Just let the belly guide you. (Medioimages/Photodisc/Getty Images)

Ardi grabbed the headlines this weekend. You know this. You were probably feeding fossil facts into your cocktail banter like your name was Ardipithecus ramidus. But here’s a story that probably escaped your notice, unless your midsection is shaped like a bowling ball and you have to make frequent bathroom trips: Pregnant women walk funny, and they have for millions of years. They waddle. It’s a kind of wobbly shuffle with the lower back extended and the belly proudly at the helm of the mother ship.

The funny walk is a good thing. It helps impending mothers distribute all the baby weight. And according to anthropologists Katherine Whitcome, Liza Shapiro and Daniel Lieberman and their study in Nature, modern moms weren’t the first to come up with it. It seems that Lucy, bless her famous hominid heart, and her female friends may have similarly adapted their bodies to the increased load of a big pregnant belly millions of years ago. Such an adjustment has persisted on the evolutionary path from Australopithecus to Homo. The researchers further hypothesize that ancient pregnant hominids may have had lower back pain, too. They don’t say whether the matriarchs also had cravings for pickles and ice cream or demands for foot rubs.

For their work on the waddle, Whitcome and her colleagues were awarded the Ig Noble physics prize. As you canny readers of the HowStuffWorks.com blogs might know, we’re covering the 2009 Ig Noble awards this week. Woohoo! Unlike the Noble prizes that honor advances in serious stuff like telomeres, the Ig Nobles heartily celebrate science that’s pretty darn funny. Read Josh’s, Sarah’s and Robert’s posts so far on one-hundred-trillion-dollar notes, happy cows and bar brawls if you didn’t find this one the least bit funny. The folks at Improbable Research probably wouldn’t mind a visit, too. But they didn’t put us up to this. Promise.

Go ahead. Read ‘em and chuckle:
Ig Noble Prizes 2009: If You Give a Cow a Name…
Ig Noble Prizes 2009: Bar Fights and Tequila Diamonds
Robert Lamb made me write this: Zimbabwe and the Ig Nobel Prize
How do the Ig Noble Prizes Work?
Stuff You Should Know: What is an Ig Nobel Prize