Biology
Mass Extinctions Change the Rules of Evolution
A reinterpretation of the fossil record suggests a new answer to one of evolution’s existential questions: whether global mass extinctions are just short-term diversions in life’s preordained course, or send life careening down wholly new paths.
Some scientists have suggested the former. Rates of species diversification — the speed at which groups adapt and fill open ecological niches — seemed to predict what’s flourished in the aftermath of past planetary cataclysms. But according to the calculations of Macquarie University paleobiologist John Alroy, that’s just not the case.
“Mass extinction fundamentally changes the dynamics. It changes the composition of the biosphere forever. You can’t simply predict the winners and losers from what groups have done before,” he said.
Furor Erupts Over the Role of Self-Sacrifice in Evolution
A furor has broken out among biologists over ant specialist E.O. Wilson’s latest attack on a concept used to explain the origins of self-sacrifice in the dog-eat-dog world of evolution.
Video: Mysterious Patterns Reveal Self-Organizing Muscle Fibers
The unexpected emergence of complex patterns in an apparently unremarkable dish of muscle cells may give researchers a valuable tool for studying self-organizing systems.
Similar patterns are seen in bird flocks, the Milky Way and even the stock market. For the last two decades, researchers have searched for unifying laws to explain how small-scale interactions lead to common behaviors in very different systems.
“This is a fundamental question of physics: How does order emerge? What is the basis of self-organization?” said Andreas Bausch, a biophysicist at Germany’s University of Munchen. “As a model system, this is as pure as it gets.”
Unlike biologists who use E. coli to investigate genetic rules and rats to study physiological function, self-organization researchers have few model systems. It’s not easy to put a starling flock under glass.
Sea Creatures Hint at Recent Trans-Antarctic Seaway
The discovery of nearly identical sea creatures on either side of a now solid Antarctic ice sheet — 1,500 miles wide and over a mile thick — points to an open ocean passage there as recently as 125,000 years ago.
Heaps of Fossils From Evolutionary ‘Big Bang’ Discovered
One of paleontology’s most revered fossil sites now has a baby brother. Scientists have discovered a group of astonishing fossils high in the Canadian Rockies, just 40 kilometers from the famous Burgess Shale location.
A paper describing the find appears in the September issue of Geology.
Micro Frog Discovered Inside Bornean Pitcher Plants
The new frog sits on a penny. Photo credit: Indraneil Das/ Institute of Biodiversity and Environmental Conservation
Scientists have discovered the Old World’s smallest species of frog living inside pitcher plants in the jungles of Southeast Asia’s Borneo.
Vault Freezes Coral Cells to Preserve Them From Extinction
In an effort to preserve the biodiversity of Hawaiian coral species, scientists at the University of Hawaii have created the first frozen coral cell bank — similar in concept to a seed bank for plants.
“Because frozen banked cells are viable, the frozen material can be thawed in one, 50 or, in theory, even 1000 years from now to restore a species or population,” said biologist Mary Hagedorn of the University of Hawaii in a press release. “In fact, some of the frozen sperm samples have already been thawed and used to fertilize coral eggs to produce developing coral larvae.”
Newly Discovered Chlorophyll Catches Infrared Light
A new kind of chlorophyll that catches sunlight from just beyond the red end of the visible light spectrum has been discovered. The new pigment extends the known range of light that is usable by most photosynthetic organisms. Harnessing this pigment’s power could lead to biofuel-generating algae that are super-efficient, using a greater spread of sunlight than thought possible.
Giant Terror Birds Used Stabbing Beaks to Kill Prey
When South America was still an isolated continent, terror birds were the creatures you didn’t want to mess with. Flightless, standing up to seven feet tall, and with giant, stabbing beaks, these birds killed their prey with fierce, axe-like motions.
Astronaut Muscle Would Wither By Mars
Even if we could farm on Mars, astronauts might be too weak by the time they get there to help plow the fields.
The first cellular analysis of muscles from astronauts who have spent 180 days at the International Space Station shows that their muscles lost more than 40 percent of their capacity for physical work, despite in-flight exercise.
