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Lecture

Conservation Biology - 3. Global Diversity


Department
Biology
Course Code
BIOL 3130
Professor
Andrew Mac Dougall

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Conservation Biology: Lecture Notes
3. Global Biodiversity
Biodiversity crisis: We’re in an age of increased species loss and increased risk of
extinction
Global biodiversity: a termed coined by E.D Wilson popularized in 1988
I. Defining Biodiversity:
Can be confusing
“The sum total of all living things”
Needed: a precise quantitative measure
Currently: “a bewildering array of diversity indices” (Magurran1988)
oRichness: measure of # of species in a given area
oAbundance : the number of individuals in each species
oDominance : species with most competitive advantage, impacts
relevant/irrelevant
oEvenness : a numerical scale
“A comprehensive approach to biodiversity conservation must address multiple levels
of biological organization and many different spatial and temporal scales”
A true measure of diversity is quantifying the number of species in a given area as well
as their relative abundance (some are common and some are rare).
Biodiversity is hierarchical
oGenes, populations, communities, ecosystems
oShort-and long-time intervals
oLocal and regional
oHuman diversity (language, land use…)
Genetic Diversity
oAllelic diversity of genes.
oPossible combinations are enormous.
oVariability as the source for speciation.
oVariability as the source for future changes.
oNew techniques = new era for genetic studies of biodiversity
Population-level Diversity
oA group of individuals of a species living in an area at the same time.
oVariability as the source for speciation.
oVariability as the source for future changes.
Diversity of Species
oSpecies: A group of actually or potentially inter-breeding natural populations
that are reproductively isolated from other such groups
o2 million cataloged species…10-50 million in total.

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oPhylogenies: descent-histories of a group of species from a common ancestor.
Cultural Diversity
o“Culture”: unique solutions and perspectives on the challenges of making a
living and coexisting.
oDifferent cultures = different impacts…?
o6526 languages
o50% at risk within the “ethnosphere
Composition : the genes, species, and habitats found at a time and place.
Structure : the vertical and horizontal arrangement of physical space (snags, riffles, litter
layers, canopy height)
Function : the processes that affect (and are affected by) biodiversity (biochemical
cycling, invasion, natural selection)
Canada’s Biodiversity Strategy
oDerived from the Rio Convention (1992)
oObjectives
- The conservation of biodiversity;
- The sustainable use of biological resources;
- The fair and equitable sharing of benefits arising from the use of genetic
resources.
oCanada possesses 20 percent of the planet's wilderness, 24 percent of its
wetlands, 20 percent of its freshwater and 10 percent of its forests.–a national
strategy for implementing the Convention (1995).
oHow’re we doing???
- SARA, many provincial acts
- Research funding
- Sustainability?
II. Inventory
How many species are there?
oMuch of the earth’s biodiversity is unexplored
o300 new species are classified every day
Carolus Linnaeus (1700s)
oBiological classification system
oEach species has two names: genus and species (ex camassia quamash)
DNA barcoding:
oUses a short genetic marker in an organism's mitochondrial DNA to identify
relatedness among species.
oMitochondrial DNA has a relatively fast mutation rate.
Species sampling issues:
oFocusing on individual species is not efficient for conservation
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oCommon species are often sampled more often than rare species (sampling bias)
oParticular locations may be isolated (and may contain rare species), limiting
possible sampling range
oDiversity hotspots indicate greater sampling effort (i.e. around towns)
oAreas lacking data may have not been surveyed
Alternatives:
A. Higher-order taxonomic targets
1. Higher levels more evolutionarily distinct, species are almost genetically identical.
2. Evolutionary lineages provide a history of life’s origins and development (e.g.,
phylogenetic trees).
3. Preserving distinctiveness can help preserve function (variety as the spice of life.)
B. Community and Ecosystem Classification
oOld emphasis on species
oNew emphasis on species aggregations
oAssumption: captures multiple species, and the processes that maintain them,
conservation efforts should be broad and not specific
- An underlying assumption of modern day conservation biology, but what are
those processes? What mechanisms create, maintain, and explain the loss of
species diversity?
oMade possible by satellites and computers
- Geographical information Systems (GIS), Landsat photos, Sub-meter GPS
mapping
III. Timelines of Diversification
The balance between speciation and extinction.
Species loss may have never occurred as it is now – extinction events in the past
(meteor, volcanic eruptions etc.) compared to human induced destruction today.
Speciation
oTriggered by
- Mass extinctions (recovery = 10 million years)
- Increasing separation of land masses
- Evolution of new life forms and types of species interactions (e.g.,
angiosperms, pollinators, flight)
oSpeciation can be periodic and not continuous as seen with extinction events.
Extinctions
oVery rare: 5 times in 3 billion years
oUsually due to catastrophic volcano or meteor impact
IV. Endemism
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