Scientists have reproduced in the lab how the ingredients for life could have formed deep in the ocean 4 billion years ago. The results of the new study offer clues to how life started on Earth and where else in the cosmos we might find it.
Astrobiologist Laurie Barge and her team at NASA’s Jet Propulsion Laboratory in Pasadena, California, are working to recognize life on other planets by studying the origins of life here on Earth. Their research focuses on how the building blocks of life form in hydrothermal vents on the ocean floor.
To re-create hydrothermal vents in the lab, the team made their own miniature seafloors by filling beakers with mixtures that mimic Earth’s primordial ocean. These lab-based oceans act as nurseries for amino acids, organic compounds that are essential for life as we know it. Like Lego blocks, amino acids build on one another to form proteins, which make up all living things.
“Understanding how far you can go with just organics and minerals before you have an actual cell is really important for understanding what types of environments life could emerge from,” said Barge, the lead investigator and the first author on the new study, published in the journal Proceedings of the National Academy of Sciences. “Also, investigating how things like the atmosphere, the ocean and the minerals in the vents all impact this can help you understand how likely this is to have occurred on another planet.”
Found around cracks in the seafloor, hydrothermal vents are places where natural chimneys form, releasing fluid heated below Earth’s crust. When these chimneys interact with the seawater around them, they create an environment that is in constant flux, which is necessary for life to evolve and change. This dark, warm environment fed by chemical energy from Earth may be the key to how life could form on worlds farther out in our solar system, far from the heat of the Sun.
“If we have these hydrothermal vents here on Earth, possibly similar reactions could occur on other planets,” said JPL’s Erika Flores, co-author of the new study.
Barge and Flores used ingredients commonly found in early Earth’s ocean in their experiments. They combined water, minerals and the “precursor” molecules pyruvate and ammonia, which are needed to start the formation of amino acids. They tested their hypothesis by heating the solution to 158 degrees Fahrenheit (70 degrees Celsius)—the same temperature found near a hydrothermal vent—and adjusting the pH to mimic the alkaline environment. They also removed the oxygen from the mixture because, unlike today, early Earth had very little oxygen in its ocean. The team additionally used the mineral iron hydroxide, or “green rust,” which was abundant on early Earth.
The green rust reacted with small amounts of oxygen that the team injected into the solution, producing the amino acid alanine and the alpha hydroxy acid lactate. Alpha hydroxy acids are byproducts of amino acid reactions, but some scientists theorize they too could combine to form more complex organic molecules that could lead to life.
“We’ve shown that in geological conditions similar to early Earth, and maybe to other planets, we can form amino acids and alpha hydroxy acids from a simple reaction under mild conditions that would have existed on the seafloor,” said Barge.
Barge’s creation of amino acids and alpha hydroxy acids in the lab is the culmination of nine years of research into the origins of life. Past studies looked at whether the right ingredients for life are found in hydrothermal vents, and how much energy those vents can generate (enough to power a light bulb). But this new study is the first time her team has watched an environment very similar to a hydrothermal vent drive an organic reaction. Barge and her team will continue to study these reactions in anticipation of finding more ingredients for life and creating more complex molecules. Step by step, she’s slowly inching her way up the chain of life.
This line of research is important as scientists study worlds in our solar system and beyond that may host habitable environments. Jupiter’s moon Europa and Saturn’s moon Enceladus, for example, could have hydrothermal vents in oceans beneath their icy crusts. Understanding how life could start in an ocean without sunlight would assist scientists in designing future exploration missions, as well as experiments that could dig under the ice to search for evidence of amino acids or other biological molecules.
Future Mars missions could return samples from the Red Planet’s rusty surface, which may reveal evidence of amino acids formed by iron minerals and ancient water. Exoplanets—worlds beyond our reach but still within the realm of our telescopes—may have signatures of life in their atmospheres that could be revealed in the future.
“We don’t have concrete evidence of life elsewhere yet,” said Barge. “But understanding the conditions that are required for life’s origin can help narrow down the places that we think life could exist.”
This research was supported by the NASA Astrobiology Institute, JPL Icy Worlds team.
