In developing countries, information about the distribution of wealth or poverty may be gleaned from someone's mobile phone records, a study reports.

The study, published in the journal Science, was done in Rwanda. In much of Africa, as in developing countries elsewhere, accurate statistics on poverty are difficult to collect.

"This could be a useful policy instrument to estimate the geographic distribution of poverty and wealth," said Joshua Blumenstock, a data scientist at the University of Washington.

He and his colleagues relied on anonymized data on billions of interactions, including details about when calls were made and received and the length of the calls. The researchers also looked at when text messages were sent, and which cellphone towers the texts and calls were routed through in order to get a rough idea of geographic location. "So it's the who, where and when of the call, but not the what or the why," Blumenstock said.

They combined this information with responses collected from about 850 cellphone owners to build an algorithm that predicts how wealthy or impoverished a given cellphone user is. Using the model, the researchers were able to answer even more specific questions, like whether a household had electricity.

when OREGON WASN'T all FOREST

Forests cover the mountainous Triangle Lake valley of the Oregon Coast Range, but that was not always the case, researchers found.

Sediment samples from 200 feet below the surface of Little Lake, the remnant of an ancient lake that was much larger, show that frosty meadowlands and patchy subalpine forest predominated in the region during the last ice age, 26,000 to 13,000 years ago.

The primary cause of erosion then was not rainfall but frost cracking. Erosion rates were at least 2.5 times higher than today's rates, said the researchers, who published their study in Science Advances. Parts of the U.S. not covered by glaciers during the period, from Oregon to Georgia, may have resembled southeastern Alaska, they said.

rare Ants With Leaping Ability

By snapping their jaws onto the ground, trap-jaw ants can flip backward and escape threats. Now researchers report that these ants can also jump forward.

A forward leap is probably an even more effective way to dodge threats, said Magdalena Sorger, an evolutionary biologist at North Carolina State University and the study's author. She reported her findings in the journal Frontiers in Ecology and the Environment.

Although jumping is common in animals like kangaroos, frogs, grasshoppers and humans, it is rarely seen in ants. Only three of 326 ant genera are known to jump. It isn't clear exactly how trap-jaw ants manage to jump forward.

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