SACRAMENTO, Calif. Melted chocolate whirred around a melanger in California Cultured’s workshop, destined to be poured, hardened and broken into little squares. A tasty dessert, not yet legal to sell in the U.S. This chocolate didn’t come from cacao pods in South America or Africa. It was grown in laboratory flasks and metal tanks inside a West Sacramento industrial park, part of a growing regional trend. Yolo County has long been an agricultural hub. Now, its food tech companies are shaping what we eat in a different way. From Davis to Woodland and West Sacramento, California, the county has ...
A new effort to tackle climate change in Washington state just got a boost of cash.
On Tuesday, the state announced the results of its first “cap-and-invest” auction. It raised an estimated $300 million from polluting companies to fund projects such as building clean energy, reducing emissions from buildings and transportation, and adapting to the effects of rising global temperatures.
Washington has set a goal to cut its carbon emissions 95 percent below 1990 levels by 2050. In that effort, the state is putting a statewide limit on carbon emissions that gradually lowers over time. Under the cap-and-invest system, businesses buy “allowances” for the greenhouse gases they emit. But these permits will become more expensive over time — both an incentive to cut emissions and a method of raising money to address climate change.
In Washington’s first auction, held last week, the permits sold out, averaging about $49 per ton of carbon dioxide. The price was nearly double that of the most recent cap-and-trade auction held by California and Quebec, where the average was $28 per ton.
“The auction price is potentially higher because Washington’s program requires stronger climate pollution cuts than anywhere else in the country,” said Kelly Hall, the Washington director for the regional nonprofit Climate Solutions. “There is strong competition for these allowances.”
Washington’s auctions, which will take place four times a year, are projected to raise nearly $1 billion annually. At least 35 percent of the revenue is slated to go toward projects that benefit communities historically and disproportionately impacted by pollution. By the end of April, once the budgeting process is ironed out, the state will begin the process of setting up these various climate initiatives, said David Mendoza, the director of public engagement and policy at The Nature Conservancy in Washington.
The state’s cap-and-invest system, which began in January, follows in the footsteps of several state and regional cap-and-trade systems — with a few key changes. It relies less on carbon offsets and is also designed to address some equity concerns around cap-and-trade. In California, for example, studies have shown that pollution in Black and Latino communities actually increased in the years since that state’s cap-and-trade program began.
Washington’s system takes the novel approach of pairing cap-and-trade with a regulatory air quality program intended to crack down on large and small sources of pollution in the hardest-hit areas. While the state is still figuring out the details, last week, its Department of Ecology announced that it had identified 16 communities where it plans to concentrate efforts to improve air quality. South Seattle, Tacoma, and Spokane made the list, as did some rural areas.
Cap-and-trade programs are now up and running in more than a dozen U.S. states, including Oregon and a regional program in the Northeast. Still, the approach remains controversial. Washington’s program has gathered criticism for giving some large emitters, such as petroleum refineries and paper mills, a free pass. While these polluters can buy allowances at little or no cost for the next dozen years, they are still covered under the program’s declining cap on emissions.
The state is currently looking into linking up its cap-and-trade program with California and Quebec, which have already joined markets. In Washington, there’s a requirement that they can only link the markets if the state determines that it won’t result in a “negative impact on overburdened communities in either jurisdiction,” Mendoza said.
After researching the potential benefits — and consequences — of linking the programs, the state is expected to issue a recommendation on whether to join California’s market by the end of summer.
Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org
The U.S. Food and Drug Administration has approved a nasal spray developed by Pfizer as a means to quickly treat the painful symptoms associated with suffering a migraine.
The drug, Zavzpret, also known as zavegepant, was approved on Thursday for the treatment of acute migraines with or without an aura in adults. It’s expected to launch in July, Reuters reported.
ORLANDO, Fla. — Another four humans are headed back to Earth after spending more than five months in space with the SpaceX Crew-5 mission departing the International Space Station aiming for a Saturday night splashdown off the coast of Florida.
The quartet of mission commander and NASA astronaut Nicole Mann, pilot and NASA astronaut Josh Cassada, Japan Aerospace Exploration Agency astronaut Koichi Wakata and Roscosmos cosmonaut Anna Kikina climbed aboard Crew Dragon Endurance and detached from the forward-facing port of the ISS’s Harmony module at 2:20 a.m.
A Tyrannosaurus-Rex skeleton dating back 67-million years will be auctioned in Switzerland next month, marking the first such sale in Europe, the auction house said Saturday.
The skeleton dubbed Trinity will go under the hammer in Zurich on April 18, the Koller auction house said.
Towering 3.9 metres (12.8 feet) in the air, Trinity has been valued at between six to eight million Swiss francs ($6.5-8.7 million), according to the auction catalogue.
But Christian Link, in charge of natural history memorabilia at Koller, told AFP he believed that was a "very low estimate".
