Lecture 11 Classification 1. Introduction to Survey of Life - The change in coverage - through the years GRE's, texts and lectures. a) major events; move to land, origin of sex. b) major importance to us: vertebrates, but also insects, fungi = why should you care. c) How organisms meet major challenges -internal challenges communication, waste, digestion, differentiation = intra and intercellular issues. - external challenges resource competition, predators, dispersal, mating, avoid unfavorable circumstances 2. New concepts of Classification.c. biological definition - Distribution curve for variatione. rule of priority for species names3. Higher Categories a.Rule of Usage: how many kingdoms. b.Basis: phyletic-- monophyly, polyphyly phenetic cladistic4. Cladistics compared to other systems homology - current difficulties in usage Shared Derived Characters= synaptomorphy 5. Problems - Equivalent trees and number of possibilities - brushpile evolution = close taxonomic distances- no discrimination - gene shifts between branches - continued differences in classification: what is a plant? - Traditional names vs "new" ones different content = different name.Lecture 12 The Diversity of Life 1. Kingdoms and "domains" Aristotle-Linneus to 1850 = two kingdoms; Animalia, Plantae(fungi, algae) 1850- Ernst Haeckel - Protista recognized monera as odd 1937- Charlton, coined terms procaryotes, eucaryotes 1956- four kingdoms (procaryota, Proctista 1959-Whittaker - 5 kingdoms - fungi 1990- 6 kingdoms Woese - Archaebacteria, Eubacteria Protista (include algae) shift from morphology to structure to biochemistry Viruses??? 2. Diversity through time. increase with periodic catastrophies, periodic major invasions of new realms. 3. Diversity in absolute numbers. a) numbers b) estimates of % known or described species c) tropical richness. 5. How Evolution Works (reminder) - brushpile evolution - try all possibilities on entering a clade. - winners and loosers/ greater vs lesser potential; 1st bird = odd reptile - Multiple solutions to evolutionary problems skeleton: hydrostatic, external, internal each solution has limitations, advantages. Lecture 13 Domain Bacteria www.ucmp.berkeley.edu/archaea/archaea.htmltrishul.sci.gu.edu.au/~bharat/courses/ss13bmm/archaea.html1. The new category "Domain" = based on cladistics.2. Morphology vs chemical pathways.3. The Three domains. a) Procaryotic vs Eucaryotic nuclear membrane, organelles, cytoskeletonn b) changes within the procaryotes. ribosomal RNA - work of Carl Woese 4. The new Picture - "Brushpile evolution"Bacterial brushpile - eucaryotes a side branch as far as biochemical evolution is concerned Bacterial reproduction haploid ring DNA transformation, transduction, conjugation exchange of fragments of info Total DNA sequence of Bacteria probability of genetic exchanges across distant species = intertwining branches of evolution.5. Archaea extremophiles, hot, cold and normal temps varied/ energy sources cell membrane, cell wall specializations some similarities to Eucaryotes some interesting industrial applications insights into origin of life6. Eubacteria. three shapes., cocci, bacillus, spirochaetes taxonomic shift from morphology to molecular level gram positive vs gram negative = staining of cell wall; based on amount of peptidoglycan gram negative - little peptidoglycan, harder to attack as antibiotics target the peptidoglycan. ecologic importance nitrogen fixation soil bacteria fermentation disease mutation rate and resistance bacteria as unsuspected causes of disease new diseases. Viruses biology - obligate parasites origin - fragments? gene transfer - importance role in oceans role in disease. Lecture 14 Protista 1. Classification see book eucaryotes large and varied group: plant, animal, fungi motile, non-motile one cell - multi cell defined by absence of traits poor taxonomyBrushpile pattern basis of taxonomic groups. algae - pigment systems protozoa - locomotion, covering slime molds - cell types.2. Origin of Diploidy - sex why? variation parasitic protection purge of bad genes variation in reproductive cycles; all patterns isomorphic, diplontic, haplontic isogamous, anisogamous3. Origin of the Eucaryotic cell steps - reasons for each Giardia - an intermediate4. Variations among Protists -how they deal with the world 5. Important Protists Malaria - resistence algae - oxygen supply 6. Drinking water water purification and pollution water treatment small vs large townsLecture 15 Fungi and early plants 1. General Characteristics - absorbtive heterotrophs absorbtive nutrition, cell wall of chitin spore reproduction 2. Structure hypha(e) mycelium - no cell division most decomposers, some parasitic, predatory 3. Reproduction mating types vs sex. haploid adults 2 types grow together, form dikaryon (2 nuclei in cell) fuse - meiosis diploid organnism = nucleus only 4. Evolution come on land- after plants 1 group aquatic - flagellated spore on land - airborne spore, dispersion and survive unfavorable conditions sex prior to spore formation - creates variety 5. Symbiosiswith algae = lichens with higher plants = root absorption important in plant dominance- diseases; ringworm, toenail rot, valley fever, frog deaths fungi in hospitals.Plants 1/ Origins of multicellularity cell differentiation 3400 million years ago life arises 1000 "" multicellular life more complicated than filiaments volvox- a model form 1000cells, differentiation. how to study;see mutants- what they do 3 genes cause initial differentiation restrict division to germ cells basics: turning off or on dna in some cells. 2. Algae - Caulerpa - one cell - microtubules Kelp - holfast, stem, leaves, floats, reproductive cells. Classification: if use chloroplast, chlorophyl a dn b, starch as storage, then green