Succession The process where plants & animals of a particular area are replaced by other more complex species over time. Primary Succession When the starting point is an ABIOTIC environment Volcano Flood Secondary Succession When an EXISTING ecosystem is disturbed Fire/lightning Disease Hurricanes Human activities Credit: Jeff Schmaltz, NASA's MODIS Rapid Response Team CARBON CYCLE Nitrogen Cycle Evolution A change in a population over time (individuals dont evolve!) The process by which modern organisms have descended from ancient organisms When comparing fossils found in rock layers, the deeper the layer, the older the fossil. How does Evolution occur? Natural Selection How does Evolution occur? Natural Selection Organisms that are best adapted to their environment survive and pass their DNA on to their offspring. Survival of the Fittest What makes animals better fit for an environment? Adaptation Physical or behavioral trait that help the individual survive and reproduce in their environment.Physical or behavioral trait that help the individual survive and reproduce in their environment. Makes them more fit.Makes them more fit. Adaptations also include: Mimicry- copying the appearance of another species for protection or other advantage. Camouflage body covering or coloring that helps them blend into the environment. Many insects evolved to mimic their environment. Mimicry Raven and Johnson, Biology Principles and Explorations Leaf Bug Yellow Jacket MimicsFly Moth Beetle Raven and Johnston, Biology Jackrabbit Raven and Johnston, Biology Camouflage Inchworm Caterpillar Raven and Johnston, Biology Flounder Raven and Johnston, Biology Camouflage Why are all these animals white?Why are all these animals white? Helpful Mutations (Adaptations) The giraffes long neck helps it reach higher in the tree for food where other animals cant. The alternating black and white stripes help keep the zebras cool. (The black absorbs heat and the white reflects it.) Adaptations of Birds Feet CatchingHangPerchWadeSwim The shape of the archerfishs body and mouth allow it to spit water above the surface, knocking insects off of low lying branches. What adaptations do the following organisms have? Where did all this diversity come from?! And how do we know? What is the evidence of a common ancestor? Homologous Structures Same structure different function Analogous Structures Flight protection Structures that are inherited, but reduced in size and not used Human tailbone Whale pelvic bone Human appendix Why do these organisms look so similar? Why do these organisms look so similar? What has shaped their appearance over time? Speciation (formation of a new species) results from reproductive isolation populations can no longer interbreed to produce fertile offspring How do populations get isolated?.... Most organisms found on the Galapagos Islands are endemic (only found there) Why? Geographic Isolation The separation of populations by barriers such as rivers, mountains, or bodies of water Giant opuntia cacti (Galapagos) Opuntia cacti (N.America) - 10,000 years ago, members of the original species of squirrel were separated by the formation of the Grand Canyon. This resulted in the two separate species evolving, The Kaibab Squirrel and The Abert Squirrel. Raven and Johnson, Biology Geographical isolation Why are Lemurs found only on Madagascar? Why are Lemurs found only on Madagascar? 34 Because environmental pressures, unrelated organisms on different continents often display similar adaptations. 36 Two organisms evolve together as a result of their interdependence (symbiosis) - insects and flowering plants Natural selection is not the only source of evolutionary change. In small small populations, a trait can become more or less common by random chance Chinese River Dolphin 2006 Tasmanian Wolf 1930s Dodo 1681 Pyrenean Ibex 1999 Passenger Pigeon Quagga Adapt or Die! More than 99% of all species that ever lived are now extinct 5 mass extinction events in Earths history Wipes out whole ecological systems (Ex: dinosaurs extinct during K/T event) Burgess Shale (many extinct organisms that were VERY different from modern organisms) Because bacteria reproduce so quickly, they represent excellent specimens for testing Natural Selection Watch how quickly they can evolve because of Natural SelectionWatch how