FAIRBANKS, Alaska—It is a misinterpretation of the application of the bedrock of scientific naming with regard to the number of moose species that Kris Hundertmark, a University of Alaska Fairbanks wildlife geneticist at the Institute of Arctic Biology, seeks to correct.

The adoption of Carl Linnaeus’ two-part, genus-species system of naming, called taxonomy, has been used for centuries on all described organisms on Earth and is considered one of the greatest triumphs in science.

Hundertmark will be presenting his research during the American Society of Mammalogists 89th Annual Meeting June 24-28 at UAF.

“When we give something its own name we’re saying this is a unit of biodiversity that deserves to be conserved,” Hundertmark said. “If you name something that doesn’t deserve a name, you’re wasting resources that could be spent on worthwhile groups.”

The reference book Mammal Species of the World, which Hundertmark calls the “unofficial bible of what is a mammal species and what isn’t,” lists two species of moose. The two-species concept is based primarily on a difference in chromosome numbers and the physical structure, or morphology, of moose

Chromosomes are ranked and numbered by size, largest to smallest, and can be depicted in a standard format knows as a karyogram. A typical chromosome pair is shaped like an “X” connected at the middle, though some are V-shaped and connected at the apex. The karyogram for North American moose show 70 chromosome pairs. A Eurasian moose karyogram shows two V-shaped chromosomes that appear to have united to form one X-shaped chromosome resulting in 68 pairs.

“We’ve always known that North American moose have one more pair of chromosomes than Eurasian moose,” Hundertmark said. “But it is a minor rearrangement rather than a functional difference.”

The morphology argument is a nonstarter because similar physical differences exist among other animals considered one species and “… moose are distributed throughout the Northern Hemisphere and would be expected to exhibit regional variation in morphology,” said Hundertmark.

One way of defining a species is whether two individuals can mate and produce viable offspring. If they can, they’re the same species; if they can’t, they’re not. But transporting moose for breeding experiments is prohibitively expensive and according to Hundertmark it is not unreasonable to assume that the two types can interbreed until it is proven otherwise.

To test the two-species hypothesis, Hundertmark examined the DNA from moose tissue samples collected by colleagues around the world. He arranged the samples into two groups based on the two-species hypothesis and into three groups based on continent of origin – Europe, Asia and North America – and examined the distribution of genetic variation within and between groups.

“It turns out that there are actually three genetic groups of moose, not two, and the genetic differences among those groups do not rise to the level of separate species. It is just regional variation,” Hundertmark said.

Source: University of Alaska Fairbanks

Scientists from Texas AgriLife Research and the Texas A&M University College of Veterinary Medicine & Biomedical Sciences (CVM) are part of a consortium of researchers who have developed an annotated sequence of the cattle genome which could lead to better disease resistance and higher quality meat for consumers, the researchers say. Their work was led by the Baylor College of Medicine Human Genome Sequencing Center and published in two reports that appear today in the journal “Science.”

The researchers used the complete sequence from a single Hereford cow and comparative genome sequences for six more breeds, looking for changes called single nucleotide polymorphisms – SNPs – markers that can help researchers identify favorable traits.

“The biggest thing that came out of the SNP project was the resource of the SNPs themselves,” said Dr. Clare Gill, a Texas AgriLife Research beef geneticist who co-led the SNP initiative. “That has changed how we operate when we do DNA studies and identification of genes.”

Texas AgriLife Research is part of the Texas A&M University System, with scientists based at Texas A&M in College Station and 13 research centers across the state.

SNPs in 497 cattle from 17 geographically and biologically diverse breeds and two related species (anoa and water buffalo) were used in the project. Using SNPs, Gill said there could be considerable progress made in cattle health as well as meat production.

“There could be progress made in disease resistance, production efficiency, tenderness and marbling,” Gill said.

Dr. James Womack, who holds the title of Distinguished Professor in the CVM and has studied the bovine genome for the past 20 years and is one of the team leaders of the project, said the work “opens the door to look at all sorts of specific interests in cattle – from disease immunity to better meat quality, better milk production and on and on.”

