Stromatolites: layers of rock with fossils
Origin of Life Big Bang Theory: formation of the universe (20 billion years ago=bya) Earth formed 4.5 bya First atmosphere: hydrogen, water vapor, nitrogen, methane, ammonia What is missing?? FREE OXYGEN Core Crust
Miller Experiment Inorganic Molecules Organic Molecules (hydrogen, water vapor,nitrogen, ammonia) (carbohydrates=sugars, Lipids=fats, proteins, DNA) Electricity No electricity 3.5 bya, so what could cause a spark? First life on earth 3.5 bya, prokaryotic cells Prokaryotic cellsEukaryotic cells (1.5 bya)
Miller Experiment: the origin of life
Plate Tectonics
What is it called, when plates move against each other? An earthquake! What is it called where the plates meet? Earthquake fault What earthquake fault do we live near? San Andreas Fault Earthquake Kit??
Continental Drift
Pangaea: continents in one land mass Laurasia: N. America Europe Asia Gondwana: Africa, S. America Australia, Antarctica, India
Quaternary: modern man Tertiary: radiation of mammals __________________________________ Cretaceous: mass extinction of dinosaurs Jurassic: dinosaurs dominant Triassic: first dinosaurs __________________________________ Permian: mass extinction of marine life Carboniferous: first reptiles Devonian: first amphibians Ordovician: first fishes Cambrian: marine life abundant Precambrian: first life on earth Cenozoic Mesozoic Paleozoic
Past vs. Current Extinction Past Slow Natural Causes Extinction with replacement Current Fast Human Causes Extinction without replacement
Taxonomy Linnaeus/binomial name (Genus species) Humans = Homo sapiens Kingdom, Phylum, Class, Order, Family, Genus, Species Homology = similarity in structure due to a common ancestor Analogy = similarity in function not due to a common ancestor DNA comparison
Homologous Structures
Schools of Taxonomy Phenetics: looks for similarity and differences whether homology or analogy Phylogenetics: use homologies to map evolutionary relationship Cladistics Clade = evolutionary branch Cladogram = series of dichotomous forks