Appl Envir & Organismal Bio
Appl Envir & Organismal Bio ISB 202
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This 96 page Class Notes was uploaded by Angelita Tillman on Saturday September 19, 2015. The Class Notes belongs to ISB 202 at Michigan State University taught by Pamela Rasmussen in Fall. Since its upload, it has received 5 views. For similar materials see /class/207790/isb-202-michigan-state-university in Biological Sciences at Michigan State University.
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Date Created: 09/19/15
rganisms and Populations 00d Water and Biodiversity Dr Pamela C Rasmussen Cinnabar Hawkowl Indonesian species discovered in 1999 Your instructor Dr Pamela C Rasmussen Ornithologist Speciation vocalizations conservation of S Asian birds 0 Katie Hanlon UEA Human Bio Project AVoCet Avian Vocalizations Center at MSU avocetzoologymsuedu Global bird sounds website database ForeSt Owlet Rediscovered in India after 114 years Course Objectives To learn and think critically about the diversity of life how it evolved and is sustained Why it is important how human impacts are threatening it how we as individuals and society can help See also Syllabus for MSU and IS Center goals Overview of class Syllabus on D2L website d21msuedu Dr Rasmussen rasmus39msuedu 3535428 Monday 12 pm or by appointment 0 20 Natural Science Katie Hanlon UEA hanlonkmsuedu of ce hours Thurs 11001200 in NS 20 or by appointment Text Text Food Water amp Biodiversity ISB 202 Customized text speci cally for our class from six different textbooks Available as hard copy from bookstore or as e book Exam schedule Exam 1 Feb 17 Exam 2 Mar 24 Final Mon 4 May 12245 2245 pm Grading Point summary Tests 65 Clicker questions 10 In olass exercises 10 Homework 15 Total 100 Up to lweek Must be current 201415 Comment on signi cance Hard copy only Can raise you up to 1A letter grade Grading scale Total 0o Final grade 90100 40 8689 35 8085 30 7679 25 707 5 20 6669 15 6065 10 059 0 Class policies Attendance Essential for learning exercises clickers Questions Welcome Reading Important Lecture notes Partial notes posted before class Full notes provided by UEA on casebycase approved excuse Exam policies Exams Cannot be made up Waiver policy Assigned seating Exams based on the lectures Mainly multiplechoice Bring 2 pencils and erasers Know your PID Clicker policies Clickers Based on presence and attentiveness in class as determlned by your answers to chcker quest10ns Clickers used each day starting the second week of classes Clicker registration in class starting 15 Jan 6 clicker sessions may be missed without penalty 0 Forgotten clicker missed participation 0 Dead batteries no backups missed participation Clicker not working Email supporticlickercom The variety of life forms on earth I Plants animals fungi microorganisms u The product of 35 billion years of continuous evolution from the common ancestor of all life Renewable resources All living things can be placed in 6 kingdoms All members of Kingdom Animalia are more closely ay 7 gt living things have much in common ar w g a 43 i Living organisms 1 Cellular 2 Metabolism 3 Homeostasis 4 Growth and reproduction death 5 Heredity and evolution All have the same type of genetic material The Organization of Life A Hierarchy of Increasing Complexity Cellular level Atoms Molecules Macromolecules Organelles 0 Cells Organismal level Tissues Organs 0 Organ systems 0 organism Raveni erg Environment ale Figure 41 Biosphere Vii quot 39 0 0 Molecule ragga Rh i i Ecosystem a i V 7 H A3 355 12 i 1quot I Cell 7 n V I m v39 i L 1 39 m6 M C ommumty Tissue 39 Body system Harco urt Inc The Organization of Life A Hierarchy of Increasing Complexity Populational level 0 Population 0 Species 0 Community 0 ecosystem Ravenl erg Environment ale Figure 41 Biosphere l rib quot 0 0 Molecule Fte hxbh V 39 l I Ecosystem a i V quot j 4quot j 5 39quotr 0 H system Harte urt Inc Eioiogicni Themes Evolution Genetic change in species over time The Flow of Energy Energy ows from sun to power life on earth Food co nau 25quot A ERS causum was shows we having a ride DECOMPGSERS 2 organic matemfg Biological Themes cont Cooperation Organisms interact with members of their species and other species Structure Determines Function Organisms have been modi ed by natural selection to have forms suited for certain activities Homeostasis Complex organism s maintain a stable internal environment Water How is Science Done Observation Keep careful records and think about what you re seeing Hypothesis Testable educated guess Predictions What you d expect to happen if a hypothesis is true Testing How to verify predictions Controls Alter one variable While keeping another constant in different experiments to see What happens Conclusion Did the testing disprove the hypotheses Was the hypothesis supported If the latter Why and how can you further support it Life occurs everywhere in biosphere Increases with decreasing latitude increasing rainfall and nutrients l 4 Highest in the forested tropics l Lowest in the polar regions 39 i a Increases with size of area I X 039 Decreases With increasing altitude Chicl quotIquot it i quot 5 Biodiversity and the Environment i Why do we need to maintain biodiversity Biodiversity maintains us e rubber tree Food Water puri cation Brazil Nut Medicines Raw materials Tourism Nature Pets FishingHunting Horticulture culturalreligious signi oanee Genetic diversity iological control Protection of water resources Formation and protection of soils Nutrient storage and cycling Pollution breakdown and absorption Contribution to climate stability Maintenance of ecosystems Protection and recovery from unpredictable events I quotfiodiversity and the 3 Environment hat is the environment all the external conditions and in uences affecting the life development and survival of an organism the earth39s crust water resources life forms and atmosphere Cu ani cm at E E 3L E Biodiversity and the Environment Why do we need environmental quality Health Enjoyment Survival Technology cannot divorce us from our dependence on a healthy environment o Biodiversity and the environment 0 What is biodiversity I The variety of life forms on earth 0 Plants animals fungi microorganisms I The product of 35 billion years of continuous evolution from the common ancestor of all life I Renewable resources 0 How do we define life 0 Living organisms I React I Grow I Reproduce I Evolve o All have the same type of genetic material 0 Viruses are borderline 0 Three levels of biodiversity 0 Genetic I The variety of genetic information in all living organisms 0 Species I The variety of species 0 Ecosystem I The diversity present within ecosystems 0 Habitat differences 0 Variety of ecological processes I The variety of habitats biotic communities and ecological processes 0 Major patterns of biodiversity 0 Life occurs everywhere in biosphere o Increases with decreasing latitude increasing rainfall and nutrients I Highest in forested tropics I Lowest in polar regions 0 Increases with size of area 0 Decreases with altitude 0 Changes in biodiversity o Biodiversity increases when I New genetic variation is produced I A new species is created I A novel ecosystem is formed 0 Biodiversity decreases when I Genetic variation within a species decreases I A species becomes extinct I An ecosystem complex is lost 0 Change in biodiversity is a natural process I Through most of earth s history biodiversity has increased Except at mass extinctions I But due to humans loss of biodiversity now reaching major crisis proportions o Biodiversity and the environment 0 Why do we need to maintain biodiversity I Biodiversity maintains us Food Medicines Raw materials Tourism Nature Pets Fishinghunting Horticulture Culturalreligious significance Genetic diversity Biological control 0 Some ecosystem services of biodiversity 0 Protection of water resources Formation and protection of soils Nutrient storage and cycling Contribution of climate stability 0 O o Pollution breakdown and absorption 0 0 Maintenance of ecosystems o Protections and recovery from unpredictable events 0 Biodiversity and the environment 0 What is the environment I All the external conditions and influences affecting the life development and survival of an organism I The earth s crust water resources life forms and atmosphere 0 Why do we need environmental quality I Health I Enjoyment I Survival 0 Technology cannot divorce us from our dependence on a healthy environment 0 The geological backdrop of life 0 Science of dynamic processes on earth I Study and analysis of rocks and earth s processes I Origin history and structure of earth 0 Why is geology important to biodiversity and the environment Soils Matter and nutrient cycling Foundation for life The changing earth 0 O Earth s crust seems static to us However constantly changing Most change gradual Ea rth s structure 0 3 major concentric zones Core 0 nnermost zone 0 Very hot 0 Center solid outer core molten Mantle 0 Mostly solid rock 0 Outer part lithosphere 0 Hot partly molten rock flows 0 Asthenosphere Crustbiosphere o Thinnest outermost Internal geological processes 0 O 0 Internal processes originate in earth s interior Tend to build up planet s surface Heat from earth s formation still being given off Heat from core provides energy for process Causes mantle asthenosphere to deform and flow slowly Minerals and rocks 0 O Earth s crust formed from minerals and rocks Still forming in some places Source of almost all of our nonrenewable resources Source of elements making up living organisms Minerals Naturally occurring solid element or compound 3 major rock types 0 O Igneous rock Formed when molten rock from upper mantle cools Forms most of earth s crust Mostly under the surface Sedimentary rock Formed from weathered rocks andor fossils Particles deposited by surface water then compressed o Metamorphic rock The rock cycle Preexisting sedimentary or igneous rock transformed by high temperature andor pressure 0 Slowest of earth s cycles 0 Occurs over millions of years Measuring age of rocks 0 Relative age By position of rockssediments relative to other rocks 0 Absolute age Measuring amounts of radioactive isotopes relative to stable isotopes Radioisotopes have different unstable numbers of neutrons than stable isotopes o Decay at steady rate halflife Fossilization Time required for half the atoms of a radioactive substance to disintegrate o Fossils are old remains of formerly living organisms o Mainly in sedimentary rocks 0 Often destroyed by rock cycle Index fossils 0 Fossil organisms that are used as indicators of geologic age 0 Criteria Abundant Existed for short time less than a million years Readily identified Hard parts Broad distribution Principle of uniformitarianism 0 States that processes affecting earth today are the same as those that operated in the pa st Plate tectonics Same time frame Indicated that hearth has a very long history 0 James Hutton o llFather of modern geology o Questioned that landscape could have been caused by one flood I llNeptune Theory 0 Charles Lyell o Rewrote Hutton s work to make it understandable 0 Darwin took on voyage of Eagle 0 Movement of plates with earth s crust I Caused by energy flow and heat in mantle o Plates composed of crust and lithosphere I C100 km thick I Move constantly above asthenosphere I Rate 25 to 15 cmyear 0 Continental drift 0 Put forward by Wegener in 1912 I He was thought to be nuts 0 First widely accepted in 1960s 0 Continents have occupied varied positions throughout earth s history Permian225 mya Pangaea Triassic200 mys Laurasia and Gondwanaland Jurassic 135 mya I Cretaceous 65 mya 0 Plate motion