Study guide Exam 2
Study guide Exam 2 Esc 1510
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This 7 page Study Guide was uploaded by Brittney Tilghman on Sunday October 9, 2016. The Study Guide belongs to Esc 1510 at University of Tennessee - Chattanooga taught by Dr. Bradley Reynolds in Fall 2016. Since its upload, it has received 6 views.
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Date Created: 10/09/16
● Evidence of evolution 1. The Fossil record: chronological appearance of fossils in rock layer. - Fossils: the preserved remnants or impressions left by organisms that lived in the past. (Usually found in sediment - Fossil record shows incomplete fossil, also evolution 2. Biogeography: the geographic distribution of species - Related species are found in close proximity. Ex the Galapagos - Species are not in environment because they are suitable, species are in an environment because they evolved from ancestors in the environment. - Darwins finches: He identified 13 species of finches in the Galapagos - Finches adapted to the environments on various islands, evolving different beaks - Adaptive Radiation: diversification of species as organisms spread into different habitats. 3. Comparative Anatomy: the comparison of body structures between different species. - Forelimbs of Mammals: all adapted to different functions - Singular anatomy: different functions, but similar origins 4. Comparative Embryology: the comparison of structures that appear during the development of different organisms. - All have fill pouches, segmented muscles, & tubular hearts 5. Molecular Biology: comparison of genes and proteins between different species ● Theory of Natural Selection (based on two observations made by Darwin) 1. Species produce excessive numbers of offsprings 2. Individual variation is abundant within a species - The peppered moth example - Same species - Individual variation - Industrial Revolution, pollution in England - Biological Species concept - Pesticide-resistant insects - Rachel Carson: pesticide Treadmill (trying to outrun evolution) ● Outcomes of Natural Selection 1. Directional Selection - Selection favors one extreme - A shift in one direction in favor of one extreme 2. Diversifying Selection (disruptive Selection) - Selection favors two or more outward characteristics - Ex. Darwins finches - Ex. Peppered Moths - This would create a two humped bell shaped curved 3. Stabilizing Selection - Maintains the variation for a particular trait within a narrow range - Selection falls in between the extreme variants - Extremes are being selected against - Occurs in stable environment with well-adapted populations - Ex. Infant mortality is higher for low-weight and high-weight babies than for average weight babies ● Mechanisms for evolution 1. Natural Selection 2. Mutation 3. Genetic drift 4. Gene flow ● Mutation - An error in cell reproduction will sometimes change the DNA - A change in DNA produces a change in inherited characteristics - Some mutations (-), some (+), most indifferent - MUTATION ADDS VARIETY! - Sexual shuffling of the genes (this is where individual variation comes from) ● Genetic drift - A change in the frequency of a gene in a population due only to chance - Splinter population vs larger population - Can be a problem… - In very small populations of endangered species - When traits not best suited to the environment predominate. ● Gene flow - A population may gain or lose genetic variability through genetic exchange with other populations - Sometimes help chances or hurt chances - Migration with sexual reproduction ● Macroevolution - How biodiversity evolves - How do new species come about - Anagenesis: linear evolution - Cladagenesis: branching evolution ● What is a species? - Latin meaning “kind” - Biological species concept: based on reproductive compatability - Ernst Mayr - New Guinea Jungle - Morphological species concept: based on what species look like - Reproductive barriers: what causes two different species to not successfully reproduce ● Biological species concept: concept based on reproductive compatibility rather than physical similarities ● Reproductive barriers 1. Pre-zygotes barriers (pre-fertilization): stop different species from mating or hinder fertilization - Failure to eleicit mating behavior - Structural differences in sex organs - Habitats do not overlap (habitat isolation) - Mating seasons do not overlap (temporal isolation) 2. Post-zygote can barriers: back up mechanisms that kick in just in case a hybrid is conceived - Offspring die before maturity (hybrid inviability) - Offspring are steril (hybrid sterility) - Ex. Mule ● How many species are there - 5-30 million in existence - 1.8 million have been described - Over 1 million of these are insects ● Mechanisms of speciation ● Speciation: formation of two or more genetically distinct groups of organisms following a split of division in a single such group ● Gene pool of population thats severed from other populations. Over time the severed population becomes so different that it is a new species 1. Allopatric speciation: physical seperation. Geographic barrier 2. Sympatric speciation: population