Textbook Notes (368,566)
Canada (161,966)
Biology (657)
BIOLOGY 1M03 (199)

From Tree Shrew to Ape (9).docx

11 Pages
Unlock Document

Ben J Evans

Chapter 9From Tree Shrew to Ape 3162013 34400 PM o Extinction of the dinosaurs at the beginning of the Cenozoic Era was coupled with the radiation of mammalsModern descendants from this radiation eg horses bats whales primates evolved from a creature that looked like the contemporary shrew o Darwins theorycomplex adaptions are assembled graduallyEach step favoured by natural selectionHuman adaptations grasping hands bipedalism toolmaking abilities language and largescale cooperationContinental Drift and Climate Change o Scenery has changed along with evolution of organisms o Climate influences our interpretations of fossil records o What is adaptive in one environment may not be adaptive in another o If the environment had not changed adaptations in human evolution would have been steady improvements towards human perfection ie evolution would progress towards a fixed goal o Since the environment has changed over time changes reflect adaptations to changing environmental conditions o The world has become much colder and drier in the last 20 million years particularly variable in the last 800000 yearsIf climate had remained warmer human ancestors would have remained in safety of trees and would not have become terrestrial or bipedalo Continental driftmovement of continents o 200 mya all of the land making up present day continents were joined together in a single large landmass Pangaea o 150 mya Pangaea began to break apartNorthern half Laurasia included present North AmericaEurasia minus IndiaSouthern half Gondwanaland rest of the landBy the time dinosaurs became extinct 65 mya Gondwanaland had broken up o Africa and India separated India headed north eventually crashing into Eurasia o Remainder of Gondwanaland stayed south eventually breaking up into South America Antarctica and Australia o 5 mya South America drifted north to join North America o Importance of continental drift 1 Oceans serve as barriers that isolate certain species from others position of continents play an important role in evolution of speciesThe long isolation of South America creaes one of the biggest puzzles in our knowledge of primate evolution 2 Continental drift is one of the engines of climate changeClimate fundamentally influences human evolutiono The size and orientation of the continents have important effects on climateVery large continents tend to have severe weatherPangaea was very large and likely had very cold weather in the winterThe period peak of warmth in Miocene era allowed palm trees to grow as far north as presentday Alaska and only the tallest peaks in Antarctica were glaciated
More Less

Related notes for BIOLOGY 1M03

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.