October 8, 2007, 11:15 AM CT

Fair Play in Chimpanzees

In the ultimatum game - which was developed by another German, Werner Güth, now at the Max Planck Institute for Economics in Jena - one person, the proposer, is given money by an experimenter. That proposer can then divide the "manna from heaven" with a second person, the responder. The responder is not powerless - if he accepts the division, both people take home the offered amounts. But if he rejects it, both get nothing. The fear of having an unfair offer rejected causes the proposer to make a fair offer. People typically make offers of close to 50%. Anything less is likely to be rejected. Sensitivity to unfair offers and a willingness to pay a cost to punish someone contradicts economic models of pure self-interest, and they have been claimed to be unique to humans.

In a study reported in Science on October 5th, the scientists confronted our closest living relatives, chimpanzees, to a simplified version of the ultimatum game. The proposer would propose an offer of raisins to the responder by partially pulling out a tray of raisins as far as he could. If the responder accepted the division of raisins, he would pull the tray the rest of the way and the two would be able eat. However, if the responder did not like what he saw, he would not pull the tray and neither of them would get anything to eat......... Posted by: Kelly      Read more         Source

October 4, 2007, 5:10 AM CT

Crocodile Tears Are Real

When someone feigns sadness they "cry crocodile tears," a phrase that comes from an old myth that the animals cry while eating.

Now, a University of Florida researcher has concluded that crocodiles really do bawl while banqueting - but for physiological reasons rather than rascally reptilian remorse.

UF zoologist Kent Vliet observed and videotaped four captive caimans and three alligators, both close relatives of the crocodile, while eating on a spit of dry land at Florida's St. Augustine Alligator Farm Zoological Park.

He observed that five of the seven animals teared up as they tore into their food, with some of their eyes even frothing and bubbling.

"There are a lot of references in general literature to crocodiles feeding and crying, but it's almost entirely anecdotal," Vliet said. "And from the biological perspective there is quite a bit of confusion on the subject in the scientific literature, so we decided to take a closer look".

A paper about the research appears in the latest edition of the journal BioScience.

Vliet said he began the project after a call from D. Malcolm Shaner, a consultant in neurology at Kaiser Permanente, West Los Angeles, and an associate clinical professor of neurology at the University of California, Los Angeles......... Posted by: Kelly      Read more         Source

Wed, 03 Oct 2007 11:40:04 GMT

Animal Meme

I've been tagged by Anne-Marie at Pondering Pikaia. She has a very cool German Shepard and writes an excellent blog.

An interesting animal I had:
This is difficult because there is no shortage of candidates: Madagascan Giant Hissing Cockroaches, Praying Manti, Praying Manti, tarantulas, frogs, lizards, rodents etc. I suppose for sheer strangeness, however, my Praying Mantiwould take the prize. To forestall the inevitable questions, I fed it snails.

An interesting animal I ate:
Again there is no shortage of candidates; among animals, I've knowingly eaten from eight phyla (Cnidaria, Uniramia, Chelicerata, Crustacea, Mollusca, Annelida, Echinodermata, & Chordata). Unknowingly, who knows.... I'd have to guess at least half of the phyla. The most recent unusual organism was a jellyfish. How was it? Kind of like chewy noodles.

An interesting animal in the Museum:
One of my favorite animals went extinct quite some time ago: Praying Manti (depicted above). It derives from the Praying Manti ~530 mya. Its reconstructed image was greeted with laughter as a pretty good joke when first presented at a scientific meeting in 1972. We are still not sure what exactly it is.

An interesting thing I did with or to an animal:
I held a 3 day old pronghorn fawn while it was weighed and tagged. It was a bag of bones with giant eyes and a furiously beating heart. I don't think any wild animal has so touched me before or since.

An interesting animal in its natural habitat:
My favorite wild animals encounter was with a mom Grizzly and her three cubs in Yellowstone NP. To this day, Praying Manti, wildlife biologist par excellence at the University of Missouri: Columbia, believes he saved my life by preventing me from trying to get closer. He is probably right.

I'm tagging Praying Manti, Cesar, Praying Manti, Praying Manti and Carl. I'm guessing they will have interesting responses.

Photo from the Praying Manti collection.
Praying Manti Posted by: Dennehy      Read more     Source

October 1, 2007, 10:13 PM CT

Three-way mating game of North American lizard

An intricate three-way mating struggle first observed in a species of North American lizard has been discovered in a distant relative, the European common lizard. The two species are separated by 5,000 miles and 175 million years of evolution, yet they share behavioral and reproductive details right down to the gaudy colors of the males, as per new research reported in the recent issue of American Naturalist and now available online.

