Bacterial Competition In Lab Shows Evolution Never Stops

The plate on the left contains about equal numbers of colonies of two different bacteria. After the bacteria compete and evolve, the lighter ones have taken the lead in the plate on the right.  

Evolution is relentless process that seems to keep going and going, even when creatures live in a stable, unchanging world.

That's the latest surprise from a unique experiment that's been underway for more than a quarter-century.

Evolution is so important for biology, medicine and a general understanding of our world that scientists want to understand it as fully as possible. That's why, in 1988, biologist Richard Lenski took a dozen glass flasks and added identical bacteria to each of them. Those 12 populations have been evolving ever since, letting scientists watch evolution in real time.

Michigan State's Richard Lenski pulls cultures of bacteria from a lab freezer.

Day after day — including holidays and weekends — workers in Lenski's lab at Michigan State University in East Lansing feed and care for the E. coli bacteria. The bacteria eat and divide again and again. The original microbes have produced more than 50,000 generations over the last 25 years.

Random mutations have allowed them to get fitter, meaning they reproduce faster. "In evolutionary biology, fitness is this representation of the ability of an organism to survive and reproduce," says Lenski. He explains that all else being equal, organisms that reproduce more quickly will have an advantage when competing with those that reproduce more slowly.

Early on, Lenski predicted his bacteria would adapt and adapt but eventually hit a wall — that they would reach a peak level of fitness they couldn't improve on.

"Evolutionary biologists have long thought of evolution as a process that continues indefinitely because the world is constantly changing," says Lenski. But his bacteria live in an unchanging world — their glass bottles stay at a steady temperature and they constantly are fed the same food.

It turns out, though, that the bacteria haven't stopped evolving, and it looks like they never will, according to a report Lenski's group has now published in the journal Science.

Lenski, along with colleagues Michael Wiser and Noah Ribeck, dug into a freezer that holds samples of the bacteria that were taken every few months over the course of the whole experiment. The researchers can pull out, say, the 10,000th or 40,000th generation and bring these frozen bacteria back to life.

"We can actually compete organisms that lived at different points in time, so we can compete the evolved bacteria head to head against their ancestors," says Lenski.

What they've found is that the bacteria just keep getting fitter and fitter and fitter. The pace of improvement is slowing down, but shows no sign of stopping.

In their tests, the original ancestor doubles its population in about an hour, says Lenski, but the 50,000th generation can do that in around 40 minutes. And the researchers calculate that future generations will reproduce even faster. "We predicted that in about a million years, their doubling time might be on the order of about 20 minutes," says Lenski.

He says some bacteria can actually achieve that, in environments more rich in nutrients than the flasks in his lab, so it doesn't seem like a crazy, ridiculous prediction.

Still, that would be a lot of change for creatures living in an unchanging world, and it offers a new insight on how evolution can just keep on going and going.

Does Lenski think his long-term experiment will still be around in million years, to test his predictions? "I doubt it," he says.

But he would love to see it last another 25 years, at least. "I think it's still got a lot to teach us about how evolution works under these very idealized but very transparent conditions," says Lenski, who eventually plans to pass the experiment on to a younger scientist.

Ancient Seawater Found in the Chesapeake Bay

Seawater discovered near the Chesapeake Bay is up to 150 million years old

Not only is the Chesapeake Bay so enormous it can be seen from space, it essentially came from outer space.

An asteroid or huge chunk of ice slammed into Earth about 35 million years ago, splashing into the Early Cretaceous North Atlantic, sending tsunamis as far as the Blue Ridge Mountains and leaving a 56-mile-wide hole at the mouth of what is now the bay.

But a newly published research paper written by U.S. Geological Survey scientists shows that wasn’t the end of it. While drilling holes in southern Virginia to study the impact crater, the scientists discovered “the oldest large body of ancient seawater in the world,” a survivor of that long-gone sea, resting about a half-mile underground near the bay, according to the USGS.

