/science

Gazing Into Danakil Depression’s Mirror, and Seeing Mars Stare Back - The New York Times
▻https://www.nytimes.com/2017/01/30/science/danakil-depression-ethiopia.html?rref=collection%2Fsectioncollection%2Feart

https://static01.nyt.com/images/2017/01/31/science/31DANAKILJP/31DANAKILJP-facebookJumbo.jpg

In oppressively dry heat and a miasma of sulfur and chlorine, the rocky landscape sprouts patches of neon green and yellow that resemble oozing scrambled eggs.

Near-boiling pools of acidic water bubble between odd formations of rocks and minerals: white beehive-shaped mounds of salt, yolk-colored lattices of sulfuric crust, purplish-red crumbles. Nearby, iron-rich rock fans out into flat mushroom shapes. The ground crackles hollowly underfoot and emits the hiss of bubbling liquid. Cones and small mineral chimneys babble from one-holed spouts in alien whispers.

Though it looks like an extraterrestrial scene, this landscape belongs to the Danakil Depression, in a remote northeast region of Ethiopia aptly named Afar, near Eritrea.

About 100 meters below sea level, the Danakil Depression is one of the world’s lowest places. It is also one of the hottest places on Earth, with average daily temperatures of 34.4 degrees Celsius (93.9 degrees Fahrenheit) and only about 100 millimeters of rain each year.

This volcanic region is known as a geological wonder. Indeed, most of the relatively scant scientific research on the Danakil Depression involves its fantastical geology, not its biology. Now, scientists are studying this area to understand the possibilities of life on other planets and moons, despite the region’s political volatility and sporadic violence between Ethiopia and Eritrea. This month, a team of astrobiologists from Europlanet, a consortium of research institutions and companies doing planetary research, returned to study the depression’s geology, mineralogy and especially its biology, as an analogue to Mars.

#Danakil #Mars #recherche #géologie #biologie #vie

In Many Species, a Family Dinner Means Something Else
▻https://www.nytimes.com/2017/01/30/science/cannibalism-animal-biology.html

https://static01.nyt.com/images/2017/01/31/science/31Cannibal/31Cannibal-superJumbo.jpg

Until relatively recently, the party line among scientists was that cannibalism occurred in only a few species in the wild, like black widow spiders and praying mantises. Cannibalism, researchers felt, was an aberrant behavior resulting from a lack of alternative forms of nutrition or the stresses associated with captive conditions.

But over the decades, evidence has been gathering for an alternative view. Cannibalism, it turns out, occurs in hundreds of species, perhaps thousands. The behavior varies in frequency between major animal groups — nonexistent in some, common in others. It varies from species to species and even within the same species, depending on local environmental conditions.

As important, the behavior serves a variety of functions, depending on the cannibal, and some of these have nothing to do with stress or captive conditions.

#cannibalisme