ANT101H5S PRIMATE ORIGINS: Rise of the Primates February 1 , 2011
A species way of life considered in the context of its environment.
Environment-ecology dictates species, species adapt to habitat, changes-origin of species.
Rapid diversification of an evolving population as it adapts to a variety of available niches
-adapts to a multitude of available niches
-populations diverse with ecological
Climatic event-change In speciation
glaciers-15% of earths water froze.
Dropping sea levels
expose continent bridges
increase carniforous trees-speciation
Cenezoic era=epoch, what happens in each epoch ?
Beginning of the order primates ?
Probably occurred 65 mil years ago in paleoscene epoch-orgin or primates.
Major Periods & Epochs of Evolution of Life
Paleozoic – Permian Period (280 mil ya)
Permian Deposits show mammal–like reptiles
– Flesh eaters
– Reduction in bones
– Shifting limbs
– Beginning of separation between mouth & nasal cavity
– Dental differentiation
mammals-reduction of body
appendix-move to side
differentiation in dentition-mammal like reptiles
Mezozoic (Triassic, Jurassic, Cretaceous periods)
Reptiles prominent land vertebrates (dinosaurs)
1 mammals appeared: end of triassic period (190 mil ya)
– Small flesh eaters (insects)
– Nocturnal (active at night)
enhanced smell & hearing
– Enlarged cerebral cortex
– Loss of color vision
CENOZOIC (Age of Mammals)
(including 1 appearance of Primates)
Associated with Large Climatic change
– Separation of continents away from equator
– Cooler temperatures - tropical & subtropical forests
– Dinosaur extinction
– Changing ecological niche
– Radiation of new varieties of plants
– Proliferation of deciduous forests
– Mammalian adaptive radiation – adaptive radiation of mammals -eco niches open up dinosaurs go extinct, global climate change
temperature decreased. Seperation of continents (continental drift)
– tropical--->deciduous/subtropical form -new niches for mammals to exploit.
Before-high energy requirement-hard to have a proper diet.
Increased decidious -diversification
PALEOCENE PRIMATES (65 mya)
– Extinct mammal – common ancestry with primates
– Squirrel like Insectivore
– Flexible digits,wrists,ankles
1 primate (60mya)
Fossil evidence: Morocco
– Dentition similar to modern mouse lemur (strepsirhine)
1 primate-gliding squirrels-small,aboreal,clingers,mobile wrist, ankle joints, insectivores.
Eocene Primates (55-34 mya) Age of the Prosimians
– Complete postorbital bar
– Larger frontal lobe
– Forward placed eyes
– Slightly reduced snout
– Limbs for gra