Gas bubbles in groundwater flowing from the open drill-stem casing during the drilling project. Very high helium concentrations were used to help identify the saline water’s origin as Early Cretaceous North Atlantic sea water. Credit: Herbert Pierce

“What we essentially discovered was trapped water that’s twice the salinity of [modern] seawater,” said Ward Sanford, a USGS hydrologist. “In our attempt to find out the origin, we found it was Early Cretaceous seawater. It’s really water that’s from the North Atlantic.”

The findings showing that the water is probably between 100 million and 150 million years old were published Thursday in the journal Nature.

The Chesapeake Bay Impact Crater was discovered in 1999 by a tandem of USGS and Virginia Department of Environmental Quality scientists.

They theorized that a huge rock or chunk of ice slammed into an ancient ocean, sending enormous pieces of debris skyward and forcing monster tsunamis hundreds of miles inland.

Over centuries, the crater became hidden under 400 to 1,200 feet of sand, silt and clay, hampering its discovery for decades.

“It’s the largest crater discovered so far in the United States, and it’s one of only a few oceanic impact craters that have been documented worldwide,” USGS hydrologist David Powars said at the time.

The bay crater is shallower and smaller than another off the coast of Mexico, which most scientists believe caused the extinction of dinosaurs, Powars said.

Five years after the Chesapeake crater’s discovery, Sanford’s USGS team started drilling at Cape Charles, Va., under a $1.5 million grant from the International Continental Drilling Program to study how the earth’s crust absorbed the blow. “We weren’t looking for ancient seawater,” he said.

As the team drilled a half-mile from the surface, it encountered standing water. They first thought it was salty water that occasionally shows up at coastal drill sites. Saltwater is found underground all over the world all the time, often because of huge salt deposits in the ground.

In this case, “we didn’t hit any salt while drilling” at the Cape Charles site, a mile from the bay, Sanford said.

So researchers considered the possibility of boiling, when a meteor impact is so forceful that it heats water and increases its salinity. But after further tests, the boiling theory also didn’t make sense.

Results from more testing showed the water was twice as salty as today’s ocean water. When they analyzed its chemistry, they found high levels of chlorides and bromides, the fingerprint of sea­water from another time, Sanford said.

More tests and digging through research established that the chemistry was consistent with the “vast halite deposits created during the Jurassic and Cretaceous periods in the Gulf of Mexico and South Atlantic Basins,” the research paper said.

In other words, the groundwater at Cape Charles, about 220 miles south of the District, had the same salinity as the long-gone Early Cretaceous North Atlantic. When the meteor or whatever it was struck North America and disfigured the landscape, “the ancient seawater was preserved like a prehistoric fly in amber,” the USGS said in a statement.

“This was a surprising site discovery,” Sanford said. “This was not something we were looking for or even expected.”

It wasn’t the first time teams drilling for oil or geologic studies have come across deep groundwater with strangely high salinity, said Jerad Bales, acting USGS associate director for water.

Bales said numerous theories had been offered to help explain those findings. “But, up to this point, no one thought that this was North Atlantic ocean water that had essentially been in place for about 100 million years,” Bales said.

The USGS said the discovery would help scientists to better understand the hydrology of the area, at the very least.

Fourteen years ago, when the crater itself was found, Bales made a prescient statement. He said the discovery would help explain a few strange features in the region, including earthquakes around the crater’s perimeter, a higher rate of sea-level rise around Norfolk and “salty groundwater.”

New Tyrannosaur Discovered in Southern Utah

Paleontologists on Wednesday unveiled a new dinosaur discovered four years ago in southern Utah that proves that giant tyrant dinosaurs like the Tyrannosaurus rex were around 10 million years earlier than previously believed.

A full skeletal replica of the carnivore — the equivalent of the great uncle of the T. rex — was on display at the Natural History Museum of Utah alongside a 3-D model of the head and a large painted mural of the dinosaur roaming a shoreline.

It was the public's first glimpse at the new species, which researchers named Lythronax argestes (LY'-throw-nax ar-GES'-tees). The first part of the name means "king of gore," and the second part is derived from poet Homer's southwest wind.

