Animals

The lush biodiversity of the Amazon may be due in part to the dynamics of branching rivers, which serve as invisible fences that continuously barricade and merge bird populations.

Some animal neuropeptides have been around longer than nervous systems.

The optical properties of mitochondrial bundles in the retina may improve how efficiently the eye captures light.

Large blocks of genes conserved through hundreds of millions of years of evolution hint at how the first animal chromosomes came to be.

New studies reveal the ancient, shared genetic “grammar” underpinning the diverse evolution of fish fins and tetrapod limbs.

Rapid advances in large-scale connectomics are beginning to spotlight the importance of individual variations in the neural circuitry. They also highlight the limitations of “wiring diagrams” alone.

The spate of furious wildfires around the world during the past decade has revealed to ecologists how much biodiversity and “pyrodiversity” go hand in hand.

Crows recently demonstrated an understanding of the concept of zero. It’s only the latest evidence of animals’ talents for numerical abstraction — which may still differ from our own grasp of numbers.

Showy male competitions over mating privileges have grabbed scientists’ attention more often, but new work hints that sexual selection is also widespread among females.