Anthropogenic Extinctions -- Eric R. Pianka

Anthropogenic Extinctions

© Eric R. Pianka

"The diversity of organisms is good, and the
untimely extinction of populations and species is bad.
Other species have intrinsic value in themselves that should
motivate respect and restraint in our dealings with them" -- Michael Soule

"Most evolving lineages, human or otherwise, when threatened with extinction,
don't do anything special to avoid it" -- George C. Williams

Hundreds of species, especially megafauna, in many different taxa went extinct during the transition from the Pleistocene to the present day. Possible causes of this "Quaternary extinction event" (Koch 2006) include climate change and overkill by human hunters as people migrated to many previously uninhabited regions in the New World and Australia during the late Pleistocene and Holocene. Humans first reached Australia about 50,000 years ago but did not get to the Americas until about 14,000+ years ago. Massive extinctions followed soon thereafter on both continents, strongly suggesting that anthropogenic activities were involved. Fossil records show that Pleistocene extinctions following human invasions were extensive and among others included many large mammals, such as mammoths, mastodons, chalicotheres, gomphotheres, pampatheres, glyptodonts, many ungulates, saber-toothed cats, cave lions, cave bears, diprotodons, several marsupial carnivores, lemurs, as well as various apes including other humans. Some birds that perished include giant South American Adzebills and huge Australian emu-like Dromornithids.

A more recent wave of extinctions followed human colonization of many islands, including the Caribbean and Galapagos Archipelagos, Indian Ocean islands, Hawaii and other Pacific islands, Madagascar, islands of the Mediterranean, and New Zealand. Many flightless island birds, including dodos and moas, went extinct (Steadman 2006), as did other island endemics such as land tortoises. Of course, little evidence is available for how people might have affected smaller species such as most lizards, but at least one gigantic Australian monitor lizard is known to have gone extinct during the Pleistocene following human colonization.

Several major episodes of extinction stand out in the fossil record. These events are so striking that they are used to mark the boundaries between geological periods, eras and epochs. A potentially greater anthropogenic extinction event is currently underway.

Humans are rapidly driving many other species extinct, so many that the anthropogenic Holocene extinction event has been named the Sixth Extinction (Kolbert 2014).

Last updated 4 September 2014 by Eric R. Pianka