Review: Type I vs. Type II Error
• Null Hypothesis (H0): We do not need
1000+ acres to prevent extinction of the
spotted owl.
• Type I Error: We DO NOT need 1000+
acres, but conclude that we do.
• Type II Error: We DO need 1000+ acres, but
conclude that we don’t.
• The importance of “reversibility”.
Study Questions
• Compare and contrast preservation and
conservation.
• Distinguish conservation biology from both basic
biology and natural resource management.
• Why is the distinction between type I and II error
important in conservation biology (Hint: how is
this distinction relevant to making decisions in
spite of limited data).
What is Biodiversity?
• “The variety of living organisms considered
at all levels of organization, including the
genetic, species, and higher taxonomic
levels, and the variety of habitats and
ecosystems, as well as the processes
occurring therein.” - Meffe and Carroll
Taxonomic Organization
• Kingdom, Phylum, Class, Order, Family, Genus species
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King Philip Came Of Fairly Good Size.
Kings Play Chess On Fat Girls’ Stomachs.
Kids Picking Cacti On Fridays Get Stuck.
Kiss Pigs Carefully Or Face Grimy Smiles.
Keep Peeling Cold Onions For Good Smells.
Karen's Pups Chew On Furry Grey Squirrels.
Keep Privates Clean Or Forget Getting Sex.
Levels of Biological Organization
Genes
Individual
Population
Species
Community
Ecosystem
Biodiversity
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The “Species” in Conservation
• “Species” includes any subspecies of fish or
wildlife or plants, and any distinct
population segment of any species of
vertebrate fish or wildlife which interbreeds
when mature. – Endangered Species Act
Vertebrates
Invertebrates and Plants
Species Concepts
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Biological . . .
Evolutionary . . .
Isolation . . .
Recognition . . .
Cohesion . . .
Pluralistic . . .
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Cladistic . . .
Phenetic . . .
Morphological . . .
Typological . . .
Ecological . . .
Phylogenetic . . .
Biological Species Concept
• “Groups of actually or potentially
interbreeding populations which are
reproductively isolated from other such
groups.” – Ernst Mayr, 1963
Ring Species
D. E. Irwin, S. Bensch, T. D. Price, Nature 409, 333-337 (2001).
Too Little Sex
ASEXUAL GROUPS
Too Much Sex
SYNGAMEONS
A. R. Templeton, in Speciation and Its Consequences D. Otte, J. A. Endler, Eds. (Sinauer Associates, Sunderland, MA, 1989) pp. 3-27.
Cohesion Species Concept
Selection
ASEXUAL
Limits to
Gene Flow
BIOLOGICAL
SPECIES
CONCEPT
Selection
SYNGAMEONS
Cohesion Species Concept
A. R. Templeton, in Speciation and Its Consequences D. Otte, J. A. Endler, Eds. (Sinauer Associates, Sunderland, MA, 1989) pp. 3-27.
Concepts vs. Identification
• “What a species is,” or “Is that a species?”
Morphological Species Concept
http://www.mnh.si.edu/rc/big_images/big_birds.html
Phylogenetic Species Concept
• Phylogenetic Species Concept
– Evolutionary lineage / history
– Shared derived characters (morphological or
molecular)
• Character: Any describable trait of an organism.
• Derived: Unique
Phylogenetic Species Concept
• Hybrid Species
• Genetic Management
Evolutionary Significant Units
• A set of populations that is morphologically
and genetically distinct from other similar
populations.
• A set of populations with a distinct
evolutionary history.
The “Population” in Conservation
• IUCN
– Population is defined as the total number of
individuals of the taxon . . .
– Subpopulations are defined as geographically
or otherwise distinct groups in the population
between which there is little exchange
(typically one successful migrant individual or
gamete per year or less.
DPS’s
• “Species” includes . . . any distinct population
segment of any species of vertebrate . . .”
• Discreteness
– “It is markedly separated from other populations . . .
Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation.”
• Significance
– “The discrete population segment differs markedly
from other populations of the species in its genetic
characteristics.”
http://endangered.fws.gov/policy/pol005.html
Causes of Extinction
• Deterministic factors
(stacked deck)
– Realized growth rate is
negative.
– Deaths > Births
• Stochastic factors (bad
luck)
– Intrinsic
• genetic stochasticity
• demographic stochasticity
– Extrinsic
• environmental variation
(EV)
• catastrophe
K
Deterministic decline
to extinction
ln(N)
time
Population fluctuates
due to demographic and
genetic stochasticity
K
ln(N)
time
K
ln(N)
catastrophes
time
Population extinction
due to environmental
variation
Catastrophe
Severe and rare environmental variation
(Remember for Vortex)