New diving beetle species discovered


The two beetle species

This picture shows the two species which scientists have shown are genetically divergent, Meladema coriacea (left) and Meladema lepidoptera (right). Credit: David Bilton – University of Plymouth.

From the University of Plymouth in England:

‘Hiding in plain sight:’ Discovery raises questions over scale of overlooked biodiversity

October 17, 2017

Scientists have used cutting-edge DNA technology and museum samples collected over the past two centuries to reveal a new species of diving beetle living in streams around the Mediterranean.

Meladema coriacea is among Europe’s largest water beetles and has been considered common across the south of the continent and in North Africa since the early 19th century.

But academics from the University of Plymouth and the Institute of Evolutionary Biology in Barcelona have now shown what was long thought to be one common species is actually two.

Using DNA sequence data and detailed analysis of morphology, they have described a new species — Meladema lepidoptera — which appears virtually identical to Meladema coriacea at first glance, but is very divergent genetically.

Meladema lepidoptera is restricted to Corsica, Sardinia, adjacent small islands and some areas of the Italian mainland, where it apparently occurs to the exclusion of Meladema coriacea.

David Bilton, Professor of Aquatic Biology at the University of Plymouth, led the study having first collected samples of the beetles in the late 1990s.

He said: “We began studying the genetics of these beetles to try to understand how animals had colonised islands — we certainly weren’t looking for, or expecting, a new species. Meladema are some of the largest and best-known water beetles in Europe, so we were very surprised with the genetic results suggesting that there were two species hiding under what everyone thought was only one.”

The new species was in fact ‘hiding in plain sight’, since a study of material from a number of European museums revealed specimens of the newly identified species had been collected as long ago as the mid-19th century. But without the genetic data, these had all been thought to belong to the one, common, species.

Genetic data on more specimens, and a careful study of the appearance of the beetles themselves, has now allowed scientists to identify subtle, but consistent, ways in which the two species differ. This includes the precise sculpturing of their wing cases, with lepidoptera’s appearing rather like the interlocking scales on a butterfly’s wing, hence its name.

Dating based on the DNA analyses suggests that Meladema originated approximately 14.4 million years ago, and that the current species appeared more recently, separating around 1.5 million years ago, perhaps as a result of climate and sea level changes during ice ages.

Professor Bilton added: “This is only one new species, but it’s been hiding amongst one of the largest, most obvious freshwater species in Europe, in an area we have supposedly explored pretty thoroughly. The fact that discoveries like ours are still possible emphasizes how little we know about the biodiversity of this planet, something which should be a major priority, particularly when so much of it is threatened by human activity. To effectively conserve biodiversity, we need to understand what’s out there, because ignorance can lead to the wrong decisions being made about species and habitats.”

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Fossil sea turtle baby, new research


Tasbacka danica, photo by Johan Lindgren

From North Carolina State University in the USA:

Keratin, proteins from 54-million-year-old sea turtle show survival trait evolution

October 17, 2017

Researchers from North Carolina State University, Lund University in Sweden and the University of Hyogo in Japan have retrieved original pigment, beta-keratin and muscle proteins from a 54 million-year-old sea turtle hatchling. The work adds to the growing body of evidence supporting persistence of original molecules over millions of years and also provides direct evidence that a pigment-based survival trait common to modern sea turtles evolved at least 54 million years ago.

Tasbacka danica is a species of sea turtle that lived during the Eocene period, between 56 and 34 million years ago. In 2008 an extremely well-preserved T. danica hatchling was recovered from the Für formation in Jutland, Denmark. The specimen was less than 3 inches (74 millimeters) long. In 2013 paleontologist Johan Lindgren of Lund University uncovered soft tissue residues from an area located near the sea turtle’s left “shoulder.” He collected five small samples for biomolecular analysis.

The shells of modern sea turtle hatchlings are dark colored — this pigmentation gives them protection from aerial predators (such as seagulls) as they float on the ocean surface to breathe. Since turtles are reptiles, and therefore cold-blooded, the dark coloration also allows them to absorb heat from sunlight and regulate their body temperature. This elevated body temperature also allows more rapid growth, reducing the time they are vulnerable at the ocean surface.

The T. danica hatchling specimen appeared to share this coloration with its living counterparts. The researchers observed round organelles in the fossil that could be melanosomes, pigment-containing structures in the skin (or epidermis) that give turtle shells their dark color.

