ANN ARBOR, Mich.— Nature teems with examples of evolutionary arms races between predators and prey, with the predator species gradually evolving a new mode of attack for each defensive adaptation that arises in the prey species.
These adaptations are often portrayed as reciprocal, with prey and predator acting as two sides in an endless evolutionary tug of war known as co-evolution. (more…)
*Feeding habits haven’t always been what they are today*
The feeding habits of mammals haven’t always been what they are today, particularly for omnivores.
Some groups of mammals almost exclusively eat meat–take lions and tigers and other big cats as examples.
Other mammals such as deer, cows and antelope are predominantly plant-eaters, living on a diet of leaves, shoots, fruits and bark. (more…)
The theory that pigeons’ famous skill at navigation is down to iron-rich nerve cells in their beaks has been disproved by a new study published in Nature.
The study shows that iron-rich cells in the pigeon beak are in fact specialised white blood cells, called macrophages. This finding, which shatters the established dogma, puts the field back on course as the search for magnetic cells continues. (more…)
U researchers map emperor penguin colonies by satellite
Emperor penguins may be icons of the Antarctic, but they aren’t immune to disturbances in their environment.
As climatic and other changes unfold, emperors may dwindle in numbers. But how to tell, when researchers can’t access all the emperor colonies dotting the Antarctic ice shelves and count heads every year?
Satellites, that’s how. (more…)
AUSTIN, Texas — Seed size is controlled by small RNA molecules inherited from a plant’s mother, a discovery from scientists at The University of Texas at Austin that has implications for agriculture and understanding plant evolution.
“Crop seeds provide nearly 70 to 80 percent of calories and 60 to 70 percent of all proteins consumed by the human population,” said Z. Jeff Chen, the D.J. Sibley Centennial Professor in Plant Molecular Genetics at The University of Texas at Austin. “Seed production is obviously very important for agriculture and plant evolution.” (more…)
Bat wings are like hands: meaty, bony and full of joints. A new Brown University study finds that bats take advantage of their flexibility by folding in their wings on the upstroke to save inertial energy. The research suggests that engineers looking at flapping flight should account for wing mass and consider a folding design.
PROVIDENCE, R.I. [Brown University] — Whether people are building a flying machine or nature is evolving one, there is pressure to optimize efficiency. A new analysis by biologists, physicists, and engineers at Brown University reveals the subtle but important degree to which that pressure has literally shaped the flapping wings of bats.
The team’s observations and calculations show that by flexing their wings inward to their bodies on the upstroke, bats use only 65 percent of the inertial energy they would expend if they kept their wings fully outstretched. Unlike insects, bats have heavy, muscular wings with hand-like bendable joints. The study suggests that they use their flexibility to compensate for that mass. (more…)
ANN ARBOR, Mich.— When tropical marine cone snails sink their harpoon-like teeth into their prey, they inject paralyzing venoms made from a potent mix of more than 100 different neurotoxins.
Biologists have known for more than a decade that the genes which provide the recipes for cone snail toxins are among the fastest-evolving genes in the animal kingdom, enabling these predatory gastropods to constantly refine their venoms to more precisely target the neuromuscular systems of their prey. (more…)
HONOLULU – A species of lizard is now extinct from the Hawaiian Islands, making it the latest native vertebrate species to become extirpated from this tropical archipelago.
The copper striped blue-tailed skink (Emoia impar) — a sleek lizard with smooth, polished scales and a long, sky-blue tail — was last confirmed in the Na’Pali coast of Kauai in the 1960s. But repeated field surveys on Kauai, Oahu, Maui and Hawai’i islands from 1988 to 2008 have yielded no sightings or specimens. (more…)
