World's Oldest Sperm Is Discovered In Shrimp Fossil, And It's Huge

Researchers found the oldest sperm ever discovered--belonging to a small crustacean called a seed shrimp up to 23 million years old--in a pile of bat poop, but lost the robotic submersible Nereus when it imploded thousands of miles below the surface of the ocean in the Kermadec Trench near New Zealand. Elephant seals have as much carbon monoxide in their blood as a two-pack-a-day cigarette smoker; this possibly helps them survive deep dives in the ocean while hunting.

The oldest petrified sperm ever discovered is gargantuan, at least for a gamete.

The sperm comes from the early Miocene epoch, between about 23 million and 16 million years ago, and belonged to a tiny crustacean called a seed shrimp or ostracod. Seed shrimp are bivalves like mussels, but sport tiny appendages that make them look like walking beans. Though they measure just millimeters long, their sperm often reaches more than 0.4 inches (1 centimeter) in length.

The new fossilized sperm comes from an ancient cave deposit in Australia, where bat guano falling into the water may have helped preserve the cells.

"We can distinguish the typical helical organization of the organelles in the sperm cell, which makes its surface look like a hawser or cable," study researcher Renate Matzke-Karasz, a geobiologist at Ludwig-Maximilian-University in Germany, said in a statement. "But the most astounding aspect of our findings is that it strongly suggests that the mode of reproduction in these tiny crustaceans has remained virtually unchanged to this day." [See images of the giant sperm and ancient ostracods]

Ancient animals, strange sperm

Seed shrimp aren't the only organisms with absurdly long sperm. The longest sperm in nature today belongs to Drosophila bifurca, a fruit fly whose seed stretches to more than 2 inches (5 centimeters).

A modern ostracod (Newnhamia). These tiny crustaceans create sperm longer than their own bodies.

But ostracod sperm is extra odd, because it lacks the familiar tail, or flagellum, thatpropels most sperm cells. Instead, ostracod sperm consists of a large, elongate head. This entire structures moves by contracting organelles along its membrane, which causes the sperm cell to ripple and rotate.

Matzke-Karasz and her colleagues discovered the fossilized sperm cells in five specimens of ostracods from the Riversleigh fossil site in northwest Queensland, Australia. This site preserves what was once a cave, with copious ancient bat bones and cave formations. Ostracods once lived in standing water inside the cave.

The sperm are at least 16 million years old and fossilized in rock, making them the oldest petrified sperm cells ever discovered. (The previous oldest-known ostracod sperm was only a few thousand years old.) One other sperm find does beat out the ostracod find in age: An insect-like springtail trapped in amber about 40 million years ago had sperm inside its body. But preservation in amber is different than preservation in rock, as amber frequently preserves soft tissue and rock rarely does.

Giant sperm

Matzke-Karasz and her colleagues studied 66 ostracod fossils from the Queensland site using X-ray tomography, which enables a three-dimensional peek inside the fossils.

In 2009, Matzke-Karasz and her team discovered a 100-million-year-old female ostracod with large receptacles for giant sperm, but the cells inside had degraded. The new study proved more fruitful. The researchers discovered sperm cells in various states of preservation in one male and three female ostracods of the speciesHeterocypris collaris, and one female of the species Newnhamia mckenziana.

A cross section of a male Heterocypris collaris, showing Zenker organs, which act as sperm pumps, as well as sperm stored in the seminal vesicle and ducts.

The researchers could not discern the length of the sperm in all of the fossils, but the researchers estimate that the 0.05-inch-long (1.26 mm) H. collaris male had sperm almost exactly its own length — 0.047 to 0.051 inches long (1.2 to 1.3 mm).

The fossils also preserved the ducts in the female ostracod anatomy where the sperm would enter the body. These spiral ducts are longer even than ostracod sperm, sometimes reaching lengths four times that of the ostracod body. The discovery of the giant sperm and giant receptacle ducts provides evidence that these body parts co-evolved and have changed little in millions of years, the researchers report today (May 13) in the journal Proceedings of the Royal Society B: Biological Sciences.

