Tag Archives: mammals

Selfish Gene may Undermine Genome Police

By Guest PostMarch 18, 2013Scienceaubergine, brown university, chromosomes, father of genetics, fruit fly, genome police, gregor mendel, humans, mammals, police gene, robert reeenan, sd, segregation distorter, selena gell, selfish gene, selfish genetic entity, sex cells, sperm, strings of biochemicals

Biologists have been observing the “selfish” genetic entity segregation distorter (SD) in fruit flies for decades. Its story is a thriller among molecules, in which the SD gene destroys maturing sperm that have a rival chromosome. A new study reveals a tactic that gives SD’s villainy an extra edge.

PROVIDENCE, R.I. [Brown University] — For a bunch of inanimate chemical compounds, the nucleic and amino acids caught up in the infamous “selfish” segregation distorter (SD) saga have put on quite a soap opera for biologists since the phenomenon was discovered in fruit flies 50 years ago. A new study, a highlight in the March issue of the journal Genetics, provides the latest plot twist. (more…)

Environmental Issues: How True the Climate Changes Affecting Biodiversity

By Guest PostDecember 12, 2012Environmentalgae, annual migratory cycle, biodiversity, biological behavior, biosphere, brianne, caribbean species, changes in climate, changing climate, changing temperatures, climate changes, colonization, corals, current scenario, eccentric rainfall, ecology, ecosystem, elkhorn, environmental conditions, erratic courses, evolution, fishes, fossilized remains, global warming, great barrier reef, mammals, melting, melting of permafrost, migration of animals, migratory birds, oceans, offsprings, penguins, permafrost, phytoplankton, polar bears, polar regions, pollen distribution, regal cigs, satellite pictures, species, staghorn corals, temperature, underwater life, warm air currents, zooplanktons

A changing climate has implications on biodiversity without any doubt. Species in the past have been sensitive to changes in the climate; that has been proved time and again by the fossilized remains and pollen distribution studies. It has been seen or can be concluded safely that climate changes have led to extinction of species in one area and colonization in another.

It is improbable that all species can or will be able to adapt to changing conditions specially the sudden changes. This leads to impact in ecosystem dynamics and also on community composition. (more…)

Asteroid that Killed the Dinosaurs also Wiped out the ‘Obamadon’

By Guest PostDecember 11, 2012Nature, Scienceage of dinosaurs, alberta, asteroid collision, asteroid strike, bhart anjan bhullar, boundary, canada, carnivorous lizards, cerberophis, cretaceous, dinosaur species, dinosaurs, diversification, ecosystem, edmontosaurus, evolution, extinct lizard, flood, fossils, gracilis, harvard, jacques a gauthier, kill, lizard, mammals, mass extinction, montana, new mexico, nicholas r longrich, North America, obamadon, obamadon gracilis, odon, palaeosaniwa, paleogene, political significance, polyglyphanodontia, slender, snake, species, survivor, swamps, t rex, taxonomy, tooth, triceratops, united states, us president, yale, yucatan peninsula

The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.

“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)

Yale Study Reveals New Family Tree for Ray-Finned Fish

By Guest PostAugust 7, 2012Natureage of fishes, alex dornburg, bass, bonefishes, bonytongue fish, devonian period, dinosaurs, eels, evolutionary birthday, family tree, fishes, fossil record, freshwater, genetic analysis, kristen l kuhn, lineages of fish, mammals, ray finned fish, ron i eytan, salmon, second age, teleost fish, teleost lineages, teleosts, thomas near, tropical, tuna, yale university

The most common lineages of fish found today in oceans, lakes, and rivers evolved about the same time as mammals and birds, a new Yale University-led study shows.

The comparative genetic analysis of more than 200 fish species, reported the week of Aug. 6 in the Proceedings of the National Academy of Sciences, gave an earlier than expected evolutionary birthday to well-known teleost — or ray-finned — fish such as salmon, bass, or tuna.

