Credit Ian Harrowell, Christine Austin, Manish Arora / Harvard School of Public Health
This model of a molar shows color-coded barium banding patterns that reveal weaning age.
Credit Alyson Hurt, Adam Cole / NPR / Christine Austin / Westmead Centre for Oral Health
Top: Lines on a 100,000-year-old Neanderthal tooth mark the passage of time. Bottom: The distribution of barium shows dietary transition: low barium before birth (1), high barium during breast-feeding (2) and falling barium as the Neanderthal transitions to a mixed diet (3).
Our closest relatives, chimpanzees and gorillas, breast-feed their offspring for several years. Some baby orangutans nurse until they are 7 years old.
But modern humans wean much earlier. In preindustrial societies, babies stop nursing after about two years. Which raises the question: How did we get that way? When did we make the evolutionary shift from ape-like parenting, to the short breast-feeding period of humans?
After five marathon sessions debating 150 proposed amendments, the Senate Judiciary Committee approved a landmark rewriting of the nation's immigration laws this week — and the bill emerged largely intact.
Three Republicans voted with the panel's 10 Democrats on Tuesday night to forward the bill to the full Senate. That strong showing followed a wrenching choice for Democrats on the committee: whether to risk shattering support for the bill by amending it to recognize equal rights for same-sex couples.
Public opinion about the scandals plaguing the Obama administration is decidedly mixed.
Republicans believe that the trio of controversies — concerning Benghazi, the IRS, and the Justice Department snooping on media phone records — are evidence enough that President Obama is either running a government motivated by partisan politics, or is badly out of touch.
Democrats, however, are proving to be much more forgiving.
For the first time, the U.S. government has acknowledged killing four American citizens in lethal drone strikes far outside traditional battlefields, confirming information that had been widely known but has only recently been unclassified under orders of the president.
What is the case against Wisconsin farmer Vernon Hershberger really about? It depends on whom you ask.
To hear the prosecution, it's about licensing, not raw milk: Hershberger, a dairy farmer hailing from the town of Loganville, is on trial this week for operating without three licenses. He's also accused of continuing to sell raw milk to members of his private club after he was ordered not to.
If convicted, the father of 10 faces more than a year in jail and more than $10,000 in fines.
"I'm shocked by the optimism here," Howard Yana-Shapiro, the chief agricultural officer for Mars Inc. said Tuesday to the audience of the Chicago Council on Global Affairs' Global Food Security Symposium in Washington, D.C.
Seated there before him were some of the leaders from the wealthiest international organizations and multinational companies of the fight to end hunger. And Shapiro told them they weren't even close.
A British driver who struck a cyclist with her car — and who then bragged about the incident on Twitter — has issued an apology. The incident caused an uproar after the collision Sunday.
"Definitely knocked a cyclist off his bike earlier - I have right of way he doesn't even pay road tax! #bloodycyclist," tweeted Emma Way, in a message that has been widely circulated despite her apparent attempts to delete it, and seemingly her Twitter account, @EmmaWay20.
Add this to the list of Democratic worries surrounding the wave of Obama administration scandals: the downstream effect.
It's prime candidate-recruiting season right now — the period in the two-year election cycle when officials in both parties fan out across the map in hopes of persuading prospective candidates to run for Congress. Issues and money always get plenty of attention, but the ability of party leaders to attract strong, capable candidates is vital to success on Election Day.