Seven new glowing mushroom species have been discovered in Belize, Brazil, Dominican Republic, Jamaica, Japan, Malaysia and Puerto Rico.
Four of the species are completely new to scientists, and three previously known species were discovered to be luminescent. All seven species, as well as the majority of the 64 previously known species of luminescent mushrooms, are from the Mycena family.
“What interests us is that within Mycena, the luminescent species come from 16 different lineages, which suggests that luminescence evolved at a single point and some species later lost the ability to glow,” said biologist Dennis Desjardin of San Francisco State University, lead author of the study published Monday in the journal Mycologia.
The new discoveries might help scientists understand when, how and why mushrooms evolved the ability to glow. Desjardin suspects that luminescence might attract nocturnal animals, which would then help the mushrooms spread their spores.
Image above: Mycena silvaelucens (forest light) was collected in the grounds of an Orangutan Rehabilitation Center in Borneo, Malaysia and was found on the bark of a standing tree. The mushrooms are tiny with each cap measuring less than 18 millimeters in diameter. / Brian Perry, University of Hawaii
Above: Mycena luxaeterna (light eternal) was collected in Sao Paulo, Brazil and was found on sticks in an Atlantic forest habitat. These mushrooms are tiny with each cap measuring less than 8 millimeters in diameter and their stems have a jelly-like texture. The species’ name was inspired by Mozart’s Requiem. /Cassius V. Stevani, Chemistry Institute, University of Sao Paulo
Above: Mycena luxarboricola (light tree dweller) was collected in Paraná, Brazil and was found on the bark of a living tree in old growth Atlantic forest. These mushrooms are tiny with each cap measuring less than 5 millimeters in diameter. / Cassius V. Stevani, Chemistry Institute, University of Sao Paulo
This year’s Nobel Prize in medicine went to a trio of scientists who discovered the enzyme telomerase, which allows cells to divide without any limits, making them effectively immortal.
It may be nature’s greatest double-edged sword. Coax cells into producing telomerase, and they will survive indefinitely, but they will also become cancerous.
To safeguard against cancer, adult cells keep track of how many times that they have multiplied, and once they have reached a pre-set limit — often around 80 divisions — they die. Telomerase interferes with this record keeping.
If you can find a drug or gene therapy that interferes with telomerase, it could fight the unchecked growth of cancer cells, said Mark Muller, a cancer researcher who studies telomeres at the University of Central Florida.
“Ninety percent of all cancer cells are telomerase rich,” Muller said.
Several companies, including Geron, have started testing drugs that gum up the telomerase enzyme, so that it can’t extend the lives of cancer cells.
Telomerase lengthens telomeres, repetitive DNA sequences that sit at the ends of chromosomes. Each segment of a telomere is like a ticket that gives it permission to divide. When cells run out of those credits, they cease dividing.
Geron is developing a modified DNA molecule that gets stuck inside of telomerase, so that it can’t build up the ends of telomeres in cancer cells. The company is also working with a vaccine that trains cancer patients’ immune systems to attack cells that produce telomerase. In adults, almost all of the cells that produce telomerase are cancerous.
Those cancer treatments took shape almost 20 years after academics made a breakthrough discovery.
In the early 1980’s Elizabeth Blackburn, Carol Greider and Jack Szostak identified telomerase and learned how it works. Some scientists speculated people could live longer by using the enzyme to buy extra time for their aging cells, but that idea remains risky and unproven.
“By itself, lengthening telomeres would probably just increase the rate of tumor formation,” said Chris Patil, a researcher at the Buck Institute for Age Research in Novato, California. “Experiments with mice have shown that lengthening telomeres extends lifespan, but only if you introduce multiple other mutations to block cancer.”
Considering the risks of telomere-extension therapy, he thinks that scientists have bigger fish to fry.
“In the absence of a comprehensive understanding, it’s very dangerous,” Muller said. “We have to figure out how to do maintenance on our telomeres.”
Muller thinks humans could live for 90 to 210 years once scientists know more about the molecular basis of aging.
