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Levels of Biodiversity
Genetic diversity - different genes & combinations of
genes within populations
Species
Organisms that have the potential to interbreed in nature
and produce viable, fertile offspring
Population
A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.
Species diversity - number of different species represented in a
given community
Ecosystem diversity -
variation in the
ecosystems found in a
region
Which is more diverse?
A B
Which is more diverse?
A B
Which is more diverse?
A B
A B
Which is more diverse?
Which has more biodiversity?
A B
There is an estimated 8.74 million
species on the planet.
86% of all land species and 91% of all
marine species have NOT been
discovered yet.
Genetic diversity: source of variations that enablepopulations to adapt to environmental changes
Species diversity: important in maintaining structureof communities and food webs
Ecosystem diversity: provides life-sustaining servicessuch as nutrient cycling and waste decomposition
Threats to biodiversity•H•I•P•P•O
http://en.wikipedia.org/wiki/File:Lacanja_burn.JPG
Habitat Loss
Habitat loss is the greatest reason for
biodiversity loss.
Mid 1960’s Mid 1970’s Mid 1980’s
Primary Forest Secondary Forest
Invasive / Exotic Species
Introduced usually by human activities.
They are generally thought to cause
economic or environmental harm.
Are all invasive/introduced species harmful?
•Most introduced species are beneficial to society.
• Introduced species provide food, shelter, medicine, and aesthetic pleasure.
•Some organisms are introduced to control the populations of invasive species.
Pollution
Pollution (Oil spills, human agricultural waste,
fertilization, pesticides, acid deposition,
greenhouse gases, etc) caused by human activities
has a negative effect on biodiversity.
Population (Overpopulation)
•7.3 Billion and counting.
•The expansion of human population and affluence, especially in the developing world harms natural ecosystems.
Overharvesting, Overuse, Overexploitation
•Overhunting, overfishing, destructive harvesting practices (cyanide, dynamite), illegal trade, exotic pet industry
Destructive Fishing Practices
Seventy percent of each haul of
trawler fishing is considered by-
catch.
Dolphin as by-catch in drift net.