A new study released Tuesday found that children are more than twice as likely to be obese if they have an obese sibling, as opposed to if they have an obese parent. If the sibling is of the same gender, the risk is even stronger.

Researchers at the Mongan Institute for Health Policy at Massachusetts General Hospital looked at data from roughly 2,000 respondents to the Family Health Habits Survey, a nationwide survey of parents that looks at health between family members. The study, which will be published in the October issue of the American Journal of Preventive Medicine, found that younger children turn to older siblings as examples, whether good or bad.

"Younger children look up to their big brother or sister for behavioral cues, often seeking their approval," Dr. Mark Pachucki, the author of the study, said in a statement. "Siblings may spend more time each other than with their parents, often eating and playing sports together."

In one-child families, having an obese parent more than doubled the risk the child would be obese, though high levels of physical activity lowered the child's risk. But for households with two children, the obese parent risk factor was true for the older child, but not the younger sibling.

Having an obese older sibling created a risk more than five times greater than a non-obese sibling, but an obese parent didn't affect the younger sibling's risk. For siblings of the same gender, the results were even more alarming: The older sibling created an obesity risk 8.6 times greater for girls and 11.4 times greater for boys.

"While this study doesn't allow us to say that one sibling's obesity directly influences the other's, the associations we found are pretty interesting," Pachucki said. "Now we need to try and replicate these analyses with other national datasets and think through how to use this information to improve family-based health intervention models."

In an attempt to curb overpopulation, wildlife authorities in western Victoria, Australia secretly killed hundreds of koalas in 2013 and 2014.

Environment minister Lisa Neville said it was a "very challenging and complex issue" and the koalas were suffering due to ill health and starvation. "That's just not good enough and that's a terrible way to treat koalas," she said. "I'm wanting to make sure that we're taking the best action we can in this terrible situation of overpopulation."

Almost 700 koalas were captured, sedated, and then euthanized, Australia's ABC reports. Neville said that despite the cull, there are still too many koalas in the area. "We need to stop their suffering," she said. "Our priority must be about treating these koalas humanely." Neville said that she is working with experts to put together a management program for the marsupials.

When Disney brought on Leonard Nimoy to direct Three Men and a Baby, Tom Selleck thought, "Well, there's a good choice — you've got this guy with no emotions who's gonna do a funny little comedy," Selleck told Seth Meyers on Tuesday night's Late Night. But it turns out, "Leonard was irreplaceable," he added. Not only was Nimoy "a lovely guy — he's not Spock, he's a warm, funny guy" — but he was a "fine director" whose contribution to the 1987 hit can't be overstated." Not that everything went smoothly — Nimoy's decision to hire twin babies wasn't such a success. Watch Selleck's remembrance — and reason the first director didn't work out — below. —Peter Weber

More information is coming out about the homeless man shot and killed by police in Los Angeles on Sunday, including that he was a convicted bank robber who took over a French man's identity 15 years ago in order to gain entrance to the United States.

"He fooled a lot of people, including us, years ago," French consul general Axel Cruau told the Los Angeles Times. He said that the man, identified by the LAPD as Charley Saturmin Robinet, stole the identity of the real Robinet in the late-1990s. The man calling himself Robinet was convicted of a bank robbery in 2000, and Cruau said that French officials let the United States know that Robinet had assumed someone else's identity and was not a French citizen. The actual Charley Saturmin Robinet is still alive and living in France.

Students in Selma, Alabama, have started a petition to change the name of a bridge that honors a purported member of the Ku Klux Klan.

Protestors marching for black voting rights were beat after they crossed the Edmund Pettus Bridge on "Bloody Sunday," March 7, 1965, and for the 50th anniversary this weekend President Obama will visit the landmark and give an address. Most area residents don't know much about Pettus, who was a Confederate soldier, U.S. Senator, and alleged grand dragon of the Alabama Klan in 1877. "They're responsible for too much death and misery," Rev. Joseph Lowery, a veteran civil rights leader, told The Associated Press. "We don't need to honor them. I'm with the kids. Let's change it."

There are conflicting opinions on Pettus; Selma historian Alston Fitts believes he was not part of the KKK, as Selma did not have much Klan activity following the Civil War, while history professor Michael Fitzgerald at Minnesota's St. Olaf College is almost certain Pettus was a member of another terrorist organization, the White League. Pettus himself shared his insights into race relations when he testified in front of a congressional committee investigating the KKK in July 1871: He stated that whites were the real victims in the post-Civil War South, not blacks.

On Tuesday night, the Alabama Supreme Court ruled, 7-1, to bar state probate judges from issuing marriage licenses to same-sex couples. The order is a direct violation of several orders by U.S. District Judge Callie Granade, allowed to take effect by the U.S. Supreme Court. The justices also issued a lengthy defense of defining marriage as between one man and one woman.

