Tuesday, January 27, 2009

There's no fossil in that fossil

With a heavy heart,  someone  must reveal the secret about the trilobites for sale at the Peabody Museum gift shop.

Otherwise, a visitor may pay hundreds of dollars for a lump of mostly epoxy formed to look like a trilobite fossil.  Or, a few real fossils epoxied onto a piece of Devonian rock.

All of this confusion could be avoided if the merchandise was correctly labelled. For example, "model fossil for educational purposes or display."

For those who don't appreciate a good trilobite, they are long-extinct marine creatures with antennae, lots of legs, shells, and other arthropod features. They also possessed compound eyes.

Trilobites, as the name suggests, are composed of three segments, a central "spine" with rows of "legs" or "gills" on both sides. They lived between 550 million and 250 million years ago. There were hundreds of species, from the tiny to foot-long. 

They are found in sedimentary rock that is 250 to 550 million years old. Such outcroppings occur in the Western United States, New York state, Europe, Asia, and Africa. Basically, everywhere except New England.

Some of the most spectacular specimens are found embedded in rock that comprises the Atlas Mountains in Morocco.  Many of these fossils are laboriously removed from the rock using tiny sand blasting tools and picks. These fossils tend to be expensive because separating one kind of rock from another complex shape of different composition, is time consuming.

Enterprising Moroccans also dislodge fossils from the same areas. They do not have expensive tools or the inclination to spend days slowly removing the matrix rock. Instead, they use screw drivers, nails, and and whatever else is handy to scratch away the matrix. 

Thus, it's possible to instantly recognize most inexpensive Moroccan fossils. They are crudely scratched. Others are unscathed, but sometimes assembled from  fragments of different fossils. They tend to be either tan or black, in gray or rust-colored rock. 

The fossil producers discovered a long time ago that most souvenir collectors cannot distinguish between a real fossil and one made mostly out of the type of  epoxy used to repair automobile bodies. 

Epoxy is hard, like rock, malleable before it sets, and easily scratched. 

The trilobites at the Peabody are from Morocco and some show obvious signs of modification or assembly. Hints: If many fossils are on a quilt-like surface of different shades, chances are that these real fossils were cemented together to form a more expensive plate. The other typical Moroccan fake is the large Paradoxides  of the  Redllichiida order.

The fossils appear to be tooled and outlined and the rock (or whatever that stuff is) is carved with attractive radiating lines. 

A few years ago a lunatic such as myself brought this to the attention of the museum. This guy washed off the Paradoxides he had purchased there. The underlying  "fossil" was suspiciously colored, and the border between colors was a straight line. Our sleuth disassembled more of the fossil and found that there wasn't any fossil in the fossil. 

He brought his findings to the museum's attention, but was brushed off. So today, you can go to the gift shop and still see modified, doctored trilobite fossils.

This is ironic, because the Peabody has one of the best and most significant collections of real trilobite fossils in the world.

These specimens are  beautiful and priceless. Unlike the crude recreations in the gift shop.

Coffee does a lot, but can it keep you sane?

The idea that coffee reduces the risk of dementia is kind of silly, if you think about it.

First of all, coffee has many effects. Too many to narrow down. For example, coffee could reduce the hours spent sleeping, or might increase exercise. We also know that it is a diuretic, and that it makes the heart beat faster and increases blood pressure. And it's a stimulant.

All of that aside, consider the history of coffee consumption and the incidence of Alzheimer's disease and other forms of dementia. Per capita coffee consumption was about 20 gallons in 1910. It was also about 20 gallons in 2005. Coffee drinking peaked just after World War II, to just under 50 gallons per person per year.  Then soft drink consumption rises, and coffee declines back to early 20th century levels.

So, since most dementia has a decades-long latency period, many of the people who are slipping away now were born at a time when coffee drinking was highest. Consequently, their parents drank a lot of coffee.  They were still drinking more coffee growing up than people drink today.

So, one might ask, why is dementia and Alzheimer's increasing as the rate of coffee consumption drops, if coffee protects against dementia?

One obvious factor is that people are living longer now than ever before.  Many people probably used to die from other causes before they had a chance to develop dementia. 

In other words, the coffee hypothesis makes no epidemiological sense.  The crude data seems to suggest that coffee drinking is linked to higher rates of dementia. But, as we all should know, linkage doesn't necessarily reveal any causal connection. 

The only positive side to this research is that it encourages behavior that's already taking place. People do not have to give up coffee, the same way they're supposed to quit smoking and cut back on fatty foods. 

Keep the java coming.