To determine the structural and chemical composition of the soft tissues Lindgren collected and see if the fossil sea turtle did have a dark colored shell, the researchers subjected the sample to a selection of high-resolution analytical techniques, including field emission gun scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), in situ immunohistochemistry, time-of-flight secondary ion mass spectrometry (ToF-SIMS), and infrared (IR) microspectroscopy.

Lindgren performed ToF-SIMS on the samples to confirm the presence of heme, eumelanin and proteinaceous molecules — the components of blood, pigment and protein.

Co-author Mary Schweitzer, professor of biological sciences at NC State with a joint appointment at the North Carolina Museum of Natural Sciences, performed histochemical analyses of the sample, finding that it tested positive against antibodies for both alpha and beta-keratin, hemoglobin and tropomyosin, a muscle protein. TEM, performed by University of Hyogo evolutionary biologist Takeo Kuriyama, and Schweitzer’s immunogold testing further confirmed the findings.

In the end, the evidence pointed to these molecules as being original to the specimen, confirming that these ancient turtles shared a pigmentation-based survival trait with their modern-day brethren.

“The presence of eukaryotic melanin within a melanosome embedded in a keratin matrix rules out contamination by microbes, because microbes cannot make eukaryotic melanin or keratin,” Schweitzer says. “So we know that these hatchlings had the dark coloration common to modern sea turtles.

“The data not only support the preservation of multiple proteins, but also suggest that coloration was used for physiology as far back as the Eocene, in the same manner as it is today.”

The scientific report on this is here.

Whales’, dolphins’ ‘human-like’ cultures


This video says about itself:

BBC Planet Earth / Blue Planet – Cetaceans

Some clips of whales and dolphins from the BBC’s phenomenal series. Music is Forgive by Burial.

From the University of Manchester in England:

Whales and dolphins have rich ‘human-like’ cultures and societies

October 16, 2017

Whales and dolphins (Cetaceans) live in tightly-knit social groups, have complex relationships, talk to each other and even have regional dialects — much like human societies.

A major new study, published today in Nature Ecology & Evolution (Monday 16th October), has linked the complexity of Cetacean culture and behaviour to the size of their brains.

The research was a collaboration between scientists at The University of Manchester, The University of British Columbia, Canada, The London School of Economics and Political Science (LSE) and Stanford University, United States.

The study is first of its kind to create a large dataset of cetacean brain size and social behaviours. The team compiled information on 90 different species of dolphins, whales, and porpoises. It found overwhelming evidence that Cetaceans have sophisticated social and cooperative behaviour traits, similar to many found in human culture.

The study demonstrates that these societal and cultural characteristics are linked with brain size and brain expansion — also known as encephalisation.

The long list of behavioural similarities includes many traits shared with humans and other primates such as:

  • complex alliance relationships — working together for mutual benefit
  • social transfer of hunting techniques — teaching how to hunt and using tools
  • cooperative hunting
  • complex vocalizations, including regional group dialects — ‘talking’ to each other
  • vocal mimicry and ‘signature whistles’ unique to individuals — using ‘name’ recognition
  • interspecific cooperation with humans and other species — working with different species
  • alloparenting — looking after youngsters that aren’t their own
  • social play

Dr Susanne Shultz, an evolutionary biologist in Manchester’s School of Earth and Environmental Sciences, said: “As humans, our ability to socially interact and cultivate relationships has allowed us to colonise almost every ecosystem and environment on the planet. We know whales and dolphins also have exceptionally large and anatomically sophisticated brains and, therefore, have created a similar marine based culture.

“That means the apparent co-evolution of brains, social structure, and behavioural richness of marine mammals provides a unique and striking parallel to the large brains and hyper-sociality of humans and other primates on land. Unfortunately, they won’t ever mimic our great metropolises and technologies because they didn’t evolve opposable thumbs.”

The team used the dataset to test the social brain hypothesis (SBH) and cultural brain hypothesis (CBH). The SBH and CBH are evolutionary theories originally developed to explain large brains in primates and land mammals.

They argue that large brains are an evolutionary response to complex and information-rich social environments. However, this is the first time these hypotheses have been applied to ‘intelligent’ marine mammals on such a large scale.

