Speciation Notes
- 2. SpeciationSpeciation Formation of a new speciesFormation of a new species Result of small changes over timeResult of small changes over time (evolution)(evolution) Speciation is “complete” when twoSpeciation is “complete” when two populations cannot interbreedpopulations cannot interbreed Reproductive isolationReproductive isolation
- 3. 3 ways speciation3 ways speciation happenshappens Behavioral isolationBehavioral isolation Species can interbreed, but matingSpecies can interbreed, but mating behaviors are differentbehaviors are different Ex: Eastern and western meadowlarksEx: Eastern and western meadowlarks have different mating songshave different mating songs
- 4. Geographic isolationGeographic isolation Populations separated byPopulations separated by geographic barriers suchgeographic barriers such as rivers or mountainsas rivers or mountains Albert and kaibab squirrelsAlbert and kaibab squirrels split by Grand Canyonsplit by Grand Canyon
- 5. Temporal isolationTemporal isolation Two or more species reproduce atTwo or more species reproduce at different timesdifferent times Ex: 3 species of orchids in rainforestEx: 3 species of orchids in rainforest Each releases pollen on a single dayEach releases pollen on a single day Each releases on a different dayEach releases on a different day
- 6. Example of speciationExample of speciation Darwin’s GalapagosDarwin’s Galapagos Island finchesIsland finches Ancestor finchAncestor finch changed over timechanged over time Adapted to itsAdapted to its environment andenvironment and foodfood
- 7. What is the proof of Evolution?What is the proof of Evolution? 1.1. FossilFossil recordrecord A piece of organism or imprint left behind.A piece of organism or imprint left behind. Fossils show that species have changed over time.Fossils show that species have changed over time. 2.2. Vestigial structuresVestigial structures Body structures that have shrunken and are not used anymore.Body structures that have shrunken and are not used anymore. 3.3. Homologous structuresHomologous structures Structures that share a common ancestry and look/behaveStructures that share a common ancestry and look/behave similarly.similarly. 4.4. EmbryologyEmbryology 5.5. DNA homology, Amino Acid homology,DNA homology, Amino Acid homology, Mitochondrial DNA, Photosynthetic Plant cellsMitochondrial DNA, Photosynthetic Plant cells
- 9. Geologic Strata andGeologic Strata and Carbon DatingCarbon Dating Carbon-14Carbon-14 (remember(remember isotopes?)isotopes?) Used to date anyUsed to date any object composed ofobject composed of carboncarbon Radioactive carbonRadioactive carbon decays over timedecays over time check amount of C14check amount of C14 left in sample,left in sample, enabling you to tellenabling you to tell age of objectage of object Defining age of fossils!
- 10. Did you know that whales have feet?Did you know that whales have feet? Well, sort of….Well, sort of….
- 11. Fossils help us determineFossils help us determine whale evolutionwhale evolution 60 million years ago 50 million years ago 40 million years ago Yesterday
- 12. Human tail-bone,Human tail-bone, wisdom teeth,wisdom teeth, appendix (theyappendix (they have no purpose)have no purpose) Snake feet,Snake feet, Whale feetWhale feet Vestigial StructuresVestigial Structures
- 13. Bat eyes
- 14. HomoHomologous Structureslogous StructuresLimb adapted to function means the same!
- 15. Embryology
- 16. DNA/Amino AcidDNA/Amino Acid HomoHomologylogy HumanHuman 5’A-T-C-T-T-A-C-G-A-A-T-C-A-T-G-C-C-C-T-A-5’A-T-C-T-T-A-C-G-A-A-T-C-A-T-G-C-C-C-T-A- A-C-T-T-C-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’A-C-T-T-C-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’ WhaleWhale 5’A-C-C-T-T-A-C-C-A-A-T-C-A-T-T-C-C-C-T-A-5’A-C-C-T-T-A-C-C-A-A-T-C-A-T-T-C-C-C-T-A- A-C-T-T-A-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’A-C-T-T-A-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’ FrogFrog 5’A-C-C-A-T-G-C-G-T-G-T-C-A-T-C-C-C-C-G-5’A-C-C-A-T-G-C-G-T-G-T-C-A-T-C-C-C-C-G- A-G-C-T-T-C-G-G-T-A-T-T-A-C-G-C-A-A-G-C-A-G-C-T-T-C-G-G-T-A-T-T-A-C-G-C-A-A-G-C- 3’3’ GorillaGorilla 5’A-T-C-T-T-A-C-G-A-A-T-C-A-T-G-C-C-C-T-A-5’A-T-C-T-T-A-C-G-A-A-T-C-A-T-G-C-C-C-T-A- A-C-A-T-C-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’A-C-A-T-C-G-G-C-A-T-T-A-C-G-C-T-A-G-C-3’ (Means the same!) Can you create a cladogram from the information above?