*Geologists learn how earthquakes change the landscape — down to a few inches*
Geologists have a new tool to study how earthquakes change the landscape–down to a few inches. It’s giving scientists insights into how earthquake faults behave.
In this week’s issue of the journal Science, a team of scientists from the United States, Mexico and China reports the most comprehensive before-and-after picture yet of an earthquake zone, using data from the magnitude 7.2 event that struck near Mexicali, Mexico, in April 2010. (more…)
*Study implicates “arms race” between genes and germs*
Biologists have found new evidence of why mice, people and other vertebrate animals carry thousands of varieties of genes to make immune-system proteins named MHCs–even though some of those genes make vertebrate animals susceptible to infections and to autoimmune diseases.
“Major histocompatibility complex” (MHC) proteins are found on the surfaces of most cells in vertebrate animals. They distinguish proteins like themselves from foreign proteins, and trigger an immune response against these foreign invaders. (more…)
*In “The Great Dying” 250 million years ago, the end came slowly*
The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.
It shows that mass extinctions need not be sudden events.
Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)
*Long-term study analyzes social selection and peer influence in online environments*
New research funded by the National Science Foundation and published this week in the Proceedings of the National Academy of Sciences by three Harvard University sociologists examines how we select our friends and the role that friendship plays in transmitting tastes and new ideas.
Relationships are basic building blocks of society, and understanding who befriends whom can therefore provide insight into patterns of social segregation, mechanisms for the reproduction of inequality, social support (including mental and emotional health), and access to job opportunities. Some have even viewed these relationships as a means to influence behavior whether to control obesity or target advertising. But is it really that easy, even on the Internet, to make friends with people who have different cultural upbringings, different interests, different backgrounds and different tastes in movies, music and books? (more…)
*Experiments on “slime mold” explain why almost all multicellular organisms begin life as a single cell*
Any multicellular animal, from a blue whale to a human being, poses a special challenge for evolution.
Most of the cells in its body will die without reproducing; only a privileged few will pass their genes to the next generation.
How could the extreme degree of cooperation required by multicellular existence actually evolve? Why aren’t all creatures unicellular individualists determined to pass on their own genes? (more…)
*Ecological changes from lakebed may have led to two different populations of once-related steelhead trout*
A catastrophic landslide 22,500 years ago dammed the upper reaches of northern California’s Eel River, forming a 30-mile-long lake which has since disappeared. It left a living legacy found today in the genes of the region’s steelhead trout.
Using remote-sensing technology known as airborne Light Detection and Ranging (LiDAR) and hand-held global-positioning-systems (GPS) units, scientists recently found evidence for a late Pleistocene, landslide-dammed lake along the river. (more…)