Engineers design ‘living materials’

Engineers design ‘living materials’

Hybrid materials combine bacterial cells with nonliving elements that can conduct electricity or emit light.

An artist's rendering of a bacterial cell engineered to produce amyloid nanofibers that incorporate particles such as quantum dots (red and green spheres) or gold nanoparticles. 

Inspired by natural materials such as bone — a matrix of minerals and other substances, including living cells — MIT engineers have coaxed bacterial cells to produce biofilms that can incorporate nonliving materials, such as gold nanoparticles and quantum dots.

These “living materials” combine the advantages of live cells, which respond to their environment, produce complex biological molecules, and span multiple length scales, with the benefits of nonliving materials, which add functions such as conducting electricity or emitting light.

The new materials represent a simple demonstration of the power of this approach, which could one day be used to design more complex devices such as solar cells, self-healing materials, or diagnostic sensors, says Timothy Lu, an assistant professor of electrical engineering and biological engineering. Lu is the senior author of a paper describing the living functional materials in the March 23 issue of Nature Materials.

“Our idea is to put the living and the nonliving worlds together to make hybrid materials that have living cells in them and are functional,” Lu says. “It’s an interesting way of thinking about materials synthesis, which is very different from what people do now, which is usually a top-down approach.”

The paper’s lead author is Allen Chen, an MIT-Harvard MD-PhD student. Other authors are postdocs Zhengtao Deng, Amanda Billings, Urartu Seker, and Bijan Zakeri; recent MIT graduate Michelle Lu; and graduate student Robert Citorik.

Self-assembling materials

Lu and his colleagues chose to work with the bacterium E. coli because it naturally produces biofilms that contain so-called “curli fibers” — amyloid proteins that help E. coli attach to surfaces. Each curli fiber is made from a repeating chain of identical protein subunits called CsgA, which can be modified by adding protein fragments called peptides. These peptides can capture nonliving materials such as gold nanoparticles, incorporating them into the biofilms.

By programming cells to produce different types of curli fibers under certain conditions, the researchers were able to control the biofilms’ properties and create gold nanowires, conducting biofilms, and films studded with quantum dots, or tiny crystals that exhibit quantum mechanical properties. They also engineered the cells so they could communicate with each other and change the composition of the biofilm over time.

First, the MIT team disabled the bacterial cells’ natural ability to produce CsgA, then replaced it with an engineered genetic circuit that produces CsgA but only under certain conditions — specifically, when a molecule called AHL is present. This puts control of curli fiber production in the hands of the researchers, who can adjust the amount of AHL in the cells’ environment. When AHL is present, the cells secrete CsgA, which forms curli fibers that coalesce into a biofilm, coating the surface where the bacteria are growing.

The researchers then engineered E. coli cells to produce CsgA tagged with peptides composed of clusters of the amino acid histidine, but only when a molecule called aTc is present. The two types of engineered cells can be grown together in a colony, allowing researchers to control the material composition of the biofilm by varying the amounts of AHL and aTc in the environment. If both are present, the film will contain a mix of tagged and untagged fibers. If gold nanoparticles are added to the environment, the histidine tags will grab onto them, creating rows of gold nanowires, and a network that conducts electricity. 

‘Cells that talk to each other’

The researchers also demonstrated that the cells can coordinate with each other to control the composition of the biofilm. They designed cells that produce untagged CsgA and also AHL, which then stimulates other cells to start producing histidine-tagged CsgA.

“It’s a really simple system but what happens over time is you get curli that’s increasingly labeled by gold particles. It shows that indeed you can make cells that talk to each other and they can change the composition of the material over time,” Lu says. “Ultimately, we hope to emulate how natural systems, like bone, form. No one tells bone what to do, but it generates a material in response to environmental signals.”

