Transcript COMP 6 PPT
Competency 6 Demonstrate and understand of principals that explain the diversity of life and biological evolution Kingdom Archaebacteria • Unicellular (single cell) • prokaryotic- cells lack a nucleus and membrane bound organelles • Circular DNA floating in cytoplasm • have a cell wall made of polysaccharides • Heterotrophic, autotrophic, chemotrophic • Reproduce by binary fission or conjugation • found in harsh environments Archaebacteria – ancient bacteria Methanogens Halophiles Acidophiles: Live in: Live in: Salt water Live in: Hot, acidic water Oxygen-free env. Produce methane gas Kingdom Eubacteria Characteristics • Unicellular (Single cell) • prokaryotic- cells lack a nucleus and membrane bound organelles • Circular DNA floating in the cytoplasm • have a cell wall made of polysaccharides • may be either heterotrophic or autotrophic (make their own food) • reproduce by binary fission or conjugation Eubacteria - “True” bacteria • Live in more habitable environments Heterotrophs Saprophytes (decomposers) Photosynthetic Autotrophs Need sunlight to make food Parasites (cause Example: disease) Cyanobacteria Chemosynthetic Autotrophs Need sulfur & nitrogen to make food Nitrogen fixation (FIX the nitrogen) Kingdom Fungi • Most are multicellular- more than one cell • Eukaryotic • All have cell walls made of chitin, a complex carbohydrate. • Heterotrophic • Decomposers- specifically, they obtain energy by feeding off dead or decaying organic matter. Kingdom Plantae • • • • Multicellular eukaryotic have cell walls made of cellulose Autotrophic – perform photosynthesis Plants 2 groups – Nonvascular- lack of conducting cells (liverworts, hornworts, and mosses) – Vascular (common plants like pines, ferns, corn, and oaks) Have specialized transporting cells • Xylem (for transporting water • and mineral nutrients) • Phloem (for transporting sugars from leaves to the rest of the plant) Two types of Vascular Plants 1. Gymnosperms 2. Angiosperms Gymnosperms- seeds are not protected by fruit EX: Conifers- plants with seeds inside cones and needle –like leaves ( Pine Tree) Angiosperms • Flowering plants, seeds protected by fruit • Two Types of Angiosperms a. Monocot – leaves have parallel veins EX: Corn and Grass b. Dicot- leaves are netlike EX: roses, apple tree, sunflowers Parts of a Flower Kingdom Protista • • • • • The most diverse kingdom unicellular eukaryotic may be autotrophic or heterotrophic Examples: Amoeba, Euglena, and Paramecium Kingdom Animalia • Multicellular- made of more than one cell • Eukaryotic- cells have a nucleus and membrane-bound organelles • Cells lack cell walls • Heterotrophic- are consumers…they get their energy from another food source. Animals Vertebrates Mammals Fish Invertebrates Cnidarians Flatworms True worms Reptiles Molluscs Amphibians Echinoderms Birds Arthropods Animals - Invertebrates • Phylum Proifera – Sponges, primitive filter feeders • Phylum Cnidaria – Jellyfish, corals, sea anemones • Phylum Mollusca – Bivalves - scallops, oysters, mussels, clams – Gastropods – snails, slugs – Cephalopods – squids, octopi • Phylum Echinodermata – Sea urchins and sea stars • Phylum Arthropoda – Spiders, scorpions, crabs, shrimp, insects, millipedes, and more Animals - Vertebrates • Phylum Chordata: 50,000 vertebrates • 2 groups – Jawless forms (Class Agnatha) hagfish, lamprey – Jawed forms – most of the animals we know Animals – Vertebrate Classes Condrichthyes- cartilage fish www.flmnh.ufl.edu/fish/Education/bioprofile.htm Animals – Vertebrate Classes Osteichthyes- bony fish www.flmnh.ufl.edu/fish/Education/bioprofile.htm Animals – Vertebrate Classes Amphibia- double life www.natureserve.org Animals – Vertebrate Classes Reptilia www.natureserve.org Animals – Vertebrate Classes Aves- birds --- www.natureserve.org Animals – Vertebrate Classes Mammalia www.natureserve.org Major levels in the hierarchy of taxa •Father of TaxonomyCarolus Linnaeus •Developed a two name system called Binomial nomenclature •System of classifying organisms based on organism’s form and structure Scientific Names • Taxonomy science of naming and classifying organisms • Are universal • Two latin words in italics • First word is genus- capitalized • Second word is species- lowercase Example Scientific Name - Quercus rubra Quercus is the genus Genus taxonomic category are similar species rubra is the species Species is the most specific biological unit Common Name – Red Oak Species Genus Family Order Class Phylum Ursus americanus (American black bear) Ursus Ursidae • Linnaeus ranked species