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Re: mass extinction

There was a major extinction of megafauna at the end of the Pleistocene on all major landmasses except Africa that was almost certainly caused by humans and affected a few hundred hundred species of mostly large mammals and smaller numbers of birds and reptiles.

Also there was a *very* large extinction in the Pacific when it was colonized by the Polynesians. The size is uncertain since most islands haven't been studied yet, but it certainly affected many more species than 800. From the number of extinct species found on the islands that have been investigated David Steadman estimates >2000 species *of birds alone*, i e 20% of the extant bird species
of the World.

Another major extinction occurred on Madagascar 500-2,000 years ago. Total number of affected species is not known, since there has been very limited research as yet.

In short major extinctions have occurred essentially everywhere where humans have settled, but particularly on islands. However it is not considered polite to mention extinctions that occurred before the Europeans arrived, hence that 500-year limit.

Tommy Tyrberg



At 23:26 2006-03-20, frank bliss wrote: 
A major news article about a UN report of the Convention on
Biological Diversity stated that humans have caused the biggest
extinction since the demise of the dinosaurs.
They claim that 844 plants and animals are known to have gone extinct
in the last 500 years.  I thought that there are several million
different species out there in our Biosphere currently so the 844
number seems tiny.  I was under the impression that at the end of the
Cretaceous that 75 percent of all species (land and water) were wiped
out.  Additionally, haven't several very significant extinctions
occurred at the end of the eocene and the Pleistocene that were much
more significant than the 1 percent "we" have killed off.

This news cyclel sounds like more of the psychology described in
"State of Fear"  (Michael Chichons latest).

I know that I personally have killed a significant percentage of the
mosquitos/ticks/mice/yellow jackets/black widows/rattlesnakes that I
run into.  Durn humans give the rest of the biome no respect I
guess.  Harvester ants are being pressured locally too as they
collect fossils and if I see a Harvester Ant hill, it is immediately
attacked.

I would ask the DML just to set the record straight, what were the
"major extinctions in the last 65 million years and what proportions
of the biota died off during each event?

The link to the Reuters article is: http://today.reuters.com/news/ NewsArticle.aspx?type=topNews&storyID=uri: 2006-03-20T175004Z_01_L20719283_RTRUKOC_0_US-ENVIRONMENT- DIVERSITY.xml&pageNumber=0&summit=

Frank (Rooster) Bliss
MS Biostratigraphy
Weston, Wyoming
www.cattleranch.org