Download Biodiversity and Evolution Review

Biodiversity and Evolution
Review
• Biodiversity includes these components:
– Functional diversity
– Ecological diversity
– Species diversity
- Genetic diversity
Functional Diversity
• The variety of processes, including matter
cycling and energy flow within ecosystems,
that result from species interacting with one
another in food webs
Ecological Diversity
• Variety of terrestrial and aquatic ecosystems
found in an area or on the earth
Species Diversity
• The number and abundance of species
present in different communities
Genetic Diversity
• The diversity that enables life on earth to
adapt and survive environmental changes
Natural Selection
• Occurs when some individuals of a population
have genetically based traits that enhance
their ability to survive and produce offspring
with the same traits.
Evolution
• A change in the genetic characteristics of a
population from one generation to another
Mutations
• Random changes in the structure or number
of DNA molecules in a cell that can be
inherited by offspring.
Evolution by Natural Selection Review
• Genes mutate, individuals are selected, and
populations evolve that are better adapted to
survive and reproduce under existing
environmental conditions.
Human Success
• Strong opposable thumbs
• Upright walking
• Complex brain
Survival of the Strongest
• Fitness – a measure of reproductive success
Geological Processes
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Volcanoes
Earthquakes
Mountains forming
Fragmentation of forests
Deforestation
Construction
Etc.
Extinction
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Entire species cease to exist
Endemic species are found in only one area
This makes them very vulnerable
Mass extinction is a significant rise in
extinction rates above the background level
• Large groups of species
Species Diversity
• Species richness – the number of different
species vs…
• Species evenness - relative abundance of
individuals within each species
• Higher the richness; the more sustainability
Ecological Niche
• The role a species plays in its ecosystem
• Don’t confuse with the species habitat
• Pattern of living
General vs. Specific
• Generalists have a broad niche
• Specialists have a narrow niche
Important Niche Roles
• Native species – thrive in a particular
ecosystem; equilibrium
• Indicator species – provide early warning signs
of damage
• Keystone species – large effect on types and
abundance of other species
• Foundation species – shape and enhance
habitats that benefit other species