June 11th, 2013
8 minute read
In a North Carolina laboratory, a live moth was clamped tight in a box with a microphone and made to panic. Through the panic, its powers of prediction were probed. The moth, a species of tiger moth called Bertholdia trigona, isn’t psychic. Instead, the moths’ hearing is the key. It’s one of two weapons it uses to stymy a deadly predator: the big brown bat. The panicking, if moths can truly be said to panic, may even tell us something more broadly about how, and when, animals respond to the threat of predators. Tiger moths have a peculiar response to the presence of bats, and B.trigona especially. When they hear them approaching, using ears just behind their wings, the moths start making ultrasonic clicks. The clicks—the reason for the microphone in the box— are made by an organ on their sides called a tymbal. For some species of tiger moth, ...(Read More)
March 22nd, 2013
0 minute read
Somewhere, in the depths of the ocean, a marine ambrosia descends from above; the body of a dead whale. Despite the depth, the corpse won’t be in solitude long; a mini-ecosystem will soon erupt around it, one that could last a decade. The body draws hag fish, sea cucumbers, rat tail fish, brittle star fish, a host of other invertebrates and myriad species of bacteria, all come to feast on the marine bounty. And soon the ‘bone devourers’, Osedax, come too.
January 17th, 2013
1 minute read
Within our DNA are the remains of thousands, maybe millions, of genetic nomads. They once roamed free through the landscape of our genomes; now most are silenced and still, unable to move. These are the ‘jumping genes’, or ‘transposable elements’ to give them their proper name; curious stretches of mobile DNA. Almost 50% of our DNA is made of these remnants. We see them in virtually all organisms, from bacteria, insects and fish all the way through to us humans. In mammals the only active jumping genes we’ve seen are a type called retro-transposons, which scatter copies of themselves throughout genomes. Now a new DNA sequence for a different type of jumping gene, the first active example of its kind ever to be seen in a mammal, has been spotted jumping around in the genome of the brown bat.