Science News 28/7/09

Trees are going camo
Researchers at the University of Wellington in New Zealand this week uncovered a tree that camouflages to protect itself from predators. The leaves of the New Zealand native Araliaceae tree changes colour as it matures. And scientists believe the reason it does this was to protect itself from an the moa, a giant flightless bird that became extinct 750 years ago. To show the changes are was due to the moa the team compared Araliaceae leaves to samples from a similar species of tree, that are on a island 800 km from New Zealand, where there are no Moas.

Aloe boys
Aloe vera fights cavities and bacteria as effective as commercial toothpaste says research published in May/June 2009 issue of General Dentistry. The study compared the bacteria-fighting ability of an aloe vera tooth gel to two commercially popular toothpastes and found that the aloe vera tooth gel controlled cavity-causing organisms as well as commercial toothpaste. Why? Aloe latex contains anti-inflammatory chemicals. And, it is less harsh on teeth because it doesn’t have the abrasive elements typically found in commercial toothpaste. But! Watch out! Not all aloe vera tooth gel has the medicinal form of aloe vera – products must use gel located in the center of the aloe vera plant to be effective

Evolution is heating up
Mammals that live in the tropics evolve faster than their counterparts from cooler climates. According to a study published in July from the University of Auckland, which looked at biodiversity over prolonged evolutionary periods, there is much more biodiversity in warmer areas like the tropics. The results show that species occupying warmer climates have almost 50 per cent more DNA evolution relative to those in cooler climates. This is pretty interesting because some scientists did not believe that climate could possibly have any bearing on mammal evolution given their constant body temperatures.