Barbara McClintock's Jumping Genes

Delivered on 10/27/17 in Stuart, FL

 
 

Jumping Genes Slideshow

Good morning! Madam Toastmaster, fellow members, and guests, today I want to tell you a story that involves a microscope, a lot of corn, and a remarkable woman. This is a short, simple, straight-forward story. But to give you the full context around it and to Today’s story involves a science lab, a microscope, lots of corn, and a fascinating woman. It’s a very short story, and I could tell it in 30 seconds… but what’s the fun in that.

We start in 1982 in a science lab where we find an 80-year-old woman. Her white lab coat says Barbara McClintock, Professor Emerita. Funny thing about Barbara is she was born in 1902 as Eleanor McClintock. As she grew up, her parents realized she was… let’s say, quirky. She loved to spend time alone and was a bit of a tomboy. Back then, Eleanor was a feminine, girly name. So they renamed her Barbara. And Barbara grew up very smart, an excellent student, and she graduated high school at 16.

But back to my story. In this lab, Barbara is surrounded by corn everywhere. Barbara had a special relationship with corn. After graduating high school, she really wanted to go to college. He mom said, “Barbara! How are you ever gonna find a man if you go off to college and become one of the boys?” But after begging and pleading, Barbara enrolled at Cornell University as one of the few women there. She joined the sorority and quickly realized that wasn’t for her: too many people, too much socializing. Instead, the picked up the banjo. She spent hours and hours practicing by herself, developing a skill that she could show off at the jazz band.

But she took 1 science class that changed her life. She decided she wanted to learn everything there was to learn about jeans. Not these jeans! These genes. Our traits passed from one generation to the next. Back then, genetics was a brand new field of science, and administrators at Cornell didn’t want women to major in genetics. So Barbara found a loophole: she majored in botany, the study of plants. That way she could research the genetics of those plants. And it just so happened that the campus was surrounded by cornfields, and Barbara fell in love with corn.

How many of you like corn? I love corn. I could it eat it every day and never get tired of it. But I’m telling you nobody--I mean nobody--is as obsessed with corn as Barbara. She said, “I know my corn plants intimately. It gives me great pleasure to know them.” [pause] Okay.. she’s a little quirky, but that’s Barbara for you.

But as I was saying… in the lab, surrounded by corn, Barbara walks over to a microscope. Barbara and this microscope are inseparable. Back when she first started here career in genetics, all we knew about genes is that they lived in chromosomes, these little structures here. That’s all we knew! Over the course of a decade, Barbara dedicated day and night to observing the corn plants under the microscope. She discovered that each chromosome had a different function, and she created a way to tell them apart. She also noticed chromosomes had these protective caps at the end. And after years of watching corn under a microscope, Barbara described every step of this intricate dance chromosomes do.

These are monumental discoveries. This stuff made its way to every genetics textbook in the 1930s and it’s still in textbooks today because it’s that important. The scientific community welcomed Barbara’s work with open arms. But they didn’t welcome her. She couldn’t become a professor at Cornell because she was a woman. So she moved to Missouri where she could teach, but she didn’t make nearly as much as male professors who weren’t as brilliant. But it didn’t matter to her. She had her microscope, and she loved her work. Can you imagine loving your job so much you don’t even want to sleep? That’s remarkable.

Back to my story. With her corn and her microscope, Barbara pulled out her index cards, where she had handwritten unanswered questions about genetics. That was her method. She’d ask these hard, complicated questions (sometimes out loud), then sit back and observe the corn to see if she could find the answer. Way back in the 1940s, she was already asking these tough questions. “How come, in a field of white flowers, you’ll sometimes see one red one? And why is it that when we hit corn with x-rays, the next generation of corn has these patchy speckles?” In trying to answer these questions, she realized there’s such a thing as a jumping gene. It turns out that, according to her theory, genes could jump around from one part of the chromosome to another. If that were true, it would explain all these questions Barbara had been asking.

She published paper after paper detailing her findings, and in 1951, she gathered the top geneticists from around the world so she could present to them the jumping gene theory. In that conference, the other scientists ridiculed her. They thought she was mad, insane, and not a real scientists. To them, she was just crazy corn lady.

But she put her head down and she continued to work. She stopped publishing her findings in 1953 because she was tired of being alienated. But she kept refining the jumping gene theory and studying corn all the way through the 50s. And all the way through the 60s. And all the way through the 70s. It wasn’t until the late 70s that other scientists started using new technology (x-ray crystallography, polymerase chain reaction, all these fancy words). And they found out that yeah, there is such a thing as a jumping gene after all. It turns out the crazy corn lady was right over 30 years ago.

And this brings us back to my story. Barbara is working on her latest research when the phone rings. It’s the Nobel Prize committee. They tell Barbara McClintock she won the Nobel Prize for her discovery of jumping genes, which she announced over 30 years ago. They tell her she’s the first woman to win an unshared Nobel Prize in Physiology and Medicine. She smiles, says thank you, and hangs up the phone.

And in true Barbara McClintock fashion, she puts her head down, and goes right back to work. Thank you.