CH 6.2 and CH 7

CH 6.2Species Change Over Time

CH 6 ObjectivesIdentify early ideas and observations on evolutionExplain how Darwin developed his theory of natural selectionIdentify Darwins 4 principles of natural selectionDescribe how new species can form from previous species

Essential Questions and Understandings What is evolution and who contributed to the modern theory of evolution?Compare and Contrast Artificial and Natural SelectionWhat are Darwins 4 principles and how do they lead to evolution?What is speciation?How can isolation of a group of individuals lead to a new species?

EvolutionEvolution is defined as change over timeIt is the result of changes in the genetic material that are passed from generation to generationOrganisms use adaptations to have a better chance of surviving and reproducing

HistoryLamarck was on of the first scientists to suggest the idea of change over the lifetime of an organism (Giraffes Necks)Darwin studied plant and animal species on the Galapagos Islands (178 islands)He noticed that species were different from island to islandLooked at adaptations to certain environmentsLooked at finches and their feeding behaviors

Artificial SelectionWhen people (breeders) produce new varieties of animals over timeSelect a certain desired traitBreed two animals displaying that traitThe result is offspring displaying the trait

6Natural SelectionDarwin proposed the same thing was happening naturally in the animal and plant worldHe based his ideas on 4 principles:Overproduction: When a species produces more offspring than can live in the environmentVariation: mutations that naturally occur in the genetic materialAdaptation: any inherited trait that gives an organisms an advantage to surviveSelection: if a trait helps an organism survive to reproduce, the trait has been selected

SpeciationThe evolution of new species from an existing organismCan occur when the environment changes dramatically such as a volcanic eruptionNew species can also occur when the environment changes gradually

Formation of New Species due to IsolationExample from a population of Cichlids (fish)Water level is low, one species lives in a lakeLevel rises filling shoreline, population spreads throughout the lakeLevel falls, isolating the fish from each otherNew species development that are more successful in their environment

Isolation Can Lead to New SpeciesScientist believe that Isolation is essential to speciationIsolation can occur due to geographic changes such as mountains building upCases caused by isolation have led to the great level of biodiversity on Earth

CH 7Classification of Living Things

CH 7 ObjectivesExplain why scientists classify living thingsDescribe evidence scientist use to classify organismsExplain how scientific names are determined and give examplesUse the 7 levels of classification to identify an organismDescribe organisms found in each of the current 6 kingdom system of classificationDescribe the 3 domainsDescribe how dichotomous keys can be used to identify organisms Utilize a dichotomous key to identify common household objects

Essential Questions and UnderstandingUnderstand how scientist study biological relationships to classify living organismsHow has our classification system changed over time?Describe how we give organisms scientific names and give and example.Use a dichotomous key to classify organisms correctlyIdentify characteristics of organisms found in the 6 kingdoms

1600s: organisms were classified based on appearance and behaviorPROBLEM: Can be deceiving, not universal (i.e. they could not ALL agree on a system for naming organisms)1700s: 2 Kingdoms (Plant and Animal)Linnaeus set a standard 2 name system for each animal (Genus species)Linnaeus developed a system for naming species and organizing them into groups 1866: 3 Kingdom Sytem (plant, animal, protista)20th Century: Started using DNA and genes to classify related species1925: 2 Kingdoms (Prokaryota & Eukaryota)1938: 4 Kingdoms (Monera, Protoctista, Plantae, Animalia)1969: 5 Kingdom System (Monera, Protista, Plantae, Fungi, Animalia) 1977: Current 6 Kingdom System2000s:???? 7 Kingdoms???? No Kingdoms??? Domains??ClassificationClassification is the process of arranging organisms into groups based on similaritiesTaxonomy: science of naming and classifying organismsTo classify organisms scientists use similarities and differences among speciesA classification system (such as one found in a field guide can help you identify unfamiliar organismsA taxon is a group of organisms that share certain traits based on shared ancestors. Not All organisms that look alike are closely related

Binomial NomenclatureEach organism has a 2 part nameScientific nameWritten in Latin and GreekGenus speciesGenus: a group of species with similar characteristicsSpecies: the specific name for the organism (contains the least number of organisms)EX) Homo sapiens (human), Aubrieta gracilis (flower), Chameleo gracilis (chameleon), Mammillaria gracilis (cactus) 7 Levels of Classification to Name a SpeciesEach level is more specific than the lastKings Play Chess On Fat Green StoolsKingdomPhylumClassOrderFamilyGenusSpecies

Dichotomous KeysAsks a series of questions that can be answered in only two ways.Each answer leads to another question until you identify the organism

KEY TO THE CRITTERS ON BEBONK1. Has 1 hair..2Has 2 hairs4

2. Has a belly buttonBIPHas no belly button3

3. Has 2 legsGLIPHas 4 legsFOOP

4. Has arms.GLOPHas no arms.NOP

Kingdom PlantaeMulticellularLive on water and landObtain energy from sunlightHave a nucleus, cell wall, chloroplastEX) grass, trees, moss

Kingdom AnimaliaMulticellularLive on water and landObtain energy by eating foodHave a nucleus, no cell wall, no chloroplastHave the ability to moveEX) human, elephant dog, fish bugs

Kingdom ProtistaMost are unicellularNucleusHave the ability to moveSome eat like animalsSome get energy from sunlightEX) Sea weed, Kelp, Euglena

Kingdom FungiTakes nutrients from environmentRooted in one placeHave cell wallsAct as decomposersEX) Mushroom, yeast, molds

Kingdom ArchaeaNo NucleiLive in extreme environments-high heat, high salt, high sulferEX) Methanococcoides burtonii

Kingdom BacteriaUnicellularNo NucleiReproduce by dividing in twoCan moveEX) E. Coli