To add quantum dots to the curli fibers, the researchers engineered cells that produce curli fibers along with a different peptide tag, called SpyTag, which binds to quantum dots that are coated with SpyCatcher, a protein that is SpyTag’s partner. These cells can be grown along with the bacteria that produce histidine-tagged fibers, resulting in a material that contains both quantum dots and gold nanoparticles.

These hybrid materials could be worth exploring for use in energy applications such as batteries and solar cells, Lu says. The researchers are also interested in coating the biofilms with enzymes that catalyze the breakdown of cellulose, which could be useful for converting agricultural waste to biofuels. Other potential applications include diagnostic devices and scaffolds for tissue engineering.

“I think this is really fantastic work that represents a great integration of synthetic biology and materials engineering,” says Lingchong You, an associate professor of biomedical engineering at Duke University who was not part of the research team. 

The research was funded by the Office of Naval Research, the Army Research Office, the National Science Foundation, the Hertz Foundation, the Department of Defense, the National Institutes of Health, and the Presidential Early Career Award for Scientists and Engineers.

Ab "albino" redwood

Ab "albino" redwood

Technically, albinism means lacking melanin, so a plant cannot be an albino. They do however have their own version - a plant that lacks chlorophyll. They are unable to photosynthesize, so must live parasitically off of other redwood trees in order to survive.

There are only approximately 60 "albino" redwoods known and their locations are kept top secret.

Difference between Static and Kinematic Indeterminacy

STATIC INDETERMINACY

The aim of structural analysis is to evaluate the external reactions, the deformed shape and internal stresses in the structure. If this can be accomplished by equations of equilibrium, then such structures are known as determinate structures. However, in many structures it is not possible to determine either reactions or internal stresses or both using equilibrium equations alone. Such structures are known as the statically indeterminate structures. The indeterminacy in a structure may be external, internal or both. A structure is said to be externally indeterminate if the number of reactions exceeds the number of equilibrium equations.

KINEMATIC INDETERMINACY

The joint displacements in a structure is treated as independent if each displacement (translation and rotation) can be varied arbitrarily and independently of all other displacements. The number of independent joint displacement in a structure is known as the degree of kinematic indeterminacy or the number of degrees of freedom.

Causes of Seismic Waves

Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion or a sharp impact (as used in petroleum exploration). The waves result most commonly from sharp releases of energy and the fracturing of rock accompanying fault movement, tectonic plate subduction, or activity within a magma chamber. The waves are the energy that travels through the earth and is recorded on seismographs. It has nothing to do with sound.
Seismic waves are caused by earthquakes. The earthquakes must occur underneath or near the ocean, be large and create movements in the sea floor to generate the seismic wave. They can be caused by submarine landslides or infrequently by submarine volcanic eruptions and rarely by the impact of a large meteorite in the ocean.

Also 
When an earthquake fault line shifts or moves it will send out seismic waves- they are sound waves radiated from the earthquake as it ruptures.

Brain scans show that dogs are as conscious as human children

By GREGORY BERNS

Source: How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain

FOR the past two years, my colleagues and I have been training dogs to go in an M.R.I. scanner — completely awake and unrestrained. Our goal has been to determine how dogs’ brains work and, even more important, what they think of us humans.

Now, after training and scanning a dozen dogs, my one inescapable conclusion is this: dogs are people, too.

Because dogs can’t speak, scientists have relied on behavioral observations to infer what dogs are thinking. It is a tricky business. You can’t ask a dog why he does something. And you certainly can’t ask him how he feels. The prospect of ferreting out animal emotions scares many scientists. After all, animal research is big business. It has been easy to sidestep the difficult questions about animal sentience and emotions because they have been unanswerable.

Until now.

By looking directly at their brains and bypassing the constraints of behaviorism, M.R.I.’s can tell us about dogs’ internal states. M.R.I.’s are conducted in loud, confined spaces. People don’t like them, and you have to hold absolutely still during the procedure. Conventional veterinary practice says you have to anesthetize animals so they don’t move during a scan. But you can’t study brain function in an anesthetized animal. At least not anything interesting like perception or emotion.

