When it comes to baby names, Jennifer Cifelli has a front-row seat as trend-spotter. She's the birth registrar at Pennsylvania Hospital, one of the most prolific maternity centers in the country.

So when the Phillies won the World Series last year, she was first to see the multiplying of Coles and Chases - care of Hamels and Utley. They started "coming out of the woodwork," she said.

Sure enough, last year, Chase was the 24th most popular name for boys born in Pennsylvania, and Cole was 45th - quite a jump from 10 years ago, when the names were 85th and 68th, respectively.

Baby names are funny birds. In a blend of tradition and trendiness, it seems parents attempt to choose something that sounds original but inevitably ends up on the most popular list. Still, we, as name-givers, are getting better in the originality department.

Of the approximately 5,000 names recorded each year with the Social Security Administration, the most popular names nationally in 2008 were Emma (which displaced the No. 1-since-1996 Emily) and Jacob. You undoubtedly know a couple of toddlers running around with those names, right?

Yet only 1 percent of boys born last year were Jacobs, and only 0.9 percent of girls were Emmas. Compare that with 1978, when the most popular boy's name - Michael - was given to nearly 4 percent of all boys born in the United States. Of the girls born that year, 3.3 percent were named Jennifer, the most popular girl's name. Go back one more generation, to 1951, and a quarter of all male babies had one of only six names (James, Robert, John, Michael, David, William), while Linda, the top girls' choice, alone was the name of 4 percent of all female newborns.

"Something happened when children under 5 became a market, maybe around 1983, with things like Baby Gap," said Christine Farina, associate professor of communication at the Richard Stockton College of New Jersey. "We became more conscious of each other at the same time. You wanted an upscale, slightly different name, but not too different. Gap, Williams-Sonoma, all these types of places that affected pseudo-sophistication made the difference. So that is the change from, say, Michaels and Jameses everywhere, and more Jacobs and Emmas and Joshuas."

But how do these "new" names get caught up in the moniker madness?

Like the sudden local propensity for Cole and Chase, media ubiquity can push forward unusual names, at least for a short time. Marlee and Marley, as in the wearisome dog of book and movie fame, were among the biggest upward movers for girls between 2007 and 2008, as were Miley (as in Cyrus), and Rihanna (even though the pop singer's real first name is Robyn, which isn't even in the top 1,000).

Some names, though, have an almost inexplicable rise to prominence. Mia, for instance, was 383d among girls' names in 1989, but is 14th now. Ella, which was 938th in 1991, is now 19th. Then there's Isabella, which a decade ago was not even in the top 1,000 but in 2008 was second behind Emma. The most famous Mias, Ellas and Isabellas (Farrow? Fitzgerald? That queen with Ferdinand?) are hardly current.

Joshua Berger, a professor of marketing at the Wharton School of the University of Pennsylvania, has one explanation: It's time.

Many of these names had their heyday when our grandparents' generation was born, then faded from the landscape. With the passage of time, they become prime for rediscovery.

"Names that were popular 60 to 80 years ago have been unpopular for long enough that it is safe to reinvent them as a new fashion wave," he said.

These days, even the Old Testament is new, and the trend stands to last through our tumultuous economic times, according to Michael Aaron Rockland, a social historian and a professor of American studies at Rutgers University. Keep an eye out for these boy's names - Jacob, Daniel, Joshua, David, Noah, and Joseph - which have been popular for several years now.

"People feel secure and grounded with an Old Testament name, especially in uncertain times," said Rockland, who named his own son Joshua. "While things go through cycles, I think this is a time when people are searching for solidity and a sense of tradition."

The longevity of a name may also be linked to cultural goings-on, according to Berger. Using baby names as a way to study how quickly trends rise and fall, he has discovered that the more quickly a trend becomes popular, the more quickly it fades. Jacob's slow rise, for instance, makes a longer stay at the top of the chart more likely. By this theory, Isabella could have a short stay at its current height.

As for predicting popular names for the future, Berger said that offshoots of current favorites might have a good shot. Take Jason. The more Jasons born this year, the more likely other names with similar sounds - say, those beginning with J, like Jordan and Jack - will be popular next year.

He said this also helps explain why names like Hayden, Kaiden, and Landon rise and fall together - it's the similar-sounding last syllable. In fact, among twins, almost all of the most popular pairs, according to the Social Security Administration, share sound similarities: Jacob/Joshua, Daniel/David, and Jayden/Jordan were the most popular in 2008 for boys, and Gabriella/Isabella, Madison/Morgan, and Ella/Emma were for girls.

Overall, it seems it is hip to be square. In other words, radical is passe.

"You wouldn't name your kid Venus or Raven anymore. That would be too '60s," said Stockton's Farina. "Now everyone seems to want to be in an Ann Taylor mode."

That means somewhat sophisticated, and a little different - just not too different.

That could be why Barack hasn't topped any charts (Cifelli said she's seen one), and neither has Shiloh (she's seen only a couple).

"Briana, Ella, Elena, that seems to be the way it is going, and maybe more 'juniors' with their fathers' names than before - for all races," she said. "Not boring, but not too unusual, either."

Top 10 Names for 2008

Boys

1. Jacob

2. Michael

3. Ethan

4. Joshua

5. Daniel

6. Alexander

7. Anthony

8. William

9. Christopher

10. Matthew

Girls

1. Emma

2. Isabella

3. Emily

4. Madison

5. Ava

6. Olivia

7. Sophia

8. Abigail

9. Elizabeth

10. Chloe