NORTHAMERICAEUROPEAFRICAAUSTRALIAGREATBRITAINSOUTHAMERICAATLANTICOCEANPACIFICOCEANCape ofGood HopeTierra del FuegoCape HornTasmaniaNewZealandAndesEquatorTheGalpagosIslandsPintaMarchenaGenovesaSantiagoDaphneIslandsPinznFernandinaIsabelaSanCristobalSantaFeSantaCruzFlorenzaEspaolaMost famous research took place at the Galpagos Islands ~near the equator west of South America

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Darwins Focus on AdaptationDarwin discovered:Adaptations to the environment AND the origin of new species are closely related processesExamples- Galpagos finches & TortoisesBeak ShapeShell Shape & Neck Length

Fig. 22-6(a) Cactus-eater(c) Seed-eater(b) Insect-eater

Fig. 22-6a(a) Cactus-eaterIN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!

Fig. 22-6b(b) Insect-eaterIN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!

Fig. 22-6c(c) Seed-eaterIN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Darwins two main ideas:

Descent with modification: All organisms are related through descent from an ancestor that lived in the pastFossil evidence proves this!Natural selection: individuals that are best suited to their environment survive and reproduceIncreases the adaptation of orgs to their envmntIf envmnt changes, new adaptations will appear OVER TIME b/c of natural selection

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Tortoises necks- Darwins evidence of adaptations

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Observation #1: Members of a population often vary greatly in their traitsDarwins 4 Observations

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Observation #2: Traits are inherited from parents to offspring (genetics)Observation #3: All species are capable of producing more offspring than the environment can supportObservation #4: Because there is not enough food or other resources (limiting factors), many of these offspring do not survive

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Individuals with traits that give a better chance of surviving and reproducing Have more offspring survive Unequal ability of individuals to survive and reproduce Leads to the accumulation of favorable traits in the population over generationsSurvival of the Fit

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Survival of the FitSurvival of the Fit: individuals with favorable heritable traits survive and reproduce at a higher rate than other individuals

Fig. 22-12(b) A stick mantid in Africa(a) A flower mantid in Malaysia

Fig. 22-12a(a) A flower mantid in Malaysia

Fig. 22-12b(b) A stick mantid in Africa

Copyright 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Individuals do not evolve; populations evolve over timeNatural selection can only increase or decrease heritable traits in a populationN.S. does not create new traits!Local environment determines traits selected for or selected againstImportant Notes about Evolution

Adaptations vary with different environments

**Figure 22.5 The voyage of HMS BeagleFor the Discovery Video Charles Darwin, go to Animation and Video Files.*Figure 22.6 Beak variation in Galpagos finches*Figure 22.6 Beak variation in Galpagos finches*Figure 22.6 Beak variation in Galpagos finches*Figure 22.6 Beak variation in Galpagos finches*Figure 22.12 Camouflage as an example of evolutionary adaptation*Figure 22.12 Camouflage as an example of evolutionary adaptation*Figure 22.12 Camouflage as an example of evolutionary adaptation*