Dr Michael Muthukrishna, Assistant Professor of Economic Psychology at LSE, added: “This research isn’t just about looking at the intelligence of whales and dolphins, it also has important anthropological ramifications as well. In order to move toward a more general theory of human behaviour, we need to understand what makes humans so different from other animals. And to do this, we need a control group. Compared to primates, cetaceans are a more “alien” control group.”

Dr Kieran Fox, a neuroscientist at Stanford University, added: “Cetaceans have many complex social behaviours that are similar to humans and other primates. They, however, have different brain structures from us, leading some researchers to argue that whales and dolphins could not achieve higher cognitive and social skills. I think our research shows that this is clearly not the case. Instead, a new question emerges: How can very diverse patterns of brain structure in very different species nonetheless give rise to highly similar cognitive and social behaviours?”

Alligators eat sharks, new research


This New Scientist video from the USA says about itself:

25 September 2017

A previously overlooked conflict between alligators and sharks has been going on for centuries at least, and it seems the alligators are winning. Read more here.

From Kansas State University in the USA:

Bite on this: Alligators actually eat sharks

October 16, 2017

Jaws, beware! Alligators may be coming for you. A new study documents American alligators on the Atlantic and Gulf coasts are eating small sharks and stingrays. This is the first scientific documentation of a widespread interaction between the two predators.

Jaws, beware! Alligators may be coming for you, according to a Kansas State University researcher.

While the sharks may not actually be as big as the fictional Jaws, James Nifong, postdoctoral researcher with the Kansas Cooperative Fish and Wildlife Research Unit at Kansas State University, and Russell Lowers, wildlife biologist with Integrated Mission Support Services at Kennedy Space Center, published a study in Southeastern Naturalist documenting that American alligators on the Atlantic and Gulf coasts are eating small sharks and stingrays. This is the first scientific documentation of a widespread interaction between the two predators.

“In the article, we documented alligators consuming four new species of sharks and one species of stingray,” Nifong said. “Before this, there have only been a few observations from an island off the Georgia coast, but the new findings document the occurrence of these interactions from the Atlantic coast of Georgia around the Florida peninsula to the Gulf Coast and Florida panhandle.”

Despite the freshwater and saltwater differences, Nifong said it is fairly common for sharks and rays to share the water with alligators. Many sharks and rays can swim into freshwater where opportunistic alligators can’t pass up a good meal. Although alligators don’t have salt glands like true crocodiles, they are resourceful as they travel between freshwater and marine habitats.

“Alligators seek out fresh water in high-salinity environments,” Nifong said. “When it rains really hard, they can actually sip fresh water off the surface of the salt water. That can prolong the time they can stay in a saltwater environment.”

An alligator’s diet typically consists of crustaceans, snails and fish, but because alligators are opportunistic predators, Nifong said sharks may end up on the menu.

“The findings bring into question how important sharks and rays are to the alligator diet as well as the fatality of some the juvenile sharks when we think about population management of endangered species,” Nifong said.

As part of Nifong’s dissertation research, he pumped the stomachs of more than 500 live and alert alligators to learn more about their diet. Researchers also equipped the alligators with GPS transmitters to watch their movements and found that alligators travel between freshwater sources and estuaries, which are a partially enclosed coastal water body where freshwater and salt water mix and house shark nurseries.

“The frequency of one predator eating the other is really about size dynamic,” Nifong said “If a small shark swims by an alligator and the alligator feels like it can take the shark down, it will, but we also reviewed some old stories about larger sharks eating smaller alligators.”

Nifong dug into history and found news reports from the late 1800s that described battles of large masses of sharks and alligators after flooding and high tides washed the predators together. One particular historical incident included in the journal article described how the sharks were attracted to blood from alligators feeding on fish. When the alligators were washed out to sea, the sharks attacked.

Nifong conducted the alligator diet research as part of larger research of freshwater river systems and food web dynamics. He currently is researching the drivers of native fish biodiversity in the Neosho River Basin for Martha Matter in the Kansas Cooperative Fish and Wildlife Research Unit, a part of the Division of Biology at Kansas State University.

Jane Goodall about chimpanzees


This video says about itself:

14 October 2017

Neil deGrasse Tyson speaks with Jane Goodall about the origins of her groundbreaking chimpanzee research.

Saber-toothed cats’ illnesses, new research


This video from the USA is about the La Brea Tar Pits and Natural History Museum and a saber-toothed cat.