From the beginning, we treated the dogs as persons. We had a consent form, which was modeled after a child’s consent form but signed by the dog’s owner. We emphasized that participation was voluntary, and that the dog had the right to quit the study. We used only positive training methods. No sedation. No restraints. If the dogs didn’t want to be in the M.R.I. scanner, they could leave. Same as any human volunteer.

My dog Callie was the first. Rescued from a shelter, Callie was a skinny black terrier mix, what is called a feist in the southern Appalachians, from where she came. True to her roots, she preferred hunting squirrels and rabbits in the backyard to curling up in my lap. She had a natural inquisitiveness, which probably landed her in the shelter in the first place, but also made training a breeze.

With the help of my friend Mark Spivak, a dog trainer, we started teaching Callie to go into an M.R.I. simulator that I built in my living room. She learned to walk up steps into a tube, place her head in a custom-fitted chin rest, and hold rock-still for periods of up to 30 seconds. Oh, and she had to learn to wear earmuffs to protect her sensitive hearing from the 95 decibels of noise the scanner makes.

After months of training and some trial-and-error at the real M.R.I. scanner, we were rewarded with the first maps of brain activity. For our first tests, we measured Callie’s brain response to two hand signals in the scanner. In later experiments, not yet published, we determined which parts of her brain distinguished the scents of familiar and unfamiliar dogs and humans.

Soon, the local dog community learned of our quest to determine what dogs are thinking. Within a year, we had assembled a team of a dozen dogs who were all “M.R.I.-certified.”

Although we are just beginning to answer basic questions about the canine brain, we cannot ignore the striking similarity between dogs and humans in both the structure and function of a key brain region: the caudate nucleus.

Rich in dopamine receptors, the caudate sits between the brainstem and the cortex. In humans, the caudate plays a key role in the anticipation of things we enjoy, like food, love and money. But can we flip this association around and infer what a person is thinking just by measuring caudate activity? Because of the overwhelming complexity of how different parts of the brain are connected to one another, it is not usually possible to pin a single cognitive function or emotion to a single brain region.

But the caudate may be an exception. Specific parts of the caudate stand out for their consistent activation to many things that humans enjoy. Caudate activation is so consistent that under the right circumstances, it can predict our preferences for food, music and even beauty.

In dogs, we found that activity in the caudate increased in response to hand signals indicating food. The caudate also activated to the smells of familiar humans. And in preliminary tests, it activated to the return of an owner who had momentarily stepped out of view. Do these findings prove that dogs love us? Not quite. But many of the same things that activate the human caudate, which are associated with positive emotions, also activate the dog caudate. Neuroscientists call this a functional homology, and it may be an indication of canine emotions.

DOGS have long been considered property. Though the Animal Welfare Act of 1966 and state laws raised the bar for the treatment of animals, they solidified the view that animals are things — objects that can be disposed of as long as reasonable care is taken to minimize their suffering.

But now, by using the M.R.I. to push away the limitations of behaviorism, we can no longer hide from the evidence. Dogs, and probably many other animals (especially our closest primate relatives), seem to have emotions just like us. And this means we must reconsider their treatment as property.

One alternative is a sort of limited personhood for animals that show neurobiological evidence of positive emotions. Many rescue groups already use the label of “guardian” to describe human caregivers, binding the human to his ward with an implicit responsibility to care for her. Failure to act as a good guardian runs the risk of having the dog placed elsewhere. But there are no laws that cover animals as wards, so the patchwork of rescue groups that operate under a guardianship model have little legal foundation to protect the animals’ interest.

If we went a step further and granted dogs rights of personhood, they would be afforded additional protection against exploitation. Puppy mills, laboratory dogs and dog racing would be banned for violating the basic right of self-determination of a person.