quickly they can evolve because of Natural Selection Resistance to antibacterial soap Generation 1: 1.00 not resistant 0.00 resistant Generation 1: 1.00 not resistant 0.00 resistant Resistance to antibacterial soap How natural selection works Resistance to antibacterial soap mutation! Generation 1: 1.00 not resistant 0.00 resistant Generation 2: 0.96 not resistant 0.04 resistant How natural selection works Resistance to antibacterial soap Generation 1: 1.00 not resistant 0.00 resistant Generation 2: 0.96 not resistant 0.04 resistant Generation 3: 0.76 not resistant 0.24 resistant How natural selection works Resistance to antibacterial soap Generation 1: 1.00 not resistant 0.00 resistant Generation 2: 0.96 not resistant 0.04 resistant Generation 3: 0.76 not resistant 0.24 resistant Generation 4: 0.12 not resistant 0.88 resistant How natural selection works Prokaryotes and DNA Bacteria Oldest known living organism ProkaryoticCell Type: Prokaryotic Unicellular No Nucleus No Organelles flagella or ciliaBody Structure : May have flagella or cilia for movement Identifying Bacteria: coccus- spherical bacillus- rod sprillum-spiral Diplo- pairs Strepto- chain Staphylo- clump Importance of Bacteria Decomposers Nitrogen Fixation Photosynthesis (oxygen) Oil spill clean up Digestion aid & vitamin production Foods such as cheese and yogurt Medicines Biowarfare Kingdom EubacteriaKingdom Eubacteria Normal bacteria Found everywhere Cell wall: contains peptidoglycan Kingdom ArchaebacteriaKingdom Archaebacteria Ancient bacteria Find in extreme environments Cell wall: DOES NOT contain peptidoglycan PROKARYOTIC KINGDOMS Ch:19-1 Can be autotrophs or heterotrophs Autotrophs Autotrophs: Producers Heterotrophs Heterotrophs: Consumers Photosynthetic light * Photosynthetic - use light to make food Chemosynthetic chemicals * Chemosynthetic - use chemicals to make food Sources of Energy for Prokaryotes Photo Chemo Prokaryotes reproduce in 3 ways: Binary Fission Binary Fission: splitting in half -Conjugation -Conjugation: swapping genes over a bridge between two bacteria Play for video -Spore Formation-endospores -Spore Formation- endospores form so that bacteria can remain dormant in harsh conditions and then germinate when conditions become favorable AUTOTROPHIC- Produces AUTOTROPHIC- Produces their own food EX: Plants HETEROTROPHIC- consumes HETEROTROPHIC- consumes food to get energy. Ex: animals Undergo Photosynthesis: Undergo Cell Respiration: ___________ + _________ + ___________ _______________ + __________ 6 CO 2 6 H 2 OC 6 H 12 O 6 6O 2 _____________ + _________ ________ + __________ + __________ ______________________________________________________________ C 6 H 12 O 6 6O 2 6 CO 2 6 H 2 O The two equations are exact opposites! Releasing Energy Energy can be released by: cellular respiration cellular respiration if there is oxygen available fermentation NO fermentation if there is NO oxygen. Obligate aerobes - require oxygen Obligate anaerobes - must live in the absence of oxygen Facultative anaerobes - do not require oxygen but are not killed in its presence. Passive Transport: No energy required Diffusion Facilitated Diffusion Osmosis proteins high low Uses proteins to move solutes high to low high low Move solutes from high to low concentration Water high low Moves Water from high to low concentration Osmosis in Red Blood Cells Isotonic HypotonicHypertonic (pg 186) CELL MEMBRANE (also called plasma membrane) Cell membranes are made mainly of __________________________. PHOSPHOLIPIDS Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains 2 lipid layer A lipid PG 171 LIPID TAILS ARE HYDROPHOBIC HYDROPHILIC HYDROPHOBIC Water loving Water fearing Polar molecule: a molecule (such as water) with opposite charges on opposite sides PG 171 DEOXYRIBONUCLEIC ACID ______________ STRANDED DOUBLE PHOSPHATES (Bonded covalently) sugars 5 3 Hydrogen bonds Held together by Hydrogen bonds nucleotide Double Helix structured? Image from:Pg: 297 TGCACGAATTGCAT l l l l l l l l l l l l l l. ACGTGCTTAACGTA What does it mean to be complimentary? 1. DNA Unwinds 2. two strands separate 3.Molecular bases pair up 4.two identical DNA molecules are produced, They are complimentary strands They are complimentary strands Old strand New strand DNA Replication? UNWINDSUNWINDS SEPARATESEPARATE BASE PAIRSBASE PAIRS 2STRANDS2STRANDS