Tag Archives: species

Shark Social Networking

Shark migrations studied with underwater robot along Delmarva Peninsula

University of Delaware researchers are using an underwater robot to find and follow sand tiger sharks that they previously tagged with transmitters. The innovative project is part of a multi-year partnership with Delaware State University to better understand the behavior and migration patterns of the sharks in real time.

“In the past week our new, specially equipped glider OTIS – which stands for Oceanographic Telemetry Identification Sensor – detected multiple sand tiger sharks off the coast of Maryland that were tagged over the past several years,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment. “This is the first time that a glider has found tagged sharks and reported their location in real time.” (more…)

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Cambrian Fossil Pushes Back Evolution of Complex Brains

Complex brains evolved much earlier than previously thought, as evidenced by a 520-million-year-old fossilized arthropod with remarkably well-preserved brain structures.

The remarkably well-preserved fossil of an extinct arthropod shows that anatomically complex brains evolved earlier than previously thought and have changed little over the course of evolution. According to University of Arizona neurobiologist Nicholas Strausfeld, who co-authored the study describing the specimen, the fossil is the earliest known to show a brain.

The discovery will be published in the Oct. 11 issue of the journal Nature. (more…)

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Climate Change to Cripple Southwestern Forests

Trees Face Rising Drought Stress and Mortality as Climate Warms

LOS ALAMOS, N.M. — Combine the tree-ring growth record with historical information, climate records, and computer-model projections of future climate trends, and you get a grim picture for the future of trees in the southwestern United States. That’s the word from a team of scientists from Los Alamos National Laboratory, the U.S. Geological Survey, University of Arizona, and other partner organizations.

The research, published in Nature Climate Change this week, concluded that if the Southwest is warmer and drier in the near future, widespread tree mortality likely will cause substantial changes in forest and species distributions. (more…)

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Dinosaur Die Out Might Have Been Second of Two Closely Timed Extinctions

The most-studied mass extinction in Earth history happened 65 million years ago and is widely thought to have wiped out the dinosaurs. New University of Washington research indicates that a separate extinction came shortly before that, triggered by volcanic eruptions that warmed the planet and killed life on the ocean floor.

The well-known second event is believed to have been triggered by an asteroid at least 6 miles in diameter slamming into Mexico’s Yucatán Peninsula. But new evidence shows that by the time of the asteroid impact, life on the seafloor – mostly species of clams and snails – was already perishing because of the effects of huge volcanic eruptions on the Deccan Plateau in what is now India. (more…)

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Climate Change Could Increase Levels of Avian Influenza in Wild Birds

ANN ARBOR, Mich.— Rising sea levels, melting glaciers, more intense rainstorms and more frequent heat waves are among the planetary woes that may come to mind when climate change is mentioned. Now, two University of Michigan researchers say an increased risk of avian influenza transmission in wild birds can be added to the list.

Population ecologists Pejman Rohani and Victoria Brown used a mathematical model to explore the consequences of altered interactions between an important species of migratory shorebird and horseshoe crabs at Delaware Bay as a result of climate change. (more…)

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Why are There so Many Species of Beetles and So few Crocodiles?

Answer may be ‘adaptive zones’ that limit species number, life scientists report

There are more than 400,000 species of beetles and only two species of the tuatara, a reptile cousin of snakes and lizards that lives in New Zealand. Crocodiles and alligators, while nearly 250 million years old, have diversified into only 23 species. Why evolution has produced “winners” — including mammals and many species of birds and fish — and “losers” is a major question in evolutionary biology.

Scientists have often posited that because some animal and plant lineages are much older than others, they have had more time to produce new species (the dearth of crocodiles notwithstanding). This idea — that time is an important predictor of species number — underlies many theoretical models used by biologists. However, it fails to explain species numbers across all multi-cellular life on the planet, a team of life scientists reports Aug. 28 in the online journal PLoS Biology, a publication of the Public Library of Science. (more…)

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Scientists Define New Limits of Microbial Life in Undersea Volcanoes

A third of Earth’s organisms live in rocks and sediments, but their lives have been a mystery

By some estimates, a third of Earth’s organisms live in our planet’s rocks and sediments, yet their lives are almost a complete mystery.

This week, the work of microbiologist James Holden of the University of Massachusetts-Amherst and colleagues shines a light into this dark world.

In the journal Proceedings of the National Academy of Sciences (PNAS), they report the first detailed data on methane-exhaling microbes that live deep in the cracks of hot undersea volcanoes. (more…)

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Light Pollution Transforming Insect Communities

Street lighting is transforming communities of insects and other invertebrates, according to research by the University of Exeter.

Published in the journal Biology Letters, the study shows for the first time that the balance of different species living together is being radically altered as a result of light pollution in our towns and cities.

Believed to be increasing by six per cent a year globally, artificial lighting is already known to affect individual organisms, but this is the first time that its impact on whole communities has been investigated.

This study shows that groups of invertebrates living near to artificial lights include more predators and scavengers. This could be impacting on the survival rates of different species, having a knock-on effect on birds and mammals that rely on these species for food. The effects could be affecting entire ecosystems and even humans. (more…)

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