Explore further: Hydrothermal vent experiments bring Enceladus to Earth
More information: Laura M. Barge et al. Redox and pH gradients drive amino acid synthesis in iron oxyhydroxide mineral systems, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1812098116
Journal reference: Proceedings of the National Academy of Sciences
[Attention all attention whores: the border has lots of cameras. Go on down there and get some self-aggrandizement and pretend it’s for something other than your ego.]
A performer who goes by Beatrix Lestrange organized and hosted the No Border Wall Protest Drag Show in Brownsville, Texas.Reynaldo Leanos Jr./Texas Public Radio
Drag queens from throughout Texas’ Rio Grande Valley gathered last weekend in Brownsville to protest further construction of the border wall and bring attention to LGBTQ migrants who have been detained or are seeking asylum.
In a public park, a performer who goes by Beatrix Lestrange did not have to struggle to catch the attention of protesters gathered for the No Border Wall Protest Drag Show. Lestrange, whose real name is Jose Colon-Uvalles, wore a multicolored dress, a red wig, black pumps and a choker with studs.
“Who’s ready to have a political time?” Lestrange yelled out. The audience, standing in a semicircle and dressed in similarly vivid outfits, cheered and applauded.
“We’ll try to bring joy, positivity, beauty, drag, culture to whatever this is,” Lestrange said, pointing to the section of the border fence directly behind her.
Earlier this month, Congress passed a spending bill that will allocate $1.375 billion for the construction of border infrastructure in Texas’ Rio Grande Valley. Last November, U.S. Customs and Border Protection, in partnership with the Army Corps of Engineers, awarded two contracts for the construction of a border wall in south Texas. Construction is expected to begin this month.
Lestrange organized the drag queen protest show and is a self-proclaimed “dragtavist” — a drag queen committed to social activism.
“The vision was to perform in front of this wall and project our beauty and our glamour and our empowerment against this symbol that stands for hate, racism and xenophobia,” Lestrange said.
As Lestrange set up the music, the participants lined up and prepared their own performances.
Michelangelo De Vinci, whose given name is Sabino Ponce Jr., said this moment had personal resonance for him. His dad was once undocumented.
“I know his struggle coming over and how he built himself from the ground up with his third-grade education,” he said. “There are other people who are trying to come over here and do something better for themselves and their families — my dad being one of them — and these other people as well, so they should get a chance to live here also.”
The queens also sang as part of the event, including Green Day’s “American Idiot” and Lady Gaga’s “Born This Way.”
Drag queen Arina Heys wanted to participate in the No Border Wall Protest Drag Show to showcase the beauty of the Latin culture in the region. “We are just like any other community … lovable, humble and welcoming,” the performer said.Reynaldo Leanos Jr./Texas Public Radio
David Bocanegra, who performs as Arina Heys, wanted to participate to showcase the beauty of the Latin culture in the region.
“We get painted as this one negative picture,” the performer said. “We are just like any other community, and it’s extremely family oriented, it’s lovable, humble and welcoming.”
Jorge Trujillo, a professor at the University of Texas Rio Grande Valley, was among the spectators. He said the drag show exemplifies how the Rio Grande Valley is the United States at its finest.
“We need to continue that movement and let people never forget that there [has] never been a more perfect opportunity to be Valley proud,” Trujillo said.
Lestrange wanted the protest to show solidarity with LGBTQ asylum seekers. She hoped their performance brought some awareness to the issues trans and queer migrants face.
“I get teary eyed and emotional every time,” she said, “because they’re already fleeing really horrible conditions. They’re fleeing homophobia, transphobia, violence, trauma, only to come to the doorsteps of our country and encounter more of that.”
In less than two hours, the drag queens raised about $650. All the proceeds will go to local organizations that work with LGBTQ asylum seekers.
Lestrange also wants to challenge other LGBTQ communities across the country to participate in their own form of activism.
“If we can do this in front of the border wall, then they can do something similar,” Lestrange said. “Do it now because tomorrow is too late.”