produces mountains oceanic ridges trenches o Earthquakes and volcanoes mostly at plate boundaries 0 Plate motion concentrates minerals 0 Types of boundaries between earth s plates 0 Divergent I Plates move in opposite directions I Magma forms new crust o Convergent I Plates pushed together I Causes earthquakes and builds mountains o Transform faults I Plates slide pat each other along fault I Mostly ocean floor I Cause earthquakes o Volcanoes 0 Where magma molten rock rises in plume through vent in earth s surface 0 Releases lava ash gases 0 Can devastate areas I Restarts successional process 0 Created whole islands mountain 0 Eventually creates fertile soils 0 Other implications of plate motions o Currents and climate 0 Important for evolution I Ancient organisms often widely distributed I When continents broke up they were isolated Evolved in isolation into different speciesgroups Influence of continental drift on climateslife 0 Opening of Drake Passage between S America and Antarctica 3050 mya had major impact on earth s currents and climate Cut off Antarctica from rest of earth and completed circuit for currents Caused global cooling External earth processes 0 Changes based on energy from sun and gravity 0 Erosion Not based on earth s inner heat Tend to wear down earth s surface Process of dissolving loosening wearing rock Deposits it elsewhere Streams wind human activities 0 Weathering Mechanical 0 Large rock broken up 0 Frost wedging o Collected water expands when froze Chemical 0 Acid rain Formation of ecosystems o Dependent on Soils Soils o Vulcanism o Glaciation Landforms Water retention Altitude Depth Topography Stability Isolation Climate 0 Complex mixture Rock grains Mineral nutrients Decaying organic matter Water Air I Living organisms o Billions 0 Most microscopic decomposers 0 Renewable resource I But produced very slowly over thousands of years I Not dead January 19 2011 0 Climate wind and biodiversity 0 Why is climate important to biodiversity and the environment I Gives rise to earth s climate zones 0 These determine which forms of life occur where o What roles does wind play in climate I Acts as part of planet s circulatory system for 0 Heat 0 Moisture 0 Plant nutrients o Pollutants I Important factor in climate by influencing global air circulation o What is weather I Set of physical properties of lower atmosphere troposphere at any given moment and any given place 0 Temperature 0 Pressure 0 Humidity 0 Precipitation 0 Sunshine 0 Cloud cover 0 Wind direction speed 0 What is climate I Region s longterm pattern of weather conditions I Two main factors regulate a region s climate 0 Average temperature 0 Average precipitation I These factors are influences by 0 Latitude o Altitude 0 Ocean and air currents I Climate affects o What lives where O O O 0 How organisms live Influence of global air circulation Patterns of air circulation over earth s surface strongly influence 0 Temperature 0 Precipitation These are two of the major factors affecting distribution on earth 0 Besides evolutionary history topography Major factors determining global air circulation patterns Uneven heating of earth s surface 0 Equator vs poles 0 Air heated much more at equator sun s rays direct yearround than poles sun s rays at angle spread out 0 Warm equatorial air rises and spreads N and S Earth s tilt 0 Seasons 0 Earth s axis line between N and S poles tilted 0 Regions tip toward or away from sun as earth makes yearlong revolution around sun 0 Results in seasons in N and S hemispheres Rotation of earth on its axis 0 Air circulation 0 As earth rotates surface at equator turns fastest slowest at poles o Winds swing right in N Hemisphere left in S Hemisphere 0 Results in swirling air masses 3 cellshemisphere Direction of air movement sets up prevailing winds These redistribute heat moisture I Otherwise poles would be colder equator hotter Ocean currents and regional climates Above factors plus water density create ocean currents 0 Warm water lighter than cold Currents driven by winds and earth s rotation redistribute solar heat influencing coastal climate and vegetation 0 Gulf Streamkeeps NW Europe temperature 0 Most N Hemisphere currents clockwise S Hemisphere currents counterclockwise Currents mix ocean waters distribute nutrients and dissolved oxygen Coastal upwellings o On steep coasts winds push surface water away from land 0 Mainly W coasts near equator o Outgoing surface water replaced by upwelling of cold nutrient rich bottom water 0 Upwellings bring nutrients from deep ocean to surface supporting huge food webs o How the atmosphere controls climate I What are greenhouse gases 0 Air 0 78 nitrogen o 21 oxygen 0 1 other gases 0 Gases that maintain earth s temperaturegreenhouse gases 0 Water vapor 0 Carbon dioxide 0 Methane o Nitrous oxide 0 Essential to life on earth 0 Allow visible light from sun through troposphere lowest level of atmosphere 0 Allow some infrared and UV radiation through 0 Absorb some of heat rising from earth I Chang it into longer wavelength infrared radiationthis warms air 0 Without natural greenhouse effect earth would be too cold for most life 0 When concentrations of greenhouse gases rise average temperature of troposphere rises 0 Influence of topography on climate I Topographic features of earth s surface create local climatic conditions microclimates I Rain shadow effect caused by mountains o Moist air rises cools when hits mountain loses moisture on windward side of mountain close to ocean side dries out leeward other side of mountain side I Coastal areas have cooling sea breezes by day oceanland warming land breezes at night 0 What determines what lives where I History I Biomes I Interactions with other species I Speciesspecific factors 0 Climatic determinants of major biomes I Average annual precipitation 0 Tropical forest 0 Deciduous forest 0 Grassland 0 Desert 0 Coniferous forest 0 Tundra o Processes determining species richness I Area size Speciesarea curve smaller areas support fewer species I Resources 0 higher productivity supports higher diversity I Climate mildness predictability o yearround warmth sunlight promotes higher biodiversity decreasing latitude I Historical factors 0 Extinction 0 Isolation o Ecological determinants of geographical ranges I Ecological tolerances 0 Climate 0 Carolina wrenonly sticks around if mild winter 0 Food supply 0 Cardinalpeople now put out bird feeders allowing them to survive cold winters 0 Habitat o Kirtland s Warbler and jack pineonly breeds in Michigan where jack pines are 420 yrs old 0 Other species 0 Humans and house sparrow o Snail kite and apple snailsonly occurs where apple snails are present 0 Adaptability o Brownheaded cowbird 0 Recap I Highest biodiversity in warm moist highnutrient areas I But the following actors add substantially to biodiversity o Topographic complexity 0 Geographic isolation o Climatic diversity I Ex for global bird distributions 0 Areas of high species richness 0 Tropical subtropical forests 0 main lands 0 Areas of high species turnover 0 Where ecosystems change 0 Biodiversity hot spots I Top priority areas 0 Together represent most of the earth s biodiversity 0 Especially rich in species found nowhere else and in danger of extinction Conservation in these areas most costeffective in terms of numbers of species saved Most are 3rd world countries 0 High poverty rates high population growth 0 Lots of people and animals are competing for resources Definition highly dependent on their definition 0 Number of species 0 Geographic restriction 0 Risk of extinction differ greatly 0 Only 25 overlap between all three types Patterns of marine biodiversity 0 Generally hold in known areas 0 Greatest marine biodiversity in coral reefs and deepsea floor 0 Higher near coasts than open sea 0 Greater variety of producers habitats nursery areas 0 Higher in benthicsea floor zone than pelagicopen sea region 0 Greater variety of habitats and food sources 0 The molecular and chromosomal basis of inheritance o How does inheritance work I Overview 0 DNA is replicated precisely in body cells which have 2 sets of chromosomes 0 Individuals make sex cells 0 Single set of chromosomes molecules of DNA apportioned to each sex cell by meiosis I In meiosis different gene forms alleles assort randomly I And alleles for different traits assort independently Plus some mixing of mother s and father s DNA crossing over 0 Sex cells unite in fertilization o Fertilized egg now has double set of chromosomes I One set each from mother and father 0 Genes are segments ofDNA that direct development of individual traits I DNA 0 DNA is the genetic material of all living organisms 0 Nucleic acid 0 Inherited from parents 0 Precisely replicated I Some mistakes I Recombination o Directs its own replication 0 Hereditary information encoded in chemical language I Reproduced in nearly all cells of body I Directs development and maintenance ofvirtually all traits o Hierarchy organism to nucleotide o Cells9chromosomes9genes9segments of DNA9nucleotides 0 Composition of DNA 0 Nitrogenmnlaining bases 0 DNA a molecule with three components 0 1 l 2 m M W I Nitrogenous base 4 Lo N o 0 o Adenine A 1 1 ll 0 Thymine T h r mmquot o Guanine G 0 quotquot1 o Cytosine C r H I A sugar deoxyribose QMquot N I A phosphate group I l I One baseone sugarone phosphateone nucleotide naninem Adenine Purine I DNA chain nucleic acid made up of many nucleotides 0 Nitrogenous bases cytosine c 0 Different species differ in amount of four nitrogenous bases I ButofAofTand ofCofG I Proportions ofATandCGdiffer o Nitrogenous bases always pair in specific combinations I A T I C G I Always one purine one pyrimidine 0 DNA structure 0 Base pairing rules I Cwith G andAwithT o From one strand you can know sequence of nitrogenous bases in other complementary strands I C G T A on one strand I GCAT on the other 0 Consequences of basepairing rules I Allows for sequential replication I DNA is pair of complementary templates 0 Prior to duplication chains unwind and separate 0 Each strand acts as a template for a new identical strand which becomes chain 0 DNA replication 0 Principle elegantly simple 0 Remarkable in speed and complexity I Takes a few hours for a human to copy its 6 billion bases I About one uncorrected mistake per billion nucleotides 110000 before correction I Over a dozen enzymes and others participate 0 Then what I DNA is the code that directs protein synthesis 0 Proteins give cells shape and control chemical reactions in and between them 0 C 100000 different proteins in humans 0 All important many necessary in right quantities and places 0 Defense I Immune system 0 Transport 0 Enzymes I Cause reactions to happen 0 How does a gene specify a protein I DNA does not directly catalyze protein formation 0 It s only an information storage molecule I RNA is an intermediary 0 Like DNA except 0 Thymine replaced by Uracil U o Transcription I First major step in converting genetic information into proteins 0 Process by which messenger RNA m RNA is made from DNA template o In the nucleus 0 Translation I Second major step 0 Process by which proteins and peptides are synthesized from mRNA 0 Read by ribosome in cytoplasm o 3 nucleotides at a timecodon 0 Most codons specify a particular amino acid AA 0 Proteins made up of strands of AA 0 Genes to chromosomes 0 Genes are stretches of DNA lined up lengthwise I Many genes in one chromosome 0 Normally uncoiled o Condenses into chromosomes for cell division I Mitosis meiosis o The forces of evolution 0 What is the evidence for change and ancient origins I Evidence for change through time I Fossil record 0 Process of studying fossils just beginning in Darwin s time o Fossils