Ecology and Biodiversity: definitions and levels of organization

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Ecology and Biodiversity definitions and levels
of organization

• BS 111
• Dr. Leanne Hepburn

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Course content

• Definitions, levels of organization
• Population ecology Population growth and life
  tables Population regulation
• Community Ecology Competition, predation and
  other nteractions, population mismanagement
• Behavioural ecology fixed action patterns and
  learning Sociobiology
• Ecosystem ecology Succession and zonation Energy
  flow Nutrient cycling and pollution
• Global ecology
• Organisms, light and radiation
• The atmosphere, climate and controlling factors
• Conservation Issues Conservation biology
  Conservation in estuaries

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Reading List

• Essential
• Campbell Reece (2007) Biology. Benjamin
  Cumming,8th edition
• Additional
• Begon, M. Townsend, CR Harper, JL (2006)
  Ecology from individuals to ecosystems.
  Blackwell publishing. 4th edition.
• Mackenzie, Ball Virdee (2005) Instant Notes in
  Ecology,, BIOS
• Beeby and Brennan, (2007) First Ecology
  Ecological Principles and Environmental Issues.
  Alan 2nd Edition. Oxford University Press.
• Smithson, Addison and Atkinson (2002)
  Fundamentals of the physical environment, 3rd
  edition, Routledge.

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Suggested Essential Reading from the text books

• From Campbell Reece, Biology 8th Edition.
• Chapter 51, Animal behaviour
• Chapter 52, Intro to Ecology the Biosphere
• Chapter 53, Population Ecology
• Chapter 54, Community Ecology
• Chapter 55, Ecosystems
• Chapter 56, Conservation Biology Restoration
  Ecology
• From Beeby Brennan First Ecology these
  sections of chapters are appropriate
• 2.5, 3.2, 3.5, 4.3, 5.3, 6.1, 6.2, 6.3, 6.4, 7.1,
  7.2.
• From Mackenzie et al. Instant Notes in Ecology.
• C1, C2, D1, E1, E2, E3, F1, G1, W1, W2 W3
• If you would like more detailed information on
  climate, weather and the physical environment,
  then you could see
• Smithson, Addison Atkinson, (2002) Fundamentals
  of the Physical Environment, 3rd Edition,
  Routledge. Several copies in the library, shelf
  mark GB 55.

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Learning objectives Lectures 1/2

• explain the scope of ecology and the levels of
  organization which it encompasses
• explain the significance of ecology to human
  concerns about the environment
• explain the morphological species concept
• identify the parts of the scientific name of an
  organism and write a scientific name in the
  correct form
• describe the extent of biodiversity as evidenced
  by the number of species in the major groups
• explain some of the methods used to estimate
  species richness and use the method of
  extrapolation from well studied groups to
  calculate species richness
• name the eight kingdoms, identify reasons why the
  number of kingdoms has been increased from two to
  eight and describe some of the reasons for
  thinking there could be more than eight

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What is Ecology?

• The term "ecology" was introduced by Haeckel in
  1869. His purpose was to focus attention on
  relationships, especially relationships with the
  environment, rather than on organisms and species
  
• ORGANISMS RELATIONSHIP WITH THE ENVIRONMENT
• Origin of word
• oikos the family household
• logy the study of
• Interesting parallel to economy management of
  household
• Many principles in common resource allocation,
  cost-benefit ratios

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History of Ecological Thought

• From Thoreau to modern times
• Historically has been literature-based
  appreciation of nature
• Subsequently became more of a descriptive science

Henry David Thoreau, 1817-1862
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Darwinian References

• how infinitely complex and close-fitting are
  the mutual relations of all organic beings to
  each other and to their physical conditions of
  life.
• Origin of Species

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Definition of Ecology

• Ecology is the scientific study of the processes
  regulating the distribution and abundance of
  organisms and the interactions among them, and
  the study of how these organisms in turn mediate
  the transport and transformation of energy and
  matter in the biosphere (i.e. the study of the
  design of ecosystem structure and function).
• (Jonathan Krebs, 1972)

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Cont.

• Ecology is the study of the interactions between
  organisms and their environment
• The effect of environment is both physical, (i.e.
  temperature, water) and includes influences on
  organisms by other organisms (i.e. interactions
  biotic environment competition, predation)
• The goal of ecology is to understand the
  principles of operation of natural systems and to
  predict their responses to change.

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Key Distinctions

• Ecology is a science
• Our focus in this course
• Environmentalism is a cause
• With our without scientific backing
• Conservation Biology is the integration of these
  two
• Using science to support a political cause

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Factors Influencing Organism Distribution and
Abundance

• Abiotic
• Climate
• Topography
• Latitude
• Altitude
• Biotic
• Intra-specific Interactions
• Inter-specific Interactions

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Individuals, populations, communities and
ecosystems

• 4 identifiable subdivisions of scale
• Individuals response to their environment
• Populations determinants of abundance
  populations fluctuate
• Communities mixture of populations of different
  species found within a defined area
• Ecosystems a system formed by the interaction of
  a community of organisms with their environment

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Proximate Fields

• Trends down pyramid
• Increase in geographic scale
• From single species to multiple species
• Increasing number of ecological factors that may
  be influential
• Decreasing certainty in results

Population
Community
Ecosystem
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Fields of ecology

• Behavioural ecology patterns in behaviour
• Physiological ecology consequences of
  physiology on function and behaviour
• Evolutionary ecology ecology is only
  understandable in light of evolution
• Population ecology understanding complexity
  requires models
• Community ecology interactions between species
• Molecular ecology molecular biology recently
  being used to address ecological problems

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What do ecologists investigate?