Honest to Pete, what kind of piece of shit is this? She calls for the death of Americans, she joins confirmed murderers who release videos of their handiwork – meaning objective, empirical evidence of their brutality – and can’t wait to move in with them, be passed around from piece of shit to piece of shit, birthing little babies sired by those pieces of shit, and then the bottom falls out. Turns out her beliefs and behaviors were just more shit. So much shit. And now? Now she wants to come and live in the place she wanted to see burned down? She can die in a fucking fire, as far as I’m concerned. I’m not a good man, and I don’t give a shit about that, or your approval. She can die in a fire, and if you are like her, then so can you.
I just don’t get it. If you have a referendum, the people vote “No”, and you go ahead anyway, you are worse off than you were had you simply gone ahead without the referendum. I mean, you’ve gone out of your way to demonstrate to your voting public that their opinions do not matter and any pretense at democratic principles is only that – a pretense. How in the hell is that a good idea when the very subject matter is that the USAF base feels like an Imperial occupation?? If you had a medium-term goal of leaving the islands alone, and needed to drum up political support for that, then it would be plausibly a good idea. Otherwise? ~ Rick
TOKYO (Reuters) – A majority of voters in a referendum on Okinawa opposed a plan to relocate a U.S. military base within the southern Japanese island, but the central government said on Monday it intended to press ahead with its construction plans.The relocation site for U.S. Marine Corps Air Station Futenma where land reclamation work continues is seen in the Henoko coastal district in Nago, Okinawa Prefecture, Japan, in this photo taken by Kyodo February 23, 2019. Picture taken February 23, 2019. Mandatory credit Kyodo/via REUTERS
Just over 70 percent of voters opposed relocating the U.S. Marines’ Futenma air base within Okinawa in Sunday’s non-binding referendum, with a turnout of 53 percent. Okinawa governor Denny Tamaki was elected on that platform in September.
Okinawa is host to the bulk of U.S. military forces in Japan, whose alliance with Washington is central to its security. Many Okinawa residents associate the bases with crime, pollution and accidents.
The governor is required to respect the outcome and notify the premier and the U.S. president if the top response was backed by more than 25 percent of eligible voters.
Tokyo’s central government and Okinawa authorities have long been at loggerheads over the plan to move the air base.
A U.S.-Japan agreement calls for moving the base, which is surrounded by schools, hospitals and shops, to a less populated area, called Henoko, on the northern part of Okinawa.
However many Okinawa residents, indignant at what they see as an unfair burden, want the base off the island altogether.
Japanese Prime Minister Shinzo Abe told reporters on Monday the government was taking the results seriously, and would work to obtain the understanding of Okinawa residents, but that plans to move the base could not be deferred.
“We cannot avoid the necessity of moving Futenma, said to be the most dangerous base in the world,” Abe said, noting that two decades had passed since the agreement to do so was made.
“We can’t put this off any longer,” he said.Local residents read an extra edition newspaper reporting results of a U.S. base relocation plan in a referendum in Naha, Okinawa prefecture, Japan February 24, 2019, in this photo taken by Kyodo. Mandatory credit Kyodo/via REUTERS
Tamaki called on the government to accept the “firm decision” of the Okinawa people that the base relocation was unacceptable.
“I urge the government to change their view that relocating the base to Henoko is the only way and halt construction, along with more dialogue with us on closing Futenma and returning the land to us,” Tamaki said.
The referendum result was unlikely to derail the central government’s stance, said former Chuo University professor Steven Reed.
“It’s not a matter of local government policy. It’s a matter for foreign policy. The deal has been made,” he said.
Trump says he’s happy as long as Pyongyang stops tests
The outcome could give a bit of a boost to the struggling opposition Constitutional Democratic Party of Japan (CDPJ) – the largest among Japan’s opposition groups – ahead of an upper house election this year, Reed said.
The CDPJ opposes the Futenma relocation plan.
“It could make a substantial difference in the next election in Okinawa and it could make some difference nationwide,” he said.
Support for the CDPJ was just under 6 percent in a February survey by public broadcaster NHK, dwarfed by about 37 percent for Abe’s Liberal Democratic Party.
Synthetic DNA seems to behave like the natural variety, suggesting that chemicals beyond nature’s four familiar bases could support life on Earth.
