HISTORY OF EVOLUTIONARY THOUGHT

Unit Objective #1 I CAN COMMUNICATE SCIENTIFIC INFORMATION THAT COMMON ANCESTRY AND BIOLOGICAL EVOLUTION ARE SUPPORTED BY MULTIPLE LINES OF EMPIRICAL EVIDENCE.

LIFE CHANGES OVER TIME  Earth formed 4.6 bya  Life began 3.5 bya  Most life as we know it has been here a relatively short amount of time on the geologic scale (~600 million years)

 What is a fossil:  Preserved remains or traces of an organism from the past  How to make a fossil:  Organism lives  Organism dies  Immediately, remains are buried to prevent rapid decomposition  Slowly remains (usually hard parts) are replaced w/ another material FOSSILS: OUR CLUES TO LIFE’S HISTORY

 FOSSIL ROCK ANTHEM

 Layers of the Earth show a consistently aging planet  Organisms living during the past have been preserved  Nearly all fossilized species are extinct  Therefore: life evolves as the environment changes BIG PICTURE

 Scientists have questioned how life came to be since BC  Scientists have formed theories for evolution for centuries  The widely accepted theory of evolution by natural selection explains… BIG PICTURE

PAST: ORGANISMS HAVE GONE EXTINCT

PRESENT: DIVERSITY OF LIFE ON EARTH

FUTURE: SPECIES CONTINUE TO EVOLVE