are any trace of organisms past 0 Most are skeletons or shells preserved in sedimentary rock 0 Still has gaps o Fossilization rare 0 Most never found 0 Yet millions of fossils are in museums I Extinctions 0 Species were thought unchangeable 0 Why would they then go extinct I President Jefferson believed Lewis and Clark would find living giant ground sloths o Cuvier showed the Irish elk extinct 0 Now known that far more species extinct than exist now I Transitional forms 0 Fossil species often resemble living species living in same are 0 Often are less divergent or less complex 0 Law of succession o Represent ancestordescendant relationships 0 Transitional form is a fossil with traits intermediate between older and younger species 0 Horse evolution 0 Several transitional fossils show I Increase in size length of foreleg and complexity of teeth 0 llMissing linksquot 0 Archaeopteryx I Transitional between dinosaurs and modern birds I Reptilian features 0 Toothed beak 0 Long bony tail 0 Clawed hand 0 Pubis shape I Bird feature 0 Feathers I Environmental change 0 Most parts of earth s surface previously very different 0 Sea shells in high mountains ofGrand Canyon I Mountains have uplifted in past several million years 0 Many shallow seas o Continents move 0 Theory of plate tectonics I Earth s crust made up of plates change change in position 0 Conclusion earth and species ancient and have changes 0 From living species I Vestigial traits o Reduces functionless structures clearly similar to functioning structures in other species I Ongoing observable documented evolution 0 Contemporary evolutionary events 0 Evolution of resistance by insects to insecticides bacteria to antibiotics weeds to herbicides 0 Change in front of our very eyes I What is the evidence for relatedness of species 0 Resemblances between different forms on islands 0 Suggests colonization of different islands and divergence in isolation o Phylogeny family tree of organisms o Phylogenetic tree branching diagram of relationships among organisms I Developmentalhomologies 0 Developing embryos 0 Two levels of homology I Embryonic morphology I Fates of embryonic tissue 0 Genetic homologies o Similarity in DNA sequences of genes from different species I Determines developmental homologies which determine structural homologies I Cannot have developmental or structural homology without genetic homology 0 Structural homologies o Homology I Similarity between organisms due to relationship I In common ancestor o Analogy or convergence I Independently evolved similarities I Not in common ancestor 0 Summary of the pattern component of evolution 0 Data from many independent sources show species have changed and are related I Descent with modification 0 Controversy among biologists long over I No single observation 0 Pattern of evolution consistent with data 0 Process also observed directly I Four steps in natural selection Individuals in a population vary Traits with genetic basis passed onto offspring Only some offspring survive some produce more offspring than others Outcome of natural selection is evolution 0 Genetically based change in characteristics of population over time I Traits that contribute to high reproductive success increase in frequency in population over time 0 Successful individuals more fit I Darwinian fitness biological fitness 0 Adaptation o A heritable trait that increases individual s fitness in particular environment in relation to individuals lacking trait I Increases fitness I Common misconceptions about evolution 0 Evolutionnaturalselection 0 Natural selection is the main mechanism of evolution 0 Individuals evolve 0 Selection acts on individuals 0 Evolution takes place at the level of the population Evolution is progressive All traits are adaptive Constraints on evolution Genetic constraints 0 Selection unable to optimize all aspects of trait I Genetic correlation Historical constraints 0 All traits have evolved from previously existing traits Evolutionary processes and their consequences Natural selection 0 Increases frequencies of alleles that improve fitness I Only mechanism consistently leading to adaptation 0 Sexual selection a special case I May favor nonadaptive changes Genetic drift 0 I Changes in allele frequencies due to random chance 0 Gene flow I Immigrating individuals introduce new alleles 0 Immigration coming into a population I Alleles may be lost through emigration o Emigrating leaving population 0 Mutation I Ultimate cause of all variation I Where entirely new alleles come from o Mechanism of restoration and increase of diversity I Mistakes in replication of DNA o If change in DNA that codes for protein change may result in protein with new amino acid sequence 0 Errors inevitable in all genes ofall populations 0 Random 0 Mutations in welladapted organisms mostly harmful lower fitness 0 Occasional beneficial mutations selected from o Deleterious alleles lower fitness Modes of natural or artificial selection 0 Directional selection I Peccaries prefer cacti with fewer spines 0 Cacti with more spines not eaten 0 They pollinate most flowers 0 Leave most offspring o Fewspined cacti die out morespined cacti selected for o Stabilizing selection I Parasites prefer manyspined cacti I Together with peccaries selection against extremes 0 Variation reduced 0 Disruptive selection I Population without peccaries or parasites I Near roadtourists o artic 0 Few and manyspined cacti survive 0 Sexual selection I Eggs expensive sperm cheap 0 Females invest much more in offspring than males 0 Female s fitness limited by resources for producing and rearing young 0 Male s fitness limited by number of females they can mate with I Predicts that females that invest in offspring should be choosy I Types of sexual selection 0 Two main types 0 Female choice I Intersexual selection or mate choice I When members of one sex usually females choose among individuals of the other sex Males with certain features most attractive to females These features may not be adaptive on other ways 0 Malemale completion I ntrasexual selection I Direct competition among individuals of one sex usually males for mates of opposite sex I Direct physical battles between individuals I More often ritualized displays discourage lesser competition and determine dominance Consequences of sexual selection 0 O O Affects only genes involved in competition for mates Produces change in allele and genotype frequencies Costs of extravagant features outweighed if they help individuals get matings I When female chooses mate based on appearance or behavior she perpetuates alleles that cause her to make that choice I Her choices also perpetuates alleles of males with particular phenotype she chose Underlying basis of female choice probably assessment of general health I Males with infections or poor nutrition are likely to have duller disheveled less developed characteristics unlikely to win females Sexual selection may lead to secondary sex differences I Sexes of a species often differ in secondary sexual characteristics I Not directly associated with reproduction I Sexual dimorphism I Male vertebrates usually larger showier I Overall females usually larger Differential reproductive success 0 Highly skewed in some species I Hereditary vs environmental traits o Translocation studies show some geographic variation is the result of environmental differences I Artificial selection 0 Very like natural selection except 0 People choose mates I Select for certain traits o The tree of life 0 O 0 All 5100 million species on earth are related I Morphology gene sequences biochemistry support their relatedness I From single ancestor Tree of life represents history of organismal lineages as they change through time Organisms evolve from ancestral forms into more derived forms I These retain many ancestral features I Also gradual modification of existing traits plus new traits adapts them to environment Study of phylogeny helps explain similarities and differences among groups I Guides research I Provides model for organization of biological knowledge Systematics I Study of the diversification and relationships of life on earth 0 Evidence used in tracing phylogeny evolutionary history 0 Paleontology 0 Molecular data 0 Comparative anatomy o Other approaches 0 Evolutionary reconstruction is main goal of systematics 0 Includes taxonomy I Naming and classification of taxa 0 Species and groups of species I Taxonomy uses a hierarchical classification system 0 Linnaean system 0 Proposed by Linnaeus in 10 h edition of Systema naturae in 18 h C 1758 0 Two main characteristics O 0 Each species has 2part Latinized name binomial 0 Species organized hierarchically into broader groups of organisms Binomial system I First part genus is the narrowest group to which species belong I Second part specific epithet for a species within a genus 0 First letter of genus capitalized 0 Specific epithet always lower case 0 Both names in italics underlined if handwritten I Species with more than one geographical race may have subspecies name trinomial Hierarchical classification groups species into broader taxonomic categories I Closely related species in same genus I Biology s taxonomic scheme formalized human tendency to group related objects 0 Consistent usage facilitates dissemination of information I Genera grouped into progressively broader categories 0 Family order class phylum kingdom and domain 0 Sub super any category 0 Higher categories not italicized o Capitalized when proper name I Each taxonomic level broader than previous one I The named taxonomic unit at any level is a taxon pluraltaxa I Phylogenetic trees reflect hierarchical classification of taxa 0 Each taxon falls within a more inclusive taxon Modern phylogenetic systematics cladistics I Cladistics or phylogenetics developed in 1960s I A phylogenetic diagram or cladogram is constructed from a series of dichotomies 0 Sequence of branching symbolizes historical chronology I Each branch or clade nested within larger clades o Clade is ancestral species plus all its descendants o Monophyletic group 0 Nonmonophyletic groups grades unacceptable 0 Two kinds of nonmonophyletic groups I Paraphyletic doesn t include all descendants I Polyphyletic doesn t include ancestor I Can be both I Parts of a phylogenetic tree 0 Rootmost recent ancestor o Branchhypotheticalancestor o Nodespeciation branching event 0 Polytomyunresolved node with more than 2 branches from the same point 0 Outgrouprather closely related to ingroup but less closely than any ingroup members to each other 0 Sister taxon is closet relative o Branches can be rotated at nodes without changing meaning Similarities based on shared ancestry or homology are useful in reconstructing phylogenies Similarities based on convergent evolution or analogy are misleading The more homologies genetically useful characteristics two species share the more closely they are related 0 Adaptation can obscure homology 0 Convergence creates analogies homoplasies 0 Complex structures unlikely to evolve independently 0 Differences all quantitative o The major lineages of life 0 Linnaeus divided all organisms into 2 kingdoms I Animal or plant 0 5kingdom system recognized 2 fundamentally different types of cells I Prokaryotic kingdom Monera and eukaryotic other 4 kingdoms o 3 kingdoms of multicellular eukaryotes were distinguished partially by nutrition I Plants are autotrophic 0 Make organic food by photosynthesis I Most fungi are decomposers o Extracellulardigestion o Arranging the diversity of life into the highest taxa is a work in progress I Cladistics analyses identified problems with 5kingdom system 0 2 distinct lineages