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Download 18-2 Modern Evolutionary Classification
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The Tree of Life Modern Evolutionary Classification Foothill High School Science Department Problems With Traditional Classification Appearances Are Deceiving Fish, Dolphins & Sharks Limpets, Barnacles, Crabs What Characteristics Are Important & Which Are Most Important? Foothill High School Science Department Traditional Classification Foothill High School Science Department Cladogram Foothill High School Science Department Evolutionary Classification Key Concept Biologists Now Group Organisms Into Categories That Represent Lines Of Evolutionary Descent, Not Just Physical Similarities Foothill High School Science Department Evolutionary Classification Is The Strategy of Grouping Organisms Together Based On Their Evolutionary History Use of Evolutionary History is referred to as Phylogeny It Is Not Obvious or Easy Foothill High School Science Department Cladistic Analysis Identifies and Considers Only Those Characteristics Of Organisms That Are Evolutionary Innovations New Characteristics That Arise As Lineages Evolve Over Time Foothill High School Science Department Cladistic Analysis Derived Characteristics Traits That Can Be Used To Figure Out Evolutionary Relationships Appear In Recent Parts of a Lineage But Not In its Older Members Used To Construct A Cladogram Foothill High School Science Department Cladogram A Diagram That Shows The Evolutionary Relationships Among a Group of Organisms Shows How One Lineage Branched From Another In The Course of Evolution Foothill High School Science Department Similarities In DNA & RNA 1. Beyond Physical Characteristics Are Similarities In DNA & RNA 2. Allows Comparison of Diverse Organisms 3. Allows The Tracing of Genes Over Millions of Years Foothill High School Science Department Similarities In DNA & RNA Key Concept The Genes of Many Organisms Show Important Similarities At The Molecular Level. These Similarities Can Be Used As Criteria To Help Determine Classification Foothill High School Science Department Similarities In DNA & RNA Myosin Functional Protein Unit of Muscle Fibers Found In Yeast (?) Protein In Yeast Interacts With Other Proteins To Allow Internal Yeast Structures To Move Foothill High School Science Department Similarities In DNA & RNA Has Cleared Up Classification Questions, Which Two Are More Closely Related? Storks, American Vultures, African Vultures Panda’s Foothill High School Science Department Molecular Clocks DNA Can Mark The Passage of Evolutionary Time Mutations Occur At A Somewhat Measurable Rate If They Change The Phenotype, They Are Subject To Natural Selection If They Don’t Change The Phenotype, They Accumulate In The DNA Foothill High School Science Department Molecular Clocks The Degree of Difference Due To Accumulated Mutations, Indicates How Recently They Shared A Common Ancestor Different Genes “tick” At Different Rates Allowing Comparison & Validation Foothill High School Science Department Molecular Clocks Foothill High School Science Department Foothill High School Science Department
