Tag Archives: species

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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Low Quality Genes May Cause Mutational Meltdown

Deficiencies compound over time, researchers say

Evolutionary biologists at the University of Toronto have found that individuals with low-quality genes may produce offspring with even more inferior chromosomes, possibly leading to the extinction of certain species over generations.

Their study, published in Proceedings of the National Academy of Sciences, predicts that organisms with such genetic deficiencies could experience an increased number of mutations in their DNA, relative to individuals with high-quality genes. The research was done on fruit flies whose simple system replicates aspects of biology in more complex systems, so the findings could have implications for humans. (more…)

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Another Vertebrate Species Reported Extinct from the Hawaiian Islands

HONOLULU – A species of lizard is now extinct from the Hawaiian Islands, making it the latest native vertebrate species to become extirpated from this tropical archipelago.

The copper striped blue-tailed skink (Emoia impar) — a sleek lizard with smooth, polished scales and a long, sky-blue tail — was last confirmed in the Na’Pali coast of Kauai in the 1960s. But repeated field surveys on Kauai, Oahu, Maui and Hawai’i islands from 1988 to 2008 have yielded no sightings or specimens. (more…)

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Early Spring Drives Butterfly Population Declines

“Ahead-of-time” snowmelt triggers chains of events in the Mormon Fritillary butterfly

Early snowmelt caused by climate change in the Colorado Rocky Mountains snowballs into two chains of events: a decrease in the number of flowers, which, in turn, decreases available nectar. The result is decline in a population of the Mormon Fritillary butterfly, Speyeria mormonia.

Using long-term data on date of snowmelt, butterfly population sizes and flower numbers at the Rocky Mountain Biological Laboratory, Carol Boggs, a biologist at Stanford University, and colleagues uncovered multiple effects of early snowmelt on the growth rate of an insect population. (more…)

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Hiding in Plain Sight, A New Frog Species With A ‘Weird’ Croak is Identified in New York City

In the wilds of New York City — or as wild as you can get so close to skyscrapers — scientists have found a new leopard frog species that for years biologists mistook for a more widespread variety of leopard frog.

While biologists regularly discover new species in remote rain forests, finding this one in the ponds and marshes of Staten Island, mainland New York and New Jersey — sometimes within view of the Statue of Liberty — is a big surprise, said the scientists from UCLA, Rutgers University, UC Davis, and The University of Alabama who worked together to make the unexpected discovery. (more…)

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Studying The Evolution of Life’s Building Blocks

VANCOUVER, British Columbia — Studying the origin of life at its building blocks offers a unique perspective on evolution, says a researcher at Michigan State University.

Robert Root-Bernstein, MSU physiology professor, will answer the question of why a physiologist studies the origin of life at the annual meeting of the American Association for the Advancement of Science Feb. 16-20 in Vancouver, British Columbia. (more…)

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