I suspect that society is many years away from considering dogs as persons. However, recent rulings by the Supreme Court have included neuroscientific findings that open the door to such a possibility. In two cases, the court ruled that juvenile offenders could not be sentenced to life imprisonment without the possibility of parole. As part of the rulings, the court cited brain-imaging evidence that the human brain was not mature in adolescence. Although this case has nothing to do with dog sentience, the justices opened the door for neuroscience in the courtroom.

Perhaps someday we may see a case arguing for a dog’s rights based on brain-imaging findings.

Fuel Exhaust Disrupts Scent Signals for Honeybees

Even “clean” diesel and biofuel generate gases that pose threat to pollinators.

A honeybee investigates an oilseed rape flower. A new study provides evidence of how fuel exhaust changes the chemical composition of floral odors, scrambling the scent signals for pollinators.

Photograph by Nigel Cattlin, Alamy

Helen Thompson for National Geographic

Published October 3, 2013

Fuel Exhaust Disrupts Scent Signals for Honeybees

To a bee, no two flowers smell quite the same. When honeybees forage for flowers, they search for, learn, and memorize distinctive floral scents and return to the hive to tell other bees what they’ve found through their famouswaggle dance.

It is an important ritual that is being disrupted by one of the most pervasive forms of air pollution—diesel exhaust—according to a new study published Thursday in Scientific Reports. The research pinpoints the mechanism by which the fuel-combustion pollutants degrade certain chemicals in floral odors. The absence of those chemicals affects honeybees’ ability to recognize the scent. (See related quiz: “What You Don’t Know About Cars and Fuel.”)

Engine exhaust is hardly the only threat facing the honeybee. It is well recognized that exposure to multiple pesticides can impair bees’ olfactory skills, while ground-level ozone, or smog, and ultraviolet (UV) radiation can also degrade floral odor compounds that bees pick up on. Authorities around the globe are grappling with how to address the little-understood cyclical diseases that are causing colonies to dwindle. (See related, “The Plight of the Honeybee.”)

The new study offers insight into the specific hazard for pollinators from the fumes from cars, trucks, trains, ships, and heavy machinery. Significantly, the study indicates that honeybees haven’t been helped by the "cleaner" diesel now used in Europe and the United States due to regulations that over the past decade removed sulfur from the fuel. The researchers used ultra-low-sulfur diesel fuel in their experiment. (See related: “Pictures: Cars That Fired Our Love-Hate Relationship With Fuel.”)

Odor Cues

Thousands of chemical compounds contribute to flower odors, so honeybees (Apis mellifera) need a discerning sense of smell. “A honeybee might see a red flower, and say oh is this a flower that I want to visit, and [it] uses odor cues to figure out if it’s worth visiting,” said Quinn McFrederick, an ecologist at Fresno State University in California. Odor cues can tell bees which flowers have the most nutritious nectar and pollen for harvesting.

Scientists have long thought that air pollution masked these key floral scents, but the new study provides evidence of how the exhaust actually changed the chemical composition of the odors. Using an odor palette from a common target for honeybees, oilseed rape flowers (Brassica napus), a research team at the University of Southampton in the United Kingdom exposed the compounds to diesel fumes from a generator fueled by ultra-low-sulfur diesel. Almost immediately, the diesel fumes started breaking down two of the flower odor compounds: farnesene and terpinene. After training honeybees recognize the flower scent, the researchers removed both degraded compounds from the mix.

“To our surprise, really, we saw that even changes in one of the very minor constituents of the mixture caused a major change in the responsiveness of the bee to the smell,” said Tracey Newman, a neurobiologist at the University of Southampton and a co-author of the study.

The researchers said one component of diesel exhaust takes the blame for this degradation: NOx gases, compounds that contain both nitrogen and oxygen, reacting with volatile floral odors. Although the scientists used diesel fuel, which powers the majority of cars in Europe and nearly all heavy vehicles around the world, NOx gases also are emitted by gasoline, or petrol, and even alternative fuels like biodiesel and ethanol. (See related, “Biofuel at a Crossroads.”) “The bottom line is I don’t think one can start pointing one’s finger at biodiesel, diesel, or petrol,” said Guy Poppy, an ecologist and co-author on the study. It’s a larger issue with internal combustion engines, he said.

