Extinction Fossil record shows evidence of
extinction as a natural process:
Background extinction: loss of
species at a relatively low rate, often
due to changes in local conditions;
Mass extinction: abrupt increases in
extinction rates. Mass extinctions
believed to result from global climate
changes (e.g. meteorite impacts etc.);
Five mass extinctions during past
500 million years, last one ____ million
years ago.
•Species are becoming extinct ___________ times
faster than they were before modern times.
•By the end of this century, the extinction rate is
expected to be 10,000 times the background rate.
•Conservative estimates of extinction = 0.01-1.0%
Growth of human population will increase this loss
E.O. Wilson estimates that if 1% extinction rate,
1/2 of all species will be gone by 2100
Endangered Species: Species that has so few
individuals that the species could soon become
_______ over some or most of its natural range.
Threatened Species: Species that is still relatively
abundant, but because of ______________ is
likely to become endangered in the near future.
Threatened & Endangered Species
Worldwide about 25% of mammals are at risk of
extinction.
The highest percentages at risk are: apes & monkeys (46%) moles & shrews (36%) antelopes & cattle (33%)
Threatened & Endangered Species
• economic & ___________ importance:
• scientific & ecological importance: ecological
services include nutrient recycling, watershed
value, production of oxygen, moderating
climate, & detoxifying toxic substances;
• aesthetic & recreational importance:
Why Preserve Wild Species?
Example of medical uses: The blood from 500,000
horseshoe crabs is collected each year. A component
of the blood is used to screen injectable medicine for
bacteria.
Biomimicry Video: Planes and Butterflies Biomimicry=__________________________________________________________________________________
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Bioremediation: ___________________________ _________________________________________.
Example: A bacterium called Pseudomonas putida can be used to degrade napthalene, a product of petroleum refining, from contaminated soil.
Specific types of bioremediation:
Phytoremedition = Using a ______ to solve an
environmental problem. (phyto = _________ )
___________ can be used to absorb lead and
other heavy metals from water and soil.
Mycoremediation: Using a _______ to solve an
environmental problem. (myco=__________)
__________________can be used to breakdown
diesel fuel from a spill.
http://permaculturenews.org/2014/04/10/bi
oremediation-industrial-pollution-utilizing-
fungi-bacteria-plants-reduce-oil-pollution-
ecuadorian-amazon-basin-world/
Show first 2.5 minutes of video
Why Care About Bats?
80% of bat species are _______ -eaters that control pests that damage crop, mosquitoes populations etc.
(Ecological Service)
Certain bats are pollinators of crops like mangos, and cashews
Bats (including local population) threatened by white-nose fungus
•__________________ ,
fragmentation & degradation
•_________(nonnative) species
•Population and resource use
growth
•Pollution
•Climate change & pollution
•Overexploitation
(poaching, overfishing etc.)
HIPPCO
Causes of Extinction & Depletion
•Indian
Tiger
•Black
Rhino
•African
Elephant
•Asian or
Indian
Elephant
Habitat Loss/Fragmentation Is Most Serious Threat to Biodiversity
•Former Range
•Current Range
Habitat Fragmentation Reduces Genetic Diversity in a Population
Area preserved for wildlife refugee must have adequate population size for genetic diversity
Why is Genetic Diversity Important?
_________________________________________ _________________________________________.
http://evolution.berkeley.edu/evolibrary/article/_0_0/agriculture_02
Managing populations of
waterfowl requires
multinational efforts to
protect habitats along the
flyways.
Case Studies
Introduction of Invasive Species is the 2nd biggest Cause of Biodiversity Loss
Nonnative species may have no natural
•_________
•Competitors
•Parasites
Examples: Kudzu in Southeastern US
Zebra Mussels in the Great Lakes
Zebra Mussels
Kudzu
Accidentally Introduced Species
Many accidentally introduced aquatic species were carried by the
_________________ in tankers or cargo ships.
Biological Control Gone Bad
In the 1930’s cane toads were introduced into
Australia to control beetle populations that was
devastating cane sugar crop.
Cane toad did not control the beetle population, yet its
population grew exponentially in Australia.
Cane Toads are poisonous, and are able to
outcompete many native species.
Discuss with your table partner:
Certain classes of animals, including mammals and amphibians, have higher extinction rates. Identify some characteristics that make species more vulnerable to extinction.
• ________________________(e.g., blue whale)
• specialized feeding habits (e.g., panda)
• feed at high trophic level- top of the food
chain (e.g., tiger)
• large size (e.g., elephant)
• limited breeding area (e.g., sea turtle)
• limited distribution (e.g., caribou)
Characteristics of Extinction–Prone Species:
• fixed migratory patterns (e.g., whooping crane)
• preys on livestock (e.g., timber wolf)
• small population size (e.g. endemic island species)
• _________________________(e.g. rhinos for horns)
• behaviors that contribute to extinction (e.g.,
Carolina parakeet- flocks hover over injured bird.)
Characteristics of Extinction–Prone Species Cont.
Why are top consumers more vulnerable to extinction?
Must be supported by a __________________ __________________________.
Much of energy consumed is given off as a heat.
Typically, only 10% of energy available for the next trophic level (step in the food chain).
Why are top consumers more vulnerable to extinction? Cont.
Greater risk of harmful concentrations of toxins that bioaccumulate (get stored in body tissue such as fat).
Due to the energy pyramid, toxins get biomagnified (_____________________) through the food chain.
Overfishing: Modern commercial fishing methods
enable increasing harvest. Many fish populations
decreasing drastically.
Case Studies
• National Marine Fisheries Service (NMFS) charged with
protection of marine species;
• U.S. Fish & Wildlife Service charged with listing &
protection of all other species;
Protecting Wild Species in the US
Endangered Species Act (ESA) of 1973 requires listing
& ________of endangered & threatened species in US.
Government Agencies Involved:
California Condor
Florida panther
International Treaties on Biodiversity
• 1975: Convention on International Trade in
Endangered Species (CITES)
– Signed by 172 countries
– International trade regulation for endangered
species. For example:______________________.
• 1992: Convention on Biological Diversity (BCD)
– Focuses on ecosystems
– Ratified by 191 countries (not the U.S.)
Example of an issue for consideration by CITES:
International trade of rhino horn is banned by CITES, but due to the high price of rhino horn poaching is a persistent problem. The next CITES delegation will consider whether to allow farming of rhino for their horns.
• Pro: _____________________________________ ______________________________________.
• Con: _____________________________________ ______________________________________.
Farming of crocodiles for their skins helped to preserve wild crocodile populations.
Protecting Biodiversity •Ecosystem approach: aims to preserve balanced
populations of species in their native habitats.
advantage: it focuses on ___________________ to
protect ecological integrity & provide habitat for the
majority of wild species.
•Species approach: based on identifying &
protecting endangered species on a case–by–case
basis.
Consensus among conservation biologists is that
protecting biodiversity requires both approaches
Preserving Adequate Habitat
• US Wilderness Society estimates that
a wilderness area should be at least
_____________in order to be
protected from human activity.
• About 1.8% of lower US land area is
protected as wilderness:
• In lower US only 4 are larger than
4,000 km2