Thursday, February 24, 2011

Secrets of Swimming in Sand Revealed



Using a lizard, a snaky robot and computer simulations, researchers have captured the secrets of swimming through sand.

Physicists filmed the movements of lizards and snake-like robots as they burrowed through sand, then boiled their motion down into a numerical theory. The theory ultimately led to a computer model that can emulate the fluid-like physics of sand and objects that can swim through it.

The scientists first explored sand-swimming motion by studying sandfish lizards, also known as Scincus scincus. The reptiles are native to North-African deserts and can quickly burrow into sand to escape predators and scorching heat.

The team found sine-wave-like movement allows the lizard, and their robot, to push forward in sand, but creating computer models for the experiments proved problematic. Simulating all of the tiny sand grains required a lot of money to purchase time on powerful computers. So, the team performed the same experiments using 3-millimeter-wide glass beads instead of sand.

Read more in the original article here.

Friday, February 04, 2011

Tiny Water Flea Has More Genes Than You Do


This tiny, near-microscopic water flea has more genes than you. In fact, this freshwater zooplankton is the first crustacean to have its genome sequenced, and its 31,000 genes crowns it the animal with the most genes so far. For those keeping count at home, the average human has about 20,000 to 25,000 genes.

The translucent water flea is a Daphnia pulex, and lives in ponds and lakes throughout North America, Europe and Australia. It can also reproduce without sex, is the most commonly found species of water flea and is a “model organism”, meaning it’s studied extensively and provides insight into other, rarer species.

The reason for this little critters’ super-high gene count comes down to its rapid rate of gene multiplication. Scientists estimate a rate that is three times greater than those of other invertebrates and 30 percent greater than that of humans.

As well as having a massive number of genes, more than a third of them have never been seen before in other animals. In other words, they are completely new to science.

Read more in the original article here.