The fossils were found in the Grand Staircase-Escalante National Monument in November 2009, and a team of paleontologists spent the past four years digging them up and traveling the world to confirm they were a new species.

Paleontologists believe the dinosaur lived 80 million years ago in the late Cretaceous Period on a landmass in the flooded central region of North America.

The discovery offers valuable new insight into the evolution of the ferocious tyrannosaurs that have been made famous in movies and captured the awe of school children and adults alike, said Thomas Holtz Jr., a vertebrate paleontologist at the University of Maryland department of geology.

This photo released by the Natural History Museum of Utah shows the fossilized skeleton of a newly-d …

"This shows that these big, banana-tooth bruisers go back to the very first days of the giant tyrant dinosaurs," said Holtz, who reviewed the findings. "This one is the first example of these kind of dinosaurs being the ruler of the land."

The new dinosaur likely was a bit smaller than the Tyrannosaurus rex but was otherwise similar, said Mark Loewen, a University of Utah paleontologist who co-authored a journal article about the discovery with fellow University of Utah paleontologist Randall Irmis.

It was 24 feet long and 8 feet tall at the hip, and was covered in scales and feathers, Loewen said. Asked what the carnivorous dinosaur ate, Loewen responded: "Whatever it wants."

"That skull is designed for grabbing something, shaking it to death and tearing it apart," he said.

The fossils were found by a seasonal paleontologist technician for the Bureau of Land Management who climbed up two cliffs and stopped at the base of a third in the national monument.

This image released by the Natural History Museum of Utah shows a model of a newly-discovered dinosa …

"I realized I was standing with bone all around me," said Scott Richardson, who called his boss, Alan Titus, to let him know about the fossils.

Loewen and others spent three years traveling the world to compare the fossils to other dinosaurs to be absolutely sure it was a new species. The findings are being published in the journal PLOS One.

The fossils were found in a southern Utah rock formation that also has produced the oldest-known triceratops, named "Diabloceratops," and other dome-headed and armored dinosaurs.

There are about 1 million acres of cretaceous rocks that could be holding other new species of dinosaurs, said Titus, the BLM paleontologist who oversees the Grand Staircase-Escalante National Monument. Only about 10 percent of the rock formation has been scoured, he said. Twelve other new dinosaurs found there are waiting to be named.

"We are just getting started," Titus said. "We have a really big sandbox to play in."

Holtz said the finding is a testament to the bounty of fossils lying in the earth in North America. He predicts more discoveries in Utah.

"It shows we don't have to go to Egypt or Mongolia or China to find new dinosaurs," Holtz said. "It's just a matter of getting the field teams out."

Recent Rash of Wildlife Deaths

West Coast Starfish Turning to 'Goo' Is Latest in Mass Wildlife Deaths

Marine biologists have reported widespread starfish die-offs along the West Coast, precipitated by a disease that causes their arms to fall off and the creatures to disintegrate and turn to "goo."

"Sea star wasting disease," has been flushing out a vast number of a particular five-legged species from tide pools, even wiping out up to 95 percent of the population, the AP reported. Along the western coastline stretching from southeast Alaska to Santa Barbara, the Pisaster ochraceus starfish, also known as the purple sea star or ochre starfish, are dying of the disease which causes white, abscess-like lesions to form and spread across their bodies.

Wasting disease has been reported before in southern California in 1983-84, but it remained localized then. The starfish population die-off is the latest in a series of mass animal deaths to occur this year.

Giant Oarfish Wash up in California

Not one, but two giant sea serpent-like oarfish washed up on the beaches of southern California last month. The first discovery was made by a snorkeling marine scientist who wrestled the dead 18-foot monster (with help) to shore near Catalina, while the second so-called "discovery of a lifetime" was made in less than a week. The second oarfish measured at 13.5 feet, and was found washed up on a beach in Oceanside Harbor by bewildered beachgoers.