The triangle of competing strategies, which biologists liken to the children's game rock-paper-scissors, may be far more common than previously recognized--and may even shape the way humans behave, as per lead author Barry Sinervo, professor of ecology and evolutionary biology at the University of California, Santa Cruz.

"The models we propose in this paper are a general phenomenon for all animals, humans included," Sinervo said. When faced with the task of gathering food or finding mates, he said, "You either cooperate, or take by force, or take by deception. Those are the three ways you can make a living in any social system. It's one of those basic games that structures life".

Male European common lizards (Lacerta vivipara) adopt one of those three strategies when pursuing females. A quick look at their undersides reveals the strategy: males who sport orange bellies are brutes who invade other lizards' territories to mate with any female they can catch. But while they're gone, drab yellow-bellied males slink onto the vacant territory and mate with unguarded females. White-bellied males guard their mates closely, and cooperate with other white-bellied lizards to keep the yellows at bay. Hence the analogy to rock-paper-scissors: force (orange) defeats cooperation (white), cooperation defeats deception (yellow), and deception defeats force......... Posted by: Kelly      Read more         Source

October 1, 2007, 9:30 PM CT

Brain Folding In Higher Mammals

Engineers at Washington University in St. Louis are finding common ground between the shaping of the brain and the heart during embryonic development.

Larry A.Taber, Ph.D., the Dennis and Barbara Kessler Professor of Biomedical Engineering, and Phillip Bayly, Ph.D., Hughes Professor of Mechanical Engineering, are examining mechanical and developmental processes that occur in the folding of the brain's surface, or cortex, which gives the higher mammalian brain more surface area (and hence more intellectual capacity) than a brain of comparable volume with a smooth surface.

Folding is very important in human brain development because some of the worst neurological problems such as schizophrenia, autism and lissenchephaly (smoothness of the cortex, found with severe retardation) are linked to abnormal brain folding. The neuromuscular disorder dystonia is possibly linked to faulty connectivity in the brain, which has been hypothesized to affect cortical folding. The scientists hope that increased understanding of brain folding might someday help prevent such diseases.

Eventhough folding is generally what makes higher mammals smart, Albert Einstein had an abnormally folded brain that resulted in genius. Certain folds in his brain were absent, which might have enabled the area linked to mathematical reasoning to be larger than normal because it didn't have a boundary to restrict its growth......... Posted by: Kelly      Read more         Source

September 27, 2007, 9:37 PM CT

DNA Extracted From Woolly Mammoth Hair

Stephan C. Schuster and Webb Miller of Penn State, working with Thomas Gilbert from Copenhagen and a large international consortium, discovered that hair shafts provide an ideal source of ancient DNA -- a better source than bones and muscle for studying the genome sequences of extinct animals. Their research achievement, described in a paper would be reported in the journal Science on Sept. 28, includes the sequencing of entire mitochondrial genomes from 10 individual woolly mammoths.

Schuster and Miller, working at Penn State's Center for Comparative Genomics and Bioinformatics, and Gilbert, from the Center for Ancient Genetics at the University of Copenhagen, led a team of collaborators that includes a large group of scientists and museum curators from the United States, Russia, Belgium, Denmark, France, Italy, Sweden and the United Kingdom.

The research team obtained hair from 10 woolly mammoths collected from a wide swathe of northern Siberia and with dates of death spanning approximately 38,000 years -- from 50,000 years to 12,000 years ago. Before this study, only seven mitochondrial genomes from extinct animals had been published: four from ancient birds, two from mammoths and one from a mastodon.

"DNA in bones and muscle commonly degrades and becomes contaminated with genetic material from other sources such as bacteria, limiting its usefulness in scientific studies," Schuster explained. Because only a tiny proportion of ancient bones and muscle are preserved in such a way that uncontaminated DNA can be recovered, research with such materials has involved laborious efforts, sometimes spanning as long as six years for a single study. In contrast, Miller said, "Once I get the data from the genome sequencer, it takes only five minutes to assemble the entire mitochondrial genome."........ Posted by: Kelly      Read more         Source

September 27, 2007, 9:23 PM CT

Wasp altruism evolved from maternal behavior

Scientists at the University of Illinois have used an innovative approach to reveal the molecular basis of altruistic behavior in wasps. The research team focused on the expression of behavior-related genes in Polistes metricus paper wasps, a species for which little genetic data was available when the study was begun. Their findings appear today online in Science Express.