The analysis also shows that the very earliest lineages of living teleost fish were eels and bonefishes, not tropical freshwater bonytongue fish as some scientists had proposed. (more…)

Ribbeting Research

By Guest PostJuly 13, 2012Nature, Scienceacoustic difference, amphibians, amplexus, cocktail party problem, eardrum movement, eustachian tubes, female cope, frog ears, frogs, gray treefrog, hearing aids, jackhammer, mammalian ears, mammals, mark bee, mr right, study, university of minnesota, velocity

Studies of frogs may lead to better hearing aids

When Mark Bee talks to his 106-year-old grandmother alone, her two enormous hearing aids enable her to understand him well.

“But at a table at Thanksgiving, with everybody talking, the devices don’t do well,” says Bee, an associate professor of ecology, evolution and behavior at the University of Minnesota.

Her difficulty in a noisy situation is called the cocktail party problem, after the background babble that stymies many hearing-impaired people trying to pick out individual voices at a party. But in ponds all over the world, frogs handle a similar problem, and Bee hopes to learn enough about how they do it to put the principles to work helping people like his grandmother. (more…)

Insect Glands May Illuminate Human Fertilization Process

By Guest PostMay 12, 2012Health, Scienceallan spradling, bee, cellular physiology, egg, fertilization, fruit fly, gene, hr39, human, insect glands, jianjun sun, lrh 1, mammals, receptor protein, reproductive glands, secretion, secretion glands, sperm

Baltimore, MD — Insect glands are responsible for producing a host of secretions that allow bees to sting and ants to lay down trails to and from their nests. New research from Carnegie scientists focuses on secretions from glands in the reproductive tract that help sperm survive and guide the sperm on the trip to fertilize an egg. The gene that controls the development of these glands in fruit flies provides important information about gland development in all insects, as well as potential clues to similar human reproductive glands. Their work is published this month in Current Biology.

When a female fruit fly receives sperm from a male fruit fly, lubricating secretions in her reproductive tract activate the sperm, store it, and guide it to fertilization. Without the aid of these secretions, sperm would not make it to the eggs. Carnegie’s Allan Spradling and Jianjun Sun demonstrated that the gene in charge of regulating the development of fruit fly secretion glands is called Hr39. It encodes a steroid receptor protein. (more…)

Pregnant Primates Miscarry When New Male Enters Group

By Guest PostFebruary 24, 2012Nature, Scienceamy lu, anthropology, baboons, bachelor males, breeding primate, bruce effect, clay wilton, eila roberts, ethiopia, female geladas, fertility, geladas, gestation, jacinta beehner, jared wadley, lactation, mammals, miscarriage, national park, offspring, old world monkeys, pregnant, reproduction, rodents, science express, simien mountains, thore bergman, unfamiliar male, university of michigan

ANN ARBOR, Mich.— Pregnant female geladas show an unusually high rate of miscarriage the day after the dominant male in their group is replaced by a new male, a new University of Michigan study indicates.

The “Bruce effect” – in which pregnant females spontaneously miscarry after being exposed to an unfamiliar male – has been found repeatedly in laboratory rodents. However, no conclusive evidence for this effect had ever been demonstrated in a wild population prior to this study. Geladas are Old World monkeys that are close relatives of baboons. (more…)

Severe Declines in Everglades Mammals Linked to Pythons

By Guest PostJanuary 31, 20121 commentEnvironment, Natureafrican python, alex wolf, alligators, america, beni anaconda, boa constrictor, bobcat, burmese python, camp walker, christopher gillette, cottontail rabbits, dan kimball, deschauensee anaconda, ecological impact, ecosystem, everglades, everglades ecosystem, everglades national park, everglades python, fox, geographic pattern, green anaconda, invasive species, john willson, mammal decline, mammals, marcia mcnutt, marsh, michael dorcas, michael rochford, national park, opossums, prey, python, python predation, rabbits, raccoons, robert reed, spread of pythons, therese walters, U.S. Geological Survey, united states

HOMESTEAD, Fla. — Precipitous declines in formerly common mammals in Everglades National Park have been linked to the presence of invasive Burmese pythons, according to a study published on Jan. 30, 2012, in the Proceedings of the National Academy of Sciences.

The study, the first to document the ecological impacts of this invasive species, strongly supports that animal communities in this 1.5-million-acre park have been markedly altered by the introduction of pythons within 11 years of their establishment as an invasive species. Mid-sized mammals are the most dramatically affected. (more…)