Test on the bizarrre fish failed to determine a cause of death. The terrifying-looking and toothless oarfish is also known as a ribbon fish, possessing bony, silvery bodies and bright redcrested
heads. They are thought to have spawned ancient folk tales about sea serpents.

Bees Turn Up in Parking Lot

More than 25,000 dead bees were found scattered across a parking lot in Wilsonville, Ore., in June this year, amid rapidly declining honeybee populations across North America. The cause of the deaths was later determined by the Department of Agriculture to have been related to an insecticide used on trees to kill aphids.

Across the U.S., mass bee die-offs have been attributed to colony collapse disorder, in which bees abruptly exit the hive and do not return. Beekeepers have reported losing up to 90 percent of their bee colonies since 2006, but still have no idea what causes the disorder, although one theory is that the bees are committing a type of "altruistic suicide" to save their nest-mates from dying of disease.

Manatees Threatened by Algae

So far, 2013 has been the deadliest year yet for Mantees off the Florida coast. A bloom of toxic algae that draws out essential oxygen from the water has killed at least 769 of the blubbery, seal-like mammals. The algae, also known as red-tide, settles on the sea grass that manatees feed on, which when eaten, can cause central nervous system problems, including seizures and difficulty lifting the head to breathe, eventually leading to death.

This year's number of manatee deaths was nearly double of that seen in 2012, which was then reported at around 392. Manatees are a protected species and have been highly affected by urban coastal development, and constantly face the danger of being struck by boats.

Pigs Dumped in Chinese River

When 6,000 pig carcasses were found floating in China's Huangpu River in March, many of Shanghai's 23 million residents who receive their primary water supply from the river, were unnerved. The reports from health officials who later determined that the pigs were infected with a disease known as porcine circovirus, only served to deepen their fears, although the government claimed that the water had not been contaminated and was safe to drink.

It was thought that the pigs had been dumped in a hurry (and on the cheap) because of a recent government crackdown on selling diseased pigs.

Dolphins Die of Virus on East Coast

Hundreds of bottle-nosed dolphin deaths have been reported on the East Coast since July, which scientists are blaming on the outbreak of a dolphin virus similar to measles in humans. The National Oceanic and Atmospheric Administration tested 33 of the approximate 333 dolphins that had washed ashore since July 1, and found the immune system-suppressing morbillivirus in all but one of them.

The dolphin die-off this year is the highest recorded since a similar scale viral outbreak in 1987 and 1988. As dolphins have very little resistance to the virus, NOAA scientists say they expect that wild populations will continue to die until spring 2014.

Oarfish Offer Chance to Study an Elusive Animal Long Thought a Monster

It was a big day for marine biologists: On Oct. 13, the body of an 18-foot oarfish was dragged from the water onto Santa Catalina Island off the California coast, presenting a rare opportunity for local scientists to study one of the world’s most elusive and awe-inspiring big fish.

Five days later, it was a big day again: Another oarfish washed up 50 miles away, this one 14 feet with six-foot-long ovaries full of eggs.

Pairs of oarfish have appeared within days of each other before, deepening the mystique that surrounds the animal. But the twin discoveries nevertheless sent a wave of excitement through a scientific community more used to reading about oarfish than handling them in the lab.

“These are unpredictable fish,” said Milton Love, a research biologist at the Marine Science Institute of the University of California, Santa Barbara. “And it’s hard to study unpredictable fish.”

Oarfish, which are long and eel-like in appearance, can grow to stupendous lengths — though ancient rumors of 55-foot specimens are probably exaggerated — and have inspired tales of sea monsters since ancient times.

Scientists know very little about them because they are “virtually never caught in nets or by hooks, and they’ve only been observed under water a handful of times,” Dr. Love said. “So you’re kind of left with these not random but rare events, and that’s the only way you can study them.”

It is known that oarfish are notoriously bad swimmers; their long bodies remain still while their undulating fins handle most of the propulsion, yet they have apparently learned to avoid nets, Dr. Love said.

