In a green field outside Madrid, at the foot of the snow-covered Guadarrama mountain range, lies a sun-faded snail shell. Its opening sealed with a cap of dried mud, the shell contains the larva of a wild, solitary bee, together with its first meal of bee bread — a mixture of pollen and nectar. Entomology graduate student Daniel Romero picks up the shell and, concluding that it contains the nest of a mason bee, stores it in a clear plastic tube, labels the red cap with a marker, and closes it.
Back at the Complutense University of Madrid, Romero sets ten tubes of the nesting bees he collected on his professor’s desk. They are just a fraction of the hundreds of samples that he and his colleagues will gather during a four-year Spanish government-funded study of how artificial chemicals are affecting the biodiversity of wild pollinators and their immune and reproductive systems. In the warmth of the office, some of the young adults twitch and scratch at their now-crumbly mud doors. Researchers watch the young adult bees slowly emerge into their new world. When the air cools and the humans leave the room, the bees return to their pollen pillows. Unlike honeybees, solitary bees buzz to their own drum.
See an album of photos I took while reporting this story.
Tropical climates are famously rich in biodiversity, perhaps because old lineages persist well in those regions instead of being simply replaced by new ones, or perhaps because the tropical environment promotes fast speciation. A new study of the ant family tree suggests that both these explanations may be right.
Although mutations, the driver of evolution, occur at random, a study of the bacterium Escherichia coli reveals that nature often finds the same solution to the same problem again and again. Continue reading
Testing for HIV does not simply end with the diagnosis that the virus is present in a patient; caregivers also need to track the disease’s progress to adjust ongoing treatment. Yet tests for monitoring HIV infection require sophisticated instruments, well-trained clinicians and expensive lab ware. All those are in short supply on HIV’s front line in places such as rural sub-Saharan Africa. “It’s a problem not just of cost,” explains hematologist Helen Lee of the University of Cambridge in the UK. “It’s a problem of having access.” In the last year, stripped-down standalone tests have appeared on the market, offering rural patients a cheaper, faster count of their CD4 immune cells. And in the coming months, a class of tests that measure viral load should enter routine point-of-care use, too, offering caregivers a choice of simple tools for measuring HIV infections.