lecture biodiversity
TRANSCRIPT
-
8/8/2019 Lecture Biodiversity
1/6
1
Macromolecules (e.g. DNA, proteins)
Cells
Tissues and organs
Organisms
Molecular subunits
Populations
Communities
Ecosystems
Species
Phyla
Biology is hierarchical
Atoms
Genera
Kingdoms
B i o d i v e r s
i t y
Why study biodiversity, ecology, andconservation biology?
What is biodiversity?
How do biologists organize biodiversity?
Why is biodiversity important?
What is the biodiversity crisis? How can we protect biodiversity?
Earths biodiversity Earths biodiversityBiodiversity the diversity of life on Earth
variety at all levels of biological organization
Components of biodiversity:
Genetic diversity genetic variation within populations
or species Species diversity numbers of species within an area
Diversity among higher taxa variation between genera,families, orders, etc.
Ecosystem diversity variation among ecosystems,communities, landscapes
Are different groups of organisms equally diverse?
Are different parts of the world equally diverse
-
8/8/2019 Lecture Biodiversity
2/6
2
How many species are there?
about 1.5 million species have been named
estimated to be between 5 and 30 million species on Earth
Actual biodiversity an inordinate fondnessfor beetles
How is biodiversity organized? Regions and ecosystems vary in biodiversity
Biodiversity hotspots regions with very high biodiversity mainly in the tropics , also islands , some other areas
Diverse ecosystems tropical rainforests, coral reefs, islands
Endemic species found only one place in the world, often on islands
Variation among regions and ecosystems inspecies composition and species diversity
-
8/8/2019 Lecture Biodiversity
3/6
3
Economic value resources, including food medicines and other helpful chemicals genes for better crops opportunity cost
Utilitarian value prevent erosion purify water recycle CO 2 regulate climate recycle nutrients through decomposition
collectively, ecosystem services
Psychological value direct or indirect enjoyment of nature
Intrinsic value independent of humans
Why is biodiversity important?
Humans are causing extinctions at a tremendous rate .
~100 times faster than expected without human activity
parallels or exceeds previous mass extinction events
What is the biodiversity crisis?
current rate of extinction is at least 100x background
What if extinction > speciation?
What is the biodiversity crisis?
Why is the loss of biodiversity a crisis?
economic value of biodiversity lost or threatened
ecological services lost or threatened
ecosystems more vulnerable to further degradation
Humans are causing extinctions at a tremendous rate .
~100 times faster than expected without human activity
parallels or exceeds previous mass extinction events
habitat destruction and fragmentation
What are the biggest threats to biodiversity?
-
8/8/2019 Lecture Biodiversity
4/6
4
habitat destruction and fragmentation
habitat modification
What are the biggest threats to biodiversity?
habitat destruction and fragmentation
habitat modification
introduced species
What are the biggest threats to biodiversity?
habitat destruction and fragmentation
habitat modification
introduced species
overexploitation
What are the biggest threats to biodiversity?
Human population growth exacerbates all of these threats.
habitat destruction and fragmentation
habitat modification
introduced species
overexploitation
What are the biggest threats to biodiversity?
What is the biggest terrestrial threat? marine?
-
8/8/2019 Lecture Biodiversity
5/6
5
the science of protecting and restoring biodiversity and ecological health
ecology
evolutionary biologygeneticsphysiology
basic principles goals
maintain biological diversity
and ecosystem health
What is conservation biology?
an applied science
applied to
apply ecological and evolutionary principles :
to understand biodiversity and ecosystem functioning
to understand threats to biodiversity and ecosystem health
ultimately, to protect and restore biodiversity and ecosystem health
What do conservation biologists do?
What makes a healthy ecosystem?
How can we protect and restore biodiversity and ecosystem health?
What makes a healthy ecosystem?
intact structure and function
Functional groups,e.g., pollinators:
Trophic levels:
What makes a healthy ecosystem?
intact structure and function
+
Keystone species:
-
8/8/2019 Lecture Biodiversity
6/6
6
What makes a healthy ecosystem?
intact structure and function
Nutrient cycling:
Ecosystem services,e.g., water purification:
What makes a healthy ecosystem?
intact structure and function
resiliency of ecosystems to stress
Diversity:
What makes a healthy ecosystem?
intact structure and function
resiliency of ecosystems to stress
Complexity and functional redundancy:
What is a species?
What determines whether species evolve or die?
Where does genetic variation come from?
What determines whether populations grow or crash?
How can competing species coexist?
Why do ecosystems differ in biodiversity?
How do communities and ecosystems work?
What causes extinction?
How do ecology and evolution inform conservationbiology?