Re: New Recipe: How to Make a Mass Extinction

on Tue, 31 Oct 2006 14:46:31 GMT, Roger Bagula <rlbagula@xxxxxxxxxxxxx> sez:
` pete wrote:

` >on Sun, 29 Oct 2006 18:39:21 GMT, Roger Bagula <rlbagula@xxxxxxxxxxxxx> sez:
` >` johnwl4@xxxxxxx wrote:
` >
` >` >
` >` >> Quite true. Pursuant to that, palynology is an interesting field
` >` >>wrt to this - gives a much sharper picture of just when extinctions
` >` >>occurred, at least of plants. For some reason, people seem to overlook
` >` >>the fact loss of plant species is likely to affect a great number of
` >` >>the animal species, particularly the specialists. And pollen is not
` >` >>so affected by the Signor-Lipps problem..
` >` >> Some URL's on the Yahoo group Mass Extinctions. Can't get any
` >` >>responses on the paleobotany group, and can't push it along because I
` >` >>don't know enough about the subject.
` >` >> Regards
` >` >> John GW
` >` >>
` >` >>
` >` >>
` >` Your well over my head there. Pollen science?
` >` Most big animals with large calcium based bones
` >` are what make fossils... so babies birds, and small animals like rodents
` >` are not going to show up as much a cave bears, giant sloths
` >` and mammoths... etc.
` >` In fact since Neanderthals have bigger denser bones,
` >` you would expect for equal populations of ATM ( anatomically modern humans)
` >` and Neanderthals
` >` you would find more Neanderthal fossils.
` >` Pollen just gets eaten by microorganisms ( decays away) in most cases (
` >` form dust to dust)
` >` So there has to be a real load of it ,
` >` for it to survive.
` >
` >Yipes. You'd better do some reading. Pollen is well nigh indestructible,
` >and is often what tells us about climate and ecology when nothing
` >else is preserved.
` >
` >
` Yipes, you should visit a microbiology lab...
` pollen decays real good and is the favorite food of bees.

The ingnorance in that statement leaves me almost speechless. Do
a websearch on "palynology pollen ancient durable" and spend some
time reading. Here's a quote from about ten seconds browsing the
results:

http://www.aip.org/history/climate/cycles.htm

In particular, from the early 20th century forward, a few scientists in
Sweden and elsewhere developed the study of ancient pollens
("palynology"). The tiny but amazingly durable pollen grains are as
various as sea shells, with baroque lumps and apertures characteristic of
the type of plant that produced them. One could dig up soil from lake beds
or peat deposits, dissolve away in acids everything but the sturdy pollen,
and after some hours at a microscope know what kinds of flowers, grasses
or trees had lived in the neighborhood at the time the layer of lake-bed
or peat was formed. That told scientists much about the ancient climate.
We had no readings from rain gauges and thermometers 50,000 years ago, but
pollen served as an accurate "proxy."


--
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vincent@triumf[munge].ca Pete Vincent
Disclaimer: all I know I learned from reading Usenet.
.

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