Alabama Chief Justice Roy Moore sat out the vote, but the six-justice majority asserted in its unsigned ruling that the state court could "interpret the United States Constitution independently from, and even contrary to, federal courts." One judge on the all-Republican court partially assented, and Justice James Gregory Shaw was the lone dissenter, warning his colleagues that they are overstepping their authority and "and potentially unsettling established principles of law."

Since Moore originally ordered the probate judges to disregard Judge Granade's ruling, Alabama has been a confusing jumble of marriage law. Before Tuesday's ruling, at least 48 of the state's 67 counties were issuing same-sex marriage licenses. The state order didn't say what it proposes to do with the "purported" same-sex marriage licenses already issued.

The gay-rights group Human Rights Campaign called the ruling "bizarre," "outrageous and baffling," and "extralegal." "The Alabama State Supreme Court does not have the authority to interfere with a federal court order," legal director Sarah Warbelow said in a statement.

University of Alabama constitutional law professor Ronald Krotoszynski agreed, suggesting to The New York Times that the state court is "trying to lobby" the U.S. Supreme Court ahead of its big same-sex marriage case this term. "You might read it as kind of a brief or a political document to the Supreme Court of the United States," he said.

One of the most active volcanoes in Chile erupted early Tuesday, causing thousands to flee from the city of Pucon.

The Villarrica volcano rises above Pucon, 400 miles south of Santiago. At about 3 a.m., lava started to flow and heavy smoke filled the air, and authorities became worried that mudslides would be caused by melting snow. "It was the most amazing thing I've ever seen," Australian tourist Travis Armstrong told The Associated Press. "I've never seen a volcano erupt and it was spewing lava and ash hundreds of meters into the air. Lightning was striking down at the volcano from the ash cloud that formed from the eruption."

As the volcano activity died down, some residents and tourists returned to Pucon, and by the middle of the day stores were open and public transportation was up and running. No injuries were reported. —Catherine Garcia

In an attempt to find some investors to make his Twitter screenplay Ghost Plane a reality, Aziz Ansari figured he should take advantage of his appearance on Conan and turn it into a table read. Ansari and Andy Richter were into it, but Conan O'Brien's sad attempt at portraying Jennifer Lawrence got him reprimanded by Ansari, who told him, "You are going to have to try harder, Mark Cuban is watching this thinking about whether he should invest!" Watch the clip (with a few expletives) below. —Catherine Garcia

If the organizers of Women on $20s have their way, you won't be seeing Andrew Jackson's face on the $20 bill much longer.

Instead of the seventh president of the United States, this new group would like to see Eleanor Roosevelt, Harriet Tubman, Rosa Parks, or Susan B. Anthony staring back on the $20. They're targeting this particular bill because 2020 will mark the centennial of the 19th Amendment, which gave women the right to vote, and also because they aren't fans of Jackson and his authorization and enforcement of the Indian Removal Act of 1830, along with other controversies. Susan Ades Stone, executive director of Women on $20s, told The Washington Post that Jackson wasn't even fond of paper currency, and preferred gold and silver. "The guy would be rolling in his grave to know that every day the ATM spits out bills with his face on it," Stone said.

Women on $20s has a list of 15 women they say would make excellent replacements for Jackson, and as soon as they get 100,000 signatures on their petition it will be sent to the White House. Their plan might not even be that far-fetched — The Post says that in 2013, a similar campaign in Britain was successful and put Jane Austen on the 10-pound note. —Catherine Garcia

Police are investigating reports of gunfire near the National Security Agency's headquarters in Fort Meade, Maryland, on Tuesday evening, NBC Washington reports. A spokesperson for the U.S. Park Police said that the NSA is looking into damage to one of its buildings that appears to have been caused by the gunshots. An NSA spokesperson said no one was injured.

After nearly three decades, Oprah Winfrey is saying goodbye to the Windy City and will close her Chicago-based Harpo Studios by the end of the year.

Chicago has "been everything for me," she told The Hollywood Reporter. "I've spent more hours in this building than I have any other building on Earth.... We were here when there was nothing but hoes and rats on the street, and now it's one of the hottest neighborhoods [in Chicago]. The time has come to downsize this part of the business and to move forward. It will be sad to say goodbye, but I look ahead with such a knowing that what the future holds is even more than I can see."

Winfrey is transitioning the company's productions to OWN headquarters in Los Angeles, and she broke the news to the Chicago team in person on Tuesday. For the past five years, the media mogul has been going back and forth between Hollywood and Chicago, and she decided that the whole team had to be under one roof. About 200 employees are impacted by the closure; they will remain employed through December.