into ever more Carnivora inclusive categories (like a postal address) Mammalia • Groups share certain traits Chordata • Groups do not necessarily reflect Animalia evolutionary relationships Eukarya Kingdom Domain Taxonomic Diagrams Mammals Turtles Phylogenetic Tree Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Cladogram Birds • A cladogram shows the evolutionary relationships between groups of living things. It is like a family tree for species. • The closer two species are on the cladogram, the more closely they are related. This means they evolved apart more recently. •Sometimes a cladogram will also list the characteristics that make two groups or organisms different called derived characters. Symmetry- body arrangement in which parts that lie on opposite sides of an axis are identical. Feather duster worms Patterns of Organization Three different types of symmetry: 1. Asymmetrical 2. Radial symmetry 3. Bilateral symmetry Asymmetrical animals –do not display symmetry sponge Radial Symmetrythe parts are organized in a circle around the axis Sea anemone Bilateral Symmetry – the body parts can be divided equally thru the center into left and right halves Methods of sexual reproduction • Purpose of Reproduction-To make sure a species can continue. – Definition: Reproduction is the process by which an organism produces others of its same kind. • Requires two sex cells – egg and sperm • The egg and sperm join to form a zygote – Different from the parent organism Budding • Process by which a new, duplicate plant or animal begins to form at the side of the parent and enlarges until an individual is created. • Very common in plants and sponges Regeneration • The ability to restore lost or damaged tissues, organs or limbs. • It is a common feature in invertebrates, like worms and starfish. Fission • Also called binary fission. • Becoming two by division of the complete organism. • A type of cell division. Francisco Redi (1626-1697) • Set up controlled experiment to test idea of spontaneous generation with respect to maggots appearing on rotting meat – open jar with meat – screened jar with meat – sealed jar with meat Figure 1-8 Redi’s Experiment on Spontaneous Generation (1668) OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Uncovered jars Controlled Variables: jars, type of meat, location, temperature, time Covered jars Several days pass Manipulated Variables: gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. John T. Needham (1713-1781) • Flies do not arise spontaneously but the “animalcules” described by van Leeuwenhoek must • In 1748 Needham boiled broth, stoppered and noted that flask became turbid (cloudy) • Argued that the turbidity, which included many “animalcules” must have arisen spontaneously Lazzaro Spallanzani (1729-1799) • Used flasks that were sealed by melting the glass rather than with a cork • Found that if sealed properly, flasks boiled 45 minutes would remain sterile thus refuting Needham’s conclusions Figure 1-10 Spallanzani’s Experiment Gravy is boiled. Flask is open. Gravy is boiled. Flask is sealed. Gravy is teeming with microorganisms. Gravy is free of microorganisms. Louis Pasteur (1822-1895) • Looked at air which had been filtered • Developed swan neck flask to deal with heated air problem • Settled controversy Figure 1-11 Pasteur’s Experiment Broth is boiled. Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms. • 1864- Convinced scientists that spontaneous generation was invalid • Impacted industry and medical research Early Evolutionists Hutton gradualism - same processes are responsible for both past and present events one of the first to state that the earth is really old Lyell Theory of uniformitarianism small forces acting over long periods of time can result in major changes e.g. destruction of mountains. Lamarck (1744-1829) The idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring (also known as heritability of acquired characteristics ). His ideas were universally rejected Malthus If human population was allowed to increase in an uncontrolled way, then the number of people would increase at a faster rate than the food supply. A point would come when human population would reach the limit up to which food sources could support it. Any further increase would lead to population crash caused by natural phenomena like famine or disease. Malthus’ ideas led Darwin to his idea of natural selection (competition for resources) Charles Darwin (1809 – 1882) • Traveled all over world on HMS Beagle collecting animal and plant specimens • Enormous numbers and