Both the United States and the European Union use nitrogen dioxide (NO2) levels as a proxy for all NOx gases and have set limits for the amount of NO2 in the air, but not for nitric oxide (NO) levels. Poppy said, “These are the sorts of emissions that are sometimes left out from the discussions about climate change because these emissions are not ones as heavily associated with greenhouse gases.” (See related “Pictures: A Rare Look Inside Carmakers’ Drive for 55 MPG.”)

Flower Chemistry

Oilseed rape flowers aren’t the sweetest smelling blooms. “They’re actually a bit stinky,” Newman said. But, their odors are very well understood, and these two degraded compounds appear to be a key element of odor communication for bees. Other bee species and other pollinators rely even more heavily on scent over longer distances. So, the findings could have major implications for other pollinators as well, said McFrederick, who was not affiliated with the study.

Interestingly, the degraded compounds in this experiment were present only at low levels, and removing terpinene by itself led to a significant decline in bee recognition in the experiment. “That suggests that that in some way kicks off a particular pathway in the odor perception abilities of the animal,” said Newman.

The researchers’ next step is to look at the impact of diesel on the honeybee nervous system.

How will these findings play out in the real world? “The study clearly illustrates that airborne pollution can perniciously impact the ability of bees to locate food,” said Jose Fuentes, a meteorologist at Penn State University who was not associated with the study. Fuentes spelled out two cautions: The experimental levels of pollutants were high even for urban rush hour; and the impact of the NOx gases might actually be an indirect one. That’s because NOx gases notoriously react with air and sunlight to make ground-level ozone, or smog, which may be the actual culprit in disrupting the floral odor compounds.

Urban environments expose honeybees and flowers to more diesel exhaust, but there are many important factors affecting the success of hives. The kind of neighborhood gardens found in urban and suburban areas also might provide bees with longer lasting food sources than in rural areas. Field studies could shed more light on the impact of air pollution.  “What we need to know is [for] a flower sitting in a field next to a car in a motorway, whether there actually is going to be a plume of smell coming from that flower and whether it’s going to be significantly affected because of the exhaust fumes,” said Poppy. The worst-case scenario would be to find a drastic reduction in honeybee foraging and pollination.

While it’s unclear how much impact diesel pollutants might have on pollination, the new study indicates that exhaust should be added to a growing list of known threats.

“Honeybees living in a modern world face many stresses,” including diseases, insecticides, and atmospheric pollutants, Poppy said. “Probably bees can cope with most of these stresses in isolation or when just two or three of them come together. But, when they all come together simultaneously, one might start to see significant effects and that might explain some of the things we’re seeing … with pollinators being lost around the world.”

Fuel Exhaust Disrupts Scent Signals for Honeybees

This week in Science (15-22) September

This week in science.

Typo in the third entry: perceive time SLOWER, not faster.


Mathematical jewel


Fossils


Small animals


Imagination


Microbes


Ginger gene


4D black hole


Limbless lizards


This week in Science (15-22) September

Four new species of 'legless lizards' discovered living on the edge

The Bakersfield legless lizard, (Anniella grinnelli), which today ranges from downtown Bakersfield in the southern San Joaquin Valley to the Carrizo Plain National Monument 30 miles to the west. The species has a purple belly and yellow sides. Credit: Alex Krohn

California biologists have discovered four new species of reclusive legless lizards living in some of the most marginal habitat in the state: a vacant lot in downtown Bakersfield, among oil derricks in the lower San Joaquin Valley, on the margins of the Mojave desert, and at the end of one of the runways at LAX.

"This shows that there is a lot of undocumented biodiversity within California," said Theodore Papenfuss, a reptile and amphibian expert, or herpetologist, with UC Berkeley's Museum of Vertebrate Zoology, who discovered and identified the new specieswith James Parham of California State University, Fullerton. The discoveries raise the number of California legless lizard species from one to five.

