Mass extinction due to climate changes

Typedef

http://www.cnn.com/2004/TECH/science/01/07/climate.report.ap/index.html


I found the story on slashdot. Again, while many sceptics criticise the 'human' element as significant in climate change (myself I find too much coincidence in believing non-human factors are overtly to blame), it is worrying either way, that what essentially amounts to a mass extinction event (from 15-37 of all species on the planet) is tangable in the next fifty years.

That's scary, the likehood is that with biodiversity so seriously undermind that the ability of the planet to sustain (us .. humans) and life in general ... will diminish, implying that perhaps less humans will be able to live off of the planet, because of this.

Or in other words... it's bad news folks, for feeding ourselves and our children into the next century.

Capt'n Midnight

I'll try to find the name of the book at home but on one tree in costs rica they found more species of butterfly than there are in Europe.

The only good news is thus far man has not been shown to make a species with a global distribution extince (yet).

The last great extinction was at the end of the last ice age when most of the mega-fauna ie. stuff bigger than cows outside Africia was wiped out. Mammoths, wooly rhino, horses & camels in North america, giant ground sloths, those giant meat eating birds in southern USA, large lizards and kangeroos in Oz. Along with flightless birds Moa, Roc etc. these extinctions happened around the same time humans arrived.

Typedef

Hmm.

Similarly, big cats are supposed to have caused the extinction of the large marsupals which once inhabited South America.

The cats crossed over from Russia and gradually decended down towards the South, thus, causing the extinction of all the large marsupals which once lived there.

Capt'n Midnight

and those big bear cats became extinct when ?
(that was the time 3m years ago when N america and S america joined together after along time apart)

Anyway have a look at this http://species.enviroweb.org/reports/oossales.html
one of the links is - http://www.mjvn.co.za/kean/pricelist.html

Typedef

http://www.worlddiff.com/sciences_southamermarsupials5.html

Up until the late Miocene/early Pliocene epoch (about 5-6 million years ago), South American marsupial species had the opportunity to flourish in the same way as their Australian relatives. Developing from such progenitors as Alphadon, Pucadelphys, and Mayulestes, there was considerable diversity in marsupial forms, ranging from ratlike omnivores to powerful 'sabretooth cat'-style carnivores. However, when a land connection with North America- where placental mammals were totally dominant- formed, the handwriting was on the wall for most of the marsupial life in South America, as placental mammals of all types began migrating south and challenging the native lifeforms for various ecological niches. The marsupial carnivores were likely the first to go: though their tooth structure had developed along similar lines to their placental challengers, they were at a serious disadvantage due to both their generally-smaller brain size and to their lack of an adaptation for fast running, due to the marsupial need for a grasping forepaw from early development that also denied them such placental locomotory adaptations as flippers and wings. As the marsupial predators disappeared and were replaced by placental counterparts, the marsupial herbivores- unable to cope with either the advanced new carnivores or other herbivorous animals moving into their environment- fell by the wayside as well.

Actually you're right, it was the connection of North + South, as opposed to the connection of Alask & Russia that introduce the cats to South America.

Good call.