biology 1229 extinction. “the cessation of existence of a species”
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Biology 1229
Extinction
Extinction“the cessation of existence of a
species”
IUCN categoriesExtinct
No reasonable doubt that the taxon is gone.
717 animal and 87 plant species since 1500
Lytta mirifica
huia
Labra
dor
duck
Ste
ad’s
Bush
Wre
n
Gre
at
Auk
Thyla
cine
Steller’s Sea CowPassenger Pigeon
dodo
Quagga
IUCN categoriesExtinct in the wild
Species only exists in captivity or cultivation
37 animals and 28 plants
Extinct in the wild
St Helena Redwood Wood’s Cycad
Hawaiian Crow
Redtail Shark Black-footed ferret
Partula snails
IUCN categoriesCritically endangered
Extremely high risk of extinction in the wild
3240 species (up from 3124 in 2007 and 3071 in 2006)
Includes 6 species of fungi
Baiji
North American Burying beetle
South
ern
Blu
efin T
una
Black Rhino
Kakapo
IUCN categoriesEndangered
Very high risk of extinction in the wild
4768 species
IUCN categoriesVulnerable
High risk of extinction in the wild8911 species
IUCN categories Near Threatened
Ongoing conservation measures required to prevent risk of extinction
3513 Least concern
Widespread, abundant & safe 17675
Data deficient No assessment possible 5561
Gaps in knowledgeAlmost all invertebrates
Apart from ‘showy’ ones Collected beetles Butterflies Dragonflies
Poor knowledge of tropics, esp. in Africa
The vast majority of described species are known from only a few specimens
A Global Extinction Crisis>33% of frogs threatened¼ of Mammals face extinction15-37% of species extinct by
205070% of Butterfly species in
decline
Why should we care?The sadness of losing biodiversityOur moral responsibilitiesEcosystem services
Ecosystem servicesAll the free stuff we get from
nature Water purification, decomposition,
dung removal, pollination, O2 repletion, CO2 absorption, food, pharmaceutical products etc.
$16-54 Trillion (i.e. $16 000 000 000 000) per year… in 1997!
Why do species go extinct I?Natural extinctions
Population changes Natural disasters Evolution, migration and habitat
change
Why do species go extinct II?Anthropogenic influence
Habitat destruction
Invasive speciesOverkill
Climate Change
The four horsemen of the extinction crisis I: Habitat destruction
The four horsemen of the extinction crisis II: Overkill
The four horsemen of the extinction crisis III: Invasive species
Stoat (NZ)
House Mouse (Many places!)
Red F
ox (
Aust
ralia
)
Bru
sh-t
aile
d p
oss
um
(N
Z)
Rhododendron (Scotland)Emerald Ash Borer (SW ON)
NZ Flatworm (Ireland)
Zebra Mussel (Great Lakes)Eu
ropean
Sta
rlin
g
(Many p
lace
s!)
The four horsemen of the extinction crisis IV: Climate change
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