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The Secret of Life - Wendy Sullivan

The Secret of Life - Wendy Sullivan

Mixed Media

24" x 36"


Observation, Inference, and the Discovery of DNA
Mary Bahr

Ernie crept into his parent’s closet looking for a Christmas present. Tucked away between coats he saw the dark outline of a large box. A noise on the stairs propelled him back into the hall where he bumped into Aunt Mary carrying her suitcase.
“You look like the cat who stole the cream, Ernie,” she said with a hug and a smile.

Ernie took her suitcase and whispered “I am just checking if they got the right bike. It’s in the closet”

“How do you know?’ Asked Mary, who had just seen the actual bike down in the garage.

“I saw a bike box,” Ernie replied.

“You didn’t observe the bike, you inferred it was there.” Mary corrected him.

“What?” Ernie replied, confused.

“You saw a box the right size and shape and inferred (interpreted) it contained a bike,” Mary explained.

Ernie frowned, “Do you know something?”

Aunt Mary tried to look innocent, “You’re inferring again. Let me explain.”

Ernie put her suitcase in the guestroom and they went downstairs to relax on the porch overlooking the river.

Mary Began, “My favorite story about observation and inference is the discovery of DNA.” 

Ernie settled back with his cold soda to listen.

 “Let’s visit a 1950s Kings College lab in London. Located in a basement that wound around a WW II giant bomb crater 58 feet wide, it was a typical British lab that an American scientist described as "similar to working in a Barn.” Construction noise and dust completed the scene” 

WWII history buff Ernie perked up.

“It’s midnight in the lab and chemist Rosalind Franklin, dressed in an evening gown and jewels, drops in to work on her X-Ray Crystallography machine. She pulls a yogurt cup out of her bag and inserts it into the machine which squats in a freezer. Rosalind is trying to photograph nucleic acids that scientists think are connected to genes.” 

“So, I thought molecules were too small to photograph.”  Ernie objects.

“You’re right if you use light”. Aunt Mary explains, “But Rosalind’s machine used x-rays to photograph crystallized molecules. After working night and day for months, she finally produced an extraordinarily accurate image of nucleic acids called Photo 51.”

“So how do we get to DNA?” Ernie asked

Aunt Mary nodded in approval, “Good question! The other person in the lab that night, biologist Maurice Wilkins, also studied nucleic acids. Aristocratic Rosalind intimidated Maurice. He belonged to the 1950s "Boys Science Club" that excluded female scientists. Wilkins worked with two other scientists, James Watson, and Francis Crick. Wilkins gave them Photo 51 claiming it was his.” 

Ernie recognized Watson and Crick. “Didn’t they discover DNA and get a Nobel Prize?”

Aunt Mary nodded, “You are right about the Nobel prize, but the discovery of DNA would never have happened without Rosalind’s photo 51 observation from which Watson and Crick inferred the double helix structure of DNA.”

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