Genetic diversity in a vole population
pecies diversity in a coastal redwood ecosystem
Genetic diversity in a vole population pecies diversity in a coastal redwood ecosystem 32Ecol11-1
ECOLOGY 11: BIODIVERSITY AND CONSERVATION BIOLOGY
By the end of this lecture you should be able to:
Describe three levels of biodiversity.
Explain biodiversity in terms of species richness and species diversity.
Describe the importance and benefits of biodiversity.
Outline threats to biodiversity.
Discuss conservation issues with respect to preserving biodiversity.
Text Readings: Chapter 55
VISTA quiz: Biodioversity and Conservation must be completed before class starts.
LEVELS OF BIODIVERSITY
1) Genetic Biodiversity
New material for selection
2) Species Biodiversity
You can look at the absolute number of species and the abundance of eachCommunity 1
A: 25% B: 25%
A: 80% B: 5%.
Copyright Pearson Education, Inc., publishing as Benjamin Cumminga.
Community and ecosystem diversity
across the landscape of entire region
Copyright P Pearson Education, Inc., publishing as Benjamin Cummings.
Community 1 A: 25% B: 25% C: 25% D: 25% Community 2 A: 80% B: 5%. C: 5% D: 0%. Copyright Pearson Education, Inc., publishing as Benjamin Cumminga. Community and ecosystem diversity across the landscape of entire region Copyright P Pearson Education, Inc., publishing as Benjamin Cummings. 32Ecol11-2
3) Ecosystem Biodiversity
Looking at both abiotic and biotic factors of the ecosystem
How many species?
Global pattern of diversity
Figure 55.4 a and b
Benefits of Biodiversity
- Biological processes improve abiotic environment - increase with biodiversity
- Increase in biodiversity = increase in primary production
- Helps humans learn about adaptations
- Increases the variety of food humans consume
- Helps develop medicines
- Energy (fossil fuels = extinct species)
- Ecotourism! (human enjoyment) 32Ecol11-3
Loss of species diversity – becomes a bit issue for US because humans rely on
biodiversity for food, enjoyment and knowledge
~1.5 million species are cataloged which is not even comparable to how many species
we are losing all the time
- Losing a species permanently and this isn’t specifically a bad thing as it is a
natural process however what is alarming is the RATE of extinction
100 1000 times greater than any other time in the last 550 million years!
- Estimated that 50,000 species go extinct every YEAR
- It is predicted that if we continue on this rate, at the end of this century – half the
plants and animals will have gone extinct = scary stuff
2) Endangered species
- Species that are not doing very well at all, and if conservation efforts are not
taken then these species will become extinct
- EO Wilson (famous biologists – same guy who made the island theory with birds)
started the 100 heartbeat club = conversation efforts for species that are in VERY
3) Threatened species
- Species that have decreased 50% in the last 50 years
- This includes about 20% of all freshwater fish
Domino effects, e.g. food chain disruptions
The loss of species are not just isolated happenings, everything is connected so when
one species goes, there is a large effect in the food web and many other species
NOTHING happens in “isolation” 32Ecol11-4
Why does extinction happen?
Extinction vortex – what happens if you have a small population
Remember: inbreeding is not good for the population the smaller the population
becomes genetic variability is lost therefore reduction in fitness and less go on to
survive decreasing reproduction, increase in mortality = MORE loss
Basically it’s a vortex which sucks in and is hard to get out
How small is too small?
- Depends for a large predator it needs large space therefore there are le