MODULE b ECOLOGICAL ASPECTS Resource Book Resource Biosafety MODULE b ECOLOGICAL ASPECTS Elizabeth Hodson de Jaramillo Alessandra Sensi Oliver Brandenberg Kakoli Ghosh Andrea Sonnino Resource Book Resource Food and Agriculture Organization of the United Nations Rome, 2011 Biosafety ii LIST OF CONTRIBUTORS This module has been prepared based on the lectures and contributions of: Ervin Balazs Samuel Kiboi Department of Applied Genomics School of Biological Sciences Agricultural Research Institute of University of Nairobi the Hungarian Academy of Sciences Nairobi, Kenya Martonvásár, Hungary Ednah Kunjeku Oliver Brandenberg Department of Plant Production Research and Extension Branch University of Venda Food and Agriculture Organization of Thohoyandou, South Africa the United Nations (FAO) Rome, Italy Alessandra Sensi (present address: Research and Extension Branch Institute of Medical Virology, Food and Agriculture Organization of University of Zürich, the United Nations (FAO) Zürich, Switzerland) Rome, Italy (present address: Kakoli Ghosh EuropeAid Co-operation Office, Unit A.3 Plant Protection and Production Division Centralised Operations for Europe, Food and Agriculture Organization of the Mediterranean and the Middle East the United Nations (FAO) Brussels, Belgium) Rome, Italy Andrea Sonnino Elizabeth Hodson de Jaramillo Research and Extension Branch Departamento de Biología Food and Agriculture Organization of Pontificia Universidad Javeriana the United Nations (FAO) Bogotá, Colombia Rome, Italy iii CONTEnts b MODULE LIST OF CONTRIBUTORS iii LIST OF ABBREVIATIONS vi CHAPTER 1 INTRODUCTION TO ECOLOGY: BASIC CONCEPTS - DEFINITIONS 1 1.1 What is ECOLOGY? 1 1.2 OrganizatiON OF LIFE: HIERARCHY OF INTEractiONS – LEVELS OF ECOLOgicaL OrganizatiON 3 CHAPTER 2 BIODIVERSITY: GENETICS, SPECIES AND ECOSYSTEMS 10 2.1 BIODIVERSITY 10 2.2 VALUES OF BIODIVERSITY 11 2.3 EcOSYSTEM, SPECIES, AND GENEtic DIVERSITY 12 2.4 PROBLEMS AND THREats TO BIODIVERSITY 14 2.5 COMMITMEnts AND OPPORTUNITIES 17 CHAPTER 3 EVOLUTION AND SPECIATION 18 3.1 THE DEVELOPMENT OF EVOLUTIONARY THEORY 18 3.2 GENEtic basis OF THE EVOLUTIONARY MEchanisMS 20 3.3 SPEciatiON 24 3.4 EXTINCTION 27 CHAPTER 4 AGRICULTURAL ECOLOGY – CENTRES OF ORIGIN/DIVERSITY 28 4.1 DOMEsticatiON OF SPECIES 29 4.2 CENTRES OF Origin AND DIVErsificatiON 30 4.3 AGRO-ECOSYSTEM charactEristics 34 4.4 AGRO-ECOSYSTEM pattERNS AND PROCESSES 35 4.5 SUstainabLE agricULTURE 36 4.6 AgricULTURAL BIODIVERSITY 38 iv CHAPTER 5 CONSERVATION OF GENETIC RESOURCES 40 5.1 GENEtic RESOURCES FOR FOOD AND agricULTURE 40 5.2 CONSErvatiON AND RESTOratiON 42 5.3 IN SITU AND EX SITU CONSErvatiON OF PLANT GENEtic RESOURCES 43 5.4 BIOTECHNOLOGY FOR charactErizatiON, CONSErvatiON AND sUstainabLE USE OF BIODIVERSITY 46 5.5 BIOTECHNOLOGY, BIODIVERSITY AND SUstainabLE agricULTURE 48 CHAPTER 6 GENE FLOW 50 6.1 VErticaL GENE TRANSFER 51 6.2 HORIZOntaL GENE TRANSFER 54 6.3 MEchanisMS AND EFFEcts OF HORIZOntaL anD VErticaL GENE TRANSFER 54 6.4 EvaLUatiON OF GENE TRANSFER 57 CHAPTER 7 ECOLOGY OF GM CROPS – ENVIRONMENTAL EFFECTS 61 7.1 CONCERNS AND POTENTIAL risks OF GMOs TO THE ENVIRONMENT 65 7.2 POTENTIAL BENEfits OF GMOs 72 REFERENCES 76 USEFUL READINGS 78 v MODULE ECOLOGICAL ASPECTS Resource Book Resource b iosafety B LIST OF ABBREVIATIONS AUIAB & NC All-Union Institute of Applied Botany and New Crops Bt Bacillus thuringiensis DNA deoxyribonucleic acid FAO Food and Agriculture Organization of the United Nations GIS Geographical Information System GM genetically modified GMOs genetically modified organisms GURT genetic use restriction technology HGT horizontal gene transfer IUCN International Union for Conservation of Nature MAS marker assisted selection NRC-CEI National Reseach Council-Committee on Environmental Impacts PGR plant genetic resources QTL quantitative trait loci UNCED United Nations Conference on Environment and Development VGT vertical gene transfer vi CHAPTER 1 INTRODUCTION TO ECOLOGY: BASIC CONCEPTS AND DEFINITIONS 1.1 WHAT IS ECOLOGY? The word ecology, coined in 1866 by the German biologist Ernst Haeckel, derives ECOLOGY The systematic from the Greek word “oikos” meaning “house” or “dwelling”, and logos meaning study of the “science” or “study”. Thus, ecology is the “study of the household of nature”, distribution and namely the systematic study of the distribution and abundance of living organisms abundance of living organisms and their - plants, animals, micro-organisms - and their interactions with one another interactions with and with their natural environment. The environment consists of both a living one another and with their natural component, the biotic environment (organisms) and a non-living component, the environment. abiotic environment, including physical factors such as