Let's consider the case of identical twins who were similarly active as kids. But over the past three years of their adulthood, one of them has exercised regularly, and one of them hasn't. Would there really be much difference in their fitness levels and overall health? Or, in the end, does it really all come down to genetics? The NYT's Gretchen Reynolds reports on a recent study in which "it turned out that these genetically identical twins looked surprisingly different beneath the skin and skull. The sedentary twins had lower endurance capacities, higher body fat percentages, and signs of insulin resistance, signaling the onset of metabolic problems ... The twins' brains also were unalike."

+ Kevin Roose in Fusion: "I tried Silicon Valley's favorite brain-enhancing drugs." (I miss the days when this town still ran on coffee, egomania, and greed.)

More than eight thousand Americans died of heroin overdoses in 2013. Sometimes, when we see trends like this, it's hard to pinpoint the root causes. That's not the case here. We know exactly what cart was put before this horse. Almost 80% of heroin users previously abused prescription opiates.

It's time for Obamacare to get its annual legal checkup. Supreme Court justices appeared divided as they once again asked lawyers to turn their heads and cough up more answers during today's King v. Burwell case.

+ "One section of the law says that subsidies should flow to customers 'through an Exchange established by the state.' Plaintiffs argue that language means that only people in the state-run marketplaces -- and not those in federally run marketplaces -- can get the subsidies." The Upshot with answers to frequently asked questions about the case that could crush the Affordable Care Act.

"It was him." With those three words, the legal defense team in the Boston Marathon trial of Dzhokhar Tsarnaev put to rest any doubt about their client's participation in the crime. But the blame for that role, they argued, should be placed on Tsarnaev's older brother.

It's partly due to the early market saturation of computers and gadgets, but these days, the fastest growing category of online sales is men's clothing.

+ Elizabeth Segran in Racked: The Fall of the Hipster Brand: Inside the Decline of American Apparel and Urban Outfitters.

"In his mature years, he seems to have pretty much lived on cocaine and Courvoisier. Cocaine is notorious for promoting violence. Whatever he did for black people, Pryor regularly beat up women ... In a fight with a night clerk at his apartment building, he put out the man's left eye. Another time, his wife, hearing gunshots, ran to their bedroom and found him lying in the darkness with water and glass and little, struggling fish all over the floor. The man had actually shot his fish tank." On the tenth anniversary of his death, The New Yorker's Joan Acocella reflects on Richard Pryor's path to becoming Richard Pryor.

"For public health, this is really a game changer." McDonald's will phase out the purchasing of chickens that have been treated with human antibiotics in an effort to combat the rise of dangerous superbugs.

+ MoJo: "The concept of three square meals a day has practically zero to do with your actual metabolic needs. And our dogmatic adherence to breakfast, lunch, and dinner might actually be making us sick."

The Associated Press already uses software from a company called Automated Insights to "write" stories on corporate earnings. Now, they plan to let the robot overlords write sports stories too. This story happens to have a correction at the bottom. Humans...

+ Where does Buzzfeed source its content from? (Hint: Tumblr.)

"So walk me through how you came up with the idea of a selfie stick." Maclean's Adrian Lee talks to the Canadian who invented the Selfie-Stick. It wasn't really invented for what you might consider taking a selfie.

Sony's Amy Pascal, who was removed from the top spot at her studio following the Sony hack and The Interview controversy, hasn't been able to move into her new office space. It turns out that the space was last occupied by Seth Rogen and Evan Goldberg, and it's taking longer than expected to get rid of the pot stench. (Isn't that basically what led to all Pascal's problems in the first place?)

+ Presidential candidate Ben Carson just argued that "homosexuality is a choice because many people 'go into prison straight -- and when they come out, they're gay.'"

+ Wired: Why are audiophiles paying $1,000 for this man's vinyl?

+ Girl Scout cookies (their names, tastes, and textures) can vary widely depending on where you live.

+ Is that Vince Vaughn posing for stock photos?

+ You want to see what Prince looked like when he was on his junior high basketball team. And, as per usual, the Internet delivers. He was number 3 and always in key.