# Evolution Evolution: Change with time, the development of new types of organisms from pre-existing types of organisms over time Diversity of Life: Wide variety of living things. Estimated over 10 million species Adaptation: An inherited trait that improves an organism's chance of survival. > long neck and legs of a giraffe, coloration of a moth Lamarck: Use-Disuse: Structures used develop and structures not used disappear. Inheritance of Acquired Characteristics: Acquired characteristics (obtained during the life of the organism) changes the body cells. These cannot be inherited. > long neck of a giraffe Darwin: Theory of Natural Selection: Those individuals with characteristics best suited to their environment will survive the struggle for existence, those not suited will die. Nature selects environment. Differences are present in a species before the change occurs 4 Main Parts of Darwin's Reasoning: Overproduction: Organisms produce more offspring than can survive to maturity Genetic Variation: Individuals in a species are different from one another due to traits inherited > color, speed, strength, fur, structure Struggle to Survive: Overproduction, limited resources, competition, leads to a struggle for existence Differential Reproduction: Survival of the fittest. Only the fit survive. Fittest: Those best adapted to the environment Favorable Traits Passed On: Since the traits are inherited and not acquired they will be passed on # Evidence of Evolution Fossil Record: Fossil: Organism or evidence of an organisms preserved in rock. Usually in sedimentary rock Superpostion: Older fossils are found in lower layers of rock. Younger fossils in upper layers Amber Geologic Time Scale: A time frame based on the fossil record Eras: Cenozoic, Mesozoic, Paleozoic, Precambrian Periods and Epochs Dating: Determining the age of rock and fossils. Relative Dating: Used to Determin the relative age of some rocks to other rocks. Compare layers of rock Absolute Dating: Used to determine the actual date Carbon Dating: Uses the half life to determine actual age. Half Life: Time needed for half the radioactive atoms in a sample to decay > Carbon-14 = 5.77 thousand years, Uranium-238 = 4.50 billion years Comparative Anatomy: Homologous structures, vestigal structures Comparative Embryology Comparative Biochemistry Convergent Evolution: Process where different species evolve similar traits Divergent Evolution: Process in which the descendants of a single ancestor evolve into species that fit different parts of the environment Adaptive Radiation: Species undergo different evolution until many parts of the environment are filled > darwins finches # Population Genetics Population: A group of members of the same species living in a given area > people in CR Metro area, oak trees at Rock Island, bass at Pleasant Creek Variation of traits in a population: Individuals are different When graphed, forms a bell curve (no variation in the middle and lots of variation on the edges) More individuals have similar common values, less individuals have extreme values > height of students Causes of Variation: Mutation: Random change in a gene passed to offspring Recombination: Reshuffling genes in diploid cell (independent assortment, crossing over) Random pairing of gametes Gene Pool: Common groups of genes shared by members of a population Allele Frequency: Number of times an allele is present compared to the number of times other alleles for the same trait are present. Calculated by dividing the number of alleles for one trait by the total number of alleles Adaptations cause changes in the gene frequency withing a population Genetic Equilibrium: Allele frequency in a population remains unchanged 5 Requirments: No Mutation: Allele frequency cannot change overall because of mutation Gene Flow: The size of the population remains constant. No immigration, no emigration Presence of a large population: No genetic drift (random change in allele frequency) Random Mating: Some species show nonrandom mating due to geographic areas. Others might select mates with traits similar to their own Absence of Natural Selection: When natural selection is at work, traits in a population may change Hardy Weinberg: Principle that states that the frequency of alleles does not change unless acted upon by outside forces. p^2 + 2pq + q^2 = 1 (p represents one allele, q represents the other allele) # Speciation Disruption of Genetic Equilibrium: Evolution changes the allele frequency 5 Possible Ways: Mutation: A change in genetic material, offspring different than parent Gene Flow: Genes moving from one population to another, (immigration, emigration) Genetic Drift: Allele frequency changes by random events, chance. Affects small and medium sized populations Nonrandom Mating: Many species do not mate randomly. > sexual selection: mates chosen based on certain traits Natural Selection Speciation: Process of how new species form Species: Organisms so closely related that they can mate and produce fertile offspring Interaction of Organisms: Niche: An organisms habitat and