28 August 2014

Walking Fish Polypterus Senegalus Offers Glimpse At Evolution

Scientists are studying Polypterus Senegalus, a fish that can move in land, to understand how ancient organisms managed to jump from swimming in the waters to walking into land.

Polypterus Senegalus is a fish from Africa that is able to breathe air, move in land (with their fins) and resembles prehistoric fishes that managed to evolve into tetrapods - amphibians, reptiles, birds, and mammals. The scientists studied the fish to learn how these fish move to learn the evolutionary processes that occurred 400 million years ago.

By raising the fish on land for nearly a year, they noted significant anatomical and behavioural changes. The fish walked more effectively and its biological behavior adapted to the process. The researchers hypothesized that the behavioural changes also reflect what may have occurred when fossil fish first walked with their fins on land.

27 August 2014

GPS Data Reveal How Sheepdogs Herd Sheep

Scientists using GPS technology have figured out how sheepdogs efficiently herd sheep. This may help in developing robots that can perform similar activities and other applications.

They find that the dogs follow two basic instructions which allows them to tightly reign in the sheep and move them towards a single direction. The two instructions are to (1) collect the sheep when they are loose and (2) move them forward when they are gathered.

The scientists also attached gps devices on the sheep and the dog and observed how the movements of the animals appear on screen. They also built a computer model that simulates an efficient way of herding the sheep.

Surprisingly, the two models are similar.

This discovery can help in developing applications for use by robots in activities such as crowd control, cleaning up the environment, herding of livestock, keeping animals away from sensitive areas, and collecting or guiding groups of exploring robots.