Archive for the ‘In the News’ Category

Five gallons worth of oil-derived tar balls washed up on Texas beaches this past weekend. Jerry E. Patterson, Commissioner of the General Land Office of Texas, confirmed that the tar balls were found on beaches in Galveston and the nearby Bolivar Peninsula. It’s worth nothing that the amount of oil that washed up in Texas is relatively small, enough to fill a large bucket. In addition, no one can say for sure if this unexpected tar ball arrival is due to the Deepwater Horizon oil disaster. The tar balls could have come from a ship leaking oil in the area, or from the countless gallons of oil that seep naturally from the Gulf of Mexico floor each year. Scientists and officials are looking at recent weather and ocean current patterns in the Galveston area to ascertain the likely course and direction the tar balls took to reach Texas shores. Hurricane Alex’s recent appearance south of Galveston may also be a factor in this mystery.

If these tar balls do indeed originate from the Deepwater Horizon catastrophe, then Texas would become the fifth and final American Gulf coast state to have beaches and shoreline habitats fouled by the continuing oil spill. News is still worse for Louisiana, Mississippi, Alabama, and Florida. In Louisiana, for example, tar balls and oil sheens have now reached Lake Pontchartrain, the country’s second largest salt water lake, just north of New Orleans. Near-shore oil skimming ships were held in port last week due to choppy seas from Hurricane Alex, and more oil continued to wash up on Gulf coast beaches.

Finally, the U.S. Coast Guard has restricted access for journalists to clean up sites. The new rules limit how close journalists (and other onlookers) can get to clean-up boats and containment booms, as well as beaches and other areas fouled by oil. Journalists must obtain permission a Coast Guard commander to come closer than 65 feet to any of these sites, or else face fines of up to $40,000 and felony charges. Initial reaction to these rules has been hostile from some journalists and local government officials. CNN’s Anderson Cooper in particular takes the U.S. Coast Guard to task, accusing the Coast Guard of backtracking on its initial pledge for full and complete transparency of the disaster and its lasting effects on the Gulf coast.

Finally, nearly 80 days after the Deepwater Horizon oil rig exploded and sank, oil continues to gush from the rig’s open well. BP has announced that recent choppy seas in the area have hampered its efforts to drill a relief well, which is the last best chance the company has to plug the open well permanently. BP hopes the relief well will be drilled by mid-August.

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The Planck spacecraft has delivered quite a payload of preliminary data on the origins of our Universe, and now the European Space Agency (ESA) is letting us catch a glimpse of Planck’s bounty. Named for German physicist and Nobel laureate Max Planck, the ESA launched Planck in May 2009 from the Guiana Space Centre. The spacecraft settled into a stable orbit along Earth’s nightside in a few months later. Earth’s nightside is an ideal spot for space-bound observatories: permanently shielded from the sun, spacecraft have an unobstructed view of the visible cosmos.

At the end of last summer, Planck began its ambitious mission: a survey of the entire sky. But Planck’s mission isn’t a simple pictorial survey (we’ve done that before). Planck was launched to survey the sky for wavelengths of the electromagnetic spectrum that we can’t see. Microwaves and very far infrared have longer wavelengths than visible light (see figure below), and Planck is capturing those wavelengths in its survey of the visible Universe.

It took the Planck spacecraft a little over six months to complete its first microwave and very far infrared survey of the sky, and made use of instruments designed and built by both the ESA and NASA. The embedded videos below illustrated how Planck completed this survey.

The fruits of Planck’s labor are shown below, in the spacecraft’s first microwave and very far infrared image of the sky:


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The Gulf of Mexico is home to approximately 1,700 sperm whales. Many of them feed just off the continental shelf, particularly around the Mississippi River delta, an area filled with ample food for these huge marine mammals. The whales reside in family groups, and rarely mingle with other sperm whale groups from the open Atlantic Ocean. They live as long as us, but reproduce at most only every five years. The Gulf of Mexico is their full-time home.

Since the Deepwater Horizon oil rig exploded and sank over sixty days ago, scientists have been concerned with the fate of Gulf of Mexico sperm whales. Sperm whales have been sighted in the fouled waters themselves, and no one knows what effect oil droplets will have on whale physiology and behavior. In addition, BP and the U.S. Coast Guard have been using unprecedented levels of chemical dispersants to scatter oil in the water, and no research has been done on the effect of even small amounts of these dispersants on cetaceans.