its role in that habitat No 2 species can occupy the same niche habitat for long (competition) If a species occupies an empty niche they have no competition Steps of speciation: One population Separation: Some type of separation of the population Geographical Isolation > water (ocean/river), disaster (earthqueake/flood), canyon, mountain range Reproduction Isolation: Result from barriers to sucessful breeding between populations in the same geographical area > breeding seasons Adaptation: Changes in the gene pool over time. The separated populations will adapt to their environments, as they adapt the gene pool also changes. Changes become different enough that the two populations are no longer able to breed Adaptive Radiation: Process in which one species gives rise to many > darwin's finches # Classification Taxonomy: The science of describing, naming, and classifying organisms Clasiffication: Arrangement of objects into groups Taxon: Groups into which organisms are classified Why Classify: Organization, make comparisons, naming Aristotle's Classification: Plants: Based on structure 3 Groups: Herbs Shrubs Trees Animals: Based on habitat 3 Groups: Land dwellers Water dwellers Air dwellers Carolus Linnaeus: Devised system of grouping organisms into categories according to form and structure 7 Levels: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species Naming: Binomial Nomenclature: Two word scientific name First Word: Genus name, 1st letter capitalized > Homo Second Word: Species name, 1st letter lower case > sapiens Latin and Greek: Human: Homo sapiens Lion: Panthera leo House Cat: Felis domesticus Human Taxa Groups: Domain: Eukarya Kingdom: Animal Phylum: Chordata Class: Mammalia Order: Primate Family: Hominidae Genus: Homo Species: Sapiens Basis For Classification: Homologous Structures: Structures that are similar due to evolutionary relationships Common Ancestors > penguin flipper and alligator leg, human arm and bats wing Biochemistry: Organisms with similar chemical make up are classified together Genetics: Organisms that show similarities in genetic make up (DNA) are grouped together Comparative Embryology No Basis For Classification: Analogous Structures: Structures that are similar due to function > wing of insect and wing of bird, leg of grasshopper and leg of cat # Domains and Kingdoms Prokaryotic: No nucleus Eukaryotic: Has nucleus The 3 Domains: Bacteria: Prokaryotic Archaea: Prokaryotic Eukarya: Eukaryotic Unicellular: One celled Multicellular: Many celled Autotroph: Produces own food Heterotroph: Takes in food Motile: Moves by itself Non-motile: Unable to move about The 6 Kingdoms: Eubacteria: Unicellular Prokaryotic Most eubacteria are helpful. Some produce vitamins and foods like yogurt Streptococcal bacteria can cause a variety of infections in the body including pneumonia, meningitis, ear infections, and strep throat > bacteria Archaebacteria: Unicellular Prokaryotic Found in extreme environments such as hot boiling water and thermal vents under conditions with no oxygen or highly acid environments > ancient bacteria Protista: Unicellular Eukaryotic Heterotrophic or Autotrophic > ameoba, paramecium Fungi: Multicellular Eukaryotic Heterotrophic Non-green cells with cell walls > mushroom, molds Plant: Multicellular Eukaryotic Autotrophic Cell walls of cellulose Non-motile > flowering plants, pine trees, ferns Animal: Multicellular Eukaryotic Heterotrophic Motile > insects, worms, mammals # The Animal Kingdom Aquatic Habitat: Water Fresh water Marine (salt water) Terrestrial: Land Characteristics of the Animal Kingdom: Eukaryotic Multicellular Heterotrophic Mobile at some stage of life Cells lack cell walls Body Plan: Porous Body Flattened Round body Tissue Layers Appendage: A projecting part of an organism with a distinct function or appearance > arms, legs, wings, fins Exoskeleton: Skeleton outside the body tissue Endoskeleton: Skeleton inside the body tissue Dorsal: On or near the back Ventral: Away from the back Feeding Strategies: Filter feeding Incomplete Digestive System: Has only one digestive opening 2 Digestive Openings: Mouth: ingests Anus: egests Symmetry: Divisible into similar halves Asymmetrical: No symmetry Radial Symmetry: Divisible in more than one plane Bilateral Syemmetry: Divisible in only one plane Locomotion: Walking, swimming, flying, muscular foot, water jet, sessile (fixed in one place, immobile) # The Animal Phyla Arthropoda: Insects, Spiders, Crabs Exoskeleton, jointed appendages, ventral nerve cord, bilateral symmetry, largest phylum by numbers Annelida: Earthworm, Leech Segmented Worms Bilateral symmetry, body in segments, 2 digestive openings Mollusca: Clams, Squid Soft body, usually with a shell, bilateral symmetry, 2 digestive openings, muscular foot Porifera: Sponges Aquatic (marine), asymmetrical, filter feeders, sessile Chordata: Mammals, Reptiles, Birds, Amphibians Edoskeleton, dorsal nerve cord, bilateral symmetry Cnidaria (Coelenterata): Jellyfish Radial symmetry, single digestive opening, tentacles with stinging cells Nematoda: Roundworms > hookworm