“Ten to 20 years down the line, this will lead to new avenues in cattle research that were not available to us previously,” Womack says. “It’s a huge step in the field of cattle research.”

His colleague in much of the work was Dr. Loren Skow, also a faculty member in the CVM.

Gill hosted the DNA repository from cattle around the world. Gill is using the SNP resources generated in this study to tie information into the agency’s own cattle mapping resource at the AgriLife Research Center in McGregor.

Gill also led a team that annotated the genes detailed in “Science” and received contributions from students in her applied animal genomics graduate-level course. Contributing to the research were graduate students Carl Muntean, Cody Gladney, Natasha Romero and Jungwoo Choi. Undergraduates Clayton Boldt and Jennifer Chapin contributed annotations, as well as Kris Wunderlich (doctoral candidate) and Colette Abbey (research associate). AgriLife Research scientists Drs. Penny Riggs and Tom Welsh also contributed to the annotation process.

Womack said the cattle sequence took six years to complete, annotate and analyze with more than 300 scientists from 25 countries. Most of more than 25 companion reports describing detailed analyses of the two projects by the Bovine Sequencing Project and the Bovine Hapmap Consortia appear online at www.biomedcentral.com in a special electronic issue of the BioMed Central journal group.

“The future challenge will be to explore the bovine genome sequence in greater depth to fully understand the genetic basis of the evolutionary success of ruminants as this will provide opportunities to address some of the crucial issues of the present time – efficient and sustainable food production for a rapidly increasing human population,” said Dr. Richard Gibbs, director of the BCM Human Genome Sequencing Center and principal investigator on the project.

The authors concluded that the bovine genome, consisting of at least 22,000 genes, is more similar to that of humans than that of mice or rats. They note that most cattle chromosomes correspond to part or all of human chromosomes, although the DNA is rearranged in some areas.

Source: Texas A&M University

Wild female chimpanzees copulate more frequently with males who share meat with them over long periods of time, according to a study led by researchers from the Max Planck Institute for Evolutionary Anthropology in Germany, published in the open-access, peer-reviewed journal PLoS ONE April 8.

How females choose their mating partners and why males hunt and share meat with them are questions that have long puzzled scientists. Evidence from studies on human hunter-gatherer societies suggest that men who are more successful hunters have more wives and a larger number of offspring. Studies on wild chimpanzees, humans’ closest living relative, have shown that male hunters frequently share meat with females who did not participate in the hunt. One of the hypotheses proposed to explain these findings is the meat-for-sex hypothesis, whereby males and females exchange meat for mating access. However, there has been little evidence in both humans and chimpanzees to support it.

In recent research conducted in the Taï National Park, Côte d’Ivoire, Cristina M. Gomes and Christophe Boesch show that females copulate more frequently with males who share meat with them on at least one occasion, compared with males who never share meat with them, indicating that sharing meat with females improves a males’ mating success. Although males were more likely to share meat with females who had sexual swellings (i.e., estrous females), excluding all sharing episodes with estrous females from the analysis, did not alter the results. This indicates that short term exchanges alone (i.e., within the estrous phase of the female) cannot account for the relationship between sharing meat and mating success.

According to Gomes, “Our results strongly suggest that wild chimpanzees exchange meat for sex, and do so on a long-term basis. Males who shared meat with females doubled their mating success, whereas females, who had difficulty obtaining meat on their own, increased their caloric intake, without suffering the energetic costs and potential risk of injury related to hunting.”

She adds, “Previous studies might not have found a relationship between mating success and meat sharing because they focused on short-term exchanges; or perhaps because in those groups access to females was driven by male coercion so females rarely chose their mating partners.”

Boesch concluded, “Our findings add to the ever-growing evidence suggesting that chimpanzees can think in the past and the future and that this influences their present behavior.”

“These findings are bound to have an impact on our current knowledge about relationships between men and women; and similar studies will determine if the direct nutritional benefits that women receive from hunters in human hunter-gatherer societies could also be driving the relationship between reproductive success and good hunting skills,” concludes Gomes.