of prokaryotes 0 So 3domain system bacteria archaea and eukarya 0 Multiple kingdoms of bacteria and archaea I Another problem with 5kingdom system 0 quotkingdomquot Protista 0 Why don t scientists know how many species there arewere I Differing species concepts I Poorly understood levels of differentiation I Difficulty of estimating levels of hybridization 0 Comparative diversity of vertebrate groups I Fish 25000 species I Amphibian 5500 I Reptilia 8075 I Birds c900010000 I Mammals 4700 I Highest diversity for each class in one group with mostly small body size 0 The fossil record of primates and human evolution 0 Primates lemurs monkey apes humans I llhallmark featurequot 0 Agility in trees 0 Grasping hands and feet flat nails lightly built body long tail for balance 0 Large brain 0 Binocular vision 0 Extended parental care I Early fossil primates 0 Grasping foot with opposable big toe o Grasping hand with opposable thumb o Adapted for foraging for fruits on the ends of branches in trees and for leaping between branches 0 Nails rather than claws 0 Large brains need to process a lot of information to move through a complex environment 0 Forwarddirected eyes for binocular vision overlapping fields of view 0 Lemurs tarsiers lorises o quotprosimiansquot I Most primitive living primates I Fossil record to 60 mya I Earliest forms in North Africa I Treedwelling fruit eaters some nocturnal o Monkeys the anthropoids rounded nostrils large canine teeth broad square molars 0 Old world I Catarrhines 0 Africa Asia Europe 0 Longer narrower snouts nonprehensile tails 0 New world I Platyrrhines 0 South and central America 0 Flatter faces with widely spaced nostrils prehensile tails 0 Where did anthropoids originate I Traditional view paleontologists studying fossil record from Egypt from ca 40 mya argue that anthropoids probably evolved first in Africa and share a common African ancestor I Alternative view that anthropoids originated in Asian migrated to and colonized Africa and then early forms went extinct in Asia Burma 0 By 35 mya fossil record ofanthropoids is clearly centered in Africa 0 How and when the anthropoids that are ancestral to the new world monkey reached southcentral America is unknown dispersal across the south Atlantic I Oldest fossil south American monkeys are about 25 mya o Hominoids the apes diverge from old world anthropoids in the Miocene of Africa about 25 mya 0000 And homo sapiens Earliest fossil hominoids about 24 mya from east Africa Maximum ape diversity about 15 mya in east Africa Features Loss of tail Enlarged brain Strong elbow joint Large forwarddirected eyes Flatter faces Smaller canines Within hominoids About 8 mya one lineage began developing features related to being bipedal erect stance on hind limbs This happened at approximately the same time that significantly larger brains appear Bipedalism leads to major changes and reorganizations of anatomy 0 Long straight limb bones 0 Flat feet big toe nonopposable o Knee joint straight o Pelvis faces out not down 0 Backbone vertical 0 Head directly on top of vertebral column Why become bipedal 0 East Africa shifted to an open savannah environment 0 Advantage to being able to stand upright to check for predators o Frees up hands to carry and manipulate objects Earliest direct evidence for bipedality 0 Fossil footprints in volcanic ash from Laetoli Tanzania 0 About 375 mya Earliest definitive skeletal evidence for bipedality in a hominid o quotKadunuumuuquot big man 0 36 mya in Ethiopia 0 Long straight leg bones and shoulder blade of a biped o Relatively large for time period almost 6ft tall Earliest evidence for tool use 0 Animal bones with scrapes and gouges made by stone tools 0 34 mya from Ethiopia 0 When do the first modern humans emerge I Evidence suggests approximately 160000 years ago in Ethiopia Herto man 0 Very flat face 0 llbrow ridges reduced 0 Small canine teeth 0 Large eyes 0 Very large brain cavity 0 Skull set directly above backbone I African Eve 0 Genetic data suggests that all humans share a single common ancestor who lived in Africa no longer than about 200000 years ago 0 Supported by DNA evidence as well as the concentration of fossil discoveries in Africa 0 All human races are very closely related to one another I Out of Africa 0 Timing of the spread of homo sapiens 0 Origin in Africa by 100000 years ago had spread through Africa 0 Reached Australia and southern Asia about 5000060000 yea rs ago Reached Europe about 40000 years ago Reached Americas between 15000 35000 years ago 0 O 0 Communities energy and matter flow and succession o Ecology is I Study of how organisms interact with one another and with their nonliving environment 0 Nonliving factors include o Sunlight 0 Temperature 0 Moisture o Nutrients 0 pH chemistry pressure etc 0 Some ecological termsconcepts O O 0 Population a group of interacting individuals of the same species that occupies a specific are at same time Habitat place and conditions under which a population normally lives Community interacting network of all species occupying single place at single time Ecosystem community of different species interacting with each other and nonliving environment Ecospherebiosphere o where all life exists o r lower upper r 0 all earth s ecosystems together Major types of ecosystems Terrestrial portions of ecosphere classified into biomes o Deserts prairies deciduous forest chaparral etc Marine and freshwater portions classified into aquatic life zones O Lakes streams estuaries coastlines coral reefs deep ocean etc Major components of ecosystems Abiotic nonliving Water 0 Air 0 Nutrients 0 Solar energy Biotic living 0 Plants 0 Animals 0 Fungi o Microorganisms Organisms and physical conditions Different organisms differ in needs Range of tolerance range of conditions in which a population of organisms can survive Each population of organisms has 0 Optimum range ideal best for survival and abundance Zone of physiological stress only a few individuals of population can survive Zone of intolerance no organisms of population can survive Some species have narrow tolerances others wide 0 Species with wide tolerances often do well in manaltered habitats 0 Species with narrow tolerances go extinct when natural or human caused disturbance hits Some life stages less tolerant than others 0 Eggs 0 Juveniles 0 Pregnant females 0 Major living components of ecosystems Producers autotrophs 0 Make own food from compounds taken from environment 0 Green plants bacteria on land 0 Algae including phytoplankton bacteria green plants in water Consumers heterotrophs o Depend on food made by producers 0 Flow of matter and energy Survival of all organisms depends on flow of matter and energy through body Ecosystem survives mainly through matter recycling twoway and energy flow oneway o Decomposers vital 0 Remove waste 0 Make nutrients available 0 Three factors that sustain life on earth Oneway flow of highquality energy from sun 0 Through materials and living things in feeding interactions 0 Into the environment as lowquality energy heat 0 Back into space as infrared radiation Cycling of matter or nutrients o Atomsmolecules needed for life Gravity o Allows planet to hold on to atmosphere and causes downward movement in matter cycles 0 How does the sun sustain life on earth Supplies energy for photosynthesis Lights and warms planet Powers cycling of matter Drives climate and weather systems The sun 0 Gigantic fireball of H2 and He 0 Hot inner core causes nuclear fusion 0 Releases huge amounts of electromagnetic radiation I Heat visible light UV How much of the sun s energy is used 0 Earth receives c onebillionth of sun s energy 0 Much of this fraction reflectedabsorbed by atmosphere 0 Remaining solar energy 0 Visible light 0 Infrared I Warms earth cycles water and creates wind 0 Small amount of UV radiation I Rest is absorbed by ozone layer Only about 023 is received energy used in photosynthesis 0 Basis for almost all life on earth Most solar radiation degraded into heat 0 Built up by greenhouse gases in atmosphere 0 Otherwise earth would be too cold for life I How producers make food Capture sunlight and inorganic nutrients 0 Use in photosynthesis to make sugars 0 Reaction takes place in chloroplasts o Photosynthesis overall reaction I Carbon dioxidewatersolar energyglucoseoxygen o 6COZHZOsolar energy C6H1206OZ Chemosynthesis 0 Some Archaea convert simple chemical compounds into complex compounds without sunlight I Deep sea hydrothermal vents I Powers whole food webs independently of sunlight Extremophiles o Organisms that can live where life impossible for almost all others Producers I Bacteria algae fly communities in hot springs I Bacteria in acid springs I Most other extreme environments where water available not too hot I Basis of these food chains are chemosynthetic prokaryotes I Grand prismatic spring Yellowstone o Photosynthesizing or chemosynthesizing organisms I Land plants I Algae I Some protists I Bacteria I Archaea I Many animals have symbiotic photosynthesizers At least one species of animal can photosynthesize 0 Green sea slug Elysia chlorotica I Eats alga and incorporates its chloroplasts 0 Horizontal gene transfer 0 Maintains chloroplasts in its own tissues under its own genetic control 0 Cannot make new chloroplasts 0 Consumers 0 Obtain energy nutrients by eating other organisms o Herbivores primary feed directly on producers o Carnivores feed on other consumers 0 Secondary consumers carnivores feeding directly on herbivores o Tertiary higherlevel carnivores feeding only on other carnivores I Ra re except parasites 0 Most carnivores animals also carnivorous plants 0 Omnivores feed on both plants and animals 0 Scavengers consumers that feed on already dead organisms o Detritivores organisms that feed on parts of dead organisms and waste products I Detritus feeders feed directly on detritus I Decomposers complete breakdown and recycling of organic materials from remains or wastes mostly bacteria and fungi 0 Cellular respiration energy metabolism 0 All producers and consumers use sugars etc to fuel life processes I Aerobic respiration most organisms 0 Used oxygen to convert organic nutrients back into carbon dioxide and water and energy 0 Glucoseoxygencarbon dioxidewaterenergy o C6H12066026C02H20energy 0 Relationship between photosynthesis and aerobic respiration 0 Net chemical change of aerobic respiration is the opposite of photosynthesis Anaerobic respiration some decomposers Get energy by breaking down sugars without oxygen Gives off ethanol lactic acid or methane etc Food chain and energy flow in ecosystems All organisms are potential food sources for other organisms 0 Little waste in natural ecosystems Food chain sequence of organisms that provide food for other organisms o How energy and nutrients move from one organism to another through ecosystem o Trophic level I Feeding level in food web of any given organism I Producers first trophic level I Primary consumers second I Secondary consumers third 0 Detritivores process detritus from all trophic levels Food web more complex more connections Energy flow and storage of biomass in ecosystem Each trophic level contains a certain amount of biomass dry weight of organic matter In food chain energy stored in biomass is transferred between tropic levels 0 At each step some usable energy is degraded and lost as heat 0 Only a small part of what is eaten is converted into biomass Amount of usable energy available 0 declines at each successive trophic level I 5320 carried over to next level Ecological efficiency Percentage of energy transferred form one trophic level to another o The more trophic levels in a food chainweb I Energy flow