Washington State Magazine

Winter 2002


Winter 2002

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In This Issue...

Features

Bridges to Prosperity :: When Ethiopian partisans blew up a bridge to stop the advance of Mussolini, they also split a region. Ken Frantz put it back together. by Teresa Wippel

{ WEB EXCLUSIVE–Gallery: Bridges to prosperity :: Photographs of Ethiopia by Zoe Keone.}

A matter of survival :: One of the simplest truths of nature is that if a species is to survive, it must reproduce. faculty researchers explore reproduction's mysteries and threats. by Mary Aegerter

Friendly People :: William Hewitt built his dream on Blake Island. Hewitt is gone, but his dream lives on in Native tradition and the rich aroma of roasting salmon. by Pat Caraher

Taking the University to the people :: Cooperative Extension still offers advice on how to can your tomatoes or care for your chickens. But it also does much more, probing needs and providing solutions in every corner of the state. by Tim Steury

The Puyallup Fair :: Every year in late summer, more than a million people gather in Puyallup to eat cotton candy, endure the latest thrill rides--and watch 4-H-ers show their stuff. by Pat Caraher

Panoramas

Departments

Tracking

Cover: Ken Frantz '71, right, founding executive director of Bridges to Prosperity, Inc., participates in a ribbon cutting ceremony with Ethiopian provincial officials and an Ethiopian orthodox priest. The ceremony marked the reopening of Second Portuguese Bridge, which spans the Blue Nile River in Ethiopia. Virtually impassable since World War II, the bridge had been repaired by Frantz and his crew of volunteers from Bridges to Prosperity, ending years of isolation for communities on both sides of the river. Read the story. Photo by Zoe Keone.

Panoramas
Jon Mallatt used genetic analysis to confirm his suspicions about the hagfish. Brandon D. Cole/Corbis

Jon Mallatt used genetic analysis to confirm his suspicions about the hagfish. Brandon D. Cole/Corbis

A bizarre, slimy animal shows its stuff

by | © Washington State University

Without jaws, most vertebrates-including us-would be stuck hanging around in the ocean or on the ground, unable to bite and scooping up or filtering food. We'd also be smaller. Instead, we're fearsome predators and herbivores, with big brains and an infinite range of food sources. We have evolution to thank for our fortune-and  Jon Mallatt to thank for helping us appreciate the fact.

"The evolution of jaws a half billion years ago was the single most important factor in the success of vertebrates," says Mallatt, associate professor in the School of Biological Sciences and in basic medical sciences.

Mallatt began his study of the evolution of jaws as a graduate student, with an analysis of how fish and lampreys feed. In subsequent years, his anatomical comparisons of fish, lampreys, and other animals led him to propose the then novel idea that jaws evolved as a breathing apparatus that became adapted for feeding, rather than just as a feeding apparatus.

In the process he also analyzed  the hagfish, a jawless vertebrate that has a mechanism of feeding similar to the lamprey's. Many considered it the most primitive vertebrate, but Mallatt wasn't sure.

"I wondered if hagfish were a good model of the primitive vertebrate that jaws came from or just a bizarre, slimy animal that doesn't tell us much about what early vertebrates were like," says Mallatt. "I always believed the second."

Mallatt found that he couldn't answer his questions about the hagfish and about the evolution of jaws just by studying the anatomical structures. "Anatomical characteristics are complex," says Mallatt. "Many genes control each one." It's much easier to model how evolutionary change happens at the genetic level, by looking at the DNA.

Mallatt chose the gene sequence of the 28S component of ribosomal RNA as a means to determine phylogeny, or how organisms are related to each other. Ribosomal RNA is fundamental to life, involved in making proteins, so its structure and function can't change much. If there is evolutionary change, it comes slowly, he says. Comparing the DNA sequence of this gene in distantly related animals can reveal how the animals are related to each other.

Mallatt, one of the first to use the 28S DNA sequences to study phylogeny in animals, confirmed what he had always felt about hagfish, that it is not a primitive vertebrate, but rather the second member of a natural group with the lamprey. Now he's using the sequences to address an even bigger question: how all animals are related to each other.

"If you want to tell the story of how important things evolved, you must get the relationships right first," says Mallatt.

Categories: Biological sciences | Tags: Genetics, Evolution

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