Human evolution is all about survival of the fittest. Over thousands of generations, the weak have been weeded out, and the strong have survived. But how would that kind of natural selection work in other settings - like, say, music? Well, one biologist decided to find out. He designed a website where listeners can rate collections of notes according to their musicality. The nice sounds survive, and other users listen to them. But the ugly sounds die off.
This is WEEKEND EDITION from NPR News. I'm David Greene. This morning, Egyptians have their first-ever democratically elected president. Mohamed Morsi, the Islamist Muslim Brotherhood candidate has been declared the winner of hotly disputed election.
This is WEEKEND EDITION, from NPR News. I'm David Greene. Americans are growing more and more frustrated with the gridlock in Washington, D.C. In a Gallup poll out this month, only 17 percent of Americans said they approve of the job Congress is doing. Well, Christine Quinn says it does not have to be that way. She is the speaker of the New York City Council, and she's taken heat for seeming too close to the executive branch - that would be New York Mayor Michael Bloomberg.
An Arizona law that went into effect last year essentially ruled that the Mexican-American studies program offered in the Tucson public school system was divisive and should be scrapped. At the end of the first semester without the classes, hard feelings still linger.
For eight years, until this past January, Lorenzo Lopez taught Mexican-American studies at Cholla High in Tucson, Ariz., the very school from which he graduated in 1992.
A truck drives down a highway on Salang Pass in Afghanistan's Parwan province in December. The Salang Tunnel, which crosses under the pass, provides a vital link between Central Asia and northern Afghanistan to Kabul.
Credit Sean Carberry / NPR
A truck carrying food for NATO troops drives into the northern entrance of the Salang Tunnel. This truck waited several days to be able to enter the tunnel.
Credit Sean Carberry / NPR
Vehicles drive one of the many switchbacks as the Salang Highway climbs from just over 5,000 feet at the valley floor to the Salang Tunnel, 11,000 feet up in the Hindu Kush range.
The U.S. military says it's spending an extra $100 million a month on the war in Afghanistan since Pakistan closed its border to NATO supply convoys. Now, NATO is using a route thousands of miles longer through Russia and Central Asia.
That route passes through Afghanistan's perilous Salang Tunnel, 11,000 feet up in the Hindu Kush mountains. The Soviet-built tunnel was heralded as a marvel of engineering when completed in 1964.
But years of war, neglect and geology have turned it into a dangerous bottleneck.
President Bashar Assad addresses Parliament on June 3. Syrians in the capital, Damascus, have become more willing to speak out, though they still don't want to be identified by name. Many feel the Assad regime is losing control of parts of the country.
Credit Rim Haddad / AFP/Getty Images
A Syrian soldier looks on as shooting takes place in the Damascus suburb of Douma last month. Sporadic fighting has been breaking out in and around the capital Damascus in recent weeks.
In Damascus, Syrians now openly speak their minds, but often won't offer a name for the record.
The "wall of fear" is crumbling even in the capital, where the security police have the heaviest presence. Syrians have lived under surveillance and emergency law for years, but after 15 months of anti-government protest and a brutal response by the regime, the killings have changed people.
Anticipation has reached a fever pitch, and the waiting is almost over.
This week, the Supreme Court is almost certain to issue its decision on the constitutionality of President Obama's health care law. The decision could have far-reaching implications for the legal landscape, the nation's health care system and even the Supreme Court's legacy.