Belief systemAristotleNaturalistFourteenth century---Alfred WallaceBiogeographyHow could species which live very far apart look similar to each other?d eomparative morphology--!estigial partsFossilsNautilusAmmoniteNineteenth entury"ean #amarckBeagleroute ofBeagleEQUATORGalpagosIslandsc$heory of uniformity--a b$homas %althus--$he story of &aster 'slandThe image cannot be displayed. our computer may not ha!e enough memory to open the image" or the image may ha!e been corrupted. Restart your computer" and then open the file again. If the red # still appears" you may ha!e to delete the image and then insert it again.--Natural selection---Observations about populationsNatural populations have an inherent reproductive capacity to increase in size over time. As a population expands, resources that are used by its individu-als (such asfood and living space) eventually become limited. When resources are limited, individuals of a population compete for them. Observations about geneticsIndividuals of a species share certain traits. Individuals of a natural population vary in the details of their shared traits. Traits have a heritable basis, in genes. Alleles (slightly diferent forms of a gene) arise by mutation. InferencesA certain form of a shared trait may make its bearer more com-petitive at securing a limited resource. Individuals better able to secure a limited resource tend to leave more ofspring than others of a population. Thus, an allele associated with an adaptive trait tends to become more common in a population over generations. (reat minds think alike--Fossils---abFossili)ed plant'chthyosaur---50 cm100 cmEonEraPeriodEpochmyaMajor Geologic and Biological EventsPHANEROZOICCENOZOICQUATERNARYRecent0.01Modern humans evolve. Major extinction eventPleistoceneis now underway.1.8TERTIARYPliocene5.3Tropics, subtropics extend poleward. Climate cools;Miocene23.0Oligocenedry woodlands and grasslands emerge. Adaptive33.9radiations of mammals, insects, birds.Eocene55.8Paleocene65.5Major extinction event, perhaps precipitated byMESOZOICCRETACEOUSLateasteroid impact. Mass extinction of all dinosaurs99.6and many marine organisms.Climate very warm. Dinosaurs continue to dominate. ImportantEarlymodern insect groups appear (bees, butterfies, termites, ants,and herbivorous insects including aphids and grasshoppers).145.5Flowering plants originate and become dominant land plants.JURASSICAge of dinosaurs. Lush vegetation; abundant gymno-sperms and ferns. Birds appear. Pangea breaks up.TRIASSIC199.6Major extinction eventRecovery from the major extinction at end of Permian.Many new groups appear, including turtles, dinosaurs,pterosaurs, and mammals.PERMIAN251Major extinction eventPALEOZOICSupercontinent Pangea and world ocean form. Adaptiveradiation of conifers. Cycads and ginkgos appear. Relativelydry climate leads to drought-adapted gymnosperms and299insects such as beetles and fies.High atmospheric oxygen level fosters giant arthropods.CARBONIFEROUSSpore-releasing plants dominate. Age of great lycophytetrees; vast coal forests form. Ears evolve in amphibians; penisesevolve in early reptiles (vaginas evolve later, in mammals only).DEVONIAN359Major extinction eventLand tetrapods appear. Explosion of plant diversity leadsto tree forms, forests, and many new plant groups including416lycophytes, ferns with complex leaves, seed plants.SILURIANRadiations of marine invertebrates. First appearances of landfungi, vascular plants, bony fsh, and perhaps terrestrial animals(millipedes, spiders).443Major extinction eventORDOVICIANMajor period for frst appearances. The frst land plants, fsh,and reef-forming corals appear. Gondwana moves toward the488South Pole and becomes frigid.CAMBRIANEarth thaws. Explosion of animal diversity. Mostmajor groups of animals appear (in the oceans).542Trilobites and shelled organisms evolve.Oxygen accumulates in atmosphere. Origin of aerobicPROTEROZOICmetabolism. Origin of eukaryotic cells, then protists, fungi,plants, animals. Evidence that Earth mostly freezes overin a series of global ice ages between 750 and 600 mya.ARCHAEAN2,5003,8002,500 mya. Origin of prokaryotes.AND4,6003,800 mya. Origin of Earths crust, frst atmosphere,EARLIERfrst seas. Chemical, molecular evolution leads to origin oflife (from protocells to anaerobic prokaryotic cells).*rifting continents and changing seas---Kaibab LimestoneToroweap FormationCoconino SandstoneHermit ShaleEsplanade SandstoneWescogame FormationManakacha FormationWatahomigi Formation Redwall LimestoneTemple Butte FormationMuav LimestoneBright Angel ShaleTapeats Sandstone*Sixtymile Formation*Chuar Group*Nankoweap Formation*Unkar Group*Vishnu Basement Rocks*trench hot spotridge trench riftA$% &A Plumes of molten rockrupture a tectonic plate at what are called hot spots. The Hawaiian Archipelago has been forming this way.$ At oceanic ridges, huge plumes of molten rockwelling up from Earths interior drive the movement of tectonic plates. New crust spreads laterally as it forms on the surface, forcing adjacent tectonic plates away from the ridge and into trenches elsewhere.% At trenches, the advancingedge of one plate plows under an adjacent plate and buckles it. The Cascades, Andes, and other great coastal mountain ranges formed this way.& At rifts, continentsrupture in their interior as plates slide apart from each other.ab!ulnera+le to predation,e-ual dimorphism,e-ual selection