Biodiversity and Endangered Species
“The first animal species to go are the big, the slow, the tasty,
and those with valuable parts such as tusks and skins.”
- E.O. Wilson
I.
Levels of Biodiversity
II. Measuring and Assessing Biodiversity
A. Biodiversity – sum total of all organisms in an area
B. Split into three specific levels:
1) _________________________________
2___________________________________
3)__________________________________
C. Ecosystem diversity = _______________________________
1) Also encompasses differing communities and habitats
2) Rapid vegetation change and varying landscapes within an
ecosystem promote higher levels of biodiversity
D. Species Diversity = the number or variety of species in the
world or in a particular region
1) Richness = _____________________________________
- Speciation generates new species and adds to species richness
- Extinction reduces species richness
2) Evenness or relative abundance = _____________________
_____________________________________________________
E. Genetic diversity
1) Encompasses the differences in DNA among individuals within
species and populations. The raw material for adaptation to local
conditions.
2) __________________________________________________
_____________________________________________________
3) Populations with low genetic diversity are vulnerable
- To environmental change
- Disease
Inbreeding depression = genetically similar parents mate and
produce inferior offspring
A. Scientists estimate approximately 8.7 million eukaryotic
species on the planet (Nature, 2011) - only 1.2 million species
have been successfully catalogued
B. Very difficult to identify species
1) __________________________________________________
2) Small organisms are easily overlooked
3) __________________________________________________
____________________________________________________
C. Some groups contain more species than others
1) Species are not evenly distributed among taxonomic groups
- __________________________________________________
- 40% of all insects are beetles
2) Groups accumulate species by
- Adaptive radiation
- Allopatric speciation (geographic speciation)
- Low rates of extinction
D. Biodiversity is unevenly distributed
1) Latitudinal gradient = _______________________________
___________________________________________________
E. Latitudinal gradient has many causes
1) ________________________________________________
____________________________________________________
2) Tropical biomes support more species and show more species
evenness
- Diverse habitats increase species diversity
III. Biodiversity losses and species extinction
A. Extinction = occurs when the last member of a species dies and the species ceases to exist
B. Extirpation = _______________________________________________________________________________________________
- Can lead to extinction
C. Extinction is a natural process
1) Paleontologists estimate 99% of all species that ever lived are now extinct
2) Background rate of extinction = ______________________________________________________________________
- 1 extinction per 1 to 10 million species for mammals and marine species
- 1 species out of 1,000 mammal and marine species would go extinct every 1,000 to 10,000 years
D. Earth has experienced five mass extinctions
- 1) In the past 440 million years, five mass extinctions have eliminated at least 50% of all species
___________________________________________________
E. The 6th mass extinction – Happening NOW, is human caused
1) During this Quaternary period, we may lose more than half of all species
- Hundreds of human-induced species extinctions, and multitudes of others, teeter on the brink of extinction
2) ________________________________________________________________________________________________
F. Current extinction rates are higher than normal
1) The Red List = an updated list of species facing high risks of extinctions (published since the 1960’s by the world’s leading
conservation groups). In 2014, the list included ______________, an increase of 35% in just the last ten years (15,503 species in 2004)
G. Biodiversity loss is more than extinction
1) Decreasing numbers are accompanied by smaller species’ geographic ranges
2) _____________________________________________________________________________
IV. Characteristics of a SPECIES that make it vulnerable to extinction
A. Species heading toward extinction are classified as either endangered or threatened.
B. An Endangered species has so few individual survivors that the species could soon become extinct over all or most of its natural
range.
C. A threatened species is _____________________________
__________________________________________________
D. Low reproductive rate (K strategist – 1 or two offspring, long gestation/rearing period) Examples: Blue whale, rhino
E. Specialized niche – __________________________________
F. Narrow distribution – ________________________________
G. Feeds at high trophic level – Bengal tiger, bald eagle, grizzly bear. (Side note: Birds that feed at high levels had DDT/egg issues)
H. Fixed migratory patterns – Whooping crane, sea turtles
I.