Source: Public Library of Science.

Researchers are reporting the first identification of a “magic potion” of proteins in the saliva of the black fly that help this blood-sucking pest spread parasites that cause “river blindness,” a devastating eye-disease. A better understanding of these proteins may lead to better drugs and a vaccine for river blindness and other diseases spread by biting insects. Also known as onchocerciasis, river blindness affects more than 17 million people worldwide, particularly in rural Africa. The report appears in the current edition of ACS’ Journal of Proteome Research, a monthly publication.

In the new study, José M.C. Ribeiro and colleagues explain that the saliva of adult female black flies contains substances that mute the human body’s natural defenses. This chemical cocktail makes the body more vulnerable to disease when infected flies bite into the skin. Until now, however, nobody had identified the specific chemicals involved in this devious action.

The scientists collected salivary glands from hundreds of adult female black flies and isolated the proteins using high-tech analytical gear. They identified 72 different proteins, including several new to science. These proteins could serve as the basis for developing drugs or vaccines against diseases transmitted by the black fly and other blood-sucking insects, including mosquitoes, midges, and sand flies, the researchers say. – MTS

ARTICLE #2 FOR IMMEDIATE RELEASE

“Insight into the Sialome of the Black Fly, Simulium vittatum

DOWNLOAD FULL TEXT ARTICLE:http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/pr8008429

Credit: Photo by Matt Friedman

Large size and a fast bite spelled doom for bony fishes during the last mass extinction 65 million years ago, according to a new study to be published March 31, 2009, in the Proceedings of the National Academy of Sciences.

Today, those same features characterize large predatory bony fishes, such as tuna and billfishes, that are currently in decline and at risk of extinction themselves, said Matt Friedman, author of the study and a graduate student in evolutionary biology at the University of Chicago.

“The same thing is happening today to ecologically similar fishes,” he said. “The hardest hit species are consistently big predators.”

Studies of modern fishes demonstrate that large body size is linked to large prey size and low rates of population growth, while fast-closing jaws appear to be adaptations for capturing agile, evasive prey—in other words, other fishes. The fossil record provides some remarkable evidence supporting these estimates of function: fossil fishes with preserved stomach contents that record their last meals.

When an asteroid struck the earth at the end of the Cretaceous about 65 million years ago, the resultant impact clouded the earth in soot and smoke. This blocked photosynthesis on land and in the sea, undermined food chains at a rudimentary level, and led to the extinction of thousands of species of flora and fauna, including dinosaurs.

The fossil fish on the left is not related to the modern swordfish on the right, which is for sale at a fish market. Nevertheless, the swordfish developed a size and shape similar to the fossil fish and appears to be vulnerable to extinction for some of the same reasons that the fossil form was vulnerable: it is a large predator.

Credit: Photo by Matt Friedman

Scientists had speculated that during that interval large predatory fishes might have been more likely than other fishes to go extinct because they tended to have slowly increasing populations, live more spread out, take longer to mature, and occupy precarious positions at the tops of food chains. Today, ecologically similar fishes appear to be the least able to rebound from declining numbers due to overfishing.

To build the database he needed to test this prediction, Friedman traveled around the world measuring the body size and jaw bones of 249 genera of fossil fishes that lived during the late Cretaceous. These kinds of direct measurements are possible in fossil fishes because many are represented by complete, articulated individuals. This is unlike the fossil record of most other vertebrates, where bones, teeth and other parts of the skeleton are often scattered and found in isolation.

This study is the first to test this theory with hard data and to quantify the relationship between body size, jaw function and vulnerability of fishes during the Cretaceous extinction, according to Friedman.

“Anyway you sliced it, the data showed that if you were a big fish with a fast bite you were toast,” he said.

Ironically, today’s large fishes with fast bites evolved relatively shortly after the end-Cretaceous extinction, apparently filling the functional and ecological roles vacated by the victims of that mass extinction. Although the two groups of fishes are not related to each other, their fates may end up being similar.