Digestive openings, bilateral symmetry, smooth body Platyhelminthes: Flatworms > tapeworm, planaria Bilateral symmetry, often parasitic Echinodermata: Starfish Adult radial symmetry, 5 parts, marine # Importance of Plants Plant Cultivation Argriculture: Growing plants and raising animals for human use Food Crops: Cereal: Grasses that contain grains > wheat, corn, rice, oats, sorghum Root Crops: Roots or underground stems rich in carbohydrates > beets, carrots, radishes, rutabagas, turnips Legumes: Members of the pea family, bear seeds in pods. Return nitrogren from air to soil > soybeans, alfalfa, clover, peanuts Fruits, Vegetables, Nuts > apple, bean, pea, asparagus, walnut Spices, Herbs, Flavoring: Add variety and pleasure by flavoring water beverages and food > caffeine, sage, dill, vanilla, coconut, quinine Non Food Uses of Plants: Medicine: Aspirin: Pain medicine from white willow Taxol: Cancer medicine from yew Clothing/Fabric Dyes: Cotton Indigo (blue), onion (yellow), peach (green) Fuels: Fossil fuels: stored photosynthetic energy from millions of years ago Wood: Burning Gasahol Other Uses: Ornamental Plants Landscaping Building Materials Lipstick Hair Dye Rubber Tourism Plant Ecology: Interactions between plants and the environment: Plants and Animals: Flowers and Pollinators Plants and Microbes: Bacteria fixing nitrogen with legumes Plants and Humans: Protect and care for plants that give us food, shelter, etc. Weeds: Undesirable plants that crowd out crop plants or native plant species: Water hyacinth Dandelion Crabcrass Harmful Plants: Rash > poison ivy, poison oak Ill/Poison > leaves, berries of some house and garden plants Hay Fever > pollen allergies # Plant Structure Soil: Complex mixture of sand, silt, clay, and organic matter Types: sandy, clay, loamy Inorganic nutrients plants need besides water and carbon dioxode: Nitrogen: Parts of proteins, nucleic acids, chlorophyll, ATP, color Phosphorous: DNA, ATP Calcium: Cell walls and membranes Potassium: Required for stoma opening and closing Magnesium: Part of chlorophyll Sulfur: Part of proteins Specialized Plant Tissues: Meristematic Tissue: Plant tissue where cells continuously divide, areas that grow Apical Meristem: Located at the ends of stems and roots, plants grow taller, roots grow deeper Lateral Meristems: Allow roots and stem to grow in diameter Vascular Cambium: Produces vascular tissues, increases the thickness of stems Cork Cambium: Forms the outer covering of the stem Epidermal: Outer layers of leaves, stems, and roots. Protect the plant and absorb water. Parenchyma: Storage, make up most of the roots we eat Collenchyma: Cells have thicker walls than parenchyma Support regions of a plant > celery stalks Sclerenchyma: Cells have touch thick cell walls, strengthen, support the plant > hemp fibers for making rope, hard nut and seed shells Vascular Tissue: Transports materials Xylem: transports water Phloem: transports food Roots: Anchor plants, absorb water and nutrients from soil, store food Taproot: one main primary root > carrot, radish, dandelion Fibrous roots: Many smaller secondary roots > grass, rye Root Hairs: Thin walled Increase surface area exposed to soil Absorb water and nutrients Monocot Root: Usually has a ring of xylem and phloem around the central cylinder Dicot Root: Usually has a central column of xylem in central cylinder (stele) with radiatiing arms Stems: Hold leaves up for photosynthesis, transport materials to and from leaves, store food Monocot: Vascular bundles are scattered throughout the stem Dicot: Vascular bundles form a ring around the outer edge of the stem Woody Stems: Tree Rings: Annual rings formed from vascular tissue that grows each year Shows age of tree Shows weather conditions for each year Water Transport: Water enters root by osmosis Passes through cortex (parenchyma) tissue by osmosis Passes through endodermis: One way only Combination of active transport and osmosis Enters xylem: Cohesion: The attraction of water molecules to each other Transpiration: The evaporation of water from the leaves of plants Transpiration pull: The force that pulls water upwards Cohesion holds the water column together as it moves upward through the xylem Food transport: Requires energy (active transport) Translocation: Movement of food through the phloem Pressure Flow Hypothesis (source-sink): Food moves from an area of high pressure to low pressure High Pressure (Source): Could be leaves when food is formed Could be areas of food storage (root, stem, etc.) Low Pressure (Sink): Could be where food is used for growth Could be where food is stored Auxins: Plant hormones: Stimulate or inhibit cells to grow Depends on the target organ Stem Growth: Auxins stimulate stem cell growth Root Growth: Auxins inhibit root cells growth Tropism: Response of a plant to environmental stimuli Positive: Respond toward the stimulus Negative: Respond away from the stimulus Phototropism: Response of plants to light > stem = positive Gravitropisms: Response of plants to gravity > stem = negative, root = positive Thigmotropism: Response