As titled: Are We On The Cusp Of The Sixth Mass Extinction Event? Yes, we are indeed, as we, here defined as all the lives on the Earth at the moment. Mass extinction is times when the Earth loses more than three-quarters of its species in a geologically short interval (Barnosky et al., 2011). In addition, according to the Oxford Dictionary of Geology and Earth Sciences edited by Michael Allaby (2013), mass extinction is defined as the Earth has been taken place environmental catastrophe, removes many groups from environment from record and not replaced, and ecosystems collapse. Eventually new forms appear and evolution resumes.
Throughout the decades, biologists and paleobiologists investigated on the presence of the current living species and they found extinction of species, which this can be a supporting evidence of the sixth mass extinction in terms of species extinction as stated in definition. There are reports of extinct species such as the Dodo Birds, Falkland Island wolves, Caribbean Monk Seal, which faced threats such as killing for skin and oil, over-hunting of the animal resources and removal of land and habitats due to human activities (IUCN, 2001). The number of extinct species is keep growing throughout the centuries.
At present, as categorized by the International Union for Conservation of Nature (IUCN), there are 12% of all known birds, 30% of all known amphibians and 21% of all known mammals are regarded as at risk of extinction—Threatened (IUCN, 2001), including Kiwi Birds, Polar Bears and Chinese White Dolphins. These threatened species—mammals, reptiles, amphibians or even plants, are scattered over the world, mostly in the tropics, South America and Sub-Saharan Africa, which regarded as the most biodiverse or highly biodiverse areas (Jenkins, 2003). By using the criteria of the IUCN’s The World Conservation Union’s Red List of Threatened Species, the BirdLife International carried an assessment of extinction risk in birds (2000), reported that there might be 350 species expected to become extinct within 40 years (cited in Jenkins, 2003), which resulting in an unexpected rapid average rate of 8.75 species extinct per year.
Speaking of extinction rate, it is common and reliable measure of biodiversity loss. It is essentially the amount of extinctions divided by the time over which the extinction occurred (Barnosky, 2011). In 1995, a team of scientists came up with minimum estimates of global extinction rates of about 1% of the taxon’s species per century...