The herpetologists named the new snake-like lizards after four legendary UC Berkeley scientists: museum founder Joseph Grinnell, paleontologist Charles Camp, philanthropist and amateur scientist Annie Alexander and herpetologist Robert C. Stebbins, at 98 the only one of the group still alive.

"These are animals that have existed in the San Joaquin Valley, separate from any other species, for millions of years, completely unknown," said Parham, who obtained his doctorate from Berkeley and is now curator of paleontology at the John D. Cooper Archaeology and Paleontology Center. "If you want to preserve biodiversity, it is the really distinct species like these that you want to preserve."

Papenfuss and Parham reported their discovery on Sept. 17 in the journal Breviora, a publication of the Museum of Comparative Zoology at Harvard University.

Legless lizards, represented by more than 200 species worldwide, are well-adapted to life in loose soil, Papenfuss said. Millions of years ago, lizards on five continents independently lost their limbs in order to burrow more quickly into sand or soil, wriggling like snakes. Some still have vestigial legs. Though up to eight inches in length, the creatures are seldom seen because they live mostly underground, eating insects and larvae, and may spend their lives within an area the size of a dining table. Most are discovered in moist areas when people overturn logs or rocks.

Legless lizards like this purple-bellied A. grinnelli lost their legs millions of years ago in order to burrow more quickly into loose soil and sand.

Herping the Central Valley

For the past 15 years, Papenfuss and Parham have scoured the state for new species, suspecting that the fairly common California legless lizard (Anniella pulchra), the only legless lizard in the U.S. West, had at least some relatives. They discovered one new species – yellow-bellied like its common cousin – under leaf litter in protected dunes west of Los Angeles International Airport. They named that species A. stebbinsi, because Stebbins grew up and developed an early interest in natural history in the nearby Santa Monica Mountains.

Because many sandy, loamy areas, including dunes and desert areas, offer little cover for lizards if they emerge, Papenfuss distributed thousands of pieces of cardboard throughout the state in areas likely to host the lizard. He returned year after year to see if lizards were using the moist, cool areas under the cardboard as resting or hunting grounds.

This technique turned up three other new species in the Central Valley: A. alexanderae, named after Annie Alexander, who endowed the UC Berkeley museum in 1908 and added 20,000 specimens to its collections; A. campi after Charles Camp, because of his early-career discovery of the Mt. Lyell salamander in the Sierra; and A. grinnelli after Joseph Grinnell, who in 1912 first noted habitat destruction around Bakersfield from agriculture and oil drilling.

Interestingly, all these species had been collected before and were in collections around California, but when preserved in alcohol, the lizards lose their distinctive color and look identical. Papenfuss and Parham identified the species through genetic profiling, but they subsequently found ways to distinguish them from one another via belly color, number and arrangement of scales, and number of vertebrae. However, two species – the previously known common legless lizard of Northern California and the newly named southern species found at LAX and apparently broadly distributed south of the Tehachapi Mountains – remain indistinguishable except by genetic tests or, now, the location where they are found.

Distribution of the five species of legless lizard in California. A. pulchra was already known from a wide range in the central part of the state, but four others are newly described by UC Berkeley & Cal State-Fullerton herpetologists. Credit: Breviora

Species of special concern

Papenfuss and Parham are working with the California Department of Fish and Wildlife (CDFW) to determine whether the lizards need protected status. Currently, the common legless lizard is listed by the state as a species of special concern.

"These species definitely warrant attention, but we need to do a lot more surveys in California before we can know whether they need higher listing," Parham said.

Papenfuss noted that two of the species are within the range of the blunt-nosed leopard lizard, which is listed as an endangered species by both the federal and state governments.

"On one hand, there are fewer legless lizards than leopard lizards, so maybe these two new species should be given special protection," he said. "On the other hand, there may be ways to protect their habitat without establishing legal status. They don't need a lot of habitat, so as long as we have some protected sites, they are probably OK."