• 1. Response of individuals to their environment
• 2. Response of populations of a single species to
  the environment (e.g. abundance and fluctuations)
• 3. Composition and structure of communities (e.g.
  populations occurring within defined area)
• 4. Processes occurring within ecosystems
  (community and abiotic components of environment)

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1. Response of individuals to their environment
adaptation

• Adaptation any heritable trait (behavioural,
  morphological, physical) possessed by an organism
  which aids survival or reproduction in a
  particular environment.
• E.g. Peppered moth (Biston betularia) has
  genetically based colour differences.
• Temperate nocturnal species rests on tree
  trunks during day (avian predators pluck from
  resting place)
• Lichens cover many tree trunks but these dies out
  during industrial revolution trunks became
  blackened by soot
• Genetic darkening of species in response to
  pollutants industrial melanism

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Melanic (dark coloured) individuals became
favoured in polluted areas where lichens are
absent and tree trunks are darkened by
soot. Pale individuals dominated but died out
during industrial revolution. They have now
returned. Camouflaged from avian predators
against lichen-covered trees.
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Adaptation to the environment 2

• Fitness ability of individual to produce viable
  offspring and contribute to future generations.
• Higher fitness may be due to possession of genes
  which give advantage
• E.g. Insecticide resistance Austrailian sheep
  blowfly (Lucilia cuprina) resistant to
  organophosphate insecticide malathion by the gene
  Rmal.
• Those flies homozygous for this gene can
  tolerate a high level of malathion. Those flies
  not possessing this gene will not survive.

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Adaptation to the environment 3

• Genotype genetic composition of an individual
• Phenotype is the individual organism a product
  of the interaction between its genotype and its
  environment.
• Ability of phenotype to vary due to environmental
  influences on its genotype is known as phenotypic
  plasticity (e.g. suntan in humans)

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Adaptation to the environment 4

• Natural selection (survival of the fittest)
  the inds. in a spp. which have the highest
  fitness will contribute disproportionately to
  subsequent generation
• E.g. The fly (Drosophilia melanogaster) often
  found in association with wine production where
  they are exposed to unusually high levels of
  ethanol.
• Such populations have an elevated ethanol detox
  ability as natural selection has led to
  possession of higher levels of alcohol
  dehydrogenase (ADH) enzyme.

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Significance of ecology human concerns about
the environment

• 1960's radicalism concerns about a
  deteriorating environment along with publication
  of two influential books brought the science of
  ecology into the popular culture
• Rachael Carson - Silent Spring general public
  made aware of dangers of pollution/environmental
  degrad. She envisioned a "silent spring" - song
  birds might eventually become extinct due to use
  of pesticides  (American Bald Eagle nearly
  extinct pesticide DDT)
• 2. Paul Ehrlich - "Population Bomb" said much
  the same as Essay on the Principle of Population
  written by Malthus 200 hundred years earlier.
  Both argued the earth could  support only so many
  people and population growth should be slowed.
  Ehrlich founded the organization Zero Population
  Growth, which recently changed its name to
  Population Connection.

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Ecology and the environmental movement

• 70s anxiety about environment deepened
• BUT also changed in emphasis
• More attention on energy demands rather than pop.
  Growth like 60s
• Quality of env. Related to quality of life

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Summary

• Ecology is the study of the interactions between
  organisms and their environment
• Factors influencing organism distrib. abun.
  biotic abiotic
• Hierarchy Inds., pops. comms., ecosystems
• Fields of ecology
• Adaptation to environment heritable traits,
  fitness, genotypes, phenotypes, natural selection
• Significance of ecology human concerns about
  environment

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Biodiversity
BS 111 Ecology Biodiversity
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Learning objectives

• define biodiversity
• identify the parts of the scientific name of an
  organism and write a scientific name in the
  correct form
• describe the extent of biodiversity as evidenced
  by the number of species in the major groups
• name the eight kingdoms, identify reasons why the
  number of kingdoms has been increased from two to
  eight and describe some of the reasons for
  thinking there could be more than eight
• explain some of the methods used to estimate
  species richness

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What is Biodiversity?

• Richness diversity of life number of species
  on earth????
• Dependant for goods and services (e.g. food,
  water) ecosystem services
• Economy/lifestyles Fish stocks, timber, new food
  sources, new medicines,
• Moral/ethical/philosophical
• Aesthetic/spiritual/cultural

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BD scientific certainties uncertainties

• 2004 Sargasso Sea small sample of water found
  148 new spp. Of bacteria (normally famous for
  lack of diversity)
• Modern scientific methods changing realising
  how little we know
• Diversity increases over time then some
  catastrophe, asteroid or volcanic eruption-
  reduces it for a while
• Most famous last mass extinction????

