Health & Science
A much older human ancestor
A set of human-like footprints dating to 5.7 million years ago, discovered on the Greek island of Crete, challenge existing theories of how and when our species evolved. Prior to this discovery, the oldest confirmed hominin footprints were found in Tanzania and dated at a maximum of 3.65 million years. Anthropologists believed these ancient human relatives were isolated in Africa for several million years before spreading out to Europe and Asia. A new analysis of the prints found in Crete could complicate this evolutionary tale. “What makes this controversial is the age and location of the prints,” researcher Per Ahlberg tells ScienceDaily.com. At the time the prints were made, nearly 6 million years ago, Crete was still part of the Greek mainland and early human ancestors were theoretically still living in Africa and had ape-like feet. The fossils in Crete, however, have distinctly hominin-like features, including a predominant “big toe.” The animal didn’t have claws and walked upright on the soles of its feet—not its toes. “This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate,” Ahlberg says.
Exoplanets with water?
Scientists searching for alien life have homed in on three rocky, Earth-size planets 39 light-years from Earth that may have liquid water on their surfaces, Smithsonian.com reports. The planets closely orbit a dwarf star in a solar system known as Trappist-1, but astronomers believe they originally formed much farther away, in a cold zone filled with crystals of water ice. The planets may have captured this ice, forming vast stores of water above and below ground. Using the Hubble telescope, the scientists calculated that three of Trappist-1’s seven planets are within their star’s “Goldilocks zone”—the sweet spot where temperatures are neither too hot nor too cold for liquid water and life. The study’s co-author, Julien de Wit, says “hopes are high” that water and some form of life exists in one or more of these planets.
Using Zika to attack brain tumors
The properties that make Zika devastating for unborn babies could make it an effective weapon against a common and deadly form of brain cancer. Zika targets neural stem cells—the precursors of neurons and other brain cells. For babies, this can result in severe birth defects. The virus isn’t as harmful for adult brains, which have fewer stem cells. With this in mind, scientists investigated whether Zika could be used to destroy stem cells that drive the growth of aggressive brain tumors, known as glioblastomas. The researchers found that Zika targeted and killed human glioblastoma stem cells in a lab without harming normal brain cells. Experiments on mice with glioblastomas also showed that Zika therapy slowed tumor growth and extended the rodents’ lives, reports BBC.com. “It looks like there’s a silver lining to Zika,” says researcher Michael Diamond. He says further testing is needed to make sure weakened forms of the virus are safe for humans.
Health scare of the week
Floodwater and mold
As the floodwaters of Hurricanes Harvey and Irma recede, millions of people face a new threat: mold. The humid Texas and Florida climates create the perfect breeding ground for mold, which can appear almost instantly after a hurricane—something many victims of Katrina, Sandy, and Ike learned the hard way, The Washington Post reports. Mold thrives on moisture, oxygen, and organic matter such as cloth, wood, and dust, and releases lightweight spores that spread easily through air. Intensive exposure to mold can cause coughing, congestion, sore throats, wheezing, and skin rashes. Mold can also trigger severe reactions in people with asthma or weakened immune systems. Removing mold from homes can be costly. Household items that can’t be disinfected, such as rugs, upholstered furniture, and mattresses, have to be discarded. Contaminated drywall and insulation must be replaced. “The economic impact of mold and water damage can be severe,” says scientist Mary Hayden, who studies how weather can affect health. “It’s devastating on all levels.”