Showing 20 articles starting at article 681

< Previous 20 articles        Next 20 articles >

Categories: Ecology: Sea Life, Offbeat: Paleontology and Archeology

Return to the site home page

     (via sciencedaily.com)     Original source 

Surprisingly, genome comparisons have failed to resolve a major question in animal evolution: Which living animals are the descendants of the earliest animals to evolve in the world's oceans? Scientists performed a detailed chromosomal analysis that comes down definitively in favor of comb jellies, or ctenophores, as the most recent common ancestor of all animals, or the sister taxa to all animals. Sponges evolved later.

     (via sciencedaily.com)     Original source 

Researchers investigated how the jaw shape of sharks has changed over the course of evolution. Their conclusion: in the most widespread shark species, the jaws show relatively little variation in shape over millions of years; most variable jaws were found for deep-sea sharks.

     (via sciencedaily.com)     Original source 

Inspired by clam fishermen reports, researchers used passive acoustic telemetry to gauge the interactions between two highly mobile rays. They monitored the tagged rays in the wild over two years to see how often and when they visited clam leases, designated underwater locations used to produce hard clams of all sizes from littlenecks to chowders. Results provide both good news and bad news for clammers. Rays spent even more time in these clam lease sites than clammers reported or suspected, but it's not necessarily where they prefer hanging out.

     (via sciencedaily.com)     Original source 

A new study has found humpback whales sing louder when the wind is noisy, but don't have the same reaction to boat engines.

     (via sciencedaily.com)     Original source 

In the autumn, when right whales swim towards the coasts of South Africa, they ought to be fat and stuffed full. But in recent years, they have become thinner because their food is disappearing with the melting sea ice.

     (via sciencedaily.com)     Original source 

A new paper rewrites the history of the darkest, most bizarre event in the history of palaeontology.

     (via sciencedaily.com)     Original source 

Throughout the ocean, billions upon billions of plant-like microbes make up an invisible floating forest. As they drift, the tiny organisms use sunlight to suck up carbon dioxide from the atmosphere. Collectively, these photosynthesizing plankton, or phytoplankton, absorb almost as much CO2 as the world’s terrestrial forests. A measurable fraction of their carbon-capturing muscle comes from Prochlorococcus — an emerald-tinged free-floater that is the most abundant phytoplankton in the oceans today. New research suggests the microbe's ancient coastal ancestors colonized the ocean by rafting out on chitin particles.

     (via sciencedaily.com)     Original source 

Scalloped hammerhead sharks hold their breath to keep their bodies warm during deep dives into cold water where they hunt prey such as deep sea squids. This discovery provides important new insights into the physiology and ecology of a species that serves as an important link between the deep and shallow water habitats.

     (via sciencedaily.com)     Original source 

There have been heated debates over the size of Jurassic animals. The speculation was set to continue, but now a chance discovery in an Oxfordshire museum has led to palaeontologists publishing a paper on a Jurassic species potentially reaching a whopping 14.4 meters -- twice the size of a killer whale.

     (via sciencedaily.com)     Original source 

Surveying the body sizes of Earth's living organisms, researchers found that the planet's biomass -- the material that makes up all living organisms -- is concentrated in organisms at either end of the size spectrum.

     (via sciencedaily.com)     Original source 

A fossil arthropod entombed in 100-million-year-old Burmese amber has been identified as a new genus and species of froghopper, known today as an insect with prodigious leaping ability in adulthood following a nymphal stage spent covered in a frothy fluid.

     (via sciencedaily.com)     Original source 

The theory that water-breathing animals such as fish will shrink due to global warming has been called into question by a new study.

     (via sciencedaily.com)     Original source 

One of the basic and crucial embryonic processes to unfold in virtually every living organism is the formation of hollow, tubular structures that go on to form blood vessels or a digestive tract, and through branching and differentiation, complex organs including the heart and kidneys. This study illuminates fundamental design principles of tubulogenesis for all chordates, including mammals.

     (via sciencedaily.com)     Original source 

Even without body parts that allowed for movement, new research shows -- for the first time -- that some of Earth's earliest animals managed to be picky about where they lived.

     (via sciencedaily.com)     Original source 

Humans inherited genetic material from Neanderthals that affects the shape of our noses, finds a new study.

     (via sciencedaily.com)     Original source 

Phytosterols are good for your health, but humans and other animals are not able to make them themselves, only plants can. To acquire phytosterols, humans are increasingly turning to supplements, green smoothies, or a Mediterranean diet with plenty of plant-based foods. Researchers have now discovered that tiny gutless worms from the Mediterranean can synthesize phytosterols on their own. Their study provides evidence that many other animals also have the genes needed to make their own phytosterols.

     (via sciencedaily.com)     Original source 

For decades, scientists have used the amount of seaweed at the ocean's surface as a proxy for the health of coral reefs below. However, a new global study of more than 1,200 marine locations over a 16-year period reveals that this approach has been misleading -- and may even have hidden signs of reef stress.

     (via sciencedaily.com)     Original source 

An international research team has for the first time successfully isolated ancient human DNA from a Paleolithic artefact: a pierced deer tooth discovered in Denisova Cave in southern Siberia. To preserve the integrity of the artefact, they developed a new, nondestructive method for isolating DNA from ancient bones and teeth. From the DNA retrieved they were able to reconstruct a precise genetic profile of the woman who used or wore the pendant, as well as of the deer from which the tooth was taken. Genetic dates obtained for the DNA from both the woman and the deer show that the pendant was made between 19,000 and 25,000 years ago. The tooth remains fully intact after analysis, providing testimony to a new era in ancient DNA research, in which it may become possible to directly identify the users of ornaments and tools produced in the deep past.

     (via sciencedaily.com)     Original source 

Traces of sex hormones extracted from a woolly mammoth's tusk provide the first direct evidence that adult males experienced musth, a testosterone-driven episode of heightened aggression against rival males, according to a new study.

     (via sciencedaily.com)     Original source 

In the face of global warming and other environmental changes, corals in the Atlantic Ocean have declined precipitously in recent years, while corals in the Pacific and Indian Oceans are faring better. By describing several species of symbiotic algae that these corals need to grow, an international team has found that these mutualistic relationships from the Indo-Pacific may be more flexible and ultimately resilient to higher ocean temperatures than those in the Atlantic.