Final Flashcards
(196 cards)
Continental Drift
barriers led to speciation (species geographically seperated)
continental positions led to change in ocean currents led to change in climate
climates create selective pressure
Reconstructing Global Temperature
cooling trend over the last 65 million years
more variable in last 5 million years
bones & teeth
fossilization
how moved, how big, what they ate, what mating and social structure may have been
plant & animal fossils
fossilization
reconstruct the environment
How fossils are created
burial - organic compounds replaced by minerals
soft tissues + behaviors rarely fossilize
issues with the fossil record
overestimate time of first appearance & underestimate time of extinction
oversimplifies relationships and underestimates divergence times
small animals are less likely to fossilize and some habitats are less likely to create fossils - bias
principle of superposition
stratigraphy
if rock has not been disturbed, bottom layers are older than those above
potassium-argon dating
dating techniques
date volcanic rocks around fossil
volcano erupts: potassium decays steadily into argon
biostratigraphy
dating techniques
as long as one side can be dated absolutely, infer dates of other (side by side)
primate origins
current: around equator
fossil: up to american SW, europe
characteristics of fossil primates
grasping hands + feet
nails instead of claws
forward facing eyes encased in bone
hind limb dominated locomotion
relatively large brain
generalized teeth
general overview of primate evolution
PELEOMM (party elves love epic outdoor music madness)
paleocene (65-54 mya): plesiadapiforms
eocene (40-50 mya): adaptids (early lemur) & omomyids (early lorises)
late eocene-olligogene (30-45mya) proteopithecus (early new world) & aegyptopithecus (early old world)
miocene (5-23mya): proconsul (early apes)
middle miocene (10-15mya): -pithecus (early apes)
plesiadapiforms
paleocene
maybe not primates
no binocular vision, eye on sides, no postorbital bar
small brain
some nails, some claws
grasping hands + feet in some
Eocene Primates
40-50mya
earth warm and wet
tropical forests spread into north america + europe
2 families: adaptids (like lemurs) & omomyids (like lorises)
Late Eocene-Oligogene
30-45 mya
find fossils in N America with full orbital closure: origin of Anthropoids
proteopithecus & aegyptopithecus
proteopithecus
late eocene-oligocene
fossil version of new world monkey - evolved in Africa and moved to south America
traveled by rafting: large land masses break + float
aegyptopithecus
late eocene-oligocene
fossil catarrhine (old world apes)
Miocene
5 to 23 mya
warm + wet –> cool + dry over time
10 genera + 15 species: proconsul,
not many monkes
apes v monkeys
tied to how they moved (under branches/on the ground)
apes have no tails
forelimb suspension (apes hang, monkeys walk)
short stiff lower back
mobile joints
long arms + fingers
proconsul
early miocene
africa 17-23 mya
frugivorous in forest environments
ape-like skull + teeth; monkey like body
oreopithecus (cookie monster)
7-8mya (late miocene)
N. italy in a coal mine
swamp habitat (diff from current apes)
folivore, teeth diff from other apes
sivapithecus
found in asia
some characteristics like orangutan: dish face + tall, narrow orbits
gigantopithecus
china, ate bamboo (like pandas)
5 mya
head could be oversized for body… may not actually be that big
apes in europe
disappear 8mya; move to Asia + Africa