The paper is called “Ecomorphological selectivity among marine teleost fishes during the end-Cretaceous extinction” and will appear in issue 13 of PNAS. In it, Friedman describes the results of his study as robust because the large-bodied, predatory fishes that are disproportionately devastated also have the best fossil records. “In other words, we can be convinced that these forms really do die off here, and that their disappearance can’t be chalked up to a lousy fossil record,” Friedman noted.

Nevertheless, fossil fishes are not well studied because paleontologists, as a group, tend to be drawn to other animals, such as dinosaurs. Therefore, many large-scale patterns of fish evolution remain unclear.

The fossil fishes included in the study are diverse in form, and range in length from about 20 feet to less than one inch.

“This study demonstrates that fossil datasets are germane to modern diversity and evolution by allowing us to calibrate what characteristics might relate to extinction vulnerability today,” Friedman said. “Echoes of the end-Cretaceous extinction reverberate 65 million years later.”

Source: University of Chicago Medical Center

The impact fish stocking has on aquatic insects in mountain lakes can be rapidly reversed by removing non-native trout, according to a study completed by U.S. Forest Service and University of California, Davis, scientists.

Their findings appear in a current online issue of the journal Freshwater Biology where they describe experiments that examined some effects of fisheries management practices now in use in California mountain lakes where fish do not naturally occur.

The research has value because the vast majority of mountain lakes in the western United States have been stocked with trout for several decades. Studies following lake restoration to fishless conditions will help scientists and wildlife managers understand the impact of past actions and future decisions.

Since 2000, the California Department of Fish and Game has reduced the number of wilderness lakes it stocks by about half because non-native fish feed on declining species like the Sierra Nevada yellow-legged frog. Federal and state agencies have also begun removing introduced trout in some lakes because fish can survive for years and continue feeding on sensitive species, after stocking has ceased.

Until now, scientists seldom studied the response of aquatic insect populations to the removal of non-native trout.

“These highly-mobile predators don’t naturally occur in small alpine lakes so they have significant top-down effects on ecosystems,” said Karen Pope, a Forest Service scientist at the Pacific Southwest Research Station and one of the study’s authors. “They prey upon aquatic insects that are also food for other insects, amphibians, birds and bats.”

In 2003, Pope and her colleagues began testing the effects introduced fish had on lake ecosystems in 16 lakes in Northern California’s Trinity Alps Wilderness.

The National Science Foundation, U.S. Forest Service, California Department of Fish and Game, and University of California funded the study, which matched current California fisheries management practices by including lakes with continued stocking of trout, suspension of stocking and removal of all fish. It also included fish-free lakes as reference sites for the study.

The researchers used floating nets on each lake’s surface to quantify aquatic insect populations. They also used gill nets to sample trout density at lakes where there was continued stocking or suspension of stocking.

Their results showed the presence of introduced trout was the most important factor affecting the emergence of insects from the lakes.

Aquatic insect populations quickly increased when trout were removed from lakes. However, the scientists found suspension of stocking was not effective for restoring insect abundance in most lakes. This was not surprising because suspension of stocking alone had little effect on trout density, according to the researchers.

Source: US Forest Service, Pacific Southwest Research Station

PHILADELPHIA –- A team of biologists at the University of Pennsylvania has completed a research study begun in 1915 and determined that a snail making its home in the northwest Atlantic Ocean around Mount Desert Island, Me., has experienced a dramatic increase in the size of its shell during less than a century, providing a clear illustration of how fast and effectively change can occur.

The study is published in the current issue of the Proceedings of the National Academy of Sciences.

The most striking finding, which has not been reported previously in Nucella lapillus, the Atlantic dogwhelk, is that shell length increased at all 19 sites where samples were taken. Shell lengths of N. lapillus increased by an average of 22.6 percent during the past century, with no evidence of changes in other shell characteristics. The Penn team’s results demonstrate that monitoring changes in shell morphology requires careful accounting of variation in local conditions, such as wave exposure, which can affect not only shell shape but also size.

