What is Biodiversity? Biodiversity is: the variety of life on Earth at all its levels, from genes to ecosystems, and the ecological and evolutionary processes that sustain it Source: ©AMNH-CBC Dimensions of biodiversity Genetic component Spatial component Functional component Temporal component within individuals communities daily within populations ecosystems e.g reproductive behavior, predation, parasitism between populations between species seasonal landscapes annual ecoregions geological or evolutionary biogeographic regions Hierarchy of Biodiversity Ecological diversity Biomes Bioregions Landscapes Ecosystems Habitats Niches Population Organismal diversity Phyla Classes Orders Families Genera Species Subspecies Population Individuals Genetic diversity Population Individuals Chromosomes Genes Nucleotides Source: Yves Samyn Hierarchy of Biodiversity Elements of biodiversity form nested hierarchies Source: Yves Samyn Genetic Diversity The variation in the nucleotides, genes, chromosomes, or whole genomes of organisms Source: Human Genome Project, Department of Energy Variation in genome size Source: U.S Dept of Energy, Human Genome Project http://www.ornl.gov/hgmis A greater total number of genes might not correspond with a greater complexity in the anatomy and physiology of the organism Species Organism common name Number of genes in genome Reference Arabidopsis thaliana thale cress 25,498 Oryza sativa (indica-cultivar subgroup) Caenorhabditis elegans Indian rice 46,022-55,615 Arabidopsis Genome Initiative (2000) Yu et al (2002) nematode 19,000 Drosophila melanogaster fruit fly 13,600 Homo sapiens human ca 30,000-40,000 C elegans Sequencing Consortium (1998) Adams et al (2000) International Human Genome Sequencing Consortium (2001) Phenotypic Diversity Phenotype - the physical constitution of an organism that results from its genetic constitution (genotype) and the action of the environment on the expression of the genes Thus, phenotypic diversity refers to variation in the physical traits of the organism Domroese ©AMNH-CBC An Example of Genetic Variation Source: ©AMNH-CBC Morphological diversity within and between natural populations: An example Biomes Delimited on the basis of areas in terms of: • environmental conditions; • habitat structure • patterns of biological complexity (from Olson et al 2000) Source: Yves Samyn Biodiversity hotspot Spatial scales and diversity • Alpha-diversity – Measured locally, at a single site • Beta-diversity – Measures the uniqueness; the difference between two sites • Gamma-diversity – Measured over a large scale, same concept as alpha-diversity Adapted from: Meffe et al 2002 Ecosystem management: adaptive, community-based conservation Island Press, Washington, D.C., U.S.A Beta Diversity • The number of species unique to one region relative to another This gives a measure of the relative change in species diversity between areas Source: Harrison © AMNH Gamma Diversity • Gamma diversity is a measure of the overall diversity for all ecosystems within a large region May be considered to be “geographic-scale” species diversity Alpha, beta and gamma diversity for hypothetical species of birds (A-N) in three different ecosystems This example is based on the hypothetical example given by Meffe et al (2002: Table 6.1) Hypothetical species A B C D E F G H I J K L M N Alpha diversity Beta diversity Gamma diversity Woodland habitat X X X X X X X X X X 10 Woodland vs hedge row: Hedgerow habitat X X X X X X X Hedge row vs open field: 14 Open field habitat X X X Woodland vs open field: 13 Can gamma diversity = alpha diversity? Yes! • Consider the flowering plants of Antarctica! • a single grass species, Deschampsia antarctica, and a small cushionforming plant or pearlwort, Colobanthus quintensis • These species usually cooccur Contrast Antarctica with a landscape in Vietnam Lunde © AMNH/CBC Areas of endemism • A species is endemic to a certain region if its distribution is restricted to that region • Endemism contributes to the uniqueness and special importance of the biodiversity in particular areas • Some areas of the world have particularly high levels of endemism Endemism in Madagascar Source: Koy ©AMNH-CBC The island of Madagascar is often considered to be an area of high conservation priority in the world because the majority of species are endemic Endemism in Madagascar – 52% birds – 80% flowering plants – 95% reptiles Source: Ersts ©AMNH-CBC – 99% amphibians –100% primates Source: Frey ©AMNH-CBC Endemism in Vietnam – 6% mammals – 25% amphibians – 21% reptiles Grey-shanked Douc Pygathrix n cinerea Tilo Nadler/FZS – 18% freshwater fish – 30% vascular plants Golden Vietnamese Cypress Callitropsis vietnamensis Daniel K Harder/Arboretum at UCSC Case Study: Global biodiversity consequences of local introductions: British Government introduced the Nile perch (Lates