A passion for the natural world drives many of our adventures. And when we’re not outside, we love delving into discoveries about the places we live and travel. Here are some of the best natural history links we’ve found this week.
Hurricane reveals 19th-century shipwreck: Last month, a wooden structure began to emerge from the sand of Daytona Beach, Florida. Locals had several theories of what it could be, including an old pier or bleachers from when NASCAR held races on the beach.
It is actually an old shipwreck. Hurricanes Ian and Nicole have caused enough beach erosion for the boat to become visible. Archaeologists began digging a trench around the mystery structure and found joints, ribs, and curved wood. They think that the frame belongs to a merchant ship from the 1800s.
There are no plans to fully excavate the wreck, but researchers have taken samples of the wood to analyze.
“We will let Mother Nature bury the wreck,” said maritime archaeologist Chuck Meide. “That will help preserve it. As long as that hull is in the dark and wet, it will last…hundreds more years.”
The transparent frog’s amazing secret
Scientists discover the secret power that makes glass frogs transparent: Frogs in South and Central America have a superpower. They can turn their transparency on and off. They make themselves transparent so that they don’t create any shadows. This way, they become almost invisible to predators.
The little frogs are nocturnal, hiding under leaves during the day. When they wake up, they turn their transparency off and return to an opaque reddish-brown.
Scientists now know how they achieve this. When the frogs sleep, they hide 90% of their red blood cells in their liver, so they can’t be seen through their transparent skin. They also shrink and pack their internal organs together to make them less visible.
We still need to understand how they can survive in these conditions. For most animals, restricting blood flow this much for hours would be fatal.
Do dolphins suffer from Alzheimer’s? Photo: Shutterstock
Alzheimer’s and the sick leader hypothesis in dolphins
Dolphins suffer brain damage similar to Alzheimer’s disease: Dolphins show markers of human Alzheimer’s disease. Scientists studied the brains of 22 stranded dolphins from five species off the Scottish coastline. Three of the dolphins had brain changes that are markers of Alzheimer’s.
It’s still unclear if these changes cause the same deficits associated with Alzheimer’s in humans, but this poses an important question. If it does cause similar symptoms, is this how they become stranded?
The “sick-leader” hypothesis suggests that a healthy pod of dolphins or whales can end up stranding themselves because they follow a leader who has become confused or lost. If dolphins suffer from dementia, it would support this theory.
Oldest known projectile points in the Americas uncovered: Archaeologists have found projectile points in Idaho that are thousands of years older than any other in the Americas. The 13 points, between half an inch and two inches long, are 15,700 years old. That is 2,300 years older than the previous oldest discoveries.
Researchers uncovered the tools at the Cooper’s Ferry site, where human bones date back 16,000 years. The points are very slender, with two distinct ends. One is sharpened and the other has a stem that let it attach to something.
Points like this were usually connected to spears or arrows, but these were likely attached to darts. The points are very similar to those found in Japan. This adds to the idea that there are clear connections between the Ice Age people of Northeast Asia and North America.
Stone projectile points discovered at Cooper’s Ferry in Idaho. Photo: Loren Davis
Asia’s Water Tower in crisis
The climate crisis is a water crisis in the Himalaya: The Himalaya are sometimes referred to as the Water Tower of Asia. The mountain range is the world’s largest non-polar reservoir of water as ice.
As rain and snow fall, the mountains act like sponges and soak them up. Over winter, it stores as ice, then melts in summer. Climate change disrupts this cycle. Rivers that originate in the Himalaya have less water each year, glaciers are shrinking, and groundwater is depleting.
In some areas, the number of glacial lakes is increasing. Many are close to bursting. This poses a threat to nearby human settlements. In other parts of the mountains, springs and rivers are going dry. People have to travel further to find water and struggle to irrigate farmland.
