140 likes | 424 Views
15.3 – Darwin Presents His Case. After Darwin’s journeys he wrote and published a book called On the Origin of Species In this book he proposed his thoughts on how evolution happened called natural selection. Darwin’s Publication. Natural Variation vs Artificial Selection.
E N D
After Darwin’s journeys he wrote and published a book called On the Origin of Species • In this book he proposed his thoughts on how evolution happened called natural selection Darwin’s Publication
Darwin proposed that as populations grew that there would be a struggle for existence • A key factor in the above would be survival of the fittest • Successful adaptions enable organisms to be better suited for environment • Those adaptations are then passed on to next generations • Those that are adapted best for their environment will have more offspring and those that are not will either die or have few offspring • http://www.youtube.com/watch?v=nS1tEnfkk6M • http://www.youtube.com/watch?v=GPbWJPsBPdA&feature=fvsr Evolution by Natural Selection
Darwin proposed that over long periods of time organisms developed different structures to adapt to different environments • As a result species today look different from their ancestors • Common Descent • All species-living and extinct-were derived from same ancestors Descent with Modification
The Fossil Record Archaeopteryx
Section 15-3 Beaver Beaver Muskrat Beaver andMuskrat Coypu Capybara Coypu andCapybara NORTH AMERICA Muskrat Capybara SOUTH AMERICA Geographic Distributionof Living Species Coypu
Section 15-3 Turtle Alligator Bird Mammals Homologous Body Structures Typical primitive fish
The fossil record Geographic distribution of living species Homologous body structures Similaritiesin early development Physical remains of organisms Common ancestral species Similar genes Similar genes Evidence of Evolution includes which is composed of which indicates which implies which implies Concept Map