A University of Washington researcher found that climbers using supplemental oxygen on Mount Everest had a 3% death rate during descent, compared to an 8.3% death rate for those not using oxygen. A similar pattern emerged on K2, where none of the successful climbers who used supplemental oxygen died during descent.
Scientists have found fossils of an ancient, feathered animal that lived 220 million years ago, which may be the ancestor of birds. The discovery challenges widely accepted theories about the evolutionary link between dinosaurs and birds.
Researchers study energy consumption in insect brains to better understand human brain function and develop more effective treatments for stroke patients. The team's findings could also improve our understanding of state-of-the-art scanning techniques like MRI and PET.
Researchers sequenced a region of the house finch genome, showing similarities to mammalian genomes in structure. The study found that birds' compact genomes favor metabolic demands related to flight, supporting shared basic genome structure with mammals.
Researchers found a species of frog in Puerto Rico that develops directly from eggs into fully formed adults, retaining the need for thyroid hormone despite bypassing the tadpole phase. This discovery showcases a classic case of evolutionary change in development, where the species adapted to evade predators by losing the tadpole stage.
An asteroid impact would cause catastrophic destruction and an impact winter, but a subsequent 'ultraviolet spring' could be even more devastating due to ozone depletion and acid rain. This period of intense UV radiation could lead to widespread DNA damage, mutations, cancer, and plant death.
The University of Toronto has discovered a new species of giant ground sloth, challenging the long-held assumption that mammals from South America were inferior to those in North America. The study suggests that these groups thrived for nearly two million years after migration across the Panamanian land bridge.
A leading expert warns that amphibian declines are a complex problem with multiple causes, including rising levels of UV-B radiation, pathogens, and pollutants. The lack of a single cause does not diminish the seriousness of this ecological phenomenon.
Researchers at the University of Washington found a strong correlation between the diversity of plants, algae, and bacteria in an ecosystem. The study suggests that altering biodiversity can have far-reaching effects on the entire food chain.
A new mathematical model explains changing patterns in epidemics by analyzing historical data on measles outbreaks. The research reveals that increases or decreases in birth rates or vaccination rates cause dramatic changes in epidemic patterns.
The 2000 AAAS Annual Meeting will bring together experts from various fields to share research news and discuss key topics such as nanotechnology, genome strategies, and social behavior among primates and humans. The meeting will also feature a special plenary address by U.S. Secretary of State Madeleine Albright.
Butterflies have developed ultrasound-sensitive ears on their wings to detect bat calls and exhibit evasive flight manoeuvres. The study found that rare nocturnal butterfly species in Panama possess this unique adaptation, protecting them from bat predators.
A new study at Oregon State University found that low levels of nitrate and nitrite in water can kill some species of amphibians, especially during their larval stages. The study suggests that water quality criteria set by the EPA may not guarantee the survival of all protected and endangered amphibian species.
Researchers Ally R. Harari and Jane Brockmann studied the behavior of Diaprepes abbreviatus beetles, finding that mounting females attracts larger males, improving female reproductive success. The beetle's behavior appears to suggest a different explanation for homosexual behavior than observed in domesticated animals.
Researchers from the University of Wisconsin-Madison propose a new approach to understanding ecosystem health by focusing on an organism's ability to withstand environmental stress. The study suggests that competition among species is less important than biodiversity as an insurance policy against unknown environmental fluctuations.
Researchers propose hormonal function change led to unique larval stage innovation, allowing population explosion among insect groups. Insects with complete metamorphosis have diverse habitats and food sources due to the lack of competition between juveniles and adults.
Researchers at Oregon State University have discovered a male pheromone that calms female salamanders during courtship, making them more receptive to mating. The study highlights the complex role of pheromones in animal behavior and suggests potential applications in human reproduction.
Researchers successfully eliminated an invasive South African worm that was causing deformed shells and stunted growth in California's abalone. By removing susceptible snails and using the 'epidemic threshold of transmission theory,' they were able to break the parasite's cycle, offering a new glimmer of hope for conservation efforts.
A comprehensive review of 200 endangered species recovery plans aims to evaluate their effectiveness and inform future improvements. The study, led by University of Washington zoologist Dee Boersma, will analyze factors such as species type, region, and plan revisions to determine the success of these plans.
Researchers analyze patterns in animal aggregations, such as schooling fish and flocking birds, to understand how they behave in trying conditions. This knowledge can inform predictions about group behavior under various scenarios, including the impact of climate change on fish populations.