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Why important???

• Natural env. Provides us with food, medicine,
  fuel, clothes, timber, climate regulation, water
  purification, soil regeneration, nutrient
  cycling, crop pollination FREE!!!
• Ecologists economists estimate monetary value
  of natures service to society 33 trillion per yr

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Classification

• In biology, binomial nomenclature is the formal
  system of naming species
• each species name is in (modern scientific) Latin
  and has 2 parts, sometimes called "Latin name"
  species, although scientific name is preferred
• species is the lowest rank in the system for
  classifying organisms. The seven main ranks are,
  from largest to smallest
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

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European otter Lutra lutra

• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Carnivora
• Family Mustelidae
• Subfamily Lutrinae
• Genus Lutra
• Species L. lutra

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Biological diversity The number, variety, and
genetic variation of different organisms found
within a specified geographic region.

• 1. Two Kingdoms Animalia, Plantae
• 2. 1969 Five kingdoms
• Kingdom Monera 10,000 species Unicellular and
  colonial--including the true bacteria
  (eubacteria) and cyanobacteria (blue-green
  algae).
• Eukaryotic Cells With Nuclei And Membrane-Bound
  Organelles
• Kingdom Protista 250,000 species Unicellular
  protozoans and unicellular multicellular
  (macroscopic) algae with 9 2 cilia and flagella
  (called undulipodia). 3.
• Kingdom Fungi 100,000 species Haploid and
  dikaryotic (binucleate) cells, multicellular,
  generally heterotrophic, without cilia and
  eukaryotic (9 2) flagella (undulipodia). 4.
• Kingdom Plantae 250,000 species Haplo-diploid
  life cycles, mostly autotrophic, retaining embryo
  within female sex organ on parent plant.
• Kingdom Animalia 1,000,000 species
  Multicellular animals, without cell walls and
  without photosynthetic pigments, forming diploid
  blastula
• Generally, animals then divided into Phyla and
  plants into divisions.

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• Presently 8 kingdoms or more????
• Monera split into
• Eubacteria (a large group of bacteria having
  rigid cell walls motile types have flagella 
  true bacteria)
• Archaebacteria (considered to be an ancient form
  of life that evolved separately from the bacteria
  and blue-green algae and sometimes classified as
  a kingdom).
• Protista spilt into
• Archaezoa  (proposed for 3 phyla Archaemoebae,
  Metamonada, Microsporidia, which differ from all
  other eukaryotes in lacking mitochondria,
  peroxosomes, Golgi dictyosomes and cisternae, and
  probably also in having 70S rather than 80S
  ribosomes).
• Protozoa (diverse group of eukaryotes primarily
  unicellular existing singly or aggregating into
  colonies usually non-photosynthetic)
• Chromista a further kingdom was proposed at the
  same time for the photosynthetic, but chlorophyll
  c unlike plants do not store energy as starch ,
  e.g. diatoms phylum remains controversial.

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• What is a species?
• There are several competing theories, or "species
  concepts"
• morphological species concept largely outdated
  but still widely used species are the smallest
  groups that are consistently and persistently
  distinct, and distinguishable by ordinary means.
  Or "a species is a community, or a number of
  related communities, whose distinctive
  morphological characters are, in the opinion of a
  competent systematist, sufficiently definite to
  entitle it, or them, to a specific name"
• biological species concept "a species is a group
  of interbreeding natural populations that is
  reproductively isolated from other such groups".
• phylogenetic species concept "is the smallest
  diagnosable cluster of individual organism that
  is, the cluster of organisms are identifiably
  distinct from other clusters within which there
  is a parental pattern of ancestry and descent".

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Species richness

• Species richness number of species in a
  community
• Community an association of interacting species
  inhabiting some defined area
• Species diversity number of species (richness)
  and their relative abundance (evenness)

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Estimating the number of species in communities
Both forests 5 tree species equal species
richness BUT community b more diverse than
community a because its species evenness is
higher Community b each species 20
pop. Community a 84 belong to one
species Walking through forest impression of
higher species diversity in community b despite
levels of species richness in the 2 forests
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How many species?

• This is one of the most fundamental questions an
  ecologist can ask about a community.
• However, determining this not always easy.
• Requires carefully designed, standardized
  sampling program.

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Sampling effort

• Number of species recorded in a sample of a
  community increases with higher sampling effort.
• Species richness curve
• Indicator taxa to reduce sampling effort
  required to estimate species richness
  examples????
• Standardized sampling necessary to provide a
  valid sampling basis for comparing species
  richness across communities
• Collect same number of samples from each
  community (or, for observational studies, spend
  the same amount of time observing)
• Use the same sampling methods in each study area
  (e.g. sampling devices used, way devices
  employed, time when sampling done, number of
  habitats sampled)

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Summary

• Classification/nomenclature
• What is biodiversity?
• How many kingdoms how many species????
• What is a species???
• How do we count them???
• How do we sample them?