“If we could figure out how to do maintenance, we could extend our lives,” he said. “But it has to be done very carefully, and we’d have to have a comprehensive understanding of the mechanism. ”
Images: 1) Chromosomes in a dividing cell. National Institutes of Health. 2) Wired forecasted telomeric gene extension therapy in the Found section of issue 15-09 by Alex Katz, Erik Pawassar, and Chris Baker.
Bats use echolocation to see in the dark, but unfortunately human scientists cannot do the same.
That poses a problem for ecologists who want to know, for example, how many Brazilian free-tailed bats live in the Carlsbad Caverns of New Mexico. Researchers can’t shine a light on them because that disrupts their behavior, but they can’t see them without light. The answer? Infrared cameras, of course.
By installing infrared sensors, life scientist Nickolay Hristov of Winston-Salem State University and Thomas Kunz of Boston University were able to study the bat colonies in great detail from less than 50 feet away. They discovered that only something like 4 million bats live in the large colonies, an order of magnitude less [pdf] than previously estimated by visual inspection methods in the 1950s.
The next step in this see-in-the-dark science will be taking data with multiple cameras, so that the scientists can triangulate the precise positions of the bats during flight, Hristov said.
Coins buried by anxious Italians in the first century B.C. can be used to track the ups and downs of the Roman population during periods of civil war and violence.
In times of instability in the ancient world, people stashed their cash and if they got killed or displaced, they didn’t come back for their Geld. Thus, large numbers of coin hoards are a good quantitative indicator of population decline, two researchers argue in in the Proceedings of the National Academy of Science Monday.
And it turns out that during the periods we know to have been violent — the Second Punic War, the Social War and various civil wars — hoarding behavior soars, providing a statistical peek into the life of your average Italian 2,000 years ago.
“During that period, we have a good literary record. Caesar died because he was killed by assassins,” said Peter Turchin, a population ecologist at the University of Connecticut. “We don’t know what happened to common people. [Coin hoards] tell us what happened to common people.”
The new work could help settle a long-standing historical debate about the Roman population. Census figures from the end of the second century B.C. show a population of adult males of around 400,000. Then, the record goes blank, and census figures from around a hundred years later show a population of 4 to 5 million. Some of the population explosion is explained by the extension of Roman citizenship to various groups, but far from all of it. From this evidence, a group of historians known as the “high-count” hypothesizers have argued there was excellent population growth during that period.
Another group of historians had an alternate explanation for the appearance of population growth. They figured that the later census takers had started to count women and children, rather than just adult males, as part of the official population stats.
Without more information about the ancient world, it was difficult to settle the argument one way or another. Turchin, though, knew from previous work that warfare and instability don’t tend to deliver robust population growth in societies.
“Population growth and instability are negatively correlated,” Turchin said.
He teamed up with Walter Scheidel, a Stanford classicist and historian, to create a model of population growth and decline based on coin-hoard data gathered over the years. Their model’s predictions match well with the early census data. The population projections they derive make the “high-count” hypothesis “highly implausible,” they argue.
That has important implications for Roman history, but not too much history will actually be rewritten. It was the high-counters who were hoping to revise the Italian population up from what earlier historians had assumed.
Image: A hoard of Roman coins from the Bristol Museum. flickr/Synwell Liberation Front.
Altruism might have evolved for fairly selfish reasons, at least in insects.
When a warring termite colony loses its king and queen — the only members capable of reproduction — then its survivors merge with the victor colony, treating genetically unrelated former enemies as if they were siblings.
In the short term, this makes no sense. But in the long term, because replacement royalty is recruited from among worker bugs, it’s the losers’ best shot at eventually reproducing.
“You could go off and start your own colony, but that’s risky,” said Philip Johns, a Bard College evolutionary biologist. “This way, there’s a good chance a king or queen may die, and then you have a chance at taking over.”
The drama of termite succession, described Monday in the Proceedings of the National Academy of Sciences, is the latest addition to a long, rich history of research into insect altruism, which has fascinated and perplexed scientists since Darwin.
At its most extreme, insect altruism takes the form of eusociality, in which entire insect castes are unable to reproduce, and devote their lives to caring for other colony members. This is what makes giant insect colonies possible. But through a framework of classic evolutionary genetics, it doesn’t compute. Organisms are supposed to be driven to reproduce their genes.