Why have snails gotten bigger? Within the last century, the Gulf of Maine has experienced reductions in the size and abundance of native predators of dogwhelks, increases in ocean temperatures and invasions of new predators, and all three factors could have played a role. Overfishing of native predators of dogwhelks, such as fish, and increases in temperatures could have lowered mortality and increased growth, both of which would cause an increase in size. Also, arrival of new predators as invasive species could have selected for larger body size.

Changes in the shell architecture of marine snails enhance defenses and greatly improve survival against predators. Stouter and thicker shells have been reported for N. lapillus and several other species following the introduction of predatory Carcinus maenas crabs early in the 20th century. Indeed, researchers hypothesize that when the snails are exposed to crab cues, shells of small snails first thicken and then, once defended against shell-crushing predators, grow in length to a size beyond the abilities of the crab.

N. lapillus is an important member of the North Atlantic marine ecosystems, and the results suggest that the impacts of historical changes in species’ key morphological traits on marine ecosystems remain underappreciated. The dramatic increase in size, the researchers hypothesize, may give the snail an edge when preying on large mussels and barnacles, while protecting them from predators like crabs.

Comparisons were based on archived shells collected from 1915 to 1922 from sites that were resampled in 2007. Finding samples from 1915 proved to be easy, thanks to the work of Harold Sellers Colton. Colton, a professor of biology at Penn until 1926 and a charter member of the Ecological Society of America, collected about 12,000 shells from 107 sites in Maine, depositing them for safe keeping at the Academy of Natural Sciences of Philadelphia.

The Penn team discovered the body size change simply by accident, as they were investigating the occurrence of a shell-boring worm using the shells in the collections at the Academy and noticed they were much smaller than those collected recently.

“This increase in size is a stunning observation, especially since dogwhelks are one of the best known and most widely studied organisms in the North Atlantic Ocean,” said Peter S. Petraitis, professor in the Department of Biology in Penn’s School of Arts and Sciences. “Imagine that much change in the height of humans occurring between 1915 and 2007. In 1915, the height of the average Ivy League man was 5 feet 9 inches. A 23 percent increase would now make the average height slightly over 7 feet. If Penn had a baseball squad that averaged 7 feet tall, I am sure Penn would be quite well known and perhaps doing very well in March Madness.”

Petraitis joined with graduate and undergraduate students, as well as a field associate from Portland, Me., to collect modern samples of the intertidal snail.

From the samples collected from 1915 to 1922, researchers measured shell length, shell lip thickness, aperture length and aperture width of N. lapillus shells from 19 lots and then resampled the same 19 sites in 2007 by using Colton’s site descriptions and maps of sampling locations. The team also classified the relative wave exposure at each site as exposed coast, semiexposed shore or sheltered cove, allowing the research team to test the influences of site, time period and wave exposure on N. lapillus shell morphology.

Source: University of Pennsylvania

Credit: Jonathan A. D. Fisher

A Queen’s University biologist has discovered that the shell lengths of snails in the northwest Atlantic Ocean – an important member of the Atlantic food chain – have increased by 22.6 per cent over the past century. Until now, this significant change in the marine ecosystem has gone unnoticed.

“We found a dramatic increase in size, which could affect the entire intertidal food chain,” says Jonathan Fisher, Queen’s Postdoctoral Fellow and the leader of the study. Growing larger shells is a major way for the snails to avoid predators, he explains. Previous and continuing research has also found that large snails tend to prey on mussels and barnacles and spend less time resting between feedings, compared to small snails.

The findings will appear online this week in the journal Proceedings of the National Academy of Sciences.

The team used museum collections from the Academy of Natural Sciences of Philadelphia as a base for their data. They measured the shells from 19 lots of shells gathered between 1915 and 1922, and compared them with samples from the same 19 locations today. The increase in size was striking however, the researchers are unsure exactly why the snails are growing so large, so rapidly.

“Many documented environmental changes between these time periods could affect snail survival or growth rates,” Dr. Fisher suggests. “We’re finding fewer predatory fish now, which would allow the snails to grow.” The temperature of the water today is warmer than 100 years ago, which could also account for faster growth of the snails, he adds.

