In the Andes along the border between northern Chile and northwestern Argentina, towering volcanoes, salt flats, and arid grasslands form the Puna de Atacama. Cold, severely hypoxic, and extremely dry, this region was long considered incapable of supporting mammals year-round. Yet the Andean leaf-eared mouse (Phyllotis vaccarum) ranges from the coastal lowlands of northern Chile to volcanic summits above 6,700 meters. Individuals have even been found on the 6,739-meter summit

By the 1870s, the cell theory had established that plants and animals were composed of cells, and some researchers already knew that cells could multiply by division. Yet there was still no reliable account of how a cell completed this process. The theory of "free-cell formation" had not entirely disappeared from scientific thought, and some scholars continued to believe that new cells might arise directly from an unidentified substance between existing cells. Against this ba

Anyone seeing a pigeon or dove nest for the first time might easily mistake it for a few dead twigs that happened to become lodged in a tree or on a windowsill. Several slender sticks are loosely laid across one another, with only a shallow depression in the center. Sometimes the white eggs or nestlings can be seen directly through the nest from below. The nests of many members of the family Columbidae do indeed look remarkably flimsy, but this apparent crudity reflects a con

The Namib Desert is a long, narrow coastal desert in southwestern Africa, stretching from southern Angola to just north of Cape Town in South Africa. At its center lies the Namib Sand Sea, one of the world's most iconic dune landscapes. The paradox is obvious: this desert borders the ocean, yet rain is exceedingly scarce. Under the persistent influence of the subtropical high-pressure system, descending air suppresses the growth of thick rain clouds, leaving the region dry en

Between 1980 and 2017, 67 cold wave events were recorded across the Amazon basin. In Peru, these events are locally known as friaje. In June 2023, a research team was conducting a biodiversity survey in the lowland Amazonian rainforest of southern Peru when one of these cold waves occurred. From 13 to 18 June, cold air moved northward along the Andes and entered the normally warm lowland rainforest, causing local temperatures to drop sharply within a short period of time. Thi

Homing pigeons (Columba livia domestica) can return to their loft from unfamiliar release sites. They do not rely on a single cue to do this. Sunlight, visual landmarks, environmental odors, and the geomagnetic field may all contribute to their navigation. When the sky is clear, the position of the sun can provide a stable directional reference. When the sky is completely overcast, however, solar and polarized-light cues disappear, and visual landmarks become less reliable. U

In riverine environments, many fish species need to migrate between different habitats in order to feed, reproduce, or escape unfavorable conditions. When they encounter obstacles created by changes in riverbed elevation, some fishes can use powerful bursts of acceleration to jump over relatively low barriers. If the stream gradient is gentler, they may simply swim upstream against the current and gradually reach their upstream habitats. But what happens when fishes face wate

Ant societies are highly organized groups with a striking division of labor, and in some cases their social life even includes something resembling medical care. In the ant species Camponotus floridanus, workers respond to injured nestmates in different ways depending on where the leg wound is located. In one study, researchers experimentally injured different parts of the hind leg of C. floridanus workers and observed how their nestmates treated them. When the wound was loca

Soil is a continuously running biochemical factory. When leaves, branches, fruits, and seeds fall to the forest floor, they enter the process of decomposition. Nutrients are returned to the soil, taken up again by plants, and eventually become the foundation for the next round of forest growth. For decades, studies of this cycle have focused mainly on plants, invertebrates, bacteria, and fungi. Yet mammals moving through the forest are also quietly shaping the speed and direc

Elephantiasis is a chronic disease manifestation most commonly caused by lymphatic filariasis. It is characterized by the progressive enlargement of affected body parts, thickening of the skin and underlying tissues, heaviness, disfigurement, and, eventually, impairment of mobility and appearance. Illustration showing enlarged feet in a patient with elephantiasis（Image source：James Newton，CC0 1.0 ） Illustration showing scrotal swelling in a patient with elephantiasis（Image so