pyramids explain Why big fierce animals predators are rare compared with herbivores 0 Why they are usually more susceptible to disruption and extinction than herbivores 0 Why earth can support many more vegetarians than carnivores I Rate of biomass production in different ecosystems Gross primary productivity G PP 0 Rate at which photosynthesizes to make biomass Net primary productivity NPP 0 Amount of biomass available as food to consumers in ecosystem after producers use their share for survival growth reproduction 0 Rate at which energy is stored in plants I Limits the number of consumers that can survive on earth I Earth s total NPP determines its carrying capacity Productivity of various ecosystems 0 Highest in estuaries swamps tropical rain forest 0 Lowest in open ocean tundra desert o Other ecosystems intermediate Global NPP 0 Close match between NPP and distribution and of rainforests Terrestrial vs marine productivity 0 Clustered by coasts Why can t humans use the most productive ecosystems for food production 0 Most producers inedible or not favored 0 We would destroy most other life I Including our food providers I And other natural resources 0 Tropical forest soils are nutrientpoor I When cleared only yield crops a few seasons I At expense of ecosystem destruction 0 Agricultural land I Highly modified ecosystems I Not especially productive even when monocultures are sustained by massive inputs of fertilizers and water I Biological deserts for all but one species 0 Extent of human disturbance of earth s habitable surface Habitats completely to seriously altereddegraded 73 of the earth s surface Humans now use waste and destroy 40 0 Human population growth and impacts I Humans are crowding out other species at everincreasing rate to feedplease themselves I What will happen as human population continues to increase exponential and as standards of living rise I Matter cycling in ecosystems o Biogeochemical nutrient cycles 0 Continuous cycling of nutrients from nonliving environment through living organisms and back 0 Atoms in us are ancient I Used before I Will be again 0 Driven by solar energy and gravity 0 Main cycles I Water hydrologic I Oxygen I Carbon I Nitrogen I Phosphorus I Sulfur o The water cycle 0 O 0 Essential to all organisms Reservoirs I 97 of surface water in oceans I 2 in glaciers polar ice caps I Small amount in groundwater I A fraction in organisms atmosphere Moves by I Evaporation most from ocean I Transpiration I Condensation I Precipitation mostly over land I Percolation I Runoff 0 Carbon cycle 0 O 0 Essential to all liveorganic compounds Cycle based on carbon dioxide gas in atmosphere and dissolved in water Key component of earth s temperature control system I Too much removed from atmospherecooling I Too much addedheating Carbonbased organic molecules are major constituents of all organisms Carbon reservoirs I Fossil fuels I Soils and sediments I Solutes in oceans I Organismal biomass I The atmosphere C02 is taken up and released through I Photosynthesis I Respiration I Volcanoes I Burning I Warming ocean I Cement production Cycling of carbon into organisms I Terrestrial producers remove carbon dioxide from air I Aquatic producers get it from I Consumers get it from eating producers I Cells of most organisms carry out aerobic respiration for energy I Linkage of photosynthesis and respiration circulates carbon 0 Fossil fuels I Buried deposits of dead plant matter and bacteria I Eventually over millions of years become fossil fuels like coal oil I Nonrenewable on human time scale I This carbon dioxide not usually naturally released to atmosphere I Most released upon burning 0 Human impacts on carbon cycle I Removal of trees that absorb carbon dioxide through photosynthesis I Adding huge quantities of carbon dioxide by burning fossil fuels and forests I Increased atmospheric carbon dioxide enhances natural greenhouse effect that warms troposphere I Causes global warming I The terrestrial nitrogen cycle 0 Essential for amino acids proteins and nucleic acids of all life 0 Main reservoir is the atmosphere N2 0 Must be converted to ammonia NH4 or nitrate N03 for uptake by plants I Via nitrogen fixation by bacteria 0 Organic nitrogen is decomposed to ammonia by ammonification I Ammonia is decomposed to nitrate by nitrification o The pho o Denitrification converts nitrate back to nitrogen Most abundant element in atmosphere Can t be metabolized directly by multicellular producers Two natural nitrogen processes 0 Lightning 0 Bacterial action nitrogen fixationde Excess nitrogen may undergo nitrification Nitrogen in living organism 0 Plants assimilate or take up dissolved nitrogen substances 0 Used to make organic molecules 0 Consumers get nitrogen by eating producers o Nitrogen returned to environment through decomposition and wastes of living organism I Ammonification by specialist decomposer bacteria I Then Denitrification bacteria returned to air 0 Human impacts on nitrogen cycle 0 Burning fuel adds nitric acid to atmosphere I Acid rain I Damages trees lakes buildings stimulates weeds 0 Addition of nitrous oxide to atmosphere I Livestock wastes I Inorganic fertilizers 0 Agriculture removes nitrogen from topsoil o Agriculturalsewage runoff into wetlands Algal blooms 0 Cause anaerobic environments 0 Huge changes to life in water bodies I Humans responsible for c half global nitrification sphorus cycle A major constituent of nucleic acids phospholipids and ATP Mainly as phosphate P04 3 Reservoirs O o Sedimentary rocks of marine origin 0 The oceans o Organisms Phosphate binds with soil particles and movement is often localized Processes o Weathering o Leaching 0 Uptake by producers then consumers Return through decomposition excretion O Ecological succession All communities and ecosystems change gradually Response to environmental changes 0 Colonization growth increased abundance of some species 0 Decline local extinction of others Two types 0 Primary establishment of biotic community on lifeless ground I Begins with essentially lifeless area 0 No soil or sediment 0 Rock exposed after glacial retreat o Lava field 0 Abandoned parking lots roads 0 Soils must be formed 0 Takes 100 s to 1000 s of yea rs 0 Pioneer species start soil formation 0 Hardy lichens mosses Roots help break up rock into soil 0 Decay of plants helps build up soil 0 Patches of soil build up and spread 0 New plant community ofsmall perennial grasses herbs ferns I Brought in by wind bird droppings mammals coats 0 Early successional 0 Close to ground 0 Establish large populations quickly 0 Harsh conditions 0 Shortlived o Midsuccessional 0 After 100 s of yea rs 0 Soil deeper more fertile 0 Stores moisture nutrients 0 Less hardy herbs grasses shrubs o Displaced by trees 0 Late successional o Canopy and shadetolerant species 0 Naturally becomes complex forest I Assuming other conditions permit 0 Secondary establishment of biotic community where life already present Terrestrial biomes O Reca p O 0 Where natural community removeddisturbed but some soil remains o Abandoned croplands o Burnedcut forests o Badly polluted water bodies 0 Dammedflooded land Soils seeds already present 0 Germination starts quickly 0 New seedsspores arrive o Invasives often take over Disturbance and succession Human Disturbance change in environmental conditions that disrupts ecosystem or community 0 Fire 0 Drought 0 Flooding 0 Mining 0 Clearcutting o Plowing o Pesticide application 0 Climate change 0 Invasion 0 Grazing Effects range from mild to catastrophic Natural or humancaused Convert community from present successional stage to earlier successional stage impacts Overwhelming evidence that humans are disrupting our own resources as well as biodiversity We re changing climate so many ecosystems will be dramatically disrupted Better to take precautionary approach vs purely exploitative approach Everything is interconnectedwe rely on stability of many ecosystems for our economy and survival Biomes determine distribution of earth s terrestrial biodiversity Biome distribution caused mostly by climate Climate caused by precipitation temp 0 Desert biomes Soil type Elevation Longlatitude I Where evaporation exceeds precipitation Precipitation low irregular 0 Average lt 10 inchesyear Vegetation almost absent or widely spaced low stature I Hot by day cold by night 0 Semidesert Sparse vegetation doesn t hold heat Skies clear air dry I In semiarid zones between desert and grassland or dry woodland Dominated by thorn trees and shrubs Adapted to long dry spells and brief often heavy rains o Adaptations for survival in deserts I Gettingkeepingdoing without water Long tap roots common Swelling tissues Dormancy in dry season 0 Drop leaves minimize metabolism Storage of water 0 Thick trunks roots Reduce water loss by opening pores to take up carbon dioxide only at night Waxcoated small leaves Biomass storage in dormant seeds 0 Grow quickly after rains llresurrection plants I Avoiding herbivores spines Normally can t regrown quickly I Adaptations of animals Body adaptations 0 Large ears increase heat loss Small body size Long thin limbs Thin short fur or feathers Pale colors not usually white 0000 Heavy armor to minimize evaporation I Insects reptiles Concentrated dry feces urine O 0 Ability to get water from dew food I Human impacts to deserts o Offroad vehicleslivestock o Overgrazing o Trampling 0 Irrigation o Salinization o Depletion of rivers groundwater o Disturbance not easily overcome 0 Slow plant growth 0 Slow nutrient cycling I Little bacterial activity 0 Water shortages Grassland biomes I Enough rainfall for grass growth Afforestation prevented by 0 Erratic rainfall 0 Frequent fires 0 Large grazing herbivores Mostly in interiors of continents Renewable on short time scale 0 Plants grow from the base Three main types 0 Tropical o Temperate o Tundra 0 Polar 0 Alpine Some plant adaptations to grasslands 0 Fire and grazing adapted o quotg 39 r 39 39 by g Istems 0 Mostly perennials o Windpollinated o Tolerance of 0 Extreme temperatures 0 Drought 0 Wind damage 0 Survival in saline soil I Human impacts to grasslands 0 Now mostly destroyed for cropland 0 Whole ecosystems adapted for local climates gone O 0 Removal of original plants and root systems I Causes erosion due to wind and water 0 Large areas overgrazed o Removes some species 0 Tramples roots 0 Decreases biodiversity o Grasslands are among earth s most endangered biomes Polar grass lands arctic tundra I Just south of polar ice cap I Bitterly cold most of year 0 High winds 0 Icesnow cover I Winters long 0 Dark all day I Growing season very short 0 But sun shines almost all night I Precipitation mostly as snow 0 Unavailable Vegetation thick lowgrowing o Mainly mosses lichens dwarf shrubs I Permafrost o Caused by extreme cold short summers 0 Only upper layer of soil thaws 0 Lower layers stay frozen 0 Liquid water can t percolate into lower layers 0 Waterlogged upper layers form bogs o Bogs support huge quantities of waterbreeding insects I Mosquitoes blackflies midges o Insects support arcticbreeding birds 0 Melting will release vast amounts of stored carbon Aquatic life zones 0 O O O Largest part of the biosphere water I 75 Freshwater vs saltwater I Marine 3 salt freshwater c 01 Most rainfall by evaporation from ocean Ocean temperature affects land climate and winds Photosynthetic marine organisms important in oxygen and carbon cycles Marine zonation 0 Distance from shore I Intertidal low vs high tide O O O Freshwater ecosystem O Periodically submerged and exposed o Greatly varying salinity moisture air sun levels 0 Wave action Highly stratified Rocky or sandymuddy 0 Different adaptations 0 Many sessile