becomes reproductively isolated in midst of parent population - Genetic change creates a reproductive barrier - Formation of mutant offspring ● Geological Time Scale - Based on the premise that the Earth is 4.6 billion years old - Scientists use a geological time scale to know how old the Earth is - 4 Major time periods called “Eras” - 1. Precambrian: from 4.6 bya to 570 mya > earliest living organisms (algae, bacteria, invertebrates) 2. Paleozoic: from 570 mya to 245 mya > first plants,fish, amphibians,insects, and reptiles 3. Mesozoic: from 245 mya to 65 mya > first gymnosperms, flowering plants, dinosaurs,mammals, and birds 4. Cenozoic: from 65 mya to present > first primate groups - amphibians: gelatinous (tied to water for reproduction) - reptiles: water tight skin (egg that can be incubated outside of water) - How do we know an asteroid killed dinosaurs? > rock layer 65 million years, irridium ** we see that life evolved slowly ● Classifying Diversity of Life - systematics and taxonomy (name, classifying, and organizing) ● Naming Species 1. Common names (can be misleading) Ex. Jellyfish is not a fish 2. Scientific names Ex. Linnaeus ● Hierarchial Classification Leopard Human 1. Kingdom Animalia Animalia 2. Phylum Chordata Chordata 3. Class Mammalia Mammalia 4. Order Carnivora Primate 5. Family Felidae Hominidae 6. Genius Panthera Homo 7. Species pardus sapien ● Arranging Life into Kingdoms: A work in progress - Prokaryotic: no nucleus - Eukaryotic: do have a nucleus & organelles ● The Three Domain System - 2 Domains of Prokaryotes: Bacteria and Archae - 1 Domain of Eukaryotic (divided into Kingdoms) ● Domain Bacteria - Similar to bacteria in some ways - Single-called organisms - Live under extreme environmental conditions - Extremophiles - Thermophiles (heat lovers) - Halophiles (salt lovers) - Mehangens (live in mud, lack of oxygen) ● Domain Eukarya - Kingdom fungi - Eukaryotic - Nonmotic and absorb nutrients - Mold, yeasts, mushrooms - Heterotrophic: consume other organisms by the absorbtion of nutrients - Kingdom Plant - Eukaryotic - Photosynthesis - Autotrophic photosynthesis - Mosses, gymnosperms, angiosperms - Kingdom Animalia - Eukaryotic - Well-developed tissues - Motile - Heterotrophiciby the ingestion of other organisms - Kingdom Protista - Eukaryotic - Plant-like and animal-like organisms - Algae and protozoans 1. Simple organizations 2. Reflect phylogeny (evolutionary history) ● US Forests ** Forest coverage has decreased overall in terms of quantity and quality - 1630: 1.05 billion acres - 1907: 759 million acres - 1997: 747 million acres - 2007: 745 million acres ● Why are forests not healthy? - Pollution - Overexploitation - Tree diseases (fungal in nature) - Invasive insects ● Biome: one of the major Ecosystem types of the earth - Defined by the climate and the dominant vegetation - Forest biomass are dominated by trees and other woody vegetation ● Wildfires and Parks, Preserve, and Forests **problem with fire suppression - Fire helps create new environmental opportunities for a diverse array of species - Organic matter in the form of woody debris = fuel - How do we manage our lands? 1. Physically remove excess brush/debris 2. Controlled burns: a fire lit on purpose to manage woody debris (prescribed fire) ** How can we achieve sustainable forestry? - Fast growing loblolly pines - As long as we get our wood from pine plantations it preserves old pine forests. ● 3 Major Types of Forests 1. Temperate 2. Tropical 3. Boreal 1. Temperate - Temperate rainforest - Northwest coast of North America, Northeastern Asia, Western and Central Europe - Moderate climate, well defined seasons - Distinct winters, 30-60 inches of rain per year - Broad leafed trees that she leaves seasonal, rich top soil 2. Tropical (occur near the equator) - 2 subtypes - Tropical rain forests - Climate is warm/moist year round - At least 79 inches of rain per year - Great diversity of species - Nutrient poor, acidic soil - Tropical dry forest - Less rainfall - Two seasons: rainy and dry - Trees shed leaves during the dry season 3. Borreal - Also called the Taiga - Largest terrestial biome on earth - South of the tundra and at cool high elevations - Low temperatures - thin , nutrient poor, acidic soil - Snowy precipitation, 16-40 inches annually - Cold tolerant evergreen conifer with needle-like leaves - Low biodiversity - Harsh environment ● U.S. forest - Temperate Deciduous Forest - Pine Forests on the South Coastal Plain - Rocky Mountain Pine Forest - Temperate Rainforests ** moisture and shade (no single best set of conditions for a forest) - Giant Forests - Coast Redwood (occur near the coast of Cali) - Giant Sequoia (occur inland on the western slopes of mountains) ** How do they get so big? 1. Thick bark and heavy foliage 2. High Rainfall Basal burls 3. Basal Burls ● How trees work? - Leaves take up carbon dioxide, stomata (tiny openings) chlorophyl - Leaves absorv sunlight - Roots take up water - Carbon dioxide and water are converted into glucose and oxygen in sunlight - Tree combines sugar with other chemicals to form organic compounds for life
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