of plants to touch > tendril = positive Flowering: Photoperiodicity: Response of flowering plants to different light conditions Short Day Plants: Flower when time exposed to light is short > chrysanthemums, poinsettias Long Day Plants: Flower when the amount of time exposed to light is long > clover, petunias, hollyhocks Day Neutral Plants: Length of light has no effect on flowering > corn, tomato Actually the amount of darkness, not light, that stimulates these plants # Ecology Ecology: Study of the interactions between organisms and the living and non living components of their environment Interdependence: The dependence of every organism and its connections with the over living and non-living parts of its environment Levels of Organization: Biosphere: Earth and its atmosphere that supports life Ecosystem: All organisms and the non-living environment in a particular place > pond ecosystem Community: All of the interacting living organisms in an area > pond = fish, frog, turtle, algae, bacteria Population: All the members of a species in a given area > spruce trees in a forest Organism Biotic Factors: All of the living components in an ecosystem > plants, animals, decomposers Abiotic Factors: All of the non-living components of an ecosystem > temperature/sunlight, humidity/precipitation, pH, salinity, oxygen/nitrogen Changing Environment: Tolerance Curve: Graph showing performance values of an environmental variable > swimming speed of fish vs wwater temperature Acclimiation: Organisms that adjust their tolerance to abiotic factors > adjust to air temperature extremes Dormancy: Go dormant during winter or drought conditions Migration: Move to a favorable environment Niche: Involves both the place where an organism lives and the roles that an organism has in its environment The type of food an organism eats How an organism gets its food Which other species use the organism as food Sunflower: Abosrbs light, water, and nutrients for photosynthesis Provides shelter and food for other organisms (bees, ants, etc.) Gives off oxygen # Energy Transfer and Recycling Producers: Make their own food Autotrophic organisms Most are phototrophic: Some bacteria use chemosynthesis Plants Some protists and bacteria Consumers: Take in food from other organisms Heterotrophic Herbivores: Eat plants only Carnivores: Eat meat only Omnivores: Eat both plants and meat Detrivores: Feed on garbage of ecosystem Animal wastes, dead organisms, etc. Decomposers: Becteria, Fungi Break down (decay) once living matter Recycle nutrients for autotrophs to use Trophic Levels: Indicates an organisms position in a sequence of energy transfers 1st Level: Producers 2nd Level: Herbivores 3rd Level: Carnivores and Omnivores 4th Level: Carnivores and Omnivores Food Chain: A single path for the flow of energy Food Web: The inter-related food chains in an ecosystem Energy and Biomass Pyramids: Low amount of energy is transfered from one trophic level to the next (about 10%) INSERT WATER CYCLE DIAGRAM HERE INSERT CARBON CYCLE DIAGRAM HERE INSERT NITROGREN CYCLE DIAGRAM HERE INSERT PHOSPOROUS CYCLE DIAGRAM HERE # Populations Population: Organisms that belong to the same species and ling in a particular place at the same time Population Density: How crowded a population is. Need to consider the amount of area or volume avaiable. density = population / area Dispersion: The spacial distribution of organisms Uniform: Same distance from each other > birds mark territory and try to stay away from other birds Random: Random distance from each other > nothing, just in random places Clumped: Clumped up in groups > wolves hunt in packs Population Dynamics: How a population changes in size and composition over time Birth Rate: How many organisms are being born / time Death Rate: How many organisms are dying / time Life Expectancy: How long organisms are expected to live Survivorship Curves: Show the probability that members of the population will survive to a certain age Type I: Likelihood of dying is small until late in life Type II: Probability of dying does not change Type III: Many organisms will likely die when young Growth Rate: Birth Rate - Death Rate Population Increases: Birth, Immigration Population Decreases: Death, Emigration Exponential Model: Slow start, rapid increase later J Shape No Limiting Factors Limiting Factor: retrains the growth of a population > space, food, water, etc. Logistic Model: Slow start, rapid increase, slow end Accounts for limiting factors S Shape Carrying Capacity: Number of individuals and environment can support over a long period of time Density Independent Factors: Reduce the population by same proportions regardless of population size > fire, flood, weather extremes Density Dependent Factors: Triggered by increasing population density Chance of surviving and reproducing depends on population size Resource limitations > food, water, nesting sites, etc. Environmental Factors: Food, drought, fire, etc. Predator to Prey relationship Small Populations: Vulnerable to extinction May leed to in-breeding: Reduces Genetic Variation