Tag Archives: species

Cambrian Fossil Pushes Back Evolution of Complex Brains

By Guest PostOctober 10, 2012Nature, Scienceancient animal, arachnids, arizona, arthropods, brain anatomy, branchiopod brain, branchiopods, brine shrimp, cambrian fossil, cambrian period, China, common ancestor, complex brain, course, crustaceans, dna sequence, evolution, evolutionary biologist, fuxianhuia protensa, gregory edgecombe, hypothesis, insects, malacostracans, microscope, missing link, modern brain, modern malacostracan, molecular data, morphology, mudstone, multicellular animals, Nature, neural anatomy, neurobiologist, neurocladistics, neuropils, nicholas strausfeld, optic lobes, origin, sensory organ, species, taxonomic group, transformative discovery, university, xianguang hou, xiaoya ma, yunnan province, yunnan university. kunming

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…)

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

By Guest PostSeptember 6, 2012Scienceaerosols, ammonite, antarctic peninsula, antarctic sediment, Argentina, asteroid, asteroid impact, carbon dioxide, deccan plateau, dinosaurs, earth, eduardo olivero, environmental effect, eric steig, fossil, free swimming, greenhouse gas, hell creek formation, history, India, isaac hilburn, james ross island, joseph kirschvink, magnetic field, magnetostratigraphy, mass extinction, matthew diamond, Mexico, montana, ocean floor, particles, peter ward, planet, ross mitchell, second event, sediment deposit, seymour island, species, thomas tobin, timothy raub, university, volcanic eruption, Washington, yale university, yucatan peninsula

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…)

Climate Change Could Increase Levels of Avian Influenza in Wild Birds

By Guest PostAugust 31, 2012Environment, Naturea h5n1, american black duck, Arctic, avian influenza, biogeographic population, bird flu, choreographed interaction, climate change, delaware bay, domestic poultry, heat waves, horseshoe crab, human health, human infection, increase, influenza infection, level, mallards, mathematical model, melting glaciers, michigan, migratory flight, migratory paths, migratory shorebird, north american, pejman rohani, planetary woes, population ecologist, rainstorms, risk, sea levels, species, type a virus, university, victoria brown, western hemisphere, 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…)

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

By Guest PostAugust 29, 2012Nature, Scienceadaptive zone, alligators, beetles, biodiversity, bird, cichlid fish, crocodile, daniel rabosky, diversity tree, ecological limits, eukaryote, evolutionary biology, evolutionary detectives, factor, fish, fungi, graham slater, life, lizard, mammal, michael alfaro, multi cellular, new zealand, planet, puzzle, reptile, snake, species, species diversity, species richness, theoretical model, tree of life, tuatara

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…)

Scientists Define New Limits of Microbial Life in Undersea Volcanoes

By Guest PostAugust 10, 2012Environment, Scienceaxial volcano, biogeochemical cycle, biological, biosphere, bruce strickrott, carbon dioxide, chemical, chemical factor, computer model, david butterfield, david garrison, deep ocean, earth, endeavour segment, fluid, formation, geochemical fluid, giraffe, growth rate, helene ver eecke, hydrogen, hydrogen threshold, hydrothermal fluid, hydrothermal vent, hyperthermophiles, hyperthermophilic, hyperthermophilic methanogens, james holden, julie huber, marine sediments, marvin lilley, metabolic process, methane, methane exhaling microbes, methanogen ecosystem, methanogenic, microbial composition, microbial life, microbiologist, natural gas, ocean surface, penguin, species, submarine alvin, subsurface microorganism, 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…)

Light Pollution Transforming Insect Communities

By Guest PostJune 1, 2012Environmentartificial lighting, balance, ecosystem, ecosystem services, falmouth, ground beetles, harvestmen, helston, insect communities, invertebrates, kevin murphy, light pollution, market town, scavenging species, species, street lighting, tom davies, university of exeter, urban spaces, west cornwall

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…)

Another Vertebrate Species Reported Extinct from the Hawaiian Islands

By Guest PostMarch 22, 2012Naturearchipelago, blue tailed skink, chris brown, cnrs, copper striped, cryptic extinction, emoia impar, extinction, hawaiian islands, ivan ineich, kauai, lizard, marcia mcnutt, maui, napali coast, oahu, oryx, Paris, robert fisher, skink, species, tropical, tropical pacific, united states, vertebrate species

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…)

Early Spring Drives Butterfly Population Declines

By Guest PostMarch 18, 2012Environment, Naturebutterfly population, carol boggs, caterpillars, climate change, colorado rocky mountains, david inouye, flower, life cycle, mormon fritillary butterfly, national science foundation, nectar, population, saran twombly, snowmelt, species, speyeria mormonia, university of maryland

“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…)