niloticus) to Lake Victoria in 1954 Source: ©AMNH Nile perch population exploded in the 1980s; native cichlid populations then crashed Lake Victoria cichlids Source: Boulenger, G.A (1907) Zoology of Egypt: the fishes of the Nile Plate 91 Hugh Rees Limited, London Alpha vs Gamma Diversity Local Diversity (alpha) increased initially, then crashed: • Hundreds of cichlids native to the Lake Victoria • Humans introduced species, which increased the alpha biodiversity until the perch population exploded in the 1980s and decimated the cichlids Global Diversity (gamma) decreased: perhaps 200 species lost globally Acknowledgements Mac Hunter (University of Maine), Raoul Bain, Kevin Koy, Ned Horning, Ho-Ling Poon, and Armistead Booker (American Museum of Natural History) provided assistance for production of images and accompanying text This is a product of the Network of Conservation Educators and Practitioners (NCEP) http://ncep.amnh.org [...]... quintensis • These species usually cooccur Contrast Antarctica with a landscape in Vietnam Lunde © AMNH/CBC Areas of endemism • A species is endemic to a certain region if its distribution is restricted to that region • Endemism contributes to the uniqueness and special importance of the biodiversity in particular areas • Some areas of the world have particularly high levels of endemism Endemism in... interactions among species, such as: – predation, – competition, – parasitism, – mutualism • Some of these involve very close ecological and evolutionary associations between the organisms and are an important component of community and ecosystem biodiversity – consider for example plant pollinators and seed dispersers Examples of distinct communities and ecosystems • Species associated with: ripening... Population Differences 0.242 0.076 0.258 0.315 0.135 0.097 0.169 0.263 Importance of population variation Loss of isolated populations along with their unique component of genetic variation is considered by some scientists to be one of the greatest but most overlooked tragedies of the biodiversity crisis Species concepts • Morphological • Biological • Phylogenetic – Each definition of species produces a different... et al 2002 Ecosystem management: adaptive, community-based conservation Island Press, Washington, D.C., U.S.A Beta Diversity • The number of species unique to one region relative to another This gives a measure of the relative change in species diversity between areas Source: Harrison © AMNH Gamma Diversity • Gamma diversity is a measure of the overall diversity for all ecosystems within a large region... other species • may be misidentified (and hence overlooked as being a different species) Source: Bain ©AMNH-CBC Population Diversity • Variation in the quantitative and spatial characteristics between populations Proportion of total genetic variation within species due to genetic differences between geographic populations (from Avise, 1994) Group Mammals Birds Reptiles Amphibians Fishes Insects Crustaceans... relatively large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions” (WWF, 1999) Biomes Delimited on the basis of areas in terms of: • environmental conditions; • habitat structure • patterns of biological complexity (from Olson et al 2000) Source: Yves Samyn Biodiversity hotspot Spatial scales and diversity • Alpha-diversity... natural populations: Vietnam’s examples Nguyen et al 2009 A population is: • a group of individuals of the same species that share aspects of their genetics or demography more closely with each other than with other groups of individuals of that species • a more practical way of defining a population and measuring its diversity is by the space it occupies Thus a population may be defined as a group... ecosystems within a large region May be considered to be “geographic-scale” species diversity Alpha, beta and gamma diversity for hypothetical species of birds (A-N) in three different ecosystems This example is based on the hypothetical example given by Meffe et al (2002: Table 6.1) Hypothetical species A B C D E F G H I J K L M N Alpha diversity Beta diversity Gamma diversity Woodland habitat X X X... populations and species that share an environment Ecosystem Diversity • An ecosystem is a community plus the physical environment that it occupies at a given time Some examples of ecosystems – – – – – coral reefs tallgrass prairie coastal wetlands old-growth forest tropical rainforest Mangroves, Belize Source: Harrison ©AMNH Source: Brumbaugh ©AMNH-CBC Inter-species interactions underpin ecosystem... uniqueness and special importance of the biodiversity in particular areas • Some areas of the world have particularly high levels of endemism Endemism in Madagascar Source: Koy ©AMNH-CBC The island of Madagascar is often considered to be an area of high conservation priority in the world because the majority of species are endemic