Papenfuss says they are not yet in danger of going extinct, since he has found some of the lizards in protected reserves operated by the CDFW, the U.S. Bureau of Land Management and a private water reserve outside Bakersfield, in addition to the El Segundo Dunes near LAX.

Did a hyper-black hole spawn the Universe?

Big Bang was mirage from collapsing higher-dimensional star, theorists propose.

It could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole — a scenario that would help to explain why the cosmos seems to be so uniform in all directions.

The standard Big Bang model tells us that the Universe exploded out of an infinitely dense point, or singularity. But nobody knows what would have triggered this outburst: the known laws of physics cannot tell us what happened at that moment.

“For all physicists know, dragons could have come flying out of the singularity,” says Niayesh Afshordi, an astrophysicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.It is also difficult to explain how a violent Big Bang would have left behind a Universe that has an almost completely uniform temperature, because there does not seem to have been enough time since the birth of the cosmos for it to have reached temperature equilibrium.

To most cosmologists, the most plausible explanation for that uniformity is that, soon after the beginning of time, some unknown form of energy made the young Universe inflate at a rate that was faster than the speed of light. That way, a small patch with roughly uniform temperature would have stretched into the vast cosmos we see today. But Afshordi notes that “the Big Bang was so chaotic, it’s not clear there would have been even a small homogenous patch for inflation to start working on”.

On the brane

In a paper posted last week on the arXiv preprint server¹, Afshordi and his colleagues turn their attention to a proposal² made in 2000 by a team including Gia Dvali, a physicist now at the Ludwig Maximilians University in Munich, Germany. In that model, our three-dimensional (3D) Universe is a membrane, or brane, that floats through a ‘bulk universe’ that has four spatial dimensions.

Ashfordi's team realized that if the bulk universe contained its own four-dimensional (4D) stars, some of them could collapse, forming 4D black holes in the same way that massive stars in our Universe do: they explode as supernovae, violently ejecting their outer layers, while their inner layers collapse into a black hole.

In our Universe, a black hole is bounded by a spherical surface called an event horizon. Whereas in ordinary three-dimensional space it takes a two-dimensional object (a surface) to create a boundary inside a black hole, in the bulk universe the event horizon of a 4D black hole would be a 3D object — a shape called a hypersphere. When Afshordi’s team modelled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.

The authors postulate that the 3D Universe we live in might be just such a brane — and that we detect the brane’s growth as cosmic expansion. “Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage,” says Afshordi.

Model discrepancy

The model also naturally explains our Universe’s uniformity. Because the 4D bulk universe could have existed for an infinitely long time in the past, there would have been ample opportunity for different parts of the 4D bulk to reach an equilibrium, which our 3D Universe would have inherited.

The picture has some problems, however. Earlier this year, the European Space Agency's Planck space observatory released data that mapped the slight temperature fluctuations in the cosmic microwave background — the relic radiation that carries imprints of the Universe’s early moments. The observed patterns matched predictions made by the standard Big Bang model and inflation, but the black-hole model deviates from Planck's observations by about 4%. Hoping to resolve the discrepancy, Afshordi says that his is now refining its model.

Despite the mismatch, Dvali praises the ingenious way in which the team threw out the Big Bang model. “The singularity is the most fundamental problem in cosmology and they have rewritten history so that we never encountered it,” he says. Whereas the Planck results “prove that inflation is correct”, they leave open the question of how inflation happened, Dvali adds. The study could help to show how inflation is triggered by the motion of the Universe through a higher-dimensional reality, he says.

Nature

 

doi:10.1038/nature.2013.13743

References

1. Pourhasan, R., Afshordi, N. & Mann, R. B. Preprint available at http://arxiv.org/abs/1309.1487(2013).
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2. Dvali, G., Gabadadze, G. & Porrati, M. Phys. Lett. B 485, 208–214 (2000).