BIOL 3350 Lecture 4 Outline of Last Lecture I. Radiometric DatingII. Geological Time Scale OrderIII. Evidence from the Fossil RecordIV. The Law of SuccessionV. Transitional FormsVI. Evidence from Common AncestryVII. Evolutionary change can create new speciesOutline of Current Lecture I. Plato’s notion of the typeII. European thought during the RenaissanceIII. Scala Naturae or the Great Chain of Being – AristotleIV. The Scientific RevolutionV. Focus on cataloging and describing speciesVI. Discovering a World in FluxVII. Early Ideas on Evolutionary ChangesCurrent LectureI. Plato’s notion of the typea. Plato believed that each species had an ideal formb. Things we see on the world are manifestations of that “perfect” form (with some imperfections)c. We wouldn’t expect forms to change if they were God’s perfect form à would imply some deficiencies in the original planII. European thought during the Renaissancea. Stasisi. Everything that we see in life is perfect as it is b/c it is part of God’s planii. Shouldn’t expect any kind of changeIII. Scala Naturae or the Great Chain of Being – Aristotlea. Progression from most complex to least complexb. Organisms are unchanging since they were created in perfect formi. Impossible for new forms to have arisen since creation or for existing forms to have gone extinctThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.ii. Not logical for old forms to go extinct b/c violation of idea that earth has been perfect from the beginning (concept of stasis)IV. The Scientific Revolutiona. Expansionismi. Discovery and exploration of new areasb. Advances in Science and Technologyi. Astronomers1. Keppler defended Copernicus’s theoryii. Mathematicians1. Descartes developed geometryiii. Printing Press1. Printing press allowed things to be copied for easily and efficiently à mass production & exposure to mass of new informationV. Focus on cataloging and describing speciesa. Carolus Linnaeus published Systema Naturaei. Noticed physical similarities, so a way to group similar looking things on earth1. Cataloguing the diversity of the Creator2. Was not thinking about ancestry at allVI. Discovering a World in Fluxa. Comparative Biology: Georges Cuvieri. Cuvier – probably one of the world’s first ever comparative biologistii. Idea that extinct species are similar to living onesiii. First to acknowledge extinctioniv. See extinction is a part of nature and a regular occurrencev. Continuity between alive and extinct speciesb. Organic Mutabilityi. Evidence that plants and animals were not constant in form1. Species could change through natural selectionii. Gilbert White1. Studied different breeds of pigeons trace back to Rock Dove2. Studies were important because many diverse forms can arise from a single stock3. First to realize the importance of all of the different parts of the ecosystem (ex: importance of earth worms – great promoters of vegetation)c. Principle of Geology: Lyelli. Calculated extinction rates 1. Extinction rates were relatively constant from layer to layer2. Concept that nature selects certain species to extinctii. Period of major extinction correlated with period of environmental change1. Selecting process was eliminating unfit species depending on the environmental conditionsVII. Early Ideas on Evolutionary Changesa. Inheritance of acquired characteristicsi. Lamarck:1. Use & disuse – giraffes necks increase in length in future generations to reach higher leaves to eat2. Idea of change within species was correct, but the mechanism he used to describe it was notb. Species selection versus Individual Selectioni. Selection among species1. More fit species survived, less fit species went extinctii. Evolution was a differential sorting of chance variations among speciesiii. Idea of selection operating on the individualc. Darwin’s Theory of Adaptationi. Observations made in the Galapagos Islands1. Mockingbirds from different islands looked like different species2. Same was true for tortoises and finchesa. Individual species are all related to each other through common ancestorb. Started with same species of finch that then radiated into other species3. Bills appeared to fit remarkably well with available foods4. Tortoises on the islands had different shells shapes a. Could tell where tortoises were from based on their shell shapeii. Variation according to local conditions1. Island birds changed in character when other competitors lived onthe same island2. The more species, the more specialized their beaksa. More species, the less variation within a given species3. The few species, the more generalized beak species4. Different species vary according to beak size5. Much more variation in medium islands because less speciesd. Darwin’s Postulatesi. Individuals within species are variableii. Certain of these variants are passed on to offspringiii. In every generation, more offspring are produced than can surviveiv. Differential survival and reproductione. The Natural History of Fur Color in Beach Micei. Common names: Beach Mouse or Old Field Mouseii. Habitat: Sand burrows in dunes or old fieldsiii. Fur color varies from light to dark1. Light colored sub-species live in light sand beaches2. Dark colored sub-species live in darker