Shells -Time Capsule

ambience: Conch shell being blown

We’re listening to the sounds of a conch shell being blown — it’s an age-old custom in the Pacific. Well people have found all sorts of uses for seashells — as tools, jewelry and money. A purple dye made from shells was the basis of trade in the Mediterranean 3,000 years ago. But a seashell can also be a sort of environmental time capsule that tells us what the earth was like long ago. I’m Jim Metzner and this is the Pulse of the Planet, presented by DuPont. Geerat Vermeij says seashells have many ways of conveying information. Vermeij is one of the world’s leading experts on seashells, and among other things, he compares fossilized shells with their modern-day counterparts.

“We see a really interesting story that unfolds. Many shells today, particularly in, uh, tropical waters, tend to be extraordinarily, heavily armored. They’re thick, they have narrow openings, they have intricate, outside ornaments, uh, in the form of spines and nodes and heavy ribs and so forth, and if you then go back and look at warm-water shells from the very distant past, they’re very different. They are not nearly as heavily armored. So generally speaking, there has been an increase in shell armor as time went on.”

Well that’s significant because a thick shell is a sign that an animal has to protect itself against many predators.

“The conclusion that I draw is that, at least in warm waters, it’s become a riskier, a more dangerous world for the average mollusk, and so they have evolutionarily responded in several different directions. It’s very useful to try to see things from the animals’ point of view and shells really allow you to do that. ”

Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation.

Shells -Time Capsule

Seashells are environmental "time capsules" that tell scientists about the distant past.
Air Date:07/06/2000
Scientist:
Transcript:

ambience: Conch shell being blown

We're listening to the sounds of a conch shell being blown -- it's an age-old custom in the Pacific. Well people have found all sorts of uses for seashells -- as tools, jewelry and money. A purple dye made from shells was the basis of trade in the Mediterranean 3,000 years ago. But a seashell can also be a sort of environmental time capsule that tells us what the earth was like long ago. I'm Jim Metzner and this is the Pulse of the Planet, presented by DuPont. Geerat Vermeij says seashells have many ways of conveying information. Vermeij is one of the world's leading experts on seashells, and among other things, he compares fossilized shells with their modern-day counterparts.

"We see a really interesting story that unfolds. Many shells today, particularly in, uh, tropical waters, tend to be extraordinarily, heavily armored. They're thick, they have narrow openings, they have intricate, outside ornaments, uh, in the form of spines and nodes and heavy ribs and so forth, and if you then go back and look at warm-water shells from the very distant past, they're very different. They are not nearly as heavily armored. So generally speaking, there has been an increase in shell armor as time went on."

Well that's significant because a thick shell is a sign that an animal has to protect itself against many predators.

"The conclusion that I draw is that, at least in warm waters, it's become a riskier, a more dangerous world for the average mollusk, and so they have evolutionarily responded in several different directions. It's very useful to try to see things from the animals' point of view and shells really allow you to do that. "

Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation.