MIDTERMS (1) PDF - General Ecology
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2024
Buenaventura, Shiloh Clarisse C.
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This document details a general ecology midterm exam, covering concepts of Darwin's evolutionary theory, Hardy-Weinberg equilibrium, natural selection and populations. It also contains an introduction to phylogeny.
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GENERAL ECOLOGY Unit II: Evolutionary Ecology Professor/Instructor: Rachelle Conmingo, MSc I. Concepts of Darwin’s Theory of Evolution II. Concepts of Evolutionary Ecology...
GENERAL ECOLOGY Unit II: Evolutionary Ecology Professor/Instructor: Rachelle Conmingo, MSc I. Concepts of Darwin’s Theory of Evolution II. Concepts of Evolutionary Ecology A. Concept 1. Phenotypic variation TABLE OF CONTENTS among individuals in a population results from the combined effects UNIT 1. Introduction to Ecology of genes and environment I. Definition of Ecology B. Concept 2. The Hardy-Weinberg II. Importance of Ecology equilibrium model helps identify III. Ecologists vs Environmentalists evolutionary forces that can IV. Hierarchy of Ecological Organization change gene frequencies in A. Biosphere populations B. Biome 1. Conditions of the C. Ecosystem Hardy-Weinberg D. Community equilibrium E. Population a) Random mating F. Individual / Species b) No mutations V. Division of Ecology c) Large population A. System Ecology size B. Theoretical Ecology d) No immigration C. Evolutionary Ecology e) All genotypes have VI. Classification of ecologists equal fitness A. Plant ecologist C. Concept 3. Natural selection is B. Animal ecologist differential survival and C. Synecology reproduction among phenotypes D. Autoecology 1. Kinds of natural selection VII. Specialized branches of Ecology a) Stabilizing selection A. Behavioral Ecology b) Directional B. Physiological Ecology selection C. Population Ecology c) Disruptive selection D. Community Ecology D. Concept 4. A large and rapidly E. Ecology of Interaction growing body of research on F. Ecosystem Ecology natural populations provides G. Landscape Ecology robust support for the theory of H. Geographical Ecology evolution by natural selection VIII. Basic Principles in Ecology E. Concept 5. Random processes, IX. Importance of Scale in Ecology such as genetic drift, can change A. Scale gene frequencies in populations, 1. Organism especially in small populations 2. Population III. Introduction to Phylogeny 3. Community A. What drives the evolution of new 4. Ecosystem organisms? 5. Biosphere 1. Diversity B. Types of Scale 2. Mutation 1. Spatial scale 3. Selection bias 2. Temporal scale B. Phylogenetics a) Instantaneous C. Phylogeny b) Successional D. Phylogenetic tree c) Evolutionary E. Why is phylogeny important? d) Geologic F. What we can and cannot learn from phylogenetic trees? G. Character Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 H. Cladistic Character State 3. Asteroids Definitions 4. Cosmic radiation 1. Plesiomorphy 5. Acid rain 2. Apomorphy 6. Disease / epidemic 3. Synapomorphy 7. Spread of invasive species 4. Autapomorphy C. Human causes of extinction I. Concepts of Monopphyly, 1. Increased human Polophyly, and Paraphyly population 1. Monophyletic 2. destruction/fragmentation 2. Paraphyletic of habitat 3. Polyphyletic 3. Pollution J. Homology and Homoplasy 4. Climate change/global K. Why can homoplasy occur? warming L. Cladistics D. The International Union for M. Using Phylogenies Conservation of Nature and 1. Biogeography Natural Resources (IUCN) 2. Coevolution 1. IUCN Conservation Status 3. Other phylogenetic System methods 2. IUCN Classification IV. Fossils and Artifacts E. Hotspots A. Fossil Localities 1. Factors affecting hotspots B. Archaeological Research F. Biodiversity C. Archaeological methods 1. Sub-surface testing and 1. Benefits of biodiversity survey 2. Causes of biodiversity loss 2. Remote sensing 3. Consequences of D. Dating methods biodiversity loss 1. Relative dating a) Faunal succession b) Palynology UNIT 1: Introduction to Ecology c) Seriation d) Relative dating Ecology methods for bones Derived from “okologie” 2. Numerical or absolute Coined by Ernst Haeckel dating a) Radiocarbon dating Refers to the relationship between the b) Potassium-argon environment to its organisms dating Also known as Environmental Biology c) Fission-track dating V. Extinction Importance of Ecology A. Causes of extinction Ecology affects social, political, and 1. Genetics and demographics economic issues 2. Habitat degradation Ecology is concerned with natural resource 3. predation management and has been involved with 4. Coextinction environmental issues for years 5. Mass extinction B. Natural causes of extinction Ecologists 1. Climatic Heating and Individuals who are involved in studying the Cooling 2. Changes in Sea Level or biological processes of an ecosystem Currents Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 Environmentalists Analysis and understanding of the structure they are individuals who are knowledgeable and function of ecosystem with applied about environmental laws and policies mathematics 2. Theoretical Ecology Hierarchy of Ecological Organization Modeling of some areas such as 1. Biosphere ○ Predation Part of the Earth where life can exist ○ Competition Zones: ○ Niche theory ○ Atmosphere ○ Diversity a mixture of gases that ○ Community structure surrounds the Earth ○ Community of ecosystem stability ○ Hydrosphere 3. Evolutionary Ecology the total amount of water on Interactions between organisms and their Earth biological and physical environment ○ Lithosphere Changes through time in the lineage of an made up of the parts of Earth organism where life exists 2. Biome Ecologists can be grouped as: Enormous regions in the lithosphere 1. Plant ecologist Can be classified by: 2. Animal ecologist ○ General soil type 3. Synecology (Community Ecology) ○ Climate Philosophical and deductive ○ Vegetation 4. Autoecology (Population Ecology) ○ Animal life Experimental and inductive 3. Ecosystem Community of living beings and the physical Specialized Branches of Ecology environment 1. Behavioral Ecology Types: How living organisms react to biotic and ○ Marine abiotic factors ○ Terrestrial 2. Physiological Ecology ○ Freshwater Evolution of physiological and anatomical 4. Community mechanisms Different species of organisms inhabiting a Law of use and disuse certain ecosystem ○ when certain organs become Biotic factors only specially developed as a result of 5. Population some environmental need, then that Group of organisms usually of the same state of development is hereditary species and can be passed on to progeny Biotic and abiotic factors 3. Population Ecology 6. Individual / Species Studies the structure and dynamics of a Each individual organism in a population population 4. Community Ecology Division of Ecology (Modern Ecology) Studies the interactions between organisms 1. System Ecology such as the feeding relationships among species ○ Food chain Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 ○ Symbiotic relationships of organisms Immigration of species declines as more 5. Ecology of Interaction species become established and fewer Focuses on the interactions and immigrants are new species relationships between species The ecosystem has historical aspects 6. Ecosystem Ecology Has a lot in common with community Importance of Scale in Ecology ecology Demonstrates the understanding of the Studies the physical and chemical factors proper functioning of the diverse ecological influencing the community communities in the ecosystem and the 7. Landscape Ecology nature of interaction among them Studies the different landscapes in a regional concept Scale 8. Geographical Ecology A metric that describes the spatial and Studies the ecological processes in the temporal dimensions of an object, pattern, biosphere or process Five scales of Ecology Basic Principles in Ecology ○ Organism The ecosystem is the major ecological unit. ○ Population To permit the cycles and flow, the ○ Community ecosystem must possess a number of ○ Ecosystem structured interrelationships among its ○ Biosphere components The function of ecosystems is related to the Ecosystem Ecology flow of energy Ecosystem The amount of energy that flows depends ○ Bounded ecological system upon the producers (a plant or algae that consisting of all the organisms in an can produce food for itself using the energy area and the physical environment from the sun or chemicals found in the with which they interact ocean) ○ “An energy-driven complex of a Ecosystems tend toward maturity community of organisms and its ○ Early stage - high energy flow controlling environment” (Billings, Population is the major functional unit of the 1978) ecosystem Energy A niche within a given ecosystem cannot be ○ Central theme in the ecosystem simultaneously and indefinitely occupied by concept a self-maintaining population of more than one species Types of Scale Both the environment and the amount of 1. Spatial Scale energy in an ecosystem is limited Distribution in space Changes and fluctuations in the At what spatial scale are ecosystems environment represent selective pressures defined? upon the environment Net Primary Productivity Species diversity is related to its physical ○ Productivity environment Rate at which energy is added to the bodies of Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 organisms in the form of biomass 2. Temporal Scale ○ Biomass Distribution in time Amount of matter that’s Shift from viewing ecosystems as static stored in the bodies of a (equilibrium) to dynamic (nonequilibrium) group of organisms Unbalanced inputs / outputs ○ Gross primary productivity (GPP) Human activities affect the temporal scale Rate at which solar energy is Kinds: captured in sugar molecules ○ Instantaneous (seconds) during photosynthesis ○ Successional (10 to 100s years) (energy captured per unit ○ Evolutionary (100s to 1000s years) area per unit time) ○ Geologic (1000s to 1,000,000 years) ○ Net primary productivity (NPP) Gross primary productivity UNIT II: Evolutionary Ecology minus the rate of energy loss to metabolism and Charles Darwin maintenance Darwin noted that the unique creatures on the Galapagos Islands were similar from island to island, but perfectly adapted to their environments Darwin proposed that the characteristics Forest stand producing an advantage would be ○ Community of trees uniform in “preserved” and the