The DNA of life on Earth naturally stores its information in just four key chemicals — guanine, cytosine, adenine and thymine, commonly referred to as G, C, A and T, respectively.
Now scientists have doubled this number of life’s building blocks, creating for the first time a synthetic, eight-letter genetic language that seems to store and transcribe information just like natural DNA.
In a study published on 22 February in Science1, a consortium of researchers led by Steven Benner, founder of the Foundation for Applied Molecular Evolution in Alachua, Florida, suggests that an expanded genetic alphabet could, in theory, also support life.
“It’s a real landmark,” says Floyd Romesberg, a chemical biologist at the Scripps Research Institute in La Jolla, California. The study implies that there is nothing particularly “magic” or special about those four chemicals that evolved on Earth, says Romesberg. “That’s a conceptual breakthrough,” he adds.
Normally, as a pair of DNA strands twist around each other in a double helix, the chemicals on each strand pair up: A bonds to T, and C bonds with G.
For a long time, scientists have tried to add more pairs of these chemicals, also known as bases, to this genetic code. For example, Benner first created ‘unnatural’ bases in the 1980s. Other groups have followed, with Romesberg’s lab making headlines in 2014 after inserting a pair of unnatural bases into a living cell.
But the latest study is the first to systematically demonstrate that the complementary unnatural bases recognise and bind to each other, and that the double helix that they form holds its structure.
Benner’s team, which includes researchers from various US companies and institutions, created the synthetic letters by tweaking the molecular structure of the regular bases. The letters of DNA pair up because they form hydrogen bonds: each contains hydrogen atoms, which are attracted to nitrogen or oxygen atoms in their partner. Benner explains that it’s a bit like Lego bricks that snap together when the holes and prongs line up.
By adjusting these holes and prongs, the team has come up with several new pairs of bases, including a pair named S and B, and another called P and Z2. In the latest paper, they describe how they combine these four synthetic bases with the natural ones. The researchers call the resulting eight-letter language ‘hachimoji’ after the Japanese words for ‘eight’ and ‘letter’. The additional bases are each similar in shape to one of the natural four, but have variations in their bonding patterns.
The researchers then conducted a series of experiments that showed that their synthetic sequences shares properties with natural DNA that are essential for supporting life.
To work as an information storage system, DNA has to follow predictable rules, so the team first demonstrated that, in a similar way to regular bases, the synthetic bases reliably formed pairs. They created hundreds of molecules of the synthetic DNA and found that the letters bound to their partners predictably.
They then showed that the structure of the double helices remained stable no matter what order the synthetic bases were in. This is important because for life to evolve, DNA sequences need to be able to vary without the whole structure falling apart. Using X-ray diffraction, the team showed that three different sequences of the synthetic DNA retained the same structure when crystallised.
This is a substantial advance, says Philipp Holliger, a synthetic biologist at the MRC Laboratory of Molecular Biology in Cambridge, UK, because other methods of expanding the genetic alphabet are not as structurally sound. Instead of chemicals that use hydrogen bonds to pair up, these other approaches use water-repelling molecules as their bases. These can be placed at intervals in-between the natural letters, but the structure of DNA breaks down if they are placed in a row.
Finally, the team showed that the synthetic DNA could be faithfully transcribed into RNA. “The ability to store information is not very interesting for evolution,” says Benner. “You have to be able to transfer that information into a molecule that does something.”
Converting DNA into RNA is a key step for translating genetic information into proteins, the workhorses of life. But some RNA sequences, known as aptamers, can themselves bind to specific molecules.
Benner’s team created synthetic DNA that codes for a certain aptamer and then confirmed that the transcription had occurred and the RNA sequence functioned correctly.
Holliger says that the work is an exciting starting point, but there is still a substantial distance to go before reaching a true eight-letter synthetic genetic system. One key question, for example, will be whether the synthetic DNA can be replicated by polymerases, the enzymes responsible for synthesizing DNA inside organisms during cell division. This has been demonstrated for other methods such as Romesberg’s, which uses water-repelling bases.
Variety of life
Still, Benner says that the work shows that life could potentially be supported by DNA bases with different structures from the four that we know, which could be relevant in the search for signatures of life elsewhere in the Universe.
