It’s been a rough week for Baby Boomers: First the Professor from “Gilligan’s Island,” actor Russell Johnson, died at the age of 89. And now the Captain and Tennille have called it quits after 39 years of marriage.

Toni Tennille, 73, filed for divorce from Daryl Dragon, 71, in Prescott, Ariz. on Jan. 16. The Grammy Award-winning duo was known for a string of catchy (and sometimes-annoying) 1970s hits like “Love Will Keep Us Together,” “Muskrat Love” and “Do That to Me One More Time” and even hosted their own television variety show for a season.

The split was confirmed on the couple’s Web site with the explanation: “…almost all people naturally evolve over time, & sometimes hidden feelings start to be uncovered.”

TMZ reported that Dragon said, “I don’t know why she filed.  I gotta figure it out for myself first,” and that the couple remains together in the same house.

Health insurance coverage is mentioned in the divorce documents filed by Tennille, according to TMZ, fueling speculation that health issues or health insurance may somehow be responsible. Tennille had reported on her blog in 2010 that Dragon suffers from a neurological condition, similar to Parkinson’s, characterized by such extreme tremors he can no longer play keyboards.

Whatever the reason, the Captain and Tennille are just the latest couple qualifying for AARP membership who’ve decided to untie the marital knot. A study from Bowling Green State University found that divorce among couples age 50 and older, once practically unheard of,  doubled between 1990 and 2009, and one in four couples divorcing is over 50. A new phrase, “gray divorce,” has been coined to describe the trend. Sounds better than “geriatric divorce,” doesn’t it?

One of the most surprising to me was former Vice President Al Gore and Tipper Gore, who announced their separation in 2010 just days after their 40th wedding anniversary. Who could forget that kiss at the 2000 Democratic National Convention?

Not so shocking: The end of the marriage between Maria Shriver and former California Gov. Arnold Schwarzenegger after the news broke that he’d fathered a child with the family’s housekeeper.

Last summer, Russian President Vladi­mir Putin and wife Lyudmila revealed that they were divorcing, just two months before their 30th anniversary.

Why are baby boomers turning to divorce as they approach retirement age? “Boomers, known as the ‘me generation,’ are often committed to self-fulfillment as much as to marital vows,” said Los Angeles psychotherapist Phyllis Goldberg, PhD. “The kids are out of the house and without that buffer, couples may wonder, ‘who is this person and do I want to spend the rest of my life like this?’ ” 

As people live longer, maybe they don’t want to “settle,” Goldberg said. They don’t want to compromise. They grow apart. They don’t have as much in common.

Add to that the growing independence of many women who may have their own careers. “They’re financially as well as emotionally independent,” Goldberg said, although women are still more likely than men to suffer financial difficulties after divorce.

Around two-thirds of “gray divorces” are initiated by women, said Rosemary Lichtman, PhD, who shares a therapy practice with Goldberg. The two women also have a Web site,

About 25 percent of divorces initiated by women are due to a husband’s infidelity, Lichtman said. “Often their motivation is to enjoy the years ahead by escaping an unsatisfying ’empty-shell’ marriage and focusing on their own goals and personal needs instead,” she said. “Their expectations for marriage may have changed from one based on roles and companionship to one that creates personal happiness.”

We may see more and more couples, together for years, who decide it’s time to go their own ways. The reasons may not seem clear-cut to the rest of us. And we may never know or understand why the Captain and Tennille, who looked so much in love while they performed, could even consider divorce.