unfavorable composition, structure, age, size, characteristics of other individuals would be class, distribution, spatial “destroyed” arrangement, condition, or location As a consequence of the process of to distinguish it from other forest selection by the environment, populations stands would change over time He worked for nearly half a century to Forest Stand Developmental stages and uncover the laws of inheritance. However, recovery phases he was not able to do so because it required a facility with mathematics that he had not Disturbance developed Developmental Recovery phases stages Adaptation Evolutionary process that changes the Stand initiation Establishment and anatomy, physiology, behavior of organisms, stage regeneration phase resulting in an improved ability of the Stem exclusion Young forest members of a population to live in a stage regrowth phase particular environment Canopy transition Mature and canopy Concepts of Darwin’s Theory of Evolution stage transition phase 1. Organisms beget like organisms Gap dynamics Old-growth phase a. Offspring behave like their parents stage Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 2. There are chance variations between Arose from the synthesis of the theory of individuals in a species natural selection and genetics a. Some variations can be inherited and passed to the next generation Concepts of Evolutionary Ecology 3. More offspring are produced each Concept 1. Phenotypic variation among individuals generation than can be supported by the in a population results from the combined effects of environment genes and environment 4. Some individuals, because of their physical Phenotypic plasticity or behavioral traits, have a higher chance of ○ the ability of an organism to change surviving and reproducing than other in response to stimuli or inputs from individuals in the same population the environment Theory of natural selection Concept 2. The Hardy-Weinberg equilibrium model Depended upon the passage of helps identify evolutionary forces that can change “advantageous” characteristics from one gene frequencies in populations generation to the next Mendel demonstrated mathematically that if self-fertilization was the only form of Gregor Johann Mendel fertilization in a population consisting of Able to uncover the basic mechanisms of three genotypes: inheritance that Darwin sought ○ AA (homozygous dominant) Father of Genetics ○ Aa (heterozygous) Most famous and influential work: ○ Aa (homozygous recessive) experiment on garden pea (Pisum sativum) are present in a ratio of 1AA:2Aa:1aa, the Alleles frequency of homozygous recessive (aa), ○ Alternative variations of genes and homozygous dominant (AA) individuals ○ Can be dominant or recessive would increase in the population Hardy-Weinberg equilibrium model ○ a principle stating that the genetic Sumamry of Mendel’s Pea Experiment variation in a population will remain Dominant Recessive constant from one generation to the next in the absence of disturbing Flower color purple white factors Plant height tall short Conditions of the Hardy-Weinberg equilibrium Seed color yellow green Random mating ○ Nonrandom or preferential mating, in Seed shape round wrinkled which the probability of pairing Pod color green yellow alleles is either greater or lower than would be expected based on their Pod shape Inflated (full) Constricted frequency in the population, can (flat) change the frequency of genotypes No mutations Flower axial terminal position ○ Mutations that add new alleles to the population or change an allele from one form to another have the Evolutionary Ecology potential to change allele Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 frequencies in a population and circumstances and can produce therefore disrupt the different results Hardy-Weinberg equilibrium Kinds of natural selection Large population size ○ Stabilizing selection ○ Small population size increases the prefers the average probability that allele frequencies will phenotype over an extreme change from one generation to the phenotype next due to chance alone ○ Directional selection ○ Genetic drift prefers an extreme Change in allele frequencies phenotype over the average due to chance or random phenotype events ○ Disruptive selection Reduces genetic variation in prefers two or more extreme populations over time by phenotypes than the average increasing the frequency of phenotype, which results in a some alleles and reducing diverse selection the frequency or eliminating Studies of Geospiza fortis other alleles (medium ground finch) No immigration provide one of the clearest ○ Immigration can introduce new and most complete examples alleles into a population or, because of disruptive selection in a allele frequencies are different natural population among immigrants, alter the frequency of existing alleles Concept 4. A large and rapidly growing body of All genotypes have equal fitness (equal research on natural populations provides robust survival and reproductive rates for all support for the theory of evolution by natural genotypes) selection ○ Fitness Soapberry bug populations living on native Genetic contribution of and introduced host plants have undergone individuals to future natural selection for traits that