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.
Oldest DNA reveals a two-million-year-old lost world: Researchers have sequenced ancient DNA that dates back an incredible two million years.
The DNA samples, taken from the soil in northern Greenland, show genetic traces of mastodons, reindeer, geese, several trees, and marine life. Unusually, the samples show arctic and temperate species living side by side. There is no modern-day equivalent of such species living in the same ecosystem.
There are few animal fossils from his period and so the environmental DNA has provided a window into what this region was like two million years ago. It shows that at that time Greenland was much warmer and consisted of a forest ecosystem.
Ancient ways of fire management
Indigenous Americans broke the cycle of destructive wildfires: In the United States, wildfires follow a cycle. There are wet years, then hot and dry ones, and then there are fires. By looking at scarred tree trunks, archaeological information, and by taking oral histories, researchers have found that between 1500 AD and 1900 AD, Indigenous people managed to break the cycle.
“On a smaller scale, people are having a very strong influence that’s able to dampen the effects of climate,” paleoecologist Dave McWethy said. The scarred tree trunks are a permanent record of when fires took place.
Native people managed the landscape in traditional ways, using wood as fuel and using fire to clear land. They used up the fuel harvested from the land in the hot and dry years, taking it out of circulation before it could become kindling for a wildfire.
“This is what Indigenous people have been telling us for a long time, but I don’t think Western science has always listened,” forest ecologist Lori Daniels said.
Two female Arabian leopard cubs are thriving in Saudi Arabia. Photo: David Chancellor/Leopard Breeding Centre
Arabian leopard cubs: At the leopard breeding center in Taif, Saudi Arabia, two Arabian leopard cubs are thriving. They were born earlier this year and could play a key role in bringing their species back from the brink of extinction.
The two cubs will remain in captivity their entire lives, but when they are old enough to breed, their offspring will hopefully be released on the Arabian Peninsula. Conservationists believe that there are only two or three wild leopards left in the area. The leopard population declined rapidly because of hunting and a lack of food.
The biggest challenge will be teaching captive-born leopards the skills to survive in the wild. Cubs usually learn these skills from their mother. Making it harder still, conservationists need to train them without the leopards forming positive associations with humans.
The rise of mammals
Mammals poised to take over Earth before dinosaur extinction: It is commonly thought that mammals were able to dominate Earth because of the mass extinction of the dinosaurs. But an analysis of 1,600 fossils shows that mammals were diversifying long before the asteroid strike.
Several “freshwater and small terrestrial animals were more resilient and better equipped to weather the extinction” than dinosaurs, researcher Thomas Cullen explained. They were able to eat a variety of foods, live in different climates, and reproduce quickly. They were expanding into many habitats even before the mass extinction event.
An illustration of swimming dinosaurs. Image: Yusik Choi/Smithsonian
Diving dinosaurs
First swimming dinosaur discovered in Mongolia: Dinosaurs were very diverse, but there had been almost no evidence of a species that went into the water, until now.
In the Gobi desert, paleontologists have discovered the remains of a swimming cousin of the Velociraptor. These aquatic dinosaurs were only a foot long with long jaws full of tiny teeth. Named Natovenator polydontus, their name means “many-toothed swimming hunter”.
“We realized that this was something special. It was beautifully preserved with a nice skull and an extremely long neck,” paleontologist Sungjin Lee said.
The dinosaur’s ribs resemble those of penguins and auks. The streamlined skeleton allowed the dinosaur to swim efficiently and has not been seen in any other dinosaur species. The small, sharp teeth suggest they could eat small, slippery prey.