Given these uncertainties, the National Oceanic and Atmospheric Administration’s discovery this week of a dead sperm whale near the spill zone is a particularly troubling find. On Tuesday, the NOAA ship Pisces cited the decayed corpse of a young, 25 foot long sperm whale adrift nearly 80 miles from the site of the (former) Deepwater Horizon oil rig. Based on the decay of the body and the degree of scavenging by sharks, scientists estimate the whale perished several days ago, but don’t yet know the cause of death. They have taken tissue samples to help determine how the whale may have died, and hopefully analysis of the whale’s genome will determine its sex, and whether or not it was definitely from the endangered Gulf of Mexico population (which, given its location, it probably was). Skin samples taken may determine whether the whale was exposed to large amounts of oil before it died. However, since the whale’s body was adrift for days, scientists will have to infer where it died based on current patterns in the area where the body was found, weather conditions over the past week, and forensic clues of the time of the whale’s death.

All in all, a dead sperm whale is a rare find in the Gulf of Mexico, and this discovery so close to the site of the oil spill may be a harbinger of the spill’s lasting effects on the Gulf’s ecosystem. However, more won’t be known until scientists announce the whale’s cause, time, and location of death. In the meantime, the NOAA vessel Gordon Gunter put to sea on Wednesday to survey Gulf of Mexico cetaceans and catalog some of the oil spill’s effects on their ecology, physiology, and behavior. The ship’s mission also includes orders to observe the Gulf’s endangered sperm whales, all 1,699 of them.

Image of a sperm whale diving near a deep water rig in the Gulf of Mexico provided courtesy of Christoph Richter, the Sperm Whale Seismic Study, the U.S. Office of Naval Research, the Minerals Management Service of the U.S. Department of the Interior, Oregon State University, and Texas A & M University.

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The western honeybee, Apis mellifera.

Scientists from the United States Department of Agriculture announced at a recent meeting that they have identified the primary pathogens associated with honeybee Colony Collapse Disorder (CCD). American beekeepers first reported CCD in 2007, and the implications are dire. Honeybees (Apis mellifera) are major crop pollinators. In California alone, their commercial crop value easily exceeds $1.5 billion annually. Though CCD has only been recognized for a few years, the potential loss of honeybees as crop pollinators sent scientists scrambling to determine the cause of this odd and devastating syndrome.

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Scientists from the Maryland and California-based J. Craig Venter Institute announced today that they successfully created a partially synthetic lifeform. <a href="Their efforts appear in the journal Science, and include a detailed description of the steps they took to create life.

The lifeform in question is a single-celled bacterium called Mycoplasma mycoides. A bacterial cell, like all living organisms, stores “instructions” or “blueprints” for making and maintaining itself in the form of DNA (deoxyribonucleic acid). DNA is the genome of an organism — it is a long strand of chemicals stored within living cells. In single-celled organisms like bacteria, each cell is an individual, and each cell contains a copy of the genome. The instructions for making and maintaining the cell are “read” from the genome by the cell. Thus, the complex chemicals and molecules that cells make to do work, maintain integrity, survive, and reproduce are all made using these DNA-based “instructions.” When a cell divides, DNA is copied, so that each daughter cell has a complete copy of the genome.

A colony of Mycoplasma mycoides cells.

I harp so much on DNA because much of the work done by the J. Craig Venter Institute centers on the Mycoplasma mycoides genome. Scientists had already “read” the full chemical sequence of the DNA strand (also known as the complete genome sequence) from Mycoplasma mycoides. Researchers at the Venter Institute set out to use that known Mycoplasma mycoides genome sequence to create their own Mycoplasma mycoides cell from scratch.

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Scientists from the University of Utah and Qinghai University Medical School in China’s Qinghai Province have discovered some of the genetic changes that have allowed ethnic Tibetans to survive in the high altitudes of their homeland.

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New analyses of genes from modern humans and extinct neanderthals have revealed something remarkable: some of us have a tiny amount of neanderthal ancestry.