favor their generations survival and reproduction on particular host ○ If different genotypes survive and plant species reproduce at different rates, then gene and genotype frequencies will Concept 5. Random processes, such as genetic change in populations drift, can change gene frequencies in populations, especially in small populations Concept 3. Natural selection is differential survival Genetic drift and reproduction among phenotypes ○ Theoretically most effective at Charles Darwin was one of the first to changing gene frequencies in small recognize the biological significance of populations such as those that variation among individuals in a population inhabit islands Natural selection ○ Does not take the same form Introduction to Phylogeny everywhere and at all times ○ Can act against different segments What drives the evolution of new organisms? of the population under different Diversity Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 ○ the variety of all living things and ○ A branch with more than two their interactions lineages Mutation ○ A sudden change in the DNA Dendrogram sequence of an organism a branching diagram that represents the Selection bias relationships of similarity among a group of entities Phylogenetics The study of ancestor-descendent Why is phylogeny important? relationships To understand and classify the diversity of Objective: to construct phylogenies life on Earth Study of how organisms are derived from Test evolutionary hypotheses their ancestors What we can and cannot learn from phylogenetic Phylogeny trees? A hypothesis of ancestor-descendent Phylogenetic trees show patterns of relationships descent, not phenotypic similarity Possibility of what is the expected or Phylogenetic trees do not indicate when possible relationships of a lineage from species evolved or how much change another lineage occurred in a lineage Can be based on morphological, It should not be assumed that a taxon physiological, or molecular data evolved from the taxon next to it Today, phylogenies are usually constructed using DNA sequence data Character Any attribute of an organism that can Phylogenetic tree provide us with insights into history (shared Graphical summary of a phylogeny ancestry) Limitations: do not indicate the amount of In molecular phylogenies change that occurred in a lineage ○ Characters are typically nucleotide Parts of a phylogenetic tree positions in a gene sequence ○ Ancestral lineage ○ Character states: A, C, G, T ○ Branch point Where lineages diverge Cladistic Character State Definitions ○ Sister taxa Plesiomorphy Taxa that share a recent ○ Ancestral character state common ancestor Apomorphy Two lineages that stem from ○ Derived state the same branch point ○ Different than the ancestral state ○ Basal taxon Synapomorphy A lineage that evolved early ○ A derived character state that is from the root and remains shared by two or more taxa due to unbranched inheritance from a common ancestor Polytomy ○ These character states are ○ A branch point in a phylogenetic tree phylogenetically informative using which forms an unresolved pattern the parsimony or cladistic criterion of divergence Autapomorphy Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 ○ Uniquely derived character state Cladistics Parsimony Concepts of Monophyly, Polyphyly, and Paraphyly ○ Principle: simple explanations are Monophyletic group preferred over more complicated ○ A group that includes all of the ones descendants of a common ancestor ○ Less evolutionary steps are better ○ Also known as clades than more steps to explain Paraphyletic group relationships A group that includes some, but not ○ Minimizes the total number of all of the descendants of a common evolutionary changes required to ancestor explain relationships Polyphyletic group ○ The tree with the least number of ○ Assemblages of taxa that have been steps is the most parsimonious erroneously grouped on the basis of Cladistic taxonomy = evolutionary taxonomy homoplasious characters The use of parsimony to construct evolutionary relationships Homology and Homoplasy Goal: to only recognize monophyletic Homology groups as valid taxa ○ A character state that is shared between two DNA sequences or Outgroup taxa because of a common ancestor The group is not part of the group of interest Homoplasy (analogy) but is also not too distantly related to it ○ The shared character between two Employed in constructing phylogenies different taxa because they evolved Used to polarize the character states or independently infer change ○ Example: wings of bats and birds The character state possessed by the outgroup is defined a priori as ancestral Why can homoplasy occur? Parallel evolution Phylogenies show evolutionary relationships ○ Independent evolution of the same Taxonomy feature from the same ancestral ○ Ordered division and naming of condition organisms ○ 3 spine stickleback species pairs Binomial nomenclature have evolved independently and the ○ Two-part scientific name of a factors that contributed include: species positive assortative mating and Hierarchical classification disruptive selection ○ Domain Convergent evolution ○ Kingdom ○ Independent evolution of the same ○ Phylum feature from different ancestral ○ Class conditions ○ Order ○ Example: fins of a whale and shark ○ Family Secondary loss ○ Genus ○ Reversal to ancestral condition/ ○ Species character state Using Phylogenies Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 Biogeography Taphonomy ○ Branch of science that seeks Study of the variety of natural and explanations for why organisms are behavioral processes that led to the found in some regions, but not formation of the deposits uncovered others ○ Involves the use of phylogenies to Archaeological research test hypotheses concerning the Archaeology geographic origins of different Sub-discipline of anthropology that deals species or groups of species with the study of past human cultures Coevolution through the material traces they left behind ○ Process where evolutionary changes in the traits of one species drives Culture evolutionary changes in the traits of Encompasses all aspects of human activity: another species ○ Fine arts ○ Can involve predators and prey, ○ Popular entertainment hosts and parasites, and mutualisms ○ Everyday behavior ○ Can result in co-speciation ○ Most deeply rooted religious beliefs Contains the plans, rules, techniques, and Other Phylogenetic Methods designs for living Frequency probability methods Classification: ○ Maximum Likelihood ○ Non-material culture ○ Bayesian methods of phylogenetic Refers to intangible products inference of human society that are not preserved archaeologically Fossils and Artifacts ○ Material culture Fossils Consists of the physical ○ Traces or remains of a plant, animal, products of human society or human Artifact Archaeological sites ○ An object, tool, or item that was Places of past human activity that are made by humans preserved in the ground reflect the breadth of human endeavor Fossil Localities Some are settlements that may have been Sites or places where fossils are found occupied for a considerable time May include traces of the activities of early Feature humans ○ non-movable artifacts, such as an ○ Artifacts resulting from their behavior ancient fire hearth, a pit dug in the ○ Tool manufacture ground, or a wall ○ Discarded food remains Ecofacts ○ Remains of the early humans ○ artifactual organic and Context environmental remains Refers to a fossil or artifact’s exact position in relation to the Archaeological methods surrounding sediments and any 1. Sub-surface testing and survey associated materials This may involve digging auger holes or shovel test pits at regular intervals in the Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 survey, the soil from which is examined for Dating method that provides actual ages any traces of archaeological material Several of the most important numerical Proton magnetometer dating techniques used today are based on ○ a sensor that can detect differences radioactive decay in the soil’s magnetic field caused by buried features and artifacts Types of Absolute Dating Resistivity meter 1. Radiocarbon dating ○ used to measure the electrical based on the decay of carbon 14 ( 14C) current passing between electrodes ○ A radioactive (unstable) isotope of that are placed in the ground. carbon that eventually decays into 2. Remote sensing nitrogen perspective provided by aerial photography 2. Potassium-Argon and Fission Track Dating sometimes called “aerial archaeology” Potassium-Argon Dating ○ scientists measure the decay of a Dating Methods radioisotope of potassium, known as A. Relative Dating potassium 40 ( 40K), into an inert dating methods that determine whether one gas, argon ( 40Ar) particular fossil, artifact, fossil locality, or site Fission-Track Dating dates before or after another ○ based on the decay of a radioactive isotope of uranium (238U) that Types of Relative Dating releases energy at a regular rate 1. Faunal Succession William Smith, the father of English Extinction Geology, noticed that as rock layers were occurs when the last existing member of a exposed by the construction, distinct fossils given species dies occurred in the same relative order again and again Causes of Extinction 2. Palynology 1. Genetics and demographics Remains of plant species, which have also 2. Habitat degradation evolved over time, can be used for relative Destruction of habitat dating as well ○ Save the rainforests ○ the study of pollen grains, the minute ○ Elimination of living space male reproductive parts of plants ○ Change in habitat: rainforest to 3. Seriation pasture lands based on the assumption that any particular ○ Leads to diminishing resources: artifact, attribute, or style will appear, increases competition gradually increase in popularity until it ○ Can be caused by natural processes reaches a peak, and then progressively 3. Predation decrease Introduction of predators 4. Relative Dating Methods for Bones ○ Invasive alien species FUN Trio ○ Transported by humans either on ○ Fluorine, uranium, and nitrogen in purpose or not the fossil specimens can determine ○ Can eat other species the relative age of bones ○ Eat food sources ○ Introduce diseases B. Numerical or Absolute Dating 4. Coextinction Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 The loss of one species leads to the loss of Cosmic radiation another Acid rain Chain of extinction ○ Kills acid-intolerant species Can be