USGS scientists will present research on rare plants, including soft-leaved Indian paintbrush and island jepsonia, and the effects of invasive species like feral pigs. The symposium aims to inform conservation strategies for California Channel Islands National Park.
New studies suggest ecosystems can be disrupted by small environmental changes or loss of minor species, challenging conventional wisdom on ecological protection. Research finds importance of both keystone and lesser species in ecosystem function.
Researchers at the Fred Hutchinson Cancer Research Center and the University of Washington have mapped a gene associated with prostate cancer that runs in families, also linked to primary brain cancer. The study results appear in the American Journal of Human Genetics.
The Aldo Leopold Leadership Program has selected its first cohort of 20 Fellows, including experts in water and air quality, diseases, and global climate change. The five-year program aims to enhance their ability to communicate environmental science effectively among various audiences.
A new study reveals that fruit-fly mating conflicts lead to continual changes in genes, a game of leapfrog that could have significant evolutionary consequences. Females frequently alter their genetic profiles to adjust the males' competitive odds.
A new report reveals that shrimp and salmon aquaculture may be depleting fisheries, disrupting coastal ecosystems, and polluting the ocean due to unsustainable practices. Improved practices, such as reducing fish feed requirements and minimizing pollution, are needed to make these industries more sustainable.
Researchers found that flooding in Venezuela's Lake Guri dam project isolated butterfly and ant species, causing some to thrive while others declined. The study highlights the complex effects of ecological disturbances and has implications for conservation efforts in fragmented landscapes.
Researchers find that competition for resources affects organ growth, leading to changes in traits like wings and horns. This phenomenon resolves a conundrum identified by Charles Darwin, suggesting that genes are not the sole determinant of development.
A study by Ohio State University researchers found that high-testosterone males were more likely to fertilize females other than their mates, resulting in fewer offspring with their own mates. Conversely, these males produced more offspring with the mates of their neighbors.
Researchers have discovered reproductive and hormonal problems in alligators from Lake Okeechobee, similar to those found in the highly polluted Lake Apopka. The study suggests that environmental toxicants can affect thyroid function and growth in animals.
The second Dynamics Days international conference will bring together experts in chaos, nonlinear dynamics, and complex systems to share their research. Speakers will discuss topics such as internet storms, animal coordination, extinction causes, and pattern formations.
Researchers have discovered that individual neurons in the brain can be compared to tiny computers that analyze and integrate information from different sources. These findings have implications for improving hearing aids, sonar devices, and speech recognition systems.
Male sparrow brains grow larger when housed with females, with increases of 15-20% in brain regions controlling song production. Social cues influence the birds' breeding efforts and song behavior, revealing new insights into the avian brain's plasticity.
A team of researchers found that Neandertal mitochondrial DNA falls outside normal human variation, indicating they did not contribute to the genetic makeup of modern humans. The study also confirms the origins of modern humans in Africa and suggests a divergence of 500,000 to 600,000 years ago.
A new biodiversity theory suggests that protecting ecotones along rainforest periphery is crucial for preserving biodiversity. Ecotones, the transition zones between rainforests and savannas, may be integral to generating biodiversity in tropical rain forests.
Researchers have found that penguins from the Punta Tombo reserve in southern Argentina travel more than 300 miles to find food, a significant increase from previously thought foraging ranges. The depletion of squid and other preferred foods is attributed to commercial fisheries and climate change.
Researchers tracked eight female leatherback turtles using satellite transmitters and found they prefer specific ocean corridors extending from Central America to the Galapagos Islands. The discovery highlights the importance of considering these corridors in conservation efforts, as international fishing fleets threaten turtle survival.
Ecological researchers highlight gaps in evidence on biocontrol's safety record, citing potential ecological risks. The use of biological control methods in agriculture is being reevaluated due to concerns over environmental harm, but research suggests it can be an effective solution for certain pest problems.
Researchers at the University of Washington have discovered a hormonal link between nutrition and reproduction, with leptin serving as a metabolic signal to the reproductive system. The study provides an explanation for how the body's energy stores determine reproductive readiness.
Researchers at San Francisco State University found a link between the African hornbill's seed dispersal pattern and rainforest regeneration. The team discovered that hornbills distribute seeds in treeless areas, critical for forest regeneration, particularly in cleared regions.