animals on rocks 0 Many buried in sandmud High biodiversity High nutrient levels Neritic over continental shelf Oceanic deep water Light penetration Depth Photic enough light for photosynthesis Aphotic too little light for photosynthesis Pelagic open water Open blue water 0 Mixing by winddrive ocean currents 0 High oxygen levels 0 Low nutrient concentrations Most 70 of earth s surface 0 Dominant photosynthetic organisms phytoplankton I Accounts for half earth s photosynthetic activity Benthic Coral reefs Sea bottom Abyssalbenthic zone 20006000m Formed mostly from calcium carbonate coral skeletons Animaldominated ecosystem Near shore or on continental shelf Photic zone of tropical marine waters High water clarity Need solid substrates just below water line Temperature salinity and nutrient sensitive 0 Low nutrients Need high oxygen levels Harbor extreme animal diversity Zonation Distance from shore 0 Littoral near shore o Limnetic off shore I Light penetration o Photic 0 Aphotic I Pelagic open water I Benthic bottom 0 Freshwater life zones I Lakes 0 Standing bodies of water 0 Deep enough to have light and temperature stratification 0 Oligotrophic o Nutrientpooroxygenrich o Eutrophic o Nutrientrichoxygenpoor I Wetlands 0 Shallow inundated areas 0 Extremely productive 0 High biodiversity I Streams and rivers 0 Narrow some current 0 Great variation from headwaters to downstream parts I Estuaries 0 Transition between river and sea 0 Moderate salinity 0 Highly productive 0 Human impacts I Every biomeaquatic life zone has been profoundly affected by humans I Most damagedin danger o Grasslands 0 Most easily farm 0 Tropical rainforest o Subsistence farming logging o Coral reefs o Pollution o Wetlands o Draining 0 Species interactions 0 What are species interactions I Ecological community is all species interacting in a given area at a given time I Basic types of interactions 0 Competition o Intraspecific competition I Between members of same species I For same resources 0 Interspecific I Between members of different species I For same resources I Consequences o If niche overlap significant one of competing species must do one or more of the following o Emigrate o Shift feeding habits or behavior through natural selection 0 Become rare 0 Competition avoidance I Species can evolve adaptations to reduce or avoid competition 0 Resource partitioning o Dividing up of scarce resources 0 Different species use same resources in different ways times andor places 0 Symbiosis 0 Close ecological relationship between individual of two or more species 0 Individuals of at least one species benefit 0 Types I Predation o Interactions between consumers 0 Members of one species feed directly on all or part of living organism usually other species 0 Do not live on or in prey o Predator usually larger than prey Consequences of predation o Prey usually dies I Exceptions cookiecutter sharks leeches mosquitoes 0 Individual predator benefits 0 Individual prey is harm 0 Can benefit prey population I Removes sick weak aged members I Reduces prey population which improves food access genetic stock and prevents disease transmission 0 Strategies of predators o Carnivores feed on mobile prey I Two main options pursuit chase or ambush group hunting lures camouflage traps I Parasitism I Mutualism I Commensalism Case history the large blue butterfly Phengaris arion Niche Eggs laid on wild thyme 0 Caterpillar feeds on this until third instar o Drops to ground and secretes sweet feed Picked up and milked by red ants Myrmica sabuleti o Mimics ant grub appearance and behavior then taken to ant s burrow and further milked O Eats up to 500 ant grubs then hibernates in ant nest O Mimics ant pheromones and sounds I Eaten by ants if doesn t When butterfly emerges ants escort it outside and guard it until dry Niche o The role a species plays in its ecosystem I Where it lives what it consumes and how it avoids consumption or displacement by other species Fundamental nice o Niche a species would occupy if no competition between species I Idealized niche o If resources abundant members of species can come close to occupying fundamental niche n resource partitioning due to competition each species niche becomes more specialized 0 Especially where many species coexist o On small islands where few species many species are generalists I Occupy niches other species would occupy on mainland 0 Strategies of prey Herbivores Walk right up to food sources Main problem is to avoid predators 0 Escape mechanisms 0 Quickness 0 Ability to jump 0 Shelter I Knowing territory I Tunnels o Nocturnality I Avoid detection 0 Keen senses o Welldeveloped sense of smell hearing I Mammals o Welldeveloped sight hearing I Many birds 0 Positioning of eyes 0 Size of ears 0 Protective structures 0 Armor 0 Spines o Antlers horns o Beaks fangs claws talons o Camouflage 0 Shape change 0 Color change 0 Chemicals 0 Poisonous o Irritants o Foul smell 0 Bad tasking 0 Source for many pharmaceuticals drugs 0 Warning coloration o Aposematic I Bright colorationpatterning that warns predators I Usually means toxic or badtasting 0 Many animals take advantage ofthis by mimicry 0 Behavioral strategies 0 Inflating looking large 0 Predator mimicry O o Confusingstartling predators Other distracting defenses o Slime o Brea koff parts I Commensalism 0 Parasitism Interactions beneficial to one species but neutral to the other harmful to neither Human commensals 0 Species that have followed humans into populated areas 0 Now rely on humans 0 Profit from anthropogenic habitat garbage Commensalism in birds 0 Beaters individuals of one species benefits by following or attending another to which interaction neutral Nest sites 0 O Feeding arrangements I When one species feeds on part of another organism host by living on or in it Usually only parasite benefits host is harmed Usually does not kill host 0 Typically weakens it Parasite usually much smaller than host Some move between hosts usually in different life cycle phases others stay in one host Irritating to disgusting but important in ecosystems More diverse and numerous than hosts 0 Diversity little known except for human parasites Many are highly hostspecific I Types of parasites Ectoparasites live externally 0 Must be able to I Cling or hang on I Be armored I Be able to get away I Survive scratching Endo parasites live internally 0 Many worms 0 Usually have simple absorptive bodies I Tendency to lose unneeded features I Hooks suction cups etc 0 Hosts can t physically remove 0 Some special cases 0 One time feeders carnivores Partly mutualistic parasites Brood parasites OOO Parasitoids I Kill host after completion of life cycle I Brood parasitism 0 Bird lays its eggs in another bird s nest 0 Usually lays in a different species nest 0 Host brings up the parasite young 0 Usually results in loss of host s own young 0 Hosts grow fast monopolize resources 0 Evict kill or starve out others 0 Cuckoos cowbirds widow finches honey guides 0 Some birds reject eggs desert nest or build new layer I Parasitoids o Insects that find and usually paralyze hosts 0 Drags them back to burrows 0 Lay their eggs onin them 0 Eggs hatch and larval parasitoids feed on paralyzed host I Eat nonvital organs first 0 Eventually kills host usually about when larvae pupate or emerge as adults 0 Many parasitoid wasps used as biological control agents for crop pests o Mutualism I When two species interact and both benefit I Mutual exploitation 0 Pollination relationships 0 Plants get pollinated animals get food 0 Seed dispersal 0 Seeds get dispersed animals get food 0 Root fungi o Fungi get plant s sugars improve plants nutrient and water gathering o Coevolution I Interactions between species that result in microevolution in each of their populations 0 Much of evolution is coevolution o How species continually respond to one another 0 For complex interacting networks o Populations of two different species interact over time 0 Changes in gene pool of one species can lead to changes in that of other 0 One adaptation follows another in llevolutionary armsracequot 0 Examples I Flowers and pollinators o Yucca and yucca moth I Predators and prey I Insect herbivores and plants I Insect evolution of pesticide resistance 0 Insects have evolutionary history of evolving to detoxify poisons in plants 0 Potential problem resistance to genetically engineered crops 0 Biodiversity values of life on earth 0 Major categories of biodiversity value I Ecosystem 0 Importance to ecosystem functioning I Instrumental 0 Direct value positive or negative to humans I Others 0 Aesthetics 0 Scientific interest 0 Inherent right 0 Degree of endangerment I Biodiversity value of viruses 0 Ecosystem 0 Major role in population regulation 0 Instrumental 0 Diseasecausing agents 0 Huge economic and medical importance 0 More than 250 known to infect humans I Why expect fewer for other organisms o Other 0 Scientific 0 Negatively valued smallpox AIDS 0 None known to be beneficial I Prokaryotes biodiversity values of Archaea o Ecosystem 0 Basis of food webs in extreme conditions 0 Instrumental o Biodegradation of pollutants o No pathogens disease causing known 0 Other 0 Provide clues to evolutionexistence of life on other planets Prokaryotes biodiversity values of bacteria 0 Ecosystem 0 Cause of oxygen revolution Decomposers Nitrogen fixation Photosynthesis 000 Agents of eutrophication o Symbiotic relationships 0 Instrumental 0 Many pathogens I Constant evolution of antibiotic resistance 0 Skin flora c 1 trillionhuman prevent colonization by disease causing bacteria 0 Essential to survive o Other 0 Negative public image I Some on WHO list for eradication leprosy trachoma tetanus o Antibacterial 0 Example of bacterial symbiosis 0 Fish provides bioluminescent bacteria with organic material 0 Bacterial bioluminescence lures fish prey signals its mate Eukaryotes biodiversity values of Protistsquot all unicellularProtists are euka ryotes different than proka ryotes o Ecosystem 0 Avian extinctions in Hawaii malaria 0 Many parasites o Symbiotic with hoofed mammals in gut I Digest cellulose o Photosynthesisphytoplankton o Zooplankton 0 Major components of sand soils 0 Biodiversity values of protists 0 Instrumental I Red tide I Paralytic shellfish poisoning I Major components of oil Many human diseases 0 Malaria 12 million deaths per year Index files 0 Important in paleontology geology study of ancient climates 0 Essential to oil exploration 0 Biodiversity values of llmacro algae multicellular protists seaweeds O O Ecosystem Reef building Form ecosystemshabitats Photosynthesis Food for many consumers Instrumental Food thickeners o Biodiversity values of mosses O O O Ecosystem Dominant plants near poles o Sphagnum 10 of land surface Insulate arctic permafrost Food for many animals Many higher plants grow only in peat bogs o Orchids Absorb water Instrumental Other Peat moss dead sphagnum Peat fuel Peat farming cranberries blueberries Emergency wound dressing Emergency food Garden weeds major market for herbicide products Horticulture Japan Preservation of other organisms human remains and pollen o Biodiversity values of ferns O Ecosystem Major components of ecosystems 0 Especially tropical o Epiphytes form microhabitats Invasive species O o Salviniahighly invasive in warm waterways worldwide Instrumental I Major contributors to coal deposits I Azolla 0 Green manure shades out weeds fixes nitrogen may suppress mosquitoes I Horticulture I Fold medicinereligion I Human foodyoung plants aquatic supplements I Horsetails and lycophytes biodiversity values of other primitive plants 0 Ecosystem O 0 Important to early evolution of life on earth Fixation of atmospheric