Download Chapter 5 Highlights - Orting School District

Chapter 5 Highlights
Mrs. Thompson
APES 2014
Key Ideas
• Describe biodiversity and how it is measured
• Relate biodiversity to resilience and survival
• Describe changes that lead to evolution or
extinction
• Compare and contrast different types of niche’
and why they are important to resource
partitioning
Biodiversity
• Applies to many different levels of
organization
– Genetic diversity leads to….
– Species diversity which leads to….
– Ecosystem diversity
• Biodiversity impacts a species/ecosystem’s
resilience and survival during change
• (quick forest activity)
Biodiversity
• Can measure
– Species richness (number of different species
within a given area) OR
– Species evenness (ratio of one species to another)
– Shannon’s Index represents BOTH measurements
Sources of Diversity
• Genetic Diversity—
– Mutation
– Genetic recombination (crossing over,
independent assortment, random segregation,
sexual reproduction)
– REVIEW VOCABULARY– genotype, phenotype,
genes, chromosome etc.
Sources of Diversity
• Species Diversity
Artificial selection
– selective breeding
– Genetic Engineering
– Genetically Modified
Foods (plants)
• REVIEW VOCABULARY–
fitness, adaptation,
geographic isolation,
reproductive isolation
Natural selection (5 steps)
– Overproduction
– Genetic Diversity
– Struggle to Survive
– Environmental Change
(isolation or change in
fitness)
– Differential
Reproduction
Species Diversity
• Natural Selection operates on LARGE DIVERSE
populations only…NOT
– Those with low diversity OR
– Small populations
Species Diversity
• Small populations become LESS diverse over
time
– Genetic Drift
– Bottleneck effect
– Founder effect
ALL OF THESE RESULT IN MORE HOMOGENOUS
POPULATIONS
And may result in “Extinction Vortex”
In General….
•
•
•
•
The faster the environmental change….
The less genetic diversity…
The smaller the population…
The longer it takes to mature…
THE MORE LIKELY A SPECIES WILL GO EXTINCT
Niche
• Niches partition resources to allow competing
species to survive
Types of Niche
• Fundamental Niche– ideal conditions, where it
could live
• Realized Niche– available conditions, where it
really lives
• Niche generalists– species who’s fundamental
niche is broad
• Niche specialists– species who’s fundamental
niche is narrow