Adding letters to DNA could also have more down-to-earth applications.
With more diversity in the genetic building blocks, scientists could potentially create RNA or DNA sequences that can do things better than the standard four letters, including functions beyond genetic storage.
For example, Benner’s group previously showed that strands of DNA that included Z and P were better at binding to cancer cells than sequences with just the standard four bases3. And Benner has set up a company which commercialises synthetic DNA for use in medical diagnostics.
The researchers could potentially use their synthetic DNA to create novel proteins as well as RNA. Benner’s team has also developed further pairs of new bases, opening up the possibility of creating DNA structures that contain 10 or even 12 letters. But the fact that the researchers have already expanded the genetic alphabet to eight is in itself remarkable, says Romesberg. “It’s already doubling what nature has.”
Israel has taken an important first step to the Moon following the launch of its privately-built Beresheet lunar lander, which entered space late yesterday aboard a SpaceX rocket.
The launch of Beresheet, which means “Genesis” or “In the beginning” in Hebrew, represents a significant milestone for both Israel and the private sector. The four-legged lunar lander represents the country’s first attempt to land on the Moon, but it also happens to be the first privately-funded lunar lander. Should the mission be successful, Israel would join an exclusive club of countries to have placed a lander on the Moon, the others being the United States, Russia, and China.
Beresheet was built by the Israeli not-for-profit SpaceIL, which is financed by donations from individual private sponsors. The company’s self-described vision is to “advance the discourse on science and engineering in Israel and to acquaint the young generation with the exciting opportunities in their future, which STEM studies make possible.”
To save on fuel, the spacecraft is taking a more convoluted route to the Moon than usual. As the Associated Press reports, Beresheet’s orbit around Earth will increase in size until the Moon’s gravitational tug is strong enough to capture the craft. An attempted landing at the Sea of Serenity—a large, dark, basaltic plain also known as a lunar mare—is likely to occur on April 11.
During its descent, the spacecraft will measure the Moon’s magnetic field, potentially revealing new details about iron core deep below, reports the New York Times. The landing sequence should take about 15 minutes—a delicate procedure that’ll be monitored by a joint group from the Israel Space Agency, NASA, and the Weizmann Institute of Science, reports the Jerusalem Post.
Once planted on the Moon, Beresheet will transmit photos and videos back to Earth, per SpaceNews. The probe is also equipped with a series of mirrors known as retroreflectors. Lasers from the surface of Earth will shine onto these mirrors and then reflect back to Earth, enabling scientists to measure the distance from Earth to Moon with high accuracy, the NYT reports.
Beresheet was originally designed to compete for the $20 million Google Lunar X Prize, which was discontinued on January 23, 2018 because “no team will make a launch attempt to reach the moon by the March 31, 2018, deadline,” in the words of X Prize founder and chairman Peter Diamandis. As a stipulation of the contest, lunar probes were required to move 500 meters (1,640 feet) by whichever means possible. Beresheet was supposed to achieve this by taking off and landing again nearby, but as the NYT pointed out, mission planners are no longer bound by this requirement. A decision to make the lunar hop won’t be made until after the landing in April, but there’s really nothing to gain from such a maneuver—one that could unnecessarily damage the probe.
The Beresheet mission will only last for a few days, as the lunar lander won’t be able to withstand the temperature extremes on the surface. But its legacy will endure in the form of its cargo; the probe contains hundreds of digital files, including the Torah, the Israeli flag, artwork, and an archive containing 30 million pages of information, the NYT reports.
“Congratulations to SpaceIL and the Israel Space Agency,” said NASA Administrator Jim Bridenstine in an agency press release. “This is a historic step for all nations and commercial space as we look to extend our collaborations beyond low-Earth orbit and on to the Moon.”
As for the SpaceX Falcon 9 that delivered the goods, its first stage booster made its third successful trip into space, and it landed successfully on a drone ship in the Atlantic ocean. In a tweet, however, Musk said the re-entry was not without incident.
Despite the challenge, Musk said the first stage rocket will be used for a fourth launch in April.