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…)
People living along the coast of Peru were eating popcorn 2,000 years earlier than previously reported and before ceramic pottery was used there, according to a new paper in the Proceedings of the National Academy of Sciences co-authored by Dolores Piperno, curator of New World archaeology at the Smithsonian’s National Museum of Natural History and emeritus staff scientist at the Smithsonian Tropical Research Institute.
Some of the oldest known corncobs, husks, stalks and tassels (male flowers), dating from 6,700 to 3,000 years ago were found at Paredones and Huaca Prieta, two mound sites on Peru’s arid northern coast. The research group, led by Tom Dillehay from Vanderbilt University and Duccio Bonavia from Peru’s Academia Nacional de la Historia, also found corn microfossils: starch grains and phytoliths. Characteristics of the cobs—the earliest ever discovered in South America—indicate that the sites’ ancient inhabitants ate corn several ways, including popcorn and flour corn. However, corn was still not an important part of their diet. (more…)
Smithsonian researchers report that the brains of tiny spiders are so large that they fill their body cavities and overflow into their legs. As part of ongoing research to understand how miniaturization affects brain size and behavior, researchers measured the central nervous systems of nine species of spiders, from rainforest giants to spiders smaller than the head of a pin. As the spiders get smaller, their brains get proportionally bigger, filling up more and more of their body cavities.
“The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors,” said William Wcislo, staff scientist at the Smithsonian Tropical Research Institute in Panama. “We discovered that the central nervous systems of the smallest spiders fill up almost 80 percent of their total body cavity, including about 25 percent of their legs.” (more…)
“Less than we thought,” researchers say in a new study providing insights into the distribution of biodiversity across the globe.
The temperate forests of Canada or Northern Europe may have much more in common with the tropical rainforests of Southeast Asia or South America than previously believed, according to a research group including a University of Arizona ecologist.
The assertion, published as the cover article in the journal Science, is focused on the concept of “beta-diversity” – a measure of the change in species composition between two sites, such as neighboring patches of forest. High beta-diversity means that two given sites have few species in common. (more…)
A small male bird called a golden-collared manakin performs a difficult, elaborate, physically demanding courtship dance. In new research, life scientists report that female golden-collared manakins select mates based on subtle differences in motor performance during these dances.
“The male jumps like he’s been shot out of a cannon,” said study co-author Barney Schlinger, professor and departmental chair of integrative biology and physiology and a professor of ecology and evolutionary biology at UCLA. “It’s exquisite. He sails like an acrobat and lands perfectly on a perch, like a gymnast landing a flawless dismount. Not only is there power to his muscle contractions but incredible speed as well.”(more…)
Sleeping Beauty’s kingdom was overgrown by vines when she fell into a deep sleep. Researchers at the Smithsonian in Panama and the University of Wisconsin at Milwaukee received more than a million dollars from the U.S. National Science Foundation to discover why real vines are overtaking the American tropics. Data from eight sites show that vines are overgrowing trees in all cases.
“We are witnessing a fundamental structural change in the physical make-up of forests that will have a profound impact on the animals, human communities and businesses that depend on them for their livelihoods,” said Stefan Schnitzer, research associate at the Smithsonian Tropical Research Institute in Panama and associate professor at the University of Wisconsin at Milwaukee.(more…)
Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the rescue project is the first to successfully breed this species. Image credit: Brian Gratwice, Smithsonian's National Zoo
As frogs around the world continue to disappear—many killed by a rapidly spreading disease called chytridiomycosis, which attacks the skin cells of amphibians—one critically endangered species has received an encouraging boost. Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue and Conservation Project is the first to successfully breed this species.
“We are some of the first researchers to attempt to breed these animals into captivity and we have very little information about how to care for them,” said Brian Gratwicke, international coordinator for the project and a research biologist at the Smithsonian’s National Zoo, one of nine project partners. “We were warned that we might not be able to keep these frogs alive, but through a little bit of guesswork, attention to detail and collaboration with other husbandry experts—we’ve managed to breed them. The lessons we’re learning have put us on target to save this incredible species and our other priority species in Panama.”(more…)
The steamiest places on the planet are getting warmer. Conservative estimates suggest that tropical areas can expect temperature increases of 3 degrees Celsius by the end of this century. Does global warming spell doom for rainforests? Maybe not. Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute, and colleagues report in the journal Science that nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.
About the image: This is a scanning electron microscopy image of characteristic angiosperm pollen taxa from the Paleocene-Eocene Thermal Maximum. Image credit: Francy Carvajal, Smithsonian Tropical Research Institute (more…)
