Listeria bacteria has been enlisted by researchers to selectively infect metastatic pancreatic cancer cells and deliver radioisotopes into them. The experimental treatment dramatically decreased the number of metastases (cancers that have spread to other parts of the body) in a mouse model of highly aggressive pancreatic cancer without harming healthy tissue. Mice livers are shown above. The saline control liver on the left presents a large number of metastases compared to the liver on the right which was subject to the radioactive Listeria treatment. ...

There are over 12,000 species of ants in the world, and a new tree of life has been published to better understand how they are all related. Their evolutionary origins have been traced to the tropics in South America, where they play a critical role in maintaining the health of the ecosystem.

This is a close up of a llama eye. The strange "ruffles" are called 'iridic granules' (corpora nigra) and they are used to to shade the eye from bright sunlight. In bright light these iridic granules can actually interlock to completely cover the centre of the pupil. This leaves just two holes open on either end of the pupil, reducing the amount of light that can enter the eye. These odd looking structures are also found in horses, cattle and sheep.

The coelacanth is known as a “living fossil” because it looks very much like its ancestors from 300 million years ago. Its genome has been sequenced, and it, in fact, has been found to be evolving at a very slow rate. The genetic sequence also might help give some insight into the transition from fins to limbs.

This beautiful animal is Red-bellied short-necked turtle. It is found in Australia and Papua New Guinea, and in Australia it is highly endangered. These stunning colours are highly pronounced as infants and juveniles, but fade as they age. They reach about ten inches (25 cm) in length.

Inca terns are unique and beautiful birds—slender with white-tipped gray feathers, a white curly moustache, yellow lips and a bright orange-red bill. They have a distinctive call that sounds like a high pitched laugh, which is often accompanied by bowing gestures.

Inca terns are natives of the western shoreline of South America and the islands located offshore. They are especially abundant in northern Chile and Peru in the summer. They migrate in winter, venturing to Ecuador and central Chile.

Inca terns swoop down and pluck fish from near the water’s surface. They also sometimes get scraps left behind by whales, or flock to where sea lions are eating on rocks, to steal stray bits of food.
 
A male who is interested in a female will perform aer ...

Slot canyons are much deeper than they are wide, and are most commonly sandstone or limestone.

This is Antelope Canyon, located in Northern Arizona. There is enough room to move around comfortably at the bottom, but the opening on top is only 2-3 feet wide.

Without krill, most of the marine animals in Antarctica would disappear. So what are they?

Krill are crustaceans, each about 5 cm long. In addition to their diet of phytoplankton, they have the ability to scrape ice-algae from the underside of ice formations. In turn, they are on the menu for hungry squid, penguins, seals and whales. In short, krill form an integral part of the Antarctic ecosystem.

Together, krill would number in the billions, yet their numbers are decreasing. Why? One reason may be the melting and loss of ice formation due to increased global temperatures. Another reason is humans' greed. Krill oil, high in omega-3 fatty acids, is packaged as health medication to maintain healthy cholesterol. How many krill are worth the lif ...