Domain VDomain VEvolutionEvolution

Origins of EvolutionOrigins of Evolution Jean Baptiste de Lamarck and Acquired Characteristics

Charles Darwin Charles Lyell’s Principles of Geology Thomas Malthus called The Principles of

Population 40,000-mile trip on the Beagle

Galapagos IslandsGalapagos Islands What did he find there?What did he find there?

Aquatic Aquatic iguanas Giant Tortoises Giant Tortoises Species of finchesSpecies of finches

2 Themes Emerged2 Themes Emerged Variations within a species were

dependent on the environment. Organisms on the Galapagos

Islands had become geographically separated resulting in reproductive isolation which leads to speciation.

Natural SelectionNatural Selection Changes in a population that occur when organisms with favorable variations for that particular environment survive, reproduce and pass these variations on to the next generation.

Darwin’s TheoryDarwin’s Theory Decent with modification Decent with modification

through natural selection.through natural selection. Environmental Challenges Environmental Challenges

result in certain traits result in certain traits increasing the reproductive increasing the reproductive fitness of certain individuals fitness of certain individuals within a species. within a species.

History of LifeHistory of Life Types of EvolutionTypes of Evolution

Divergent (Adaptive Radiation)Divergent (Adaptive Radiation) ConvergentConvergent

•Rates of Evolution•Gradualism•Punctuated Equilibrium

Types of Natural Types of Natural SelectionSelection

Stabilizing Selection Directional SelectionDirectional Selection Diversifying SelectionDiversifying Selection Disruptive SelectionDisruptive Selection Balancing SelectionBalancing Selection

Diversifying SelectionWhen a population is faced with conditions so diverse that no single phenotype is more successful that any other, genetic and phenotypic variability allow different selective pressures to operate at the same time.

Balancing Selection operates to counteract the loss of variant alleles in a population.

Two forms of : heterozygote advantage and frequency-dependent selection.

BiodiversityBiodiversity Resulted from divergent Resulted from divergent

evolution.evolution.

Lines of EvidenceLines of Evidence Incomplete Fossil RecordIncomplete Fossil Record >Relative Dating>Relative Dating >Time Averaging>Time Averaging >Radioisotope Dating>Radioisotope Dating Building a PhylogenyBuilding a Phylogeny >Phylogenetic Tree>Phylogenetic Tree

Mass ExtinctionsMass Extinctions Were catastrophic events the cause of mass extinctions, did they happen quickly or did they occur over a long period of time?

If they occurred over a long period of time, why did the species not adapt to their changing environment in order to survive?

Biological Biological ResistanceResistance

Oysters in Malpeque Bay Insect Resistance to Insect Resistance to

InsecticidesInsecticides Viruses Viruses Gene AmplificationGene Amplification