Change Over Time

Warm Up Question  The cockroach originated on Earth more than 250 million years ago and is still thriving all over the world today. Species of dinosaurs evolved around the same time period and went extinct 65 million years ago.

Warm Up Question  Why has this tiny species been so successful for so long, and other species die out in a relatively short time?

I. Adaptations:  Adaptation Anything that makes a species better suited to its environment. Adaptation A. Types: 1. Structural Adaptations 2. Physiological Adaptations 3. Behavior Adaptations

Adaptation Video Clip  What adaptation(s) does the mantis possess that helps it survive in it’s environment?  How did this mantis populations evolve to possess this adaptation?  What pressure would the mantis population face if their environment changed? PBS: Evolution Adaptation Clip

1. Structural Adaptation Changes in the structure of a body part.  Examples Camouflage

Mimicry

2. Physiological Adaptation Changes to an organism’s metabolic processes. Ex. -Antibiotic resistant bacteria -Insects that are resistant to pesticides

3. Behavioral Adaptation Help an organism find food, protect itself, or reproduce.

II. Evolution of Species  Species a group of organisms that are closely related and can mate to produce fertile offspring.

A. Evolution : Is the process by which species change in over time. 1. Species evolve from pre-existing species. 2. Successful organisms survive and pass on their genes, others go extinct.

Populations can change (evolve), individuals can not!!!

III. Evidence of Evolution: A. Fossils  Scientist study fossils to find evolutionary clues.  Fossils show how populations of organisms changed over a long period of time. Whale Evolution WebsiteWhale Evolution Video Clip

Transitional Fossils  Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants Transitional Fossil

Transitional Fossils  Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants

IV. Anatomy  Understanding homology and analogy

A. Homologous Structures  Modified body parts that have similar structure and function in different organisms. *Share a common ancestry. Can be used to show evolution.

B. Analogous Structures  Similar function, but different structure.  Two characters are analogous if the two lineages evolved independently.

C. Vestigial Structures  Any body structure that is reduced in function in a living organism, but may have been used in an ancestor. Examples -Appendix in humans -Hips on whales

V. DNA (Molecular Biology)  Closely related species have similar DNA patterns that code for proteins.  Ex: Human DNA is 20% identical to a mouse, and 98% identical to a chimpanzee.

A. Changes in Genes 1. Mutation a change in the nucleotide- base sequence of a gene or DNA molecule.  Ex: Sickle Cell Anemia A Mutation Story Video