Quazi accurate photo history
Evolution- change over time Fossils preserved remains Geologic Time earth s history The evidence shows changes in environment changes in species
The Theory of Evolution supported by fossil evidence life on earth began ~ 3 bya simple single celled complex single celled organisms 1 bya complex multi-cellular organisms
Extinction disappearance of a species This happens when the death rate is greater than the birth rate What factors contribute to this? Environmental changes Temperature Sea level Pollution Succession grassland become desserts
Are adaptations possible? Yes, but adaptations may not be fast enough & some animals may out number others and quickly take over Fossil records show that this has happened and a majority of species are now extinct How do humans contribute to this today? How does it happen?
Darwin s Natural Selection Theory
Darwin s Natural Selection Theory 1. Over production more produced than needed to maintain population Ex: fish 2. Competition living space & food may be limited Ex: who eats? 3. Variation size, body shape, speed, & resistance to disease Ex: who survives? 4. Adaptation adaptation to environment = survival to reproduce Ex: who lives? 5. Natural selection organisms with optimal traits survive to pass them to next generation Ex: Who Mates? Who s genes get passed on? 6. Speciation adaptations/ mutations accumulate & may become another species Ex: frogs USA & finches Galapagos
What are 4 things that can cause evolutionary changes? Over production Causes competition Struggle for survival Strong survive Variation/mutation Those with adaptable traits live Selection by environment Adaptive Value trait passed on
2 ways offspring will have different genes than parents mutations - change in base sequence of DNA genetic shuffling - sorting & random recombination during meiosis
What are the results of genetic mutation variation a. structural - ex tail, beaks, wings b. functional - resists disease, plant sun c. behavioral mating, hiding Importance of variation increase chance of survival endangered species...?
What is the Evidence of Evolution? Geological Time earth's history as revealed by layers of rock Organic Evolution changes in living things Fossil Record collection of fossils used to represent evolutionary patterns
What is the Evidence of Evolution? Homologous structures structural parts that seem to have a common origin Compare anatomy study of plant and animal structures Comparative embryology study similarities of vertebrate embryos Fossils show a series of gradual changes DNA Electrophoresis comparisons
Patterns of Change often related to environmental change species with short reproductive cycles & produce many offspring evolve quickly (ex bacteria) failure to adapt to changing environment death of the species extinction
Rate of Evolution: How is it effected? Diversity/Variation result of natural selection over period of time Physical Change linked to changes in the environment Little Environmental Change stable populations/ less change ex: sharks, horseshoe crabs
Rate of Evolution: How is it effected? Rapid Environmental Change rapid change in species those who don t adapt- die off Few Offspring & Longer Life slower evolutionary change ex: humans-millions of years Many Offspring & Short Life faster change ex: bacteria/antibiotic resistance & DDT/insects
Dichotomous Key Organization a guide comparing pairs of observable traits that help users identify and organisms Taxonomy system of classifying and naming living things kingdom, phylum, class, order, family, genus, species Binomial nomenclature scientific name of organism: Genus species organized by traits: behavioral, biochemical, cytological, embryological, & fossil structural