Fossil Record as Fair Test (Part II) Evolution Fossil Record as Fair Test (Part II)

Theory of Evolution All life on Earth descended from a common ancestor Life originated as a simple form, and became more diverse and complex over time

Fossil Record A record of the 4,600,000,000 year long natural history of our planet

I. Evidence in the Fossil Record Evidence that life changed through time: simple  complex Evidence of change in one “type” of animal through the years Transition species: evidence of “hybrids” between two types 99% of all life which has ever existed is now extinct

What does the fossil record tell us? Life originated in a simple form and become more complex and diverse with time. Example #1: Example #2: Example #3:

What does the fossil record tell us? 2) Organisms have changed over time Changes within a “type” of animal: Sea Urchins (video) Horse (video -can you describe?)

Horse Transitions Each branch tip on the tree of horse evolution indicates a different genus, though the feet of only a few genera are illustrated to show the reduction of toes through time.

What does the fossil record tell us? 2) “ One problem with the theory of evolution is the conspicuous lack of transition fossils” Is this true?

Archaeopteryx

Other Transition Fossils Transitions from one “type” into another: Skulls: reptile/mammal “hybrids” (Why is this significant?) Whale Transition Fossils (See pbs “evolution”) – Assignment!

Fossil Record: Evolution of Mammals Skulls showing the changes in the jaw articulation and the ear region in the evolution from reptile to mammal.

Whale Transitions

Whale Transitional Forms

What does the fossil record tell us? 3) 99% of all organisms which have ever existed are now extinct! (The life we observe today has not been the life through the ages!)