“It's the Only System We've Got”

How the zebrafish got its stripes

H ow the zebra got its stripes is a frequent topic in popular literature about the natural world. For developmental biologists, however, it is much easier to study the biology of pattern formation in zebrafish, where the tools of experimental embryology and genetics have proved to be very useful. Now, in eLife, David Parichy from the University of Washington and coworkers – including Dae Seok E...

How the gray wolf got its color.

www.sciencemag.org SCIENCE VOL 325 3 JULY 2009 5 COVER The Phoenix spacecraft on the martian polar plains (68°N latitude). The footpad at the bottom is about 1 meter below the spacecraft deck seen at the lower left. Overlaid images are trenches dug to either nearly pure water ice or ice-cemented soil. Analyses of samples taken from these trenches give clues to the history of the region. Results...

How the elephant got its trunk.

How the horned lizard got its horns.

Many descriptions of evolutionary adaptations are criticized as “just-so stories” (1) that are based more on intuition than on direct tests of adaptive hypotheses. The elaborate crowns of horns possessed by many species of horned lizards (genus Phrynosoma) are classic examples of intuitively adaptive features that lack direct tests of function. The bony horns that give horned lizards their name...

How the bat got its buzz.

Since the discovery of echolocation in bats, the final phase of an attack on a flying insect, the 'terminal buzz', has proved enigmatic. During the buzz, bats increase information update rates by producing vocalizations up to 220 times s(-1). The buzz's ubiquity in hawking and trawling bats implies its importance for hunting success. Superfast muscles, previously unknown in mammals, are respons...