one year older

Hey, I share a birthday with the oldest known person. Honestly, I don't know if I would want to live that long...

Maybe it was a lifetime of chores on the family farm that accounts for Edna Parker's long life. Or maybe just good genes explain why the world's oldest known person will turn 115 on Sunday, defying staggering odds.

Scientists who study longevity hope Parker and others who live to 110 or beyond — they're called supercentenarians — can help solve the mystery of extreme longevity.

"We don't know why she's lived so long," said Don Parker, her 59-year-old grandson. "But she's never been a worrier and she's always been a thin person, so maybe that has something to do with it."

On Friday, Edna Parker laughed and smiled as relatives and guests released 115 balloons into sunny skies outside her nursing home. Dressed in pearls, a blue and white polka dot dress and new white shoes, she clutched a red rose during the festivities.