nitrogen I Cycadbacterialsymbiosis 0 Instrumental 0 O 0 Coal deposits Horticulture I Shadetreesgingko I Cycads Herbal remedies I Ephedra I Seed plants biodiversity of conifers gymnosperms o Ecosystem O O 0 Dominant habitats in north temperate zone I Lower biodiversity I Specialized species Food for wildlife I Spruce grouse I Crossbills Major role in photosynthesis 0 Instrumental 0 O O Resin I Amberturpentine Timber softwoods Horticulture I Christmastrees I Landscaping Jewelry I Amber Human food O I Pine nuts juniper berries etc Other I Tourism I Biodiversity of flowering plants angiosperms o Ecosystem O O O O 0 Maintenance of climate Matter cycles Production of food by photosynthesis for most animals fungi etc I Coevolved relationships Habitats shelter Protection of soil 0 Instrumental 0 00000 O 0 Other 0 Medicines Fiber Lumber Perfumes Decoration Horticulture Tourism Nearly all human food Wildflowers I Biodiversity values of fungi o Ecosystem O O 0 Break down dead organic matter nutrient cycling I Only organisms that break down wood Most higher plants cannot grow without symbiotic fungi I Fungi are nonphotosynthetic but help plants absorb water and nutrients Food for many organisms I Pygmy parrots Many symbioses Pathogens I Partly responsible for recent amphibian declines extinctions 0 Instrumental 0 0 Make croplands more fertile Human food I Bread wine soy sauce beer cheese I Mushrooms 0 Major decay agents 0 Penicillin other antibiotics o Hallucinogens I LSD I Psilocybin amanitas o Toxic species 0 Many species diseasecausing I Most plant diseases I Biodiversity values of lichens o Lichens are a symbiosis between fungi and algae o Ecosystem 0 Main food of reindeer Used by many birds to camouflage nests 0 Significant role in ecological succession 0 Soil integrity 0 Rock breakdown soil formation 0 Nitrogen fixation in partnership with cyanobacteria 0 Instrumental 0 Sensitive air pollution indicators absent from urban areas 0 Emergency food 0 Animaliamulticellular I Biodiversity value of sponges Porifera o Ecosystem 0 Dominant in past I Reefforming 0 Many symbionts I Symbiosis with photosynthesizers 0 Calcium cycling boring sponges 0 Instrumental 0 Boring sponges I Pest of cultured oysters 0 Bath sponges I Harvested or grown 0 Use and potential as pharmaceuticals I Biodiversity values of corals jellyfish sea anemones Cnidaria o Ecosystem 0 Main architects and life forces of reef ecosystems 0 Important producers prey predators symbionts 0 Provide habitat protection 0 Instrumental 0 Some stinging treacherous to walk on o Aquarium trade 0 Major tourist draw I Scuba diving snorkeling o Other I Reefs highly imperiled I Biodiversity value of worms Rotifera o Ecosystem 0 Important predators and prey o Earthworm soil aeration nutrient cycling 0 Important parasites on wildlife 0 Instrumental 0 Aquarium trade featherdusters flatworms Horticulture Bait for fishing Food for aquarium zoo creatures Medicinal leeches 0000 Many parasites on humans and livestock I Schistosomaisis 1 million deathsyear I Biodiversity values of mollusks Mollusca o Ecosystem 0 Major prey and predators I Some birds are snail specialists I Can form habitat mussels 0 Home for hermit crabs 0 Instrumental 0 Food I Clams oysters scallops mussels I Squid octopi I Abalone escargot Pearls O Venomous O I Cones blueringed octopus o Woodboring I quotshipwormsquot o Invasivespecies I Zebra mussel o Aquaria I Giantclams I Snails o Shellcollectors o Biodiversity of arthropods I Ecosystem Most successful abundant animal group on earth Main food for many other organisms and each other Important predators Main reason plants evolved chemical defenses Disease vectors Decomposers Many symbionts coevolved relationships 0 Honeyguide o Shorebird migration and horseshoe crabs I Instrumental Spread diseases Human food Crop pests Pollinators Honey Structural goods damage Pests Poisonous Aquarium trade Butterflies Insect collectors o Biodiversity value of Nematoda I Ecosystem Live everywhere Extremely abundant Decom posers I Instrumental I Other Diseasecausing Major crop pests Major research organism o Biodiversity values of Echinoderms I Ecosystem Marine environment only Many symbionts Important grazers prey predators Major components of limestone Majors components of coral reefs abyss Coral predators o Crownof thorns starfish I Instrumental Human food 0 Sea cucumbers bechedemer 0 Sea urchins sushi roe Aquaria Obvious popular in tide pools dives Curio trade Some poisonous o Biodiversity of Chordata Tunicates I Ecosystem Major filter feeders Some in zooplankton Many symbionts 0 Including photosynthetic algae I Instrumental Human food Aquaria Fouling of ships and docks Invasives o Biodiversity values of sharks and rays I Ecosystem Many are top marine predators I Instrumental I Other Entertainment Risk to swimmers Aquaria Fisheriescommercial sport tournaments o Bycatch in trawler nets 0 Sharksfin soup 100 million sharksyear 0 Pet food fishburgers o Sharkliver oil Squalene cosmetics drugs Medicinal Many of conservation concern 0 Low population recovery capabilities o Biodiversity values of sturgeons and paddlefish I Instrumental Fisheriesmajor Caviar I Other 0 Isinglassgelatin from swim bladder used in white wines glue are restoration Most are highly endangered Intensive conservation efforts 0 Biodiversity values of fishes I Ecosystem Important or sole food for many other organisms Key species in many food chains Many symbionts one parasite I Instrumental Some poisonous o Rockfish lionfish dinoflagellate poisoning o Fugu Piranha Candiru Ecotourismdiving Billions to world fisheries Main target of sport fishing Main aquarium subjects Large numbers of endangered species due to overfishing invasive species habitat destruction etc o Biodiversity values of amphibians I Ecosystem Important predators and prey I Instrumental Pharmaceuticals Often have toxic skin Human food Pet trade Invasives o Biodiversity values of Reptilia I Ecosystem Important predators and prey especially in deserts I Instrumental Crocodile meat skin Some dangerous to humans Turtle eggs meat Chinese market Pet trade Curio trade sea turtles Leather 0 Conservation biology Invasive species brown tree snake Snake charmers o The biodiversity crisis I Human activities changing ecosystems at an increasing rate Nearly every natural ecosystem on planet altered by humans Some have completely disappeared Many reduced to tiny fragments Many degraded to point of loss of ecosystem function I Are we responsible for the crisis 0 What is conservation biology Loss of biodiversity and ecosystems is arguably our most serious and urgent problem 0 Caused by human activities Overexploitation Invasive species Pollution Global climate change Habitat destruction and alteration Overpopulation and rising standards of living We are causing a mass extinction at least equal to that of the Cretaceous I Applied scientific discipline with aim of preserving earth s biodiversity Supported by and integrated with other scientific fields I Aimed at preserving ecosystems rather than just economically important species I Normative Not neutral with respect to biodiversity preservation 0 Conservation biologists believe that preservation of biodiversity is good and loss is bad 0 Three basic principles of conservation biology I The process of evolution unites all units of biology To effectively protectI 39 39 39 processes need to 39 y I The ecological world is dynamic I Humans are part of ecosystems 0 Why should we worry about extinctions I Instrumental values I Ecosystem values I Aesthetic pleasure From interacting with other species 0 From observing other species 0 Just knowing they exist I With extinction we lose opportunity for study and understanding of ecological communities and ecosystems 0 Cannot replace what once existed I Intrinsic value of species 0 Early human impacts I North America 20000 years ago 0 Bison camels horses mammoths giant ground sloths 0 Gone within a few thousand years I Australia 40000 years ago 0 13 genera of large marsupials 1 of giant lizards one giant bird 0 1315 extinct by 18000 I Madagascar 2000 years ago 0 All species over 10 kg disappeared o All were nonforest species 0 Current threats I Overexploitation o Overhunting o Overfishing o 90 of valuable fish gone 0 Habitat destruction 0 Pet trade I Illegal hunting and poaching 0 Illegal trade of wildlife 0 45 billionyear 3rd largest illegal smuggling activity in US 0 23 die in transit o 622 species face extinction due to illegal trade 0 Armed poaching highly profitable 0 Pirate fishing vessels 0 Ghost nets I Humanwildlife conflict 0 Major concern for large carnivore conservation 0 O O Cattle and pet predation Human casualty Fear of carnivores 0 Major concern for elephant conservation 0 0 Crop and house damage Human casualty o Crocodiles o Cattle predation 0 Human casualty 0 Fear of crocodiles Snakes 0 Fear of snake human casualty Small carnivores 0 Poultry predation Exotic invasive species Exotic species introduced to new areas either purposefully or accidentally by humans 0 Lack natural predators parasites pathogens and competitors I Take over habitats from eat or parasitize native species Pollution Serious problem in wetlands ocean industrial areas cities 0 Uncontrolled increase in developing countries 0 Most still caused by develop countries 0 Oil spills etc Global warming 0 Climate change predicted to cause worst environmental disaster Habitat destruction Logging Burning Dams Dredging Trawling Plowing Suburban sprawl Habitat fragmentation Reduces habitats to size that cannot support some species Reduces dispersal o Cuts off gene flow 0 Migration Causes edge effects 0 Increases tree mortality 0 Decreased biomass o Allows invasives in Population growth Overpopulation 0 Human population growth 0 Highest in developing countries 0 Growing exponentially o More encroachment of wildness areas Per capita resource use 0 Ecological footprints I Rising fast in developed countries 0 Many times greater per person than in developed countries I Some predictions Speciesarea curve predicts that given 90 loss of habitat on average 50 of the species that depend on the habitat will disappear f current loss of tropical forests continues 2 1 million rainforest species will disappear 40 of species will disappear due to global warming I How to meet these challenges Role of biological central 0 Provision ofaccurate 0 Conservation strategies I Singlespecies approach Expensive May help protect ecosystems I In situ conservation I EX situ Protected areas Reserve design 0 Size I As large as possible I Multiple midsized reservations for maximum diversity riskspreading I Small isolated reserves soon lose much biodiversity o Corridorsstepping stones I Gene flow I Migration o Buffer zone Zoos aquaria etc Complementary to conservation in natural ecosystems Sometimes only possible hope for a species Education Maintenance of viable populations Research sites 0 Restoration of degraded ecosystems I Restoration ecology Developing methods to restore natural habitats I May need to restore disturbance patterns I Wetland restoration Creating new wetlands usually fails o Stopping the invasions I Four major ways Identify characteristics predisposing species toward invasiveness and ecosystems towards invisibility Declareinspect goods Ban transfer of invasives Ballast discharge sterilizationnitrogen pumping Pull them out o Ending trade in endangered species I CITES convention on the international trade in endangered species of wild fauna and flora Most world nations are members Prohibits illegal international trade Need permits even to export scientific specimens Customs check Not properly implemented in some countries 