Obesity subtly diminishes memory and other features of thinking and reasoning even among seemingly healthy people, an international team of scientists reports. At least some of these impairments appear reversible through weight loss. Researchers also report one likely mechanism for those cognitive deficits: damage to the wiring that links the brain’s information-processing regions.
Imagine discovering a mammal without mammary glands or an insect with eight legs. Aquatic herbs in the genus Hydatella pose a similar paradox—they lack a defining developmental feature of flowering plants, raising questions about their evolution and rampant speciation during the past 135 million years.
Evolutionary biologists group together organisms that share unique traits...
In December 1938, Marjorie Courtney-Latimer, curator of a natural history museum in East London, South Africa, went to the docks to look for interesting specimens among the day's catch. What she found one day she later described as "the most beautiful fish I had ever seen ... a pale mauve blue with iridescent silver markings." The discovery sent scientists into a frenzy.
Food for Thought
Women take note. Researchers find that a chemical that forms in overcooked meat, especially charred portions, is a potent mimic of estrogen, the primary female sex hormone. That's anything but appetizing, since studies have linked a higher lifetime cumulative exposure to estrogen in women with an elevated risk of breast cancer.
Indeed, the new finding offers a "biologically...
The eye's retina does more than register images the way film or a digital camera detector does. To allow it to begin analyzing an image, the retina has specialized nerve cells that respond to motion or other important features in the image detected by the light-sensing rod and cone cells.
Scientists discovered the specialized cells that sense motion in the retinas of cats and other...