“But regardless of the factors that contributed to the size increase, the marine landscape is changing dramatically on a historic timescale. That’s what is really important here,” says Dr. Fisher.

Source: Queen’s University

Hurdia victoria was originally described in 1912 as a crustacean-like animal. Now, researchers from Uppsala University and colleagues reveal it to be just one part of a complex and remarkable new animal that has an important story to tell about the origin of the largest group of living animals, the arthropods. The findings are being published in this week’s issue of Science.

The fossil fragments puzzled together come from the famous 505 million year old Burgess Shale, a UNESCO World Heritage Site in British Columbia, Canada. Uppsala researchers Allison Daley and Graham Budd at the Department of Earth Sciences, together with colleagues in Canada and Britain, describe the convoluted history and unique body construction of the newly-reconstructed Hurdia victoria, which would have been a formidable predator in its time.

Although the first fragments were described nearly one hundred years ago, they were assumed to be part of a crustacean-like animal. It was not then realised that other parts of the animal were also in collections, but had been described independently as jellyfish, sea cucumbers and other arthropods. However, collecting expeditions from in the 1990s uncovered more complete specimens and hundreds of isolated pieces that led to the first hints that Hurdia was more than it seemed. The last piece of the puzzle was found when the best-preserved specimen turned up in the old collections at the Smithsonian National Museum of Natural History, Washington DC. This specimen was first classified as an arthropod in the 1970s and 80s, and then as an unusual specimen of the famous monster predator Anomalocaris.

The new description of Hurdia shows that it is indeed related to Anomalocaris. Like Anomalocaris, Hurdia had a segmented body with a head bearing a pair of spinous claws and a circular jaw structure with many teeth. But it differs from Anomalocaris by the possession of a huge three-part carapace that projects out from the front of the animal’s head.

“This structure is unlike anything seen in other fossil or living arthropods,” says Ph.D. student Allison Daley, who has been studying the fossils for three years as part of her doctoral thesis.

“The use of the large carapace extending from the front of its head is a mystery. In many animals, a shell or carapace is used to protect the soft-parts of the body, as you would see in a crab or lobster, but this structure in Hurdia is empty and does not cover or protect the rest of the body. We can only guess at what its function might have been.”

Hurdia and Anomalocaris are both early offshoots of the evolutionary lineage that led to the arthropods, the large modern group that contains the insects, crustaceans, spiders, millipedes and centipedes. They reveal details of the origins of important features that define the modern arthropods such as their head structures and limbs. As well as its bizarre frontal carapace, Hurdia reveals exquisite details of the gills associated with the body, some of the best preserved in the fossil record.

“Most of the body is covered in the gills, which were probably necessary to provide oxygen to such a large, actively swimming animal,” says Allison Daley.

Source: Uppsala University

Picture it: 90-million years ago, a herd of young dinosaurs is left without a babysitter. The juveniles go roaming off on their own and soon find themselves in trouble.

Flash ahead to modern times, where paleontologists discover their mass grave and reveal what happened next.

The scene is in Mongolia’s Gobi Desert, where a team of Chinese and American scientists have been excavating the site for years.

They say the birdlike dinosaurs stumbled into a death trap on the muddy shores of a lake, sealing their fate, and preserving their bodies so well, even their stomach contents are still intact.

The find itself is rare enough, but even more unusual is what it reveals about the social behavior of these dinosaurs. Specifically that the herd made up of a single species of ornithomimid dinosaur (Sinornithomimus dongi) was left to fend for itself when adults were preoccupied with nesting or brooding.

The fossils were first found in 2001, but only last month were two of the spectacular skeletons airlifted from the site. More than 25 individuals were excavated in all, ranging in age from one to seven years, as annual growth rings in their bones revealed.

Along with herd composition and behavior, the site also turned up minute details. “We even know the size of its eyeball,” said University of Chicago paleontologist Paul Sereno.

Click here for the scientific paper on the herd site as published in Acta Palaeontologica Polonica.

Click here  for more information about team members and the expedition.