The colonisation of tropical Pacific Islands by humans is said to have led to the extinction of more than 2,000 species of native birds
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The IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrates,359 invertebratesand 87 plants) in the last 500 years.
Extinctions
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Some examples of recent extinctions include the dodo (Mauritius), quagga (Africa), thylacine(Australia), Steller’s Sea Cow (Russia) and three subspecies (Bali, Javan, Caspian) of tiger.
EXTINCTMEMBERS
dodo (Mauritius)
quagga (Africa)
thylacine(Australia)
EXTINCTTIGERS
CASPIAN
JAVAN
BALI
threat of extinction
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Adding to the grim scenario of extinctions is the fact that more than 15,500 species world-wide are facing the threat of extinction.
threat of extinction
old Data
12 % of all bird species, 23 per cent of all mammal species, 32 per cent of all amphibian species and 31per cent of all gymnosperm species in the world face the threat of extinction.
threat of extinction
Present
IUCN
Categories
IUCN
Categories
Morevulnerableare..
some groups like amphibians appear to be more vulnerable to extinction
6thMASSExtinction
Since the origin and diversification of life on earth there were five episodes of mass extinction of species. How is the ‘Sixth Extinction’ presently in progress different from the previous episodes?
The difference is in the rates
the current species extinction rates are estimated to be 100 to 1,000 times faster than in the pre-human times and our activities are responsible for the faster rates. Ecologists warn that if the present trendscontinue, nearly half of all the species on earth might be wiped out within the next 100 years.
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LOSS
In general, loss of biodiversity in a region may lead to (a) decline in plant production
LOSS
(b) lowered resistance to environmental perturbations such as drought
(c) increased variability in certain ecosystem processes such as plant productivity, water use, and pest and disease cycles.