Descent With Modification: Darwinian View of Life AP Biology Crosby High School

History Plato: Real world vs. Illusory world Aristotle: Scala Naturae Natural Theology (1700s) Carolus Linnaeus For the “Greater Glory of God” Created Binomial Nomenclature King Phillip Came Over From Great Spain

Cuvier and Catastrophism Documented succesion of fossil species in Paris Basin Deeper fossils more distant from modern life Noted that extinction is reoccuring throughout history Advocated Catastrophism Each stratum is a catastrophe Repopulation occurred by immigrating species

Geological Processes James Hutton (1795) Charles Lyell Gradualism: Profound change occurs through slow, continuous processes Charles Lyell Uniformitarianism: Same geologic processes

Jean Baptiste Lamarck Published Theory of Evolution (1809) Natural History Museum in Paris What you don’t use, you lose. Inheritance of acquired characteristics

Charles Darwin Left Edinburgh at 16 for Christ College at Cambridge Mentored by Reverend John Henslow Asked to join Captain Robert FitzRoy of HMS Beagle

The Famous Voyage Left in December of 1831 Meant to study the South American Coastline to make a better map Darwin spent time on land collecting specimens Noticed specific adaptations to environment Flora and Fauna had distinct S. American characteristics

The Discovery Returned in 1836 and looked over his notes Galapagos animals Existed nowhere else in the world Closely related to those on S. America Finches Principles of Geology by Lyell Questioned the static nature of Earth

The Idea Natural Selection was responsible for new species Alfred Wallace (1858) Darwin: “Your words have come true with a vengeance…I never saw a more striking coincidence…so all my originality, whatever it may amount to, will be smashed.” Published a paper on Natural Selection with extracts from Darwin’s work

Descent With Modification All descended from an unknown ancestor Developed diverse modifications

Darwin’s Main Ideas Natural selection is differential success in reproduction Natural selection occurs through an interaction between the environment and the variability inherent among the individual organisms making up a population The product of natural selection is adaptation of a population of organisms to their environment

How It Works Each generation has heritable variation filtered by the environment Favored traits are overrepresented in the next generation Artificial selection can help explain natural selection

Some Things to Consider Population: Interbreeding individuals belonging to a particular species in the same area Only amplifies inherited variation Natural Selection is situational

Support For Natural Selection Insect Resistance to insecticide Drug resistant HIV Homology: Similarity in characteristics resulting from common ancestry

Homology Anatomical: Homologous structures Vestigial Organs Snakes show remnants of pelvic and leg bones Embryologic: Pharyngeal Pouches Molecular: Genetic Code

Homologous Structures and Resistance

Biogeography A species is more closely related to other species in the same area Marsupials vs. Eutherians