ScienceDaily: Top Science News

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• Unique chromosomes preserved in Swedish fossil
• Dust in the wind drove iron fertilization during ice age
• Genetic factor contributes to forgetfulness
• Humans can distinguish at least one trillion different odors
• Gene silencing instructions acquired through 'molecular memory' tags on chromatin

Unique chromosomes preserved in Swedish fossil Posted: 21 Mar 2014 07:17 AM PDT Researchers have made a unique discovery in a well-preserved fern that lived 180 million years ago. Both undestroyed cell nuclei and individual chromosomes have been found in the plant fossil, thanks to its sudden burial in a volcanic eruption.

Dust in the wind drove iron fertilization during ice age Posted: 21 Mar 2014 06:55 AM PDT A longstanding hypothesis that wind-borne dust carried iron to the region of the globe north of Antarctica, driving plankton growth and eventually leading to the removal of carbon dioxide from the atmosphere has been confirmed by researchers. Plankton remove the greenhouse gas carbon dioxide (CO2) from the atmosphere during growth and transfer it to the deep ocean when their remains sink to the bottom.

Genetic factor contributes to forgetfulness Posted: 21 Mar 2014 06:50 AM PDT Misplaced your keys? Can't remember someone's name? Didn't notice the stop sign? Those who frequently experience such cognitive lapses now have an explanation. Psychologists have found a connection between such everyday lapses and the DRD2 gene. Those who have a certain variant of this gene are more easily distracted and experience a significantly higher incidence of lapses due to a lack of attention.

Humans can distinguish at least one trillion different odors Posted: 20 Mar 2014 11:07 AM PDT Humans are capable of discriminating at least one trillion different odors, new research shows. Scientists determined that our sense of smell is prepared to recognize this vast olfactory palette after testing individuals' ability to recognize differences between complex odors mixed in the laboratory. It has been said for decades that humans were limited to distinguishing only 10,000 different odors.

Gene silencing instructions acquired through 'molecular memory' tags on chromatin Posted: 20 Mar 2014 10:11 AM PDT One of the mysteries of modern genetics has been solved: how acquired traits can be passed between generations in a process called epigenetic inheritance. The new work finds that cells don't know to silence some genes based on information hardwired into their DNA sequences, but recognize heritable chemical marks that are added to the genes. These chemical tags serve as a form of molecular memory, allowing cells to recognize the genes and remember to silence them again in each new generation.

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