Holocene Extinctions

[Proteus]

How many percent of species have become extinct in the Holocene? Ie, how large is the percentage of species that are extinct now that were still extant before the Holocene began?

[skippy]

It is hard to say with a great deal of accuracy, largely because a significant percentage of the species which have become exctinct either naturally or anthropogenically have not actually been discovered and recorded yet.

 

Just to give you a rough indication, an article published in 'Nature' in 2000 had some interesting but troubling insights; About two-thirds of all species occur in the tropics, largely in the tropical humid forests. These forests originally covered between 14 million and 18 million square kilometres, depending on the exact definition, and about half of the original area remains.

http://www.nature.com/nature/journal/v403/n6772/full/403843a0.html

 

In terms of current numbers:

The 'Holocene' extinction as it is known is the largest extinction event in 65 Million years. The current rate of extinction is said to be between 30,000 and 100,000 species per year.

http://ezinearticles.com/?The-Ongoing-Holocene-Extinction&id=531079

 

 

[George Yates]

There are lots of mammals i can think of that are extant today and predate the Holocene. Pangolin's, hedgehogs, lagiomorphs, whales (not to sure about balleen whales) and anteaters.

 

Its a good question though, and i think quite a lot of the biggest megafauna died out then, like Indricotherium, but i dont think the extinction event can have been that severe, as it only appears as a minor setback when you look at it in the context of all developing mammal groups, which trimmed of only a few of the branches.

 

I dont know much about how other groups were affected like reptiles, birds (which only diversified i imagine), fish and invertabrates.

 

Afraid i cant find any figures or estimates

Edited January 6, 2011 by George Yates