order to go through lumbar reduction, the pelvis was also affected. The pelvis became shorter and widered (broad illum and laterally oriented) in humans to walk and balance without having to shift weight forward and use our knucles for stability and balance, chimps and goriillas have a narrow and long pelvis (compressed illium and vertically oriented) which helps with suspension
what species exhibit lumbar trapping and why?
gorillas and chimps b/c they have a smaller lumbar column to account for suspension
