Plant Science Exam 2 Study Guide Lecture 8 1 Plant Systematics branch of botany concerned with the naming identification evolution and classification of plants 2 Plant Taxonomy science of naming and classifying plants 3 Genus or genera a formed group of similar plant species a Genera are grouped into families b Then into orders classes divisions and kingdoms c Kingdom division class order family genus species d King David came over for great sex 4 Species name each species has a single correct scientific name in Latin called binomial two names ALWAYS italicized or underlined a First name GENUS name b Second name SPECIES name i EX human homo sapiens cat felis catus dog canis familiaris 5 Living organisms are classified into 3 domains 6 kingdoms 10 Divisions a 3 DOMAINS i Archaea ii Eubacteria iii Eukaryota b 6 KINGDOMS i Archaebacteria ii Eubacteria true bacteria iii Protista iv Plantae v Fungi vi Animalia c 10 DIVISIONS i Bryophyta mosses liverworts ii Psylophyta iii Lycophyta club mosses iv Sphenophyta horsetails v Pterophyta ferns vi Cycadophyta cycads vii Ginkgophyta Ginkgo biloba Coniferophyta conifers viii ix Gnetophyta gnetophytes x Magnoliophyta flowering plants 6 Species set of individuals that are closely related by descent from a common ancestor and ordinariy can reporduce with each other but NOT with members of any other species a Some plants look the same but due to poluploidy more than the diploid number of chromosomes they cannot interbreed EX ferns evening primrose 7 Morphological speices concept based on their morphological features SHAPTE SIZE BODY PARTS 8 Biological species concept group of interbreeding populations Offspring are fertile a Species are groups of actualy or potentially interbreeding natural populations which are reproductively isolated from other such groups 9 Evoltionary species concept group of individuals with common evolutionary lineage 10 Broccoli kale cabbage califlower are all members of SAME SPECIES 11 Carolus Lunnaeus swedish scientist doctor and botanist father of systematic botany and father of taxonomy a Established modern system of nomenclature his BINOMIAL system of nomenclature was where genus and species names were used b Compared flowered to human sexuality 12 Evolution a genetic change in a population of organisms that occurs over time often adapting to an encironment or way of life a Evolutionary changes must be GENETICALLY INHERITED not acquired 13 Creationism main belief that all organisms were specially created unchanging Evolutionary thinking 14 Aristotle 350 BC saw design and purpose in nature living organisms went from imperfect to perfect complex state 15 George Cuvier 1790 s Proposed Catastrophism with creations and extinctions caused 16 James Hutton geologist who championed Gradualism convinced that Earth was by floods and droughts millions of years old 17 Jean Baptiste Lamarck 1744 1829 French naturalist proposed a theory that organisms were driven by some inner force toward greater complexity But thought that org could pass on traits to their offspring that they acquired during their lives Lamarckism a Lamarckism traits acquired or dimished during the life of an organism can be passed to its offspring Theory is based on two observations i 1 Use it or lose it ii 2 Inheritance of acquired traits from ancestors b EXAMPLES stretching by giraffes to reach elaves leads to offspring with longer necks strengthening of muscles in a blacksmiths arm leads to sons with like muscular development THEORY WAS DISPROVED 18 Charles Darwin 1809 1882 observed island animals are similar to mainland animal species but show differences due to island conditions a Human populations are controlled by environmental factors war famine diseases b He thought or organisms not as constant unchanging or specially created beings c Concept of NATURAL SELECTION developed d Natural selection the differential survival and reproduction of individuals with inhertiable characterists nature is the selective mechanism i Evolution descent with modification 19 Microevolution change of allele frequencies in a population over a short period of time a Natural selection pool i Works on the individual phenotype which in turn changes the populations gene ii Long periods of time must be available in order to change to a completely difference species because change is slow iii Those that don t inherit the favorable genes are not likely to survive reproduce iv Gradually the species evolve as more individuals carry the favorable traits b Natural Selection 4 premises i Variation Members of a population have individual differences that must be inheritable WONT work in a population of CLONES because SEXUAL REPRODUCTION is the key to variation ii Overproduction Natural populations reproduce geometrically producting more offspring than will survive Thomas Malthus said this iii Competition Individuals compete for the same limited natural resources struggle for existence iv Survival to reproduce Only those individuals that are better suited to the environment survive and reproduce survival of the fittest c Mutations d Gene flow e Genetic drift f Non random mating and animals a Ex teosinte vs modern corn of living things 20 Artificial Selection selective breeding as practiced by humans on domesticated plants 21 Macroevolution evolution that results in the formation of new species or other groupings 22 Rates of evolution two interpretations about the speed of evolution based on FOSSIL record a Gradualism Traditional view states that evolution ovvurs as a slow and steady accumualtion of changes in organism darwinian evolution not much evidence b Punctuated equalibrium evolution proceeds with periods of inactivity followed by periods of very rapid evolutio conditions remain CONSTANT for long periods of time i Fossil records support this view ii Long periods of no change in species and then rapid change iii There may be stasis in morphology while there is still active evolutionary changes happening Lecture 9 1 3 Types of Natural Selection trait 2 Extant organisms living organisms 3 Evidence in suport of evolution a Comparative anatomy a Directional Selection one trait at the extreme of the range is favored over individuals with the average or opposite extreme of the trait b Stabilizing selection the average trait is favored over the extreme traits c Disruptive selection the extreme traits are favored over individuals with the average i Homologous organs organs similar in form in