Rare – African violet, some orchids
J. Commercially valuable parts – Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
K. Large territories – California condor, grizzly bear, Florida panther
L. Some organisms also have behavioral patterns that can put them at risk ex: 1) The Carolina parakeet nested in large flocks that
made them easy to kill, Florida Key deer are “nicotine addicts” that get killed ________________________________
____________________________________________________
V. Biodiversity loss, driven by HUMANS, has many causes
A. An acronym used by conservation biologists to describe biodiversity loss is HIPPCO
H: Habitat destruction, degradation, and fragmentation
I: _______________________________________________
P: Population and resource use growth (too many people consuming too many resources)
P: Pollution
C: Climate Change
O: Overexploitation
B. Habitat loss - The greatest cause of biodiversity loss. Farming eliminates populations, Clearing forests removes resources
organisms need , ______________________________________________ A few species (i.e., pigeons, rats) benefit from disturbance
C. Invasive species cause biodiversity loss
1) Introduction of non-native species to new environments
2) Island species are especially vulnerable
3) __________________________________________________
4) Cost billions of dollars in economic damage
D. Pollution causes biodiversity loss
1) Harms organisms in many ways: Air pollution degrades ecosystems, water pollution adversely affects fish and amphibians
2) The damage to wildlife and ecosystems caused by pollution can be severe
_________________________________________________
E. Climate change causes biodiversity loss
1) Emissions of greenhouse gases warms temperatures
Modifies global weather patterns and increases the frequency of extreme weather events. Increases stress on populations and forces
organisms to shift their geographic ranges 2) _________________________________________________
F. Overharvesting causes biodiversity loss
1) If a species is economically valuable, they are often overharvested, or poached. Animals can be used for food, clothing, or medicine.
Examples of animals being overharvested currently:
1. Sharks for their fins - Soup
2. ______________________________________________________________
3. Rhinos for their horns – Currently greatest use in Vietnam for drinking as a status symbol, and in tandem with chemotherapy.
Rhino horn costs more per ounce than any drug on the planet – so powerful economic incentive for poaching.
VI. Biodiversity provides free ecosystem services
A. Biodiversity helps maintain ecosystem function
1) Biodiversity increases the stability and resilience of communities and ecosystems
2) The loss of a species affects ecosystems differently
If the species can be functionally replaced by others, it may make little difference
_____________________________________________________________________________
B. Biodiversity enhances food security
1) __________________________________________________
- Turkey’s wheat crops received $50 billion worth of disease resistance from wild wheat
2) Wild strains provide disease resistance and have the ability to grow back year after year without being replanted
3) New potential food crops are waiting to be used
- Serendipity berry produces a sweetener 3,000 times sweeter than sugar
C. Do we have ethical obligations to other species?
1) Many people feel that other organisms have intrinsic value and an inherent right to exist. ____________________
____________________________________________________________________________________________
VII. Laws Protecting Biodiversity
A. Endangered Species Act (1973) (ESA) = _____________________________________________________________
______________________________________________________________________________________________
- To prevent extinction
- Stabilize declining populations
- Enable populations to recover
- ESA also mandates habitat protection ( does not allow development on private land if necessary)
B. As of 2014, the U.S. had 1,361 species listed as endangered or threatened
C. Successes of ESA 1. Bald Eagles: Only 600 left in the world in the 1960’s, today over 14,000.
2. Only 6 species on the endangered species list have gone extinct. Scientists estimate that without the protection of ESA, over
170 species would have gone extinct.
3. Over ______________________________________________________
4. These successes occur despite underfunding of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service
D. The ESA can be controversial
1) Many Americans support protection of endangered species
2) Opponents feel that the ESA values endangered organisms more than the livelihood of people
- __________________________________________________________
- Economic activities such as logging (Spotted Owl) may be suspended
E. What do other countries do about protecting their endangered species?
To successfully protect the environment in any way by a government, the following usually needs to be done:
1) Write and pass law
2) Fund law (money from country’s treasury)
3) Enforce law
______________________________________________________________________
F. International Species Protection
CITES – (1973) the_________________________________________________________________– Focused on trade on
wildlife and wildlife parts. In 1990, CITES was modified to include a ban on ivory. Prohibits international travel/trade of
endangered species body parts (tusks, pelts, ect).