caused by small impacts in the disease/epidemic beginning ○ Can wipe out entire species A predator loses its food source ○ Example: frogs with fungus disease Affected by interconnectedness in nature can kill frogs and other amphibians 5. Mass Extinction Spread of invasive species Extinction event A sharp decrease in the number of species Natural factors on Earth in a short period of time Usually occur at a slower rate and therefore Coincides with a sharp drop in speciation cause a low extinction rate (The process by which new biological species arise) Human activities There have been at least 5 mass extinction Occur at a faster rate and cause higher events in the history of Earth extinction rates ○ Ordovician-Silurian Extinction: 440 Mostly responsible for the present extinction million years ago rates Small marine organisms died out. Human Causes of Extinction ○ Devonian Extinction: 365 million Increased human population years ago destruction/fragmentation of habitat Many tropical marine species Pollution went extinct. Climate change/global warming ○ Permian-Triassic Extinction: 250 ○ John W. Williams million years ago By the end of the 21st The largest mass extinction century, large portions of the event in Earth's history which Earth’s surface may affected a range of species, experience climates not including many vertebrates. found at present and some ○ Triassic-Jurassic Extinction: 210 2nd-century climates may million years ago disappear The extinction of other suggested isolated climates vertebrate species on land such as the Peruvian Andes allowed dinosaurs to flourish. could change drastically ○ Cretaceous-tertiary Extinction: 65 enough to lead to species million Years Ago extinction The climate change might Natural Causes of Extinction also create new climates, Climatic Heating and Cooling providing new opportunities Changes in Sea Level or Currents for other species to thrive Asteroids ○ Causes complete devastation Habitat Degradation ○ Flattening and crater at or around Habitat loss and degradation affect: impact sites hundreds of miles wide ○ 86% of all threatened birds ○ Reverberations felt around the world ○ 86% of mammals Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 ○ 88% of threatened amphibians included in 6 continents excluding Antarctica The International Union for Conservation of Nature heavily distributed along shorelines and and Natural Resources (IUCN) near the equator Established in 1948, it is an international Affected by many factors: organization working in the field of nature ○ Logging conservation and sustainable use of natural ○ Agriculture resources ○ Hunting According to their studies, human-induced ○ Climate change extinctions are not necessarily a new ○ Government phenomena can be added and removed from the It is the world’s most comprehensive classification of “hotspot” by what recovery inventory of the global conservation status or lack of prevention is taking place in each of biological species area. The IUCN Red List Requirement: ○ sets upon precise criteria to evaluate ○ “The region must support at least the extinction risk of thousand of 1,500 plant species found nowhere species relevant to (in) all regions of else in the world, and it must have the world lost at least 70 percent of its original habitat.” IUCN Conservation Status System The rate of population decline Biodiversity The Geographic range the variation of taxonomic lifeforms for a Whether the species already possesses a given biome or ecosystem small population size Boosts ecosystem productivity Whether the species is very small or lives in Measure of the health of a biological system a restricted area Benefits: Whether the results of a quantitative ○ Food and drinks analysis indicate a high probability of ○ Medicines extinction in the wild ○ Industrial materials ○ Ecological services IUCN Classification ○ Leisurely, cultural, and aesthetic 1. EX- Extinct values 2. EW- Extinct in the Wild 3. CR- Critically Endangered Causes of Biodiversity Loss 4. EN- Endangered Species Pollution 5. VU- Vulnerable Species Loss of tropical forests 6. NT- Near Threatened Spread of urban areas 7. LC- Least Concern Warfare Large dam constructions Hotspots Road building “The concept of biodiversity hotspots was Tourism penned by British ecologist Norman Myers Loss of traditional lifestyles in 1988 as a means to address the dilemma of identifying the areas most important for Consequences of Biodiversity Loss preserving species.” (National Geographic) Loss of food Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025 Decrease in biomass Collapse of food web Loss of keystone species Reduction of ecosystem efficiency and community productivity Loss of medicinal supplies Increased vulnerability of species to disease and predation Crops Monoculture of crops lets the yield become susceptible to pests or viruses 75% of crop varieties are extinct due to the spread of modern agriculture Tropical Forest Cutting Tropical forests cover 13% of Earth and is home to 50% of all known plant and animal species Food and Agriculture Organization of the United Nations (FAO) reports that 15.4 million hectares are destroyed annually Buenaventura, Shiloh Clarisse C. BIO 5: Introduction to Ecology BSBIO 2B A.Y. 2024-2025