Summer 2006 Workshop in Biology and Multimedia for High School Teachers

The Case for Evolution Lucy McKone Lincoln County Schools, Mississippi July 2006

Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Is there any evidence to support that EVOLUTION stuff? This article is licensed under the " ” I believe so. First, let’s clarify the theory. Then we’ll review the evidence.

Basic Clarification Theory = an explanation that has been tested in many ways Life has existed for billions of years. Evolution deals the the history of life changes, not the origin. Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Image courtesy of the UC Museum of Paleontology Understanding Evolution:

The Case for Evolution Homologous (Similar) Structures Fossils DNA Embryonic Structures Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. This article is licensed under the " ”

Homologous Structures Different organisms sharing similar structures Name a bone that is found in each animal. What does that indicate???? Common ancestor? For more practice, and a comparison of homologous and analogous structures, click on the following link: milarity_hs_02 milarity_hs_02 Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Image courtesy of the UC Museum of Paleontology Understanding Evolution:

Embryonic Development Embryos of many organisms are alike in early stages of development. Body appendages (limbs) on many organisms start as buds of tissue from the body surface. These are often clues to shared ancestry. Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Image courtesy of the UC Museum of Paleontology Understanding Evolution:

Fossils Principle of Superposition: Older fossils are found toward the bottom. Radioactive Dating: determines the age of organisms: Carbon isotopes for organic matter Uranium, Potassium or Rubidium isotopes for rocks with fossil imprints. Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Image courtesy of the UC Museum of Paleontology Understanding Evolution:

Fossils Height, feet and teeth of horses evolved over 60 million years. Why? Possibly adapting to new habitat, such as grasslands as they developed These fossil organisms represent branches on the tree and not a direct line of descent leading to modern horses. It does show transition. ( 3) 3 Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. Image courtesy of the UC Museum of Paleontology Understanding Evolution:

DNA Organisms that are closely related should have similar DNA Similar DNA indicates sharing a common ancestor at one time. Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.