temperature, sunlight, soil, rainfall, wind, and marine streams (Begon et al., 2006). BIOTIC ENVIRONMENT All living Few fields of study are more relevant to the human society and condition than the components of field in ecology. The increasing globalization of our economy and the resulting the environment. changes in social and political structures have a strong impact on our environment. One example is the both intentional and accidental dispersal of organisms, including ABIOTIC pests and diseases, to all corners of the earth – ecological globalization on a grand ENVIRONMENT All non-living scale. Generally, all activities of the human population affect the natural systems. environmental Ecology, today, investigates several aspects and concerns: factors, e.g. temperature, » Interactions between organisms and the environment; rainfall, wind, » How to understand, conserve, restore and sustainably use biodiversity; insolation etc. 1 MODULE ECOLOGICAL ASPECTS Resource Book Resource b iosafety B » Impact of foreign species in ecosystems; » Strategies for management, mitigation and reduction of impacts caused by human activity. Critical considerations for ecological studies are that the natural world is diverse, complex and interconnected; that it is dynamic but at the same time stable and self-replenishing; that it is controlled by physical and biological processes, and that the order of nature is affected by human activity. Life depends upon the abiotic, physical world, and vice versa affects it. Each organism continually exchanges materials and energy with the physical environment. Organisms interact with one another, directly or indirectly, through feeding relationships or trophic interactions. Trophic interactions involve biochemical transformations of energy and the transfer of energy from one individual to the next through the process of consumption. Materials move within ecosystems, and the pathways of such movements are closely associated with the flow of energy (Purves et al., 2004). The flow of energy and its transfer efficiency characterize certain aspects of an ecosystem: the number of trophic levels, the relative importance of detritus, herbivore and predatory feeding, the steady-state values for biomass and accumulated detritus, and the turnover rates of organic matter in the community. Unlike energy, nutrients are retained within the ecosystem and are cycled between its abiotic and biotic components. BIOGEOCHEMICAL Human activities modify or disrupt the global biogeochemical cycles and create CYCLES cycles of synthetic chemicals, such as pesticides. These changes can be large enough The cycles by which an element to cause serious environmental problems. However, ecosystems have the capacity or molecule moves to recover from many disturbances if the alterations have not been too large and through the biotic and abiotic the disturbing forces are reduced or eliminated. Controlling our manipulations compartments of biogeochemical cycles so that ecosystems can continue to provide the goods of Earth. Also referred to as and services upon which humanity depends is one of the major challenges facing nutrient cycles. modern societies (Purves et al., 2004). 2 R E INTRODUCTION TO ECOLOGY: BASIC CONCEPTS AND DEFINITIONS 1 CHAPT 1.2 ORGANIZATION OF LIFE: HIERARCHY OF INTERActions – LEVELS OF ECOLOGICAL ORGANIZATION Below, in Table 1, are the most important terms and definitions listed that are employed in ecological sciences: Table 1.1 | Terms and definitions in Ecology Individual An individual is a single organism inhabiting the environment as an isolated entity or as a member of a social group. Species Is the basic unit of classification of closely related organisms that have a SPECIES high level of genetic similarity, are capable of interbreeding producing fertile A group of offspring, and are reproductively isolated from other groups of organisms. organisms capable This definition works well with animals. However, in some plant species fertile of interbreeding crossings can take place among related species. producing fertile Population A population is a group of individuals of the same species living in a particular offspring, and area. Populations are characterized by several parameters, such as abundance reproductively and distribution of their member organisms. The amount of resources available, isolated from diseases, competition for the limited resources, predation, birth and death other groups of rates, immigration and emigration affect the size of a population. Populations organisms. show characteristic age structures and age distributions. They are also characterized by an intrinsic rate of increase, the biotic potential. Populations do not show unlimited growth, they are limited by the carrying capacity of their