From Science News in the USA:

Surgeon aims to diagnose deformities of extinct saber-toothed cats

By Lesley Evans Ogden

9:00am, October 13, 2017

Robert Klapper has examined scores of damaged and diseased human knees, hips and shoulders. But a visit to the La Brea Tar Pits and Museum introduced the orthopedic surgeon to the suffering of an extinct cat — and a scientific mystery. In 2000, Klapper took a break from his patients at Cedars-Sinai Medical Center in Los Angeles to visit the nearby tar pits, where myriad mammals and other animals (SN: 5/17/14, p. 18) have been getting stuck for the last 40,000 years. (Yes, modern birds and insects still wander in).

After examining a museum display of broad-snouted dire wolf (Canis dirus) skulls, Klapper made a beeline for the security guard and asked to see a curator. He badgered then collections manager Chris Shaw with questions about why the skulls looked so perfect — no signs of cancers, fractures or arthritis.

“Instead of throwing me out,” Klapper says, Shaw took Klapper into the bowels of the museum and pulled out a drawer of bones from saber-toothed cats (Smilodon fatalis), one of the abundant prehistoric animals preserved in the pits about 14,000 years ago. Klapper noticed a pelvis with a surface that reminded him of a medieval mace: One hip socket was spiky with sharp edges, a telltale sign of arthritis. At the healthy hip socket, the bone was billiard ball smooth.

That kind of bone damage did not happen overnight. The arthritic animal had been disabled for years, Klapper estimated, perhaps even from birth. The surgeon asked a favor: “I’d love to get a CT scan.” Signing out the ancient cat’s pelvis, he says, was a thrill.

Paleontologists have long debated whether saber-toothed cats were solitary or social hunters. If this lame cat had been unable to hunt for years, which is what its traumatized hip bone indicated to Klapper, it could have survived only with help from other cats.

Klapper scanned that fossilized cat pelvis but left the images untouched for years, occupied with his hospital job and hosting ESPN Radio’s Weekend Warrior, a health and sports program. Now, collaborating with Emily Lindsey, a paleoecologist at La Brea, Klapper plans to use more sophisticated radiology techniques to diagnose the deformity and possibly deduce clues about the cat’s lifestyle.

It’s still early days for the revitalized project, Lindsey cautions, but “I’m really excited about it.” The museum houses some 2,000 fossils of saber-toothed cats, several of which the two plan to scan in the months ahead.

Cormorants prove Charles Darwin’s hypothesis on plants


This video from Taiwan says about itself:

The Cormorants (1 of 4)

9 March 2010

The [great] cormorant is a large water bird with black plumage. It has a wingspan of about 100 centimeters. From the Ussuri River region of Siberia and the northern-east region of China they fly to spend about five months in Kinmen; they do not embark on their return journey to the breeding grounds until April the following year.

The cormorant is equipped with webbed feet, a strong bill, easily wet-able feathers and a special flexible pouch on its throat, making the bird an efficient catcher of fish. Highly gregarious, the cormorants like to feed and roost in large numbers. They also fly in line formations. Every year the entertaining antics and sheer number of these birds attract many visitors, both domestic and abroad, to Kinmen.

From Biology Letters:

Great cormorants reveal overlooked secondary dispersal of plants and invertebrates by piscivorous waterbirds

Casper H. A. van Leeuwen, Ádám Lovas-Kiss, Maria Ovegård, Andy J. Green

4 October 2017

Abstract

In wetland ecosystems, birds and fish are important dispersal vectors for plants and invertebrates, but the consequences of their interactions as vectors are unknown. Darwin suggested that piscivorous birds carry out secondary dispersal of seeds and invertebrates via predation on fish.

We tested this hypothesis in the great cormorant (Phalacrocorax carbo L.). Cormorants regurgitate pellets daily, which we collected at seven European locations and examined for intact propagules. One-third of pellets contained at least one intact plant seed, with seeds from 16 families covering a broad range of freshwater, marine and terrestrial habitats.

Of 21 plant species, only two have an endozoochory dispersal syndrome, compared with five for water and eight for unassisted dispersal syndromes. One-fifth of the pellets contained at least one intact propagule of aquatic invertebrates from seven taxa. Secondary dispersal by piscivorous birds may be vital to maintain connectivity in meta-populations and between river catchments, and in the movement of plants and invertebrates in response to climate change. Secondary dispersal pathways associated with complex food webs must be studied in detail if we are to understand species movements in a changing world.