0 Things we can do to improve the future I Reduce global warming Drive 0 Less 0 Fuel efficient vehicles 0 Car pool 0 Public transportation Use 0 Bicycle I Reduce pollution Avoid chemical pesticides or fertilizers Use biodegradable cleaning fluids Buy organic 39 Reduce resource use Food 0 Don t overeat 0 Less meat and seafood Energy 0 Light bulbs 0 Turn appliances off 0 Use dryer less cold water in washer 0 Reduce house heating and cooling 0 Insulate o Shorter showers o Smaller houses 0 Do things by hand Water 0 Landscape with dryadapted plants I Mitigate habitat loss Don t support suburban sprawl Support businesses that use good environmental practices Yards 0 Native plants 0 Small or alternative lawns Get involved in habitat restoration projects I Avoid harming wildlife and habitats Overexploitation 0 Only buy domestic pets 0 Don t by products form endangered animals Invasive species 0 Don t plant invasives 0 Control invasives on your property Mortality 0 Have cat declawed use a bell keep inside I Think globally act locally Stay informed Vote environmental Support cunseu 39 39 39 0 Support population control efforts Be innovative Speak for conservation Think before you act Be an ecotourist Biodiversity values of birds 0 Ecosystem I Important predator prey pollen seed dispersers I Can be disease vectors I Nest constructionused by other species I Indicator species I Popularity can save entire ecosystems I Carrion disposal 0 Instrumental Food Hunting Falconrya living human heritage Captivity Feather dusters feather cloaks Headdresses Bird watching ecotourism Diseases Crop pests National symbols 0 Biodiversity values of mammals o Ecosystem Main grazers predators etc Manuring Trampling tree destruction Burrowing 0 Instrumental Food Hunting Pets zoos Working animals Tourism Pests 0 Population ecology 0 Study of populations in relation to their environment Population group of individuals of one species living in the same area and time period Likely to interact interbreed Evolves in response to natural selection on heritable traits of individuals 0 How abiotic and biotic factors affect a population Density and dispersion o Boundaries 0 Natural 0 Artificial 0 Density 0 Number of individuals in defined area 0 How do we determine density I Direct counting 0 Works if big obvious slowmoving or stationary 0 Not usually practicable I Estimation 0 Individual variation 0 Markreca pture o Mistnetting 0 Point counts 0 Pitfall traps 0 Change in density I Birth 0 Any form of reproduction I Death 0 Mortality I Immigration 0 Movement into a population Emigration 0 Movement out of a population I Passenger pigeon 0 Once the world s most numerous wild bird 0 Flocked and nested in the billions 0 Shot for market target practice and local consumption 0 Last major nesting in Petoskey MI 0 Failed due to persecution o RIP 1914 0 Density independence I Birthdeath rates don t change with population density 0 Density dependence I Birth rate fallsdeath rate rises with rising density 0 Rarely the reverse 0 Life history factors may be differentially affected 0 Dispersion 0 Pattern of spacing 0 Variations in local density I Inform us about environmental associations social interactions of species I In environment patchy organisms living there will be too 0 Patterns of dispersion I Clumped 0 Individuals aggregated in patches 0 Often due to patchy environment resources 0 Most common pattern I Uniform o Evenly spaced 0 Territoriality toxins etc 0 Not very common I Random 0 Independent of other individuals 0 No strong attraction or repulsion 0 Environment uniform 0 Rare 0 Wind or current dispersed I Distribution I Size Age structure I Demographics 0 Demography study of vital statistics of population 0 Their change over time 0 Birth rates 0 Death rates 0 Life tables 0 Agespecific summaries of population survival patterns 0 Follows cohort from birth until all are dead 0 Survivorship curves 0 Plot of survivorship of cohort at each age I Type o Convex line low early mortality increases upon aging I Type II 0 Straight line constant rates of death I Type III 0 Concave line high early mortality little later mortality 0 Reproductive rates 0 Concentrate on females I Only they have offspring 0 Reproductive table fertility schedule I Agespecific summary of reproductive rates in population 0 Varies tremendously between species due to lifehistory traits I Life history 0 Traits that affect organism s schedule of reproduction and survival 0 Shaped by natural selection I Three main variables 0 Age at first reproduction 0 Frequency of reproduction 0 Number of offspring per reproductive event I Semelparity vs iteroparity 0 Single reproduction event per individual vs multiple salmon vs human 0 Has major implications for resource utilization o Tradeoffs in life history I No species can maximize all reproductive variables 0 Species constrained by time energy nutrients o Reproducing organisms more subjective to early death through predation nutrient deprivation illness etc o Tradeoffs I Species vary greatly in numbers of offspring produces o If few produced more parental investment likely 0 Higher survivorship of offspring o If many produced no parental investments likely 0 Low survivorship of offspring o Exponential vs logistic growth I If resources not limiting organisms can increase in population very rapidly o Exponential growth I In real world resources almost always limiting 0 When population reaches carrying capacity K logistic growth 0 Sigmoidal S curve 0 Leveling off 0 May temporarily overshoot I Logistic model useful for predicting population increases determining sustainable harvest sizes formulating conservation strategies 0 rrisk low resources vs Kkeep high resourcesselection I Logistic model predicts different growth rates at high or low density depending on carrying capacity 0 At high densities few resourcesindividual slow growth 0 Traits are sensitive to population density are Kselected o Densitydependent o Populations near carrying capacity K 0 At low densities abundant resourcesindividual rapid growth 0 Traits that maximize reproduction at low densities are r selected 0 Densityindependent o Populations well below carrying capacity or little competition o Densitydependent population regulation I Factors that create negative feedback to slow or stop exponential growth 0 Resource competition 0 Territoriality Disease Predation Toxic wastes Intrinsic factors 0 The human population I Very low human populations until 1650 0 Then exponential increase 0 Now over 66 billion 0 6 billion by 1999 o 7 billion by 2012 0 Rate of growth is slowing 0 Much more rapid growth in most thirdworld countries 0 Population disproportionately young in 3rd world countries I Global human carrying capacity 0 Not yet established 0 Depends on ecological footprint 0 Depends on how much else we sacrifice 0 Best course education and choice leading to zero or negative population growth 0 Global warming and climate changes 0 Global warming I Increase in average temperature of nearsurface air and oceans I Observed over last several decades 0 Each of last 10 years is one of the 11 warmest years on record 0 2008 slightly cooler due to La Nina 0 Current changed cooling Pacific 0 Projected to increase in near future I What s happening 0 Fossil fuels are burned the carbon they contain combines with oxygen producing C02 0 Societies for last 150 years have been using accelerating amounts of fossil fuels 0 No one thought harmful 0 Thought atmosphere limitless 0 CO2 transmits sun s energy but traps heat 0 Causes greenhouse effect I Essential for life on earth I Otherwise average temperature would be 20 degrees Celsius I Fingerprints of climate change Highest average temperatures on record in last few years Permafrost thawing Glacier retreat Opening of northern sea route Sealevel rise 0 Beach loss 0 Marsh mangrove loss Ocean warming Atmosphere shifting 300m higher I Harbingers of climate change Migratory birds arriving earlier leaving later appearing farther north Coral bleaching throughout tropics Malaria and other lowland diseases moving up mountains Driestwettest seasons on record More fires storms Increasingly acid oceans by 30 in 250 yrs I Some predictions Massive displacements of humans Extinction of some island nations Increased arable land in far north 1835 extinction of plant and animal species by 2050 Water disputes I Examples Grizzly bears in Yellowstone 0 Important grizzly bear food is white bark pine nut o Naturally occurs at high elevations too high for pests I Since 2000 warming temperatures have enabled mountain pine beetles to survive at higher elevations o Beetles now devastating white bark pine forests also nut crop o Beetles have to kill the tree to reproduce I Grizzlies will probably have to forage around people 0 Will lead many to be shot Polar bears in the arctic 0 Live mainly on sea ice I Swim between ice floes I Feed on seals that haul out on or use breathing holes in Ice 0 Reproductive rates and weight have recently declined significantly 0 Several drowned bears found 0 Planet Earth male filmed swimming long icefree distances then attacking adult walruses and being killed 0 Arctic warming fastest o Walruses 0 Lots of walrus calves found abandoned by mothers 0 Walruses resting on rocky shores instead of ice shelves 0 Herds turning up in new places 0 Opening of Northwest Passage 0 For first time in human memory ships could pass without icebreaker in August 2007 o Harp seals 0 Normally born in spring on ice floes I Cannot swim o C 300000 usually killed for fur o In 2007 lack of ice led to disappearance of all pups in Gulf of St Lawrence I Hunt suspended I In 2002 5 ofall pups drowned I 5 h bad ice year of last 7 o Penguins 0 Emperor penguins I Population halved in 50 years I Require fast ice for breeding 0 Total failure in one colony ice broken up 0 At another ice broke up early so chicks drowned o Adelie penguins I Breeding failed locally 0 Fast ice due to calm waters forced them to walk 90 hrs each way between sea and nests I Abandoning Antarctic Peninsular northernmost colonies o Chinstrap penguins moving in 0 Sub Antarctic prince Edward island polar front where warmer and cold waters meet and food is abundant shifting southward I Major population declines in penguins o Antarctic penguins thermally stressed in mid30 s I Cannot leave eggschicks to cool off 0 Can only pant eat snow I Snowmelt can drown eggs 0 Longer melt seasons I 917 days per decade 0 Lowest in sea ice covered areas 0 Highest in north America I What this means 0 Shorter ice growth season 0 Thinner sea ice 0 Less extensive summer sea ice cover I Change in number of days of snow covered ground 0 Overall trend is 612 fewer days I Arctic temperature trends 0 Overall trend in high northern latitudes is 12 degrees Celsius warmer I Glacier retreat 0 Mountain glaciers disappearing worldwide 0 Serious threat to water supplies 0 Exacerbating the effects of global warming I As ice melts pollutants concentrate o Soot absorbs more of sun s energy and heat than the ice or snow 0 Causes faster melting 0 Loss of ice cover decreases reflectance 0 Causes faster melting faster warming 0 Melting permafrost I 14 of world s carbon stored in permafrost 0 Now thawing decomposing I Billions of tons of methane o 20x more potent greenhouse gas than C02 I Tipping point reached 0 Related issues in climate change 0 Global dimming I Gradual reduction in irradiance at earth s surface 0 4 per decade since 1950s to 1990s 0 Trend reversed past decade I Creates cooling effect 0 Masked global warming I Due to aerosol particles 0 Mainly of human origin and volcanic Declining levels worldwide
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