• Cain, M.L., H. Damman, R.A. Lue, and C.K. Yoon. 2002. Discover Biology, 2nd edition. Sinauer Associates, Inc. Sunderland, MA. ISBN 0-393-94055-1. Library copy: UWD 1508 (3hr)

marks

• assignments (3 x 10%) 30%
• tests (2 * 15%) 30%
• final 40% (thirds worth 15%, 15%, 70%)

• characteristics of life: built of cells, reproduction via hereditary DNA, grow/develop, get energy from environment, sense & respond to environment, high level of organization, evolve
• DNA: deoxyribonucleic acid molecule, hereditary instructions for new organisms assembly
• steps: replication of DNA, transcription to RNA, translation to protein
• viruses: do reproduce via DNA/RNA, have a high level of organization, evolves, but not other life characteristics
• biological organization increasing scale: molecules/DNA, cells, tissues, organs, organ systems, individuals, populations, communities, ecosystems, biomes, biosphere
• systematists: look for organism commonalities that indicate common ancestry
• cladistics: concerned with tree branching, not degree of difference; uses a particular class of features for classifying; uses shared/derived features to identify close relatives which leads to evolutionary relationships
• features assesed for cladistics: homologous structures, comparative embryology, molecular biology, artificial selection
  • homologous structures: same embryonic origin but may do same/different things
  • comparative embryology: eg human fetus with vestigial gill slits
  • molecular biology: similarities in amino acid sequences that make up protein, and the base sequence of DNA
  • ?? artificial selection: domestication and selection of certain traits, the brassica types are the same species
• homologies (shared/derived features) showing common ancestry vs. analogies (convergent features)

• convergent evolution vs shared/derived trait: if most of a group don't have feature, it's not shared/derived
• highest level taxa (domain then kingdom):
  • Bacteria
  • Archaea
  • Eucarya: Protista, Plantae, Fungi, Animalia
• Protists: not a real group; do not share derived features (which types branched first?)
• Fungi: more closely related to animals than they are to plants
• Bacteria ~3.5 bya, then Archaea, then Eucarya
• Eucarya: uniquely, have compartments, with specialized function
• Prokaryotes (*only* single-celled) vs Eukaryotes (have nuclear membrane, organelles); not formal grouping
• Prokaryotes can be heterotrophs, photosynthetic autotrophs, or chemosynthetic autotrophs (cyanobacteria) this needs work, his notes are buggy
• Eukaryotes arose from prokaryotes; Organelles were free-living bacteria engulfed by other prokaryotes
• Giardia lamblia (prokaryote, causes giardiasis): cysts ingested in food/water, they excsyt with trophozoites colonizing small intestine, passed through feces, reservour host(s) (beavers), back into food/water
• slime molds: in protista? (1) single-celled myxamoebas (2) transition (3) multicellular pseudoplasmodia (4) stalked
• Plantae: "pioneers" of life on land; 4 major groups: mosses, ferns, gymnosperms, angiosperms
  • basic form: roots (anchor, water, nutrients), stem (support, towards sun), vascular system (transport water, minerals), leaves (absorb CO2, photosynthesize), fruits/etc (seeds), flowers (reproductive)
  • Gymnosperms (300-250 mya): first seed-bearer
  • Angiosperms (200-150 mya): flowers (= faster pollination/fertilization(?))
• Fungi: decomposers, parasites, and mutualists; 3 groups: Zygomcytes, Ascomycetes, Basidiomycetes
  • yeast
  • mushroom: spores, hyphae make up mycelium, chitin cell walls
• Animalia: evolved tissues, organs, organ systems (porifera don't have true tissues, but cnidaria+ do
  • later evolved protostomes (mollusca, annedlia, arthropoda), then deuterostomes (echinodermata, vertebrata)
  • formed by cavity: first opening in protostomes becomes mouth, in deuterostomes becomes anus and 2nd becomes mouth
  • body plans are variations on a few themes (eg segments)
• viruses: not in any kingdom, unclear evolutionary relationship, they don't grow, reproduce outside of a host, gather energy, photosynthesize, or consume others
  • highly degenerative, maybe evolved many frimes from many kingdoms
  • eg measles, influenza, hepatitis, viral pneumonia, meningitis, SARS. *not* mad cow, that's from prions
• total species known 1.412 million: 751,000 insects, 281,000 other animals, 248,400 plants, 69,000 fungi, 57,700 protists, 4,800 prokaryotes
  • total species estimate: 3-30 million
  • 1 tropical tree has 163 spp beetles in canopy; 50,000 tropical trees = 8 million beetle spp (beetles are 40% of arthropods)
  • 20M + 10M non-canopy = 30M (?refers to which?)
• beginning of present-day mass extinction
  • human activity: species decline with human population rise; extinctions at 27K/year (3/hour)
  • fewer species means fewere new species
  • will humans also go extinct?
  • threats: habitat loss, introduced species, climate change
• 5 previous mass extinctions: 440, 350, 250 (end of Permian biggest, 80-90% of marine spp), 206, 65 (end of cretaceous and non-bird dinosaurs) mya
  • recovery took millions of years
• importance of biodiversity: proportional to productivity (biomass), stability, reslience
• rivet hypothesis: few extinctions mean no problem, but a fe w more could lead to collapse
• ecosystem functions/services
  • nutrient cycling (N in useable form for plants)
  • purification of air and water
  • make and preserve soils
  • waste decomposition
  • pollination
  • pest control by natural enemies
  • plants provide food for animals
• other stuff we get from nature
  • 25% of prescription drugs are plant extracted
  • wood
  • wild species eaten: insects, iguanas, guanaco, capybara
  • aesthetic
  • spiritual refreshment (?)
  • intrinsic value
• ecosystem function: processes that keep ecosystem working and changing
  • does function go up with species (rivet) or plateau (redundancy)?