Weekly News Bites: An ancient migration route, chemical cues for beetles, and mountaintop microplastics

Asia Research News monitors the latest research news in Asia. Some highlights that caught our attention this week are the confirmation of a route that humans took to migrate from Africa, how pheromones can influence beetle behavior, and microplastics found in cloud water.

Researchers from University of Southampton and Shantou University found that humans used a route of ancient rivers through Jordan to migrate north from Africa over 80,000 years ago. The people stopped at small wetlands, that have now dried up, to meet their water needs and hunted in the bigger grasslands for their food.

More than 100 intricate bronze mirrors were found in a burial mound in Nara Prefecture, Japan. These mirrors feature images of gods and animals and are named after a queen Himiko. The amount of material in these findings leads researchers to think that the occupants held great power or were perhaps even royal.

Play dead! Red flour beetles can feign death to make a predator lose interest, but this can hamper other necessities such as eating and reproduction. Scientists from Okayama University studied how pheromones can jolt the beetles out of this state, showing the power of chemical cues on insect behavior.

Even mountaintops aren’t safe from microplastics. Waseda University scientists collected cloud water from the top of Mt Oyama and Mt Fuji and found nine distinct types of microplastics in the samples. Aside from contributing to pollution, these particles could trigger cloud formation and also release greenhouse gases by being degraded by UV radiation in the atmosphere.