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The homepage for the movie I mentioned in the last posting ( jerwood.nhm.ac.uk/archives/paleonet/2003/msg02210.html ) is: www.4threvolt.com . I asked Dennis after his Expanding Earth talk (at the 5th Biennial meeting of the Systematics Association at Cardiff Uni.) whether there was enough evidence for extra matter hitting the land crust as meteorites etc in the last 200mys - presumably he didn't mean it was being "beamed in"... , but he said there was a net influx of subatomic particles into the earth. Hmm...would that have created the pattern of elements and minerals we suspect throughout the earth? But maybe the person who knows exactly what the missing mass in the universe is doing is the one entitled to say it's impossible! Remember, it was the rejection due to unknown mechanism that unjustifyably prevented continental drift from being accepted. Nonetheless I'd guess neither beams nor meteorites have increased the earth's mass. However the convenor during that strand said, quite rightly, "...if we accept the expanding earth for the moment, just for the sake of argument..." and there was a beautiful moment as a slight flutter of nervous laughter and a lot of anxious looks went round the room. The theory does claim to explain a few things nothing else can at the moment: the funny fossil record of India (it didn't have to rush anywhere in much of a hurry, I am told), and in particular why there is absolutely no deep ocean crust over 200my old anywhere, but from that date there's a reasonable amount of all ages. Dennis also says the Tethys is being accepted as being closed (or surely that was "pretty closed" at a certain time). I don't mind what happens - I'd love it to be true, but if it isn't, it's another splendid example of nature being misleading. I'd guess the true story will turn out to go something like this (though I don't believe *exactly* this more than anything else): At one time, perhaps just after the surface became solid (and after the moon thing happened), the earth really was 20% of its current volume, and the crust fitted perfectly all over, just as EE says it did 200mya. Gradually an accretion of meteorites etc pumped it up to it's current volume (only a lot earlier) and the scars were removed by melting underneath, surface erosion, vulcanism etc, but at least the pieces of the ripped waistcoat pattern of recent times were established. The exact matching across the southern Pacific of both coastlines and interrupted species ranges is explained equally well by both EE and versions of current tectonic plate theory positing a mesozoic split between Australia and S. Am, so doesn't count as evidence. The "coastline matching" in the north Pacific (very much edge of continental plate stuff there) might be explained by a very much earlier split, and maybe the species matching there can be explained by frequent Berengia links sharpened by subsequent climatic strictures. (Not saying it's exactly a good match for alligators, but that explanation works for their current China/SE USA distribution, utilising a Panama gap.) This could include freshwater fish lines even the ones without ocean-going representatives. There is still the neat complete absence of pre 200myo deep sea crust and normal service for everything since to be explained, though perhaps it is accounted for by standard plate tectonics. One strand of the symp. was biogeography, and Isabel Sanmartin's talk on the event-based approach to historical biogeography mentioned a characterisic pattern of animal relationships between Australia, NZ and S.Am as: (NZ(Aus, S.Am)) whereas for plants (S.Am(Aus, NZ)) is more characteristic. A native commented later that NZ is considered to have been 81% - 91% entirely submerged in the "Oligocene drowning" of 30mya; many now think all NZ's flightless birds flew there in the last 40mys. Dennis the EE man has NZ's original positioning as due south of Tasmania, with T fitting into the bay at the top of N NZ, though that may be old hat now for all I know. But those familial groupings might be explained by all mammals and birds on NZ being exterminated by floods, glaciation and extreme fragmentation, but plants either survived as seeds or isolated specimens on small islands, or enjoyed preferential driftability along with Sphenodon (whose source population on Aus then died out). (contd. on next posting.) JJ __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com
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