May 5, 2000

Sweetwater District Students Win Big at County Science Fair

A Bonita Vista High senior studying the genetics of native orchids and a SAILS seventh grader studying the taste sensitivities of the common housefly were sweepstakes winners in the 46th annual Greater San Diego Science & Engineering Fair held in Balboa Park.

Arietta Fleming-Davies of Bonita Vista High and Michael Evaristo Jr. of SAILS (Sweetwater Academy for Individual Learning Styles) of the Sweetwater District earned among the highest honors of the competition and were joined by 59 other Sweetwater district students who also won in different categories.

Arietta studied the DNA of the native orchid species designated Epipactis gigantea and found that they reproduce sexually. During her research, Arietta took samples from two of the three known San Diego County locations for the orchid—Noble Canyon in the Cleveland National Forest and Mission Trails Park.

By extracting DNA from cells in the leaves of the plants, Arietta discovered extensive genetic variations, meaning the orchids were reproducing through pollination rather than through the vegetative process of sending off shoots.

"The variation between both populations also showed there were specific differences between the populations in Noble Canyon and Mission Trails Park, which is good for the survival of the population," said Arietta, who was participating in her fifth science fair.

Arietta's research was supported by the San Diego Orchid Society and earned her a $2,000 scholarship from the Reuben H. Fleet Science Center and a $2,500 prize from the Biomedical Research Institute.

Arietta will attend Stanford University in the fall, where she'll study biology.

This was the first science fair competition for Mitchael Evaristo, Jr, a seventh grader at SAILS, and his participation was the first ever by a SAILS student.

Mitchael raised flies from pupa and then studied which form, and concentration, of sugar the flies preferred.

Mitchael created five different concentrations for each of three sugars —sucrose, fructose, glucose and two artificial sweeteners— saccharin and Nutrasweet. He dipped rings of paper into each of the concentrations and planted the flies on the sugared paper. With a special camera equipped with a magnifying lens, Mitchael videotaped the flies' actions and recorded the number of times they licked each concentration.

He found that the flies really like the sucrose, frustose and Nutrasweet. They didn't like glucose and they hated the saccharin, he said.

How could Mitchael's discovery be useful?

"I thought it would be handy to see what flies like for the setting of traps," Mitchael said.

The win —which earned Mitchael $200— was very exciting for his parents and the teachers at SAILS and gratifying for him, he said.

"I've always had an excitement about science," said Mitchael, who says he would like to go to UCSD and be an oceanographer.

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