Narwhal – Evolution

Narwhal – Evolution
Music
Ambiance: Narwhal song – CD 06.01.12-1

Every once in a while, nature along with something that just baffles scientists. Like a whale with a giant, inside-out, asymmetrical tusk-like tooth. I’m Jim Metzner and this is the Pulse of the Planet.

“If you look at most of the books about evolution, what you’ll find somewhere is a footnote about a narwhal. Because most evolutionary biologists are a little bit perplexed about the narwhal, cause it doesn’t really fit into anything.”

Dr. Martin Nweeia is a dentist from Sharon, Connecticut who’s been studying the narwhal: an arctic whale with an 8-foot long tooth that extends from its forehead. In the background, we’re hearing the underwater vocalizations of narwhals.

“Keep in mind that this is one of two teeth that normally develop in the adult narwhal. The other one remains embedded inside its upper jaw, at usually less than a foot and a half in length. And it’s always on the left side! Why does a tooth on the left side always come out in the male, or usually come out in the male, 8 to 9 feet and the right one just stays there! Teeth are basically mirror image — they’re a symmetric organ. If you do a line down your teeth, for example, as a human, both the size and shape on either sides should be roughly the same size and roughly mirror-image shapes. The narwhal is exactly the opposite. Opposite! In every way! I mean, you start adding up all these aspects of teeth And you don’t have a good sense of an evolutionary picture because there’s no animal before this that had a single tusk that gives you a link to tell you, “Oh, well this is how you came about in evolution,” so when you go back and, you know, look 20 or 30 million years ago, guess what: it ain’t there! So, now you’ve got everybody scratching their head, going, “so how did this happen? What in nature created this? How did it get created?”

Dr. Nweeia and his associates are continuing to work on these puzzling questions. To hear more programs on narwhals, please visit our website at pulseplanet.com. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.

Narwhal - Evolution

The narwhal, with its inside-out, eight-foot long tooth, doesn't just look odd; it is a genuine evolutionary anomaly.
Air Date:03/29/2012
Scientist:
Transcript:

Narwhal - Evolution
Music
Ambiance: Narwhal song - CD 06.01.12-1

Every once in a while, nature along with something that just baffles scientists. Like a whale with a giant, inside-out, asymmetrical tusk-like tooth. I'm Jim Metzner and this is the Pulse of the Planet.

"If you look at most of the books about evolution, what you'll find somewhere is a footnote about a narwhal. Because most evolutionary biologists are a little bit perplexed about the narwhal, cause it doesn't really fit into anything."

Dr. Martin Nweeia is a dentist from Sharon, Connecticut who's been studying the narwhal: an arctic whale with an 8-foot long tooth that extends from its forehead. In the background, we're hearing the underwater vocalizations of narwhals.

"Keep in mind that this is one of two teeth that normally develop in the adult narwhal. The other one remains embedded inside its upper jaw, at usually less than a foot and a half in length. And it's always on the left side! Why does a tooth on the left side always come out in the male, or usually come out in the male, 8 to 9 feet and the right one just stays there! Teeth are basically mirror image -- they're a symmetric organ. If you do a line down your teeth, for example, as a human, both the size and shape on either sides should be roughly the same size and roughly mirror-image shapes. The narwhal is exactly the opposite. Opposite! In every way! I mean, you start adding up all these aspects of teeth And you don't have a good sense of an evolutionary picture because there's no animal before this that had a single tusk that gives you a link to tell you, "Oh, well this is how you came about in evolution," so when you go back and, you know, look 20 or 30 million years ago, guess what: it ain't there! So, now you've got everybody scratching their head, going, "so how did this happen? What in nature created this? How did it get created?"

Dr. Nweeia and his associates are continuing to work on these puzzling questions. To hear more programs on narwhals, please visit our website at pulseplanet.com. Pulse of the Planet is made possible by the National Science Foundation. I'm Jim Metzner.