Precisely what will be learned from the two newfound fish, which were dissected and divvied up among a handful of research institutions, remains to be seen. “You can only learn so much from a dead fish,” Dr. Love said. But by last week, a coterie of researchers, including a comparative ophthalmologist and a gill expert, were lining up to study them.

Early observations revealed that the second fish, found in Oceanside, was apparently ready to spawn. “There were probably hundreds of thousands of eggs in those ovaries,” said H. J. Walker, the marine biologist at the Scripps Institution of Oceanography who extracted the eggs. Its stomach was nearly empty, supporting the theory that a strong current, possibly the northeast-flowing Kuroshio, had carried it and the other oarfish, a male, away from their preferred environment and food sources.

A variety of parasites, including large larval tapeworms and a spiny-headed worm, were found in the intestines of the male, potentially giving a clue about where these particular oarfish lived and fed. Their species, Regalecus russelii, is most populous in the Western Pacific.

Oarfish fans noted with excitement that the male was missing some of the posterior part of its body, colloquially known as the tail. Tyson Roberts, an ichthyologist with the Smithsonian Tropical Research Institute who is widely regarded as the world’s leading oarfish expert, has long hypothesized that oarfish can jettison sections of their bodies below the abdomen, much the way lizards can shed their tails.

As the world’s largest bony fish, oarfish have no known natural predator, so unlike with lizards, any shedding of the body is probably not done in self-defense, Dr. Roberts said. Such behavior is more likely meant to make swimming more efficient, among other reasons. “There may also be energetic benefits in shedding the posterior part of the body if it does not have much survival value, as apparently is the case in oarfishes,” he added.

Even oarfish experts disagree on some basic facts. Most refer to them as deep-sea creatures, contending that they live 500 to 1,000 feet below the surface. Dr. Roberts says that is not so.

“Mostly they spend their time quite near the surface, suspended vertically with their heads up, just passively floating,” said Dr. Roberts who championed the idea that there was more than one species of oarfish. He also believes that they have the capacity to change gender. “It may be that all individuals pass through a stage in which they are males and then pass through a stage in which they’re females,” he said.

Just how deep the oarfish resides may become clearer in the coming months as researchers study the eyes of the new specimens, possibly learning whether they are designed to see in the low light of the deep ocean. “There’s not much information on the oarfish eye, which is unusually large,” Dr. Walker said.

At California State University, Fullerton, Misty Paig-Tran, a biomechanist, will use CT scans to make a three-dimensional model of the female specimen, most of which she now possesses (the head will soon be delivered to Dr. Walker). Her preliminary X-rays gave researchers a closer look at the structures that support the dorsal fin, which may help explain the animal’s unusual way of swimming.

Oarfish have been a source of fascination for centuries. With long bodies, toothless jaws and giant red dorsal fins that protrude from their heads, they are often mistaken for monsters. “Most biologists will tell you it probably is the species responsible for the sea serpent legend,” Dr. Walker said.

An ancient Japanese myth holds that washed-up oarfish are a sign of an impending earthquake, a theory that regained popularity after about 20 oarfish beached themselves in Japan before the 2011 earthquake and tsunami. In Japan, the oarfish is known as ryugu no tsukai, or “messenger from the sea god’s palace.”

In California, the one-two arrival of the latest oarfish brought feverish speculation that an earthquake was imminent. But researchers said there was little science behind the myth. “If something about tectonic movement is killing these fish, why aren’t the other fish in the environment doing the same thing?” Dr. Love said.

The Catalina specimen might still be under water had Jasmine Santana, 26, a marine science instructor at the Catalina Island Marine Institute, not spotted it about 15 feet down while snorkeling on her day off. “I recognized it because my colleague had shown me pictures of it,” she said. After dragging the fish to land, she and some of her co-workers placed it on ice in a ditch outside the institute.

“We wanted the kids to see it,” said Jeff Chace, a program director at the institute. “We dissected it on the Wednesday after we found it, then packed up all the organs, tissue samples, skin samples and eyeball samples and sent them off to various institutions.” Dr. Chace has put the rest of the carcass in deep freeze until he can find someone who can clean and mount the skeleton.