Like honey bee workers, wasp workers give up their reproductive capabilities and focus entirely on nurturing their larval siblings, a practice that seems to defy the Darwinian prediction that a successful organism strives, above all else, to reproduce itself. Such behaviors are indicative of a eusocial society, in which some individuals lose, or sacrifice, their reproductive functions and instead work to benefit the larger group.

Behavioral researchers have long noted the similarity between the maternal behaviors of some wasps and the nurturing and provisioning activities of workers. Until now, no study had uncovered a genetic link between the two.

The scientists observed that the pattern of behavior-related genes expressed in the brains of worker wasps was most similar to that seen in foundresses, the female wasps who alone build new colonies and devote much of their early lives to maternal tasks......... Posted by: Kelly      Read more         Source

September 26, 2007, 8:10 PM CT

Nutrient Pollution Drives Frog Deformities

High levels of nutrients used in farming and ranching activities fuel parasite infections that have caused highly publicized frog deformities in ponds and lakes across North America, as per a new study led by the University of Colorado at Boulder.

The study showed increased levels of nitrogen and phosphorus cause sharp hikes in the abundance and reproduction of a snail species that hosts microscopic parasites known as trematodes, said Pieter Johnson of the University of Colorado, Boulder. The nutrients stimulate algae growth, increasing snail populations and the number of infectious parasites released by snails into ponds and lakes. The parasites subsequently form cysts in the developing limbs of tadpoles causing missing limbs, extra limbs and other severe malformations, Johnson said.

"This is the first study to show that nutrient enrichment drives the abundance of these parasites, increasing levels of amphibian infection and subsequent malformations," said Johnson. "The research has implications for both worldwide amphibian declines and for a wide array of diseases potentially associated with nutrient pollution, including cholera, malaria, West Nile virus and diseases affecting coral reefs".

Johnson is the lead author of a study on the subject published online the week of Sept. 24 in the Proceedings of the National Academy of Sciences. The National Science Foundation funded the work......... Posted by: Kelly      Read more         Source

September 26, 2007, 8:09 PM CT

Interbreeding Between Invasive and Native Salamander Species

Interbreeding between the California Tiger Salamander--which is a native, endangered species--and the invasive Barred Tiger Salamander has produced a swarm of hybrid salamanders that is more likely to survive than either parent species, as per a new study.

Found in Salinas, California, the swarm of hybridized salamanders may comprise the first population of sustainable hybrids created by an interbreeding involving an endangered species, and is among the first known sustainable populations of a hybrid animal.

The conservation issues raised by the discovery of the salamander hybrid may "serve as a model" for those issues to be raised by future discoveries of hybrids created by interbreeding between an endangered species and an invasive species, says Brad Shaffer of the University of California, who is a co-author of the study. Because of advances in genetic analyses and because of increases in invasive species, Shaffer expects increasing numbers of hybrids to be discovered in the future.

The study of the hybridization of the California Tiger Salamander and the invasive Barred Tiger Salamander, which was introduced to the study area about 50 years ago as fishing bait, is described in the September 17 issue of The Proceedings of the National Academy of Sciences. This research was partially funded by the National Science Foundation (NSF)......... Posted by: Kelly      Read more         Source

September 26, 2007, 8:04 PM CT

Hybrid Salamanders Contradict Common Wisdom

A new UC Davis study not only has important findings for the future of California tiger salamanders, but also contradicts prevailing scientific thought about what happens when animal species interbreed.

The study, by former UC Davis doctoral student Benjamin Fitzpatrick (now on the faculty of University of Tennessee, Knoxville) and professor Bradley Shaffer, was published recently in the Proceedings of the National Academy of Sciences' online edition.

The salamander experts studied the survival rates and genetic makeup of three types of salamanders: native California tiger salamanders (Ambystoma californiense), which are protected under the U.S. Endangered Species Act; barred tiger salamanders that were introduced in California from Texas in the 1950s (Ambystoma tigrinum mavortium); and the hybrid offspring born when the two species mated.

They observed that more of the hybrid young survived in the wild than did young of the native or the introduced species -- quite a surprise, since animal hybrids are commonly less fit than their parents ("hybrid vigor" is largely limited to plant crosses).

That raises difficult questions for managing endangered native salamander populations, Shaffer said. Some conservationists might say that hybrids are an acceptable change, since they are favored by natural selection, and "improve" the original species. Others might consider hybrids to be genetically impure and regard them as threats to the native salamanders, their competitors and their prey......... Posted by: Kelly      Read more         Source