Round the twist: 92 per cent of vines have been found to twist in a left-handed, anti-clockwise direction.
Credit: Angela Moles/UNSW
SYDNEY: Over 90 per cent of vines twist anti-clockwise, according to a massive Australian study of plants in 75 locations from Zambia to Patagonia.
The discovery is one of many likely to come from a huge and ongoing study into the global variation between plants. Lead scientist behind the research Angela Moles, an evolutionary biologist at the University of New South Wales, in Sydney, also collected height data for plants of 35,000 species.
Curious question
In another project, she compiled information on the seeds of 12,669 species, revealing that tropical seeds are, on average, 300 times bigger than the seeds of species found in temperate forests much further north.
The vine orientation finding was reported in the journal Global Ecology and Biogeography and detailed on Tuesday at a Melbourne event which announced the 2008 L’Oréal Australia For Women in Science Fellowships, where Moles won a A$20,000 funding award to continue her research.
Moles was already globe-trotting between nine countries, for her World Herbivory Project, when co-worker Will Edwards, a botanist from James Cook University in Cairns, requested that she collect some further data.
When asked by a student why all vines appeared to twist in the same way, Edwards had been stumped, and enlisted the help of Moles.
The pair tested three hypotheses: that plants twine in a random direction; that twining direction is determined by plant tips following the movement of the Sun across the sky; and that twining direction is determined by the Coriolis effect.
This Coriolis effect is the phenomenon incorrectly reported in popular culture to cause water running down the plughole to swirl in different directions in the Northern and Southern hemispheres.
Left-handed bias
Prior to the study, Moles she asked 100 scientists why plants appeared to twist in the same direction and 95 answered that it was the Coriolis effect.
However, "we found no difference in the proportion of stems twining clockwise versus anticlockwise between the… hemispheres," she said. "Ninety-two per cent of the stems we recorded twined in an anticlockwise direction."
In fact, the pair rejected all three of their theories.
"We are now investigating the possibility that the widespread phenomenon of anticlockwise twining arises as a function of the left-handed bias of all biological molecules on earth," said Moles.
"All [natural] proteins on Earth are left-handed molecules with a tendency to twist in one direction," she explained. "In plants, the cell skeletons are made of proteins. If the proteins have a tendency to twist to the left, so might the plant stems."
Other research has shown that 94 per cent of spiral sea shells twist in the same direction, while 90 to 93 per cent of humans are right-handed.
Moles will be using the $20,000 award from the fellowship to bring more researchers aboard on her project. It is hoped that further research into trends in plant variation may help with designing better ecological models to predict the effects of climate change.