The conundrum was solved for a while by Bill Hamilton, an evolutionary biologist who showed that eusociality could be explained by the relatedness of colony members. In some insect species, workers share more genes with their siblings than with their own hypothetical offspring.
But Hamilton’s position has become controversial, partly because of termites species who aren’t so closely related to their siblings, but practice eusociality nonetheless. The cooperation described in the PNAS paper is especially striking: The species weren’t related to one another at all, yet came together like family.
When the researchers studied the newly joined colonies 18 months later, however, the merging made sense. They found individuals from both original colonies, as well as new, hybrid members. Kings and queens could be chosen from among the newcomers, and termite royalty is frequently replaced: In termite battles, they’re always the first targets.
The species used in the study, Zootermopsis nevadensis, is especially primitive, with colonies comprising a few dozen members. It’s believed to resemble the first termite species to evolve eusociality.
Later on, when colonies expanded from a few dozen members to millions, and entire sterile castes there no longer had any meaningful chance of being picked to reproduce, it didn’t matter.
“There’s a point of no return,” Johns speculated. “The colonies have huge advantages over non-eusocial colonies.” They out-competed one another.
“They posit what early human societies were like: small populations, high rates of encountering others. And when they did meet, there was a fight,” Johnson said.
Citation: Nonrelatives inherit colony resources in a primitive termite.” By Philip M. Johns, Kenneth J. Howard, Nancy L. Breisch, Anahi Rivera and Barbara L. Thorne. Proceedings of the National Academy of Sciences, Vol. 106, No. 39, October 5, 2009.
Brandon Keim’s Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecosystem and planetary tipping points.
A new project to create a 3D map of space so large that scientists can find a 500 million-light-year-size remnant from the early universe inside it began operation last month.
The Baryon Oscillation Spectroscopic Survey opened its eyes to the universe, taking in data from hundreds of galaxies and quasars in the constellation Aquarius, from its perch on the Apache Point Observatory in New Mexico. Eventually, it will image two million galaxies and quasars.
"The data from BOSS will be some of the best ever obtained on the large-scale structure of the universe,” said David Schlegel, an astronomer heading the team from Lawrence Berkeley National Laboratory, in a press release.
BOSS was built atop the Sloan Digital Sky Survey infrastructure, which created a smaller map of the universe in our neighborhood. The scientists put in new CCDs to better capture the infrared light that arrives redshifted from its trip across billions of light-years. They also remade the fiber optics system so they could capture more objects.
“We’ve rebuilt this telescope to make a much bigger map of the sky. We put in more optical fibers. We jammed in as many as we could fit,” Schlegel said. “It’s a mix of high-tech and low-tech. Every object we observe, we machine these plug plates and plug in these optical fibers.” (See the image at the top of the page.)
Over vast areas millions of light-years across, the astronomers will map the enormous imprint of compression waves that blew through the early, hot universe and became etched into the distribution of matter. It’s like measuring a sound wave pushing air molecules around, Schlegel said, but what the wave has moved is galaxies instead of molecules.
“These sound waves have been imprinted on the structure of everything in the universe. Most famously, they are seen in the microwave background,” Schlegel told Wired.com. “But you can also see it imprinted on all the structures of the galaxies today.”
That imprint, called the baryon acoustic oscillation, will yield important insights about the nature of dark energy, about which we know next to nothing. Scientists will be able to use the BAO as an enormous ruler for measuring how the universe has expanded.
“It’s a big-ass ruler,” said Schlegel. “It happens to be about 500 million light-years. Even for us, that’s big.”
BOSS will be observing the sky for the next five years. What the scientists hope the ruler will allow them to do is understand the period of accelerating expansion that began about six billion years ago.
“What we think happened is that we’ve entered this period of acceleration of the universe just in the last six billion years,” Schlegel said. “When the universe was half as old as it is now, it was decelerating and then all of a sudden it started accelerating, which we don’t understand.”
The problem is that we don’t have good data from that time period. Thanks to intensive study of the cosmic background radiation, we have expansion information from when the universe was only 400,000 years old. Then we have very recent observations from supernovae.
“But we don’t have much in between,” Schlegel said.
If BOSS can fill in that gap, we could not only learn about this mysterious something we call dark energy, but also grasp what happened during the universe’s adolescent growth spurt.
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