Neanderthals were a group of hominids (human-like great apes) who last shared a common ancestor with all modern humans over 500,000 years ago. Based on fossil records, neanderthals lived primarily in Europe and some parts of Asia. For most of neanderthal history, we humans occupied parts of Africa. However, a small group of humans left Africa in a series of migration waves starting 50,000 to 80,000 years ago. As humans migrated out of Africa, neanderthal numbers declined. Neanderthals ultimately died out sometime around 30,000 years ago. However, the timing and cause of our robust cousin’s disappearance is a matter of intense debate, as is their interaction with modern humans as they left Africa and spread to Eurasia, Oceania, and the Americas.

  • As humans migrated out of Africa, did they interact with neanderthals?
  • Did ancient humans breed with neanderthals?
  • If ancient humans bred with neanderthals, did this breeding extend to human populations who remained in Africa?
  • (more…)

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New research published in the journal Nature Genetics is shedding more light on adaptations that allowed woolly mammoths to thrive in frigid latitudes during our planet’s recent ice ages. Woolly mammoths (Mammuthus primigenius) inhabited extreme northern latitudes starting about 150,000 years ago, and died out approximately 10,000 years ago. To study the cold adaptations of this mammal, scientists had to do something remarkable: they rebuilt a blood protein from this extinct species.

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On the left is the African Clawed Frog (Xenopus laevis), while its cousin (the Western Clawed Frog, Xenopus tropicalis), sits on the right. Image provided courtesy of Robert Grainger.

Platannas are 18 species of clawed frogs native to sub-Saharan Africa. Their genus name, Xenopus, means “strange foot,” in reference to the curved claws present on each hind foot. Two members of this genus, Xenopus laevis (the African Clawed Frog) and Xenopus tropicalis (the Western Clawed Frog), are also model organisms studied by biologists to understand the basics of vertebrate development and vertebrate genetics. Yesterday, scientists announced that one of these species, the Western Clawed Frog, became the first amphibian to have its genome sequenced.

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The threespine stickleback made a brief appearance in yesterday’s New York Times. I pay attention to such things (albeit one day late) because I study threespine sticklebacks and their close relatives for my thesis research on the evolution of sex chromosomes.

However, the stickleback’s appearance yesterday had nothing to do with my research. But, a team from the University of Bonn, led by Marion Mehlis, looked at the threespine stickleback to address a very specific question: cannibalism. Many animals, for one reason or another, eat their young. Sticklebacks are no exception. Male sticklebacks guard nests of fertilized eggs during the breeding season (female sticklebacks play no part in parenting). But, sometimes, a male will eat some or all of the eggs in his nest. Why? What triggers this behavior?

It certainly seems counterproductive. Male sticklebacks do all the work in the breeding season: defending a territory, building a nest, courting female after female, chasing a female away once she lays her eggs in the nest, fertilizing the nest, and caring for the eggs until they hatch. Why would any male in his right mind go to all the effort of building a nest a courting a female when he’s just going to devour his kids before they hatch? Well, as it turns out, he might do that when those aren’t his kids in the nest.

In the stickleback field (as in other fields), there is another group of males — the sneaker males. These males don’t typically build nests and defend territories. They lurk near a courting couple, waiting until a female has laid her eggs in another male’s nest. Then, the sneaker male enters the nest (usually while the hard-working male is busy chasing away the female) and fertilizes the eggs. Sneaker male (now sneaker dad) swims away, leaving the hapless hard-working male to tend his offspring.

Mehlis and colleagues wondered: do stickleback males eat the eggs in their nest when those eggs were fertilized by another male? They conducted trials to test this, switching batches of eggs (we call them “clutches”) in a nest tended by one male with eggs that were fertilized by another male. As it turns out, a male stickleback is much more likely to consume eggs if those eggs weren’t fertilized by him — if he wasn’t the dad. Mehlis and colleagues aren’t exactly sure what kind of signal the male is sensing that indicates paternity, but it’s likely some sort of olfactory (“smell”) cue.

The study sheds some light on the puzzle of male stickleback cannibalism. As for the type of signal at work in these fish, stay tuned!

Image of female (upper) and male (lower) threespine sticklebacks provided courtesy of Dr. Joseph Ross.

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