Study Guide Exam 2: Ecology and Evolution
Study Guide Exam 2: Ecology and Evolution BIO 203
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This 4 page Study Guide was uploaded by Sarah Glover on Sunday March 6, 2016. The Study Guide belongs to BIO 203 at University of New Mexico taught by Dr. Kelly Miller in Fall 2016. Since its upload, it has received 206 views. For similar materials see Ecology and Evolution in Biology at University of New Mexico.
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Date Created: 03/06/16
Ecology and Evolution Study Guide Exam #2 Two major Eons Precambrian 4.5 billion years to 540 million years ago. General Conditions bombardment with asteroids, origin of continents, carbon dioxide, methane, and ammonia, no mountains, huge ice ages. By the end of period all five evolutionary events have occurred. Phanerozoic 540 million years ago to present day. Three Eras rapid emergence of all lineages of animals, life went on to land, pulses of variation, and 5 major mass extinctions. o Paleozoic Origin of Trilobites Cambrian (540500) origin of most modern groups of animals, many of them are extinct now, origin of plants (green algae), Gondwana (Large southern land mass), and Cambrian explosion rapid diversification of life. Ordovician(500440) – Invasion of the land. First land plants (moss). First land animals sea scorpions. Sharks were in the water st rd Ordovician Mass Extinction (440) 1 major mass extinction (3 largest) – the marine diversity was reduced by half. Silurian (440400) stable environment for marine and terrestrial life. 1 bony fish movable jaw. Diversification sea scorpions 69 feet long. Brachiopods (lampshells) Terrestrial life diversification of mosses, and 1 vascular plants Myriopods relatives of centipedes and millipedes they found trace fossils. Devonian (400350) development of Laurasia( Northern land mass) Devonian explosion tons of diversification in terrestrial and marine. Marine origin of amities, extinct mollusks, many sharks Terrestrial amphibious, origin of seeds, trees and forest, origin of insects (powered flight), giant fungi. Late Devonian Mass Extinction marine mass extinction 75%. Terrestrial was not impacted. Carboniferous (350285) extensive glaciation. Low temperatures in Gondwana. Low sea levels. Beginning of Pangea. Many invertebrate groups are well represented. Bony fish diversity sharks undergo radiation. Terrestrial Origin of Bark baring lignin (natural polymer) to protect from insects. Does not decay very well. Big forests. Origin of conifers and ferns. High oxygen levels. Origin of reptiles. Permian(285245) development of Pangea and mountains. Warming and drying large deserts. Marine higher sea levels less coastline Terrestrial dominance of conifers. Origin therapsids, arenosaurs (relatives of dinosaurs and birds), synapsid( relatives of mammals) Arthropods roaches, dragonflies, 2ft scorpions, and 8ft millipedes o Mesozoic Triassic Jurassic Cretaceous o Cenozioc Paleogene Neogene Five Major Events in Evolution 1. Origin of Life ( Earliest life may have been Protobionts) Abiogenesis life from nonlife Needed Components for life Organic Molecules, Metabolism, Replication Primordial Soup methane, ammonia, water, h2s, CO2, CO, PO4 Simple nucleic acids and amino acids form naturally Membranes they form spontaneously from phospholipids Debate over whether metabolism or replication came first 2. Origin of Photosynthesis lead to oxygen catastrophe 1 known life from fossils was stromatolites films of cyanobacteria trap sediment. Have been around 3.5 billion years. Before photosynthetic life there were many anaerobic organisms. However, oxygen is lethal to anaerobic. 3. Origin of Complex Cells Eukaryotes formed by fusion of 2 prokaryotes. A eubacteria ( cytoplasm) and Archean (nucleus), Mitochondria and aproteobacteria similar size and morphology, double membrane, similar enzymes and inner membrane, circular DNA, and phylogenetics. 4. Origin of Sex benefits are that you can avoid having a high number of deleterious mutations, and advantageous alleles can persist. 5. Origin of Multicellular life Colonial Theory colonies of same species of unicellular life came together to make multicellular life. Symbiotic Theory symbiosis of species Cellualrisation theory single cell divide multiple nuclei and divided. Speciation and Phylogenetics Isolating mechanisms- any factor that stops two populations from producing viable fertile hybrid offspring. ( Isolation of gene pools preventing gene flow) Prezygotic Isolation- before the fertilization of an egg. Something that can stop mating or hinder fertilization. o Geographic Isolation- populations live in different geographic locations o Habitat Isolation- populations live in different habitats in the same area. o Behavior Isolation- differences in attraction signals and courtship o Temporal isolation- breed at different times of day or different seasons o Mechanical Isolation- different anatomical don’t all for mating o Gametic Isolation- gametes can’t fuse to form a zygote. Postzygotic isolation- after the egg is fertilized. Things will prevent it from turning into an adult. o Reduced Hybrid Viability- genetic incompatibility may abort fetus o Reduced Hybrid fertility- hybrids are sterile o Hybrid Breakdown- first generation of hybrids can reproduce and survive but later one die and cannot. Speciation- when a new species is formed- is asexual species it is due to mutation. In sexual taxa it is due to isolation of gene pools. o Allopatric- is due to geographic separation of species Vicariance- division of the original distribution of a species by a geographic barrier. Dispersal- colonization of a new geographic area by members of a population. Adaptive radiation- evolution of many diversely adapted species from a common ancestor. o Sympatric- occurs without physical separation o Reinforcement- once you have two different populations natural selection increases reproductive isolation. Biological Species Concept- a group of organisms capable of interbreeding and producing fertile offspring. Phylogenetic Species Concept- group of populations or lineages that share a unique combination of fixed character states. Lineage Species Concept- populations separated by a permanent reproductive splitting event and connected between a splitting event and another spitting event. Modern Synthesis- genetics and evolution combined o Population genetics- the study of variation in allele populations and micro evolutionary processes. Phylogenetic-origin of groups Phylogeny- relationships among taxa. Criteria of remane- 3 ways to assess homology 1. Positional Criterion- features are on the same relative areas on the body 2. Structural Criterion- one or more special qualities in common 3. Transitional Criterion- intermediate forms to connect two traits Homology- the central concept for biology. Identify attributes across taxa based on similar form and position of biologically similar due to common descent. Character- a heritable attribute showing variation among species that defines their group: morphology, behavior, physiology, molecular, evolution o Character State- one of the particular conditions of a particular character. o Trait- Variations among populations Evolutionary taxonomy no particular methodology based on authority of an expert. o Phenetics grouping by overall similarity character and states o Cladistics (William Hennig) 1. Synapomorphies ( shared feature) – provide the evidence for common ancestry 2. The phylogenetic hypothesis should be based on the greatest number of data possible, 3. Classification should be based on historical relationships. Homoplasy similarity due to something other than common ancestry. Adaptation leads to this. Two independent traits Apamorhphy a derived character state, a mew evolutionary innovation Synapomorphy a shared derived character state Plesiomorphy an ancestral character state do not have the apomorphy Fossils o Trace fossil tracks or imprints of organism o Index fossils used to define geological time periods.
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