diversity of species • Evidence Darwin Collected 1. extinct species related to living (extant) organisms 2. characteristics of species varied from place to place 3. great variety of organisms on young volcanic islands, e.g., finches Galapagos Island Galapagos Tortoise Finches Darwin’s The Origin of Species Common Descent • Species descend from common ancestors Theory of Natural Selection 1. There is variation in all species 2. Some heritable traits in the population are advantageous in environment (adaptation) 3. Adaptations make some individuals more fit and as a result, they can survive and reproduce more 4. Over many generations, there are more beneficial traits in the population Alfred Russel Wallace • A contemporary of Darwin, who also came up with the theory of Natural Selection independently. • He sent his work to Darwin • Darwin’s work “THE ORIGIN OF SPECIES” was published • Wallace insisted that Darwin get all the credit, because Darwin had done more extensive work and research on it than Wallace. Lamarck vs. Darwin/Wallace Evidence of Evolution • Morphology - change from the body form of a common ancestor • Similar structure (homology) are evidence for a common ancestor • Vestigial Structuresorgan that is no longer used but may have been present in ancestors Problems with classification by morphology • Convergence- unrelated species have similar adaptations • Similar structures evolving in separate lineages as adaptations to the same environmental pressures (ANALOGY) • Convergent (ANALOGOUS) structures did not evolve from a common ancestor! Use of molecular data • DNA/amino acid sequences will be similar if they come from a recent common ancestor 1 Deletion 2 Insertion 3 4 Evidence of Evolution –Embryology– Many organisms are very similar in appearance and have common features as embryos but vary significantly as adults. • These similarities provide evidence for evolution from common ancestors Natural Selection Microevolution is changes in the gene pool of a population over time that result in changes to the varieties of individuals in a population such as a change in a species' coloring or size. Macroevolution If the changes are over a very long time and are large enough that the population is no longer able to breed with other populations of the original species, it is considered a different species. Evolution and Adaptation Macroevolution Microevolution Microevolution • Changes in a population’s gene pool over time. • Four Processes cause Microevolution – Mutation (random changes in DNA— ultimate source of new alleles) – Natural Selection (more fit = more offspring) – Gene flow (movement of genes between pop’s) – Genetic drift (change in gene pool due to random/chance events) Mechanisms of Evolution Mutation -Flow of Information Fig. 18.5, p. 287 Speciation • Two species arise from one –Requires Reproductive isolation • Geographic: Physically separated • Temporal: Mate at different times • Behavioral: Bird calls / mating rituals REPRODUCTIVE ISOLATION Geographic isolation: • Two species living in separate habitats within the same area may encounter each other rarely – e.g., Two species of garter snakes occur in the same areas, but one is primarily aquatic and the other is primarily terrestrial REPRODUCTIVE ISOLATION Behavioral isolation • Elaborate courtship behavior and other signals unique to a species are likely the most important reproductive behaviors between closely related species – e.g., Firefly flashing patterns, bird songs, elaborate mating dances, etc. REPRODUCTIVE ISOLATION Temporal isolation • Two species may breed during different times of the day, different seasons, or different years – e.g., Ranges of western spotted skunk and eastern spotted skunk overlap, but the western mates in late summer and eastern mates in late winter Applications of Evolution through Natural Selection – Pesticide Resistance & Antibiotic Resistance • Occasionally, some insects or bacteria in a population have slight variations that make them able to survive the pesticide or antibiotic used to kill them. • Those organisms survive and reproduce to create a new generation of insects or bacteria that are resistant to the pesticide or antibiotics. • This requires different and stronger pesticides and antibiotics to be continuously created to kill these resistant organisms. Endosymbiotic Theory Eukaryotic cells may have resulted from the symbiotic relationship with photosynthetic (the chloroplast) and aerobic heterotrophic (mitochondria) prokaryotes. Both chloroplast and mitochondria have their own DNA