Exam II study guide Lecture 8 PLANT DIVERSITY Plant Systematics Common names have evolved for plants over time but one problem with that is there are several different names in different regions and can be mixed up Genus similar plant species form a group genera plural Genera form families Families go into orders class divisions and kingdoms Kingdom Division Class Order Family Genus Species King David Came Over For Great Spaghetti Names are binomials of genus and species Example Homo Sapiens humans Acer rebrum red maple Acer saccharum sugar maple Taxonomic Hierarchy King David Came Over For Great Spaghetti 3 domains Archaea Eubacteria Eukaryota 6 Kingdoms Archaebacteria Eubacteria true bacteria Protista Plantae Fungi Animalia 10 divisions Bryophyta mosses liverworts Psylophyta Lycophyta club mosses Sphenophyta horsetails Pterophyta ferns Cycadophyta cycads Ginkgophyta ginkgo biloba Coniferophyta conifers Gnetophyta gnetophytes Magnoliophyta flowering plants Species A set of individuals closely related by a common ancestor can reproduce with each other but not others Morphological species concept based on their morphological features body Biological species a group of interbreeding populations fertile offspring Evolutionary species a group of individuals with common evol Lineage Many species look different but can still interbreed dogs plants HOWEVER some plants look the same but due to POLYPOIDY cant interbreed ferns evening primrose Carlos Linnaeus Father of Taxonomy systematic botany Modern system of nomenclature Named flowers after husband and wife parts stamen pistil Published Systema Naturae in 1753 Evolution Genetic change in population of organisms occurring over time Inherited not acquired traits Jean Baptiste Lamarck PRE DARWIN Theory that organisms have a force towards greater complexity But he believed acquired traits could be passed on to generations Use it or lose it theory and inheritance of acquired traits Stretching of giraffes to get higher leaves long necks Charles Darwin 1809 1882 born in England 5 yr world tour as a naturalist Observes that island animals are similar to mainland animals but they show differences that are a reflection of their island lifestyles Marries his cousin and works for 16 yrs to publish On the Origin of Species by Means of Natural Selection 1859 Controversial because of creationism Natural Selection Variation Member within a species exhibit individual differences must be inheritable Sexual Reproduction is KEY Overproduction Competition Survival to reproduce Natural populations increase geometrically producing more offspring than will survive Competing for the same resources struggle for existence Only best suited individuals will survive and reproduce survival of the fittest Works on the individual phenotype in turn changes the population gene pool lost period of time are necessary offspring inherit favorable traits increasing chance of survival eventually new better species come to existence Selective breeding by humans on other species Artificial Selection Rates of Evolution Gradualism States that evolution occurs slowly Darwinism Punctuated Equilibrium Evolution proceeds with periods of inactivity followed by high activity Gould Eldridge model Fossil records support this view However fossil records only have evidence of morphology so there might be stasis in morphology while evolutionary change is till active Lecture 9 Natural Selection Directional Stabilizing Disruptive Evolution Evidence One trait at the extreme of the range is favored over individuals with the average or opposite extreme trait The average trait is favored over the extreme traits The extreme traits are favored over individuals with the average trait Comparative anatomy Homologous organs similar in form in different species due to common evolutionary origin Share same common origin but different functions Example same bone structure in human arm and in bat arm Plants lettuce leaves pea tendrils and cactus spines have different functions but all come from the same origin leaf Analogous organs similar look and or function in different organisms but do not share common evolutionary Origin Example Wings of insects vs wings of birds In some plants stem may look like leaves but different origins Convergent evolution process in which unrelated organisms in a similar environment adapt similarly Example Cacti milkweed and euphorbia Vestigial organs organs parts that are non functional No selective function to keep it but non to get rid also Example leg bones in snakes whales wisdom teeth appendix Mimicry and protective coloration Mimicry A harmless species may resemble a dangerous one Example moths as wasps viceroy mimics monarch Protective Coloration coloration allows an organism to blend with the environment Example stone plants in SW Africa resemble stones Developmental Biology Early embryos of different mammal species look very much alike and share common features Biogeography Unequal distribution of organisms on earth Kangaroos in Australia Each species originated only once in a certain area Then they spread out once they have barriers Artificial Selection Selective breeding as practiced by humans Biochemistry Molecular Biology Genes provide and evolutionary record If common ancestor then Same genetic molecule DNA Use DNA the same DOGMA Portions should be the same FOSSILS Any trace left by a previous organism Most are preserved in sedimentary rocks Oldest rocks have simplest life form most recent have complex life forms Horsetail plant and fern Most compelling argument towards evolution Rare and not complete it is ever growing Adaptation Process by which genetic changes occur Traits that promote the survival and reproductive success of an organism in a particular environment Specific anatomical physiological or biochemical structures mechanisms arise during evolution as a response to environment May originate as mutations Without the adaptations species can become extinct Example in plants Protection trying to avoid predation from herbivores Desert plants with thorns Morphological Adaptations Strawberries grow underground stems that break so that a new plant can grow asexually Plant adaptations leaves adapted to many functions in many plants Co evolution Long term evolutionary adjustment of one group of organisms to another Reciprocal process in which characteristics evolve in response to characteristics of another species Symbiosis ways in which two organisms can