Extinction is the total cessation of a species or higher taxon level, reducing the overall level of biodiversity

• It can result gradually, as one population of organisms progressively evolve into something else (phyletic extinction)
  

• Alternatively, a species may not leave any identifiable descendents and simply cease to exist (abrupt extinction)
  

Mass extinction events are categorised by an unusually high number of species dying out in a relatively short period

• There have been five mass extinction events in the history of the Earth – with human activity responsible for a sixth current anthropogenic mass extinction
  

• Examples of species that have gone extinct as a consequence of human activity include the North Island giant moas, the Caribbean monk seals and the Tasmanian tiger
  

North Island Giant Moa

• The giant moa (Dinornis novaezealandiae) was a large flightless bird (terrestrial megafauna) that occupied New Zealand’s North Island
  

• Before the arrival of humans, the moa’s only predator was the massive Haast’s eagle – meaning the moa was extremely vulnerable to ecosystem perturbances

• Following colonisation by polynesian settlers (1200 – 1300), the giant moa was quickly driven to extinction by overhunting and, to a lesser extent, habitat destruction 
  

  

Caribbean Monk Seal

• The Caribbean monk seal (Neomonachus tropicalis) was a marine species that lived in the oceans around the gulf of Mexica and the Caribbean
  

• Their docile nature made them easy prey to humans, who hunted them for their oil and blubber – additionally, overfishing of their food source led to starvation

• The species was declared officially extinct in 2008, although the last confirmed sighting occurred much earlier (in 1952)
  

  

Tasmanian Tiger (Thylacine)

• The Tasmanian tiger (Thylacinus cynocephalus) is an extinct carnivorous marsupial that was native to the Australian mainland and the island of Tasmania

• The Tasmanian tiger died out on the mainland roughly 3,500 years ago (possibly due to competition with dingoes), but continued to exist on Tasmania 

• Upon the arrival of European settlers in the 1800s, the Tasmanian tiger was intensively hunted to extinction

  

Anthropogenic Species Extinction