Science notes/Climatology, genetics
11/19/2006
Associated Press
Phytoplankton seems to affect the amount of clouds over Antarctica.
Plankton may have
an influence on clouds
Phytoplankton, microscopic plants that live in the ocean in vast quantities, may play a role in cloud formation, which in turn may have an effect on how much sunlight reaches and warms Earth's surface, a surprising study has found.
Researchers from the Georgia Institute of Technology and North Carolina State University discovered the link between clouds and the biosphere as they were examining increases in cloud cover over part of the Southern Ocean that encircles Antarctica. Using satellite observations, they found that the increased cloudiness coincided with a large phytoplankton bloom.
The scientists theorize that oxidation of the chemical isoprene, which phytoplankton emit, produce airborne particles that help double concentrations of cloud droplets in the region.
The team calculated that the increased cloudiness reduced the absorption of sunlight by the same amount that has been observed in the more polluted areas of Earth. The researchers, who reported their findings in the journal Science, suggest the study could point toward new ways to curb global warming.
"Studies like this one may help reshape the way we think about how the biosphere interacts with clouds and climate," said Georgia Tech assistant professor Athanasios Nenes, who co-authored the paper. "We can now see very strongly the influence of marine biology on oceanic clouds."
- Washington Post
How to make a sea urchin:
DNA code mapped
An international team of nearly 250 scientists have determined the exact order of all 814 million letters of DNA code that carry the instructions for making and maintaining a sea urchin.
If you think that's relevant only to scuba divers and sea otters, you're wrong. Among life-forms that lack backbones, these spiky critters - which are kissing cousins of starfish and can live 100 or more years - are our closest relatives. They are more similar to us than fruit flies or worms, those classic laboratory workhorses that for decades have provided insights into human biology and genetics.
Sea urchins, it turns out, have 23,300 genes, only slightly fewer than humans have. Many are similar to genes that cause human diseases, including Huntington's disease and muscular dystrophy. That means urchins may provide a new venue for studying the molecular origins of those ailments.
Surprisingly, urchins have 979 genes that appear to be involved in sensing light or odors - not bad, considering they have neither eyes nor noses. Lots of those genes are most active in urchin "feet," suggesting those appendages are as important for vision and other senses as for movement.
In reports in journals Science and Developmental Biology, the team also anticipates learning from the urchin's spectacular array of immune system genes and the genes for making its dome-shaped skeleton - which is made of different minerals than ours.
- Washington Post
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