Trinity is "one of the most spectacular T-Rex skeletons in existence, a well-preserved and brilliantly restored fossil," the auction house said.
The sale would mark "the first time in Europe and only the third time worldwide (that) a skeleton of an entire T-Rex dinosaur of exceptional quality will be offered at auction".
Koller pointed to a 2021 study in the scientific journal Nature indicating that only 32 skeletons of adult T-Rex's -- one of the largest terrestrial predators ever to walk the Earth -- had been found worldwide.
'Incredibly well-preserved'
The Trinity skeleton is made up of bone material from three T-Rex specimens.
They were excavated between 2008 and 2013 from the Hell Creek and Lance Creek formations in Montana and Wyoming in the United States, the auction catalogue said.
The two sites are known for the discoveries of two other significant T-Rex skeletons that have gone to auction: Sue went under the hammer in 1997 for $8.4 million, and Stan, which took the world-record hammer price of $31.8 million at Christie's, in 2020.
Last year, Christie's withdrew another T-Rex skeleton -- also excavated from Montana -- days before it went to auction in Hong Kong, after doubts were reportedly raised about parts of the skeleton.
Link said Koller was intent on being open and transparent about the origins of the bones that make up Trinity.
Just over half of the bone material in the skeleton comes from the three Tyrannosaurus specimens, he said.
Trinity's skull meanwhile is "incredibly well-preserved" and comes from a single T-Rex specimen, according to Koller.
The skeleton was provided by a "private individual", and had been flown in nine large crates to Switzerland, for reassembly, Link said.
Auction sales of dinosaur skeletons and other fossils have raked in tens of millions of dollars in recent years, but experts have warned the trade could be harmful to science by putting the specimens in private hands and out of the reach of researchers.
Koller noted "the rare skeletons of adult T-Rex specimens which have been unearthed are almost all now in institutional collections."
"The Zurich auction is therefore an exceptional opportunity to acquire such a fossil of the highest quality," it said in a statement.
Link also said he would like to see a museum snap up Trinity, adding that several had already voiced interest.
The skeleton will be the star of an auction set to feature a number of other rare fossils, as well as a 2.145-kilo rock that is "among the largest Martian meteorites ever found on earth", according to the catalogue.
The Greek historian Herodotus reported over 2,000 years ago on a misguided forbidden experiment in which two children were prevented from hearing human speech so that a king could discover the true, unlearned language of human beings.
There are two common answers to why language should be learned or innate. For one, complex languages can often respond to local conditions as they are learned. A second answer is that complex communication is often difficult to produce even when individuals are born with some knowledge of the correct signals. Given that the ways honeybees communicate are quite elaborate, we decided to study how they learn these behaviors to answer this language question.
What is a waggle dance?
Astonishingly, honeybees possess one of the most complicated examples of nonhuman communication. They can tell each other where to find resources such as food, water, or nest sites with a physical “waggle dance.” This dance conveys the direction, distance and quality of a resource to the bee’s nestmates.
This video, from PBS Nova, shows bees getting their “waggle dance” on.
Essentially, the dancer points recruits in the correct direction and tells them how far to go by repeatedly circling around in a figure eight pattern centered around a waggle run, in which the bee waggles its abdomen as it moves forward. Dancers are pursued by potential recruits, bees that closely follow the dancer, to learn where to go to find the communicated resource.
The waggle dancer gives the instructions, and the followers learn where they can find the indicated resource. Dong Shihao, CC BY-ND
Longer waggle runs communicate greater distances, and the waggle angle communicates direction. For higher-quality resources such as sweeter nectar, dancers repeat the waggle run more times and race back faster after each waggle run.
Making mistakes
This dance is difficult to produce. The dancer is not only running – covering about one body length per second – while trying to maintain the correct waggle angle and duration. It is also usually in total darkness, amid a crowd of jostling bees and on an irregular surface.
Bees therefore can make three different types of mistakes: pointing in the wrong direction, signaling the wrong distance, or making more errors in performing the figure eight dance pattern – what researchers call disorder errors. The first two mistakes make it harder for recruits to find the location being communicated. Disorder error may make it harder for recruits to follow the dancer.
This video, from the Nieh lab, shows the bees’ “waggle run.”
Scientists knew that all bees of the species Apis mellifera begin to forage and dance only as they get older and that they also follow experienced dancers before they first attempt to dance. Could they be learning from practiced teachers?
A ‘forbidden’ bee experiment
My colleagues and I thus created isolated experimental colonies of bees that could not observe other waggle dances before they themselves danced. Like the ancient experiment described by Herodotus, these bees could not observe the dance language because they were all the same age and had no older, experienced bees to follow. In contrast, our control colonies contained bees of all ages, so younger bees could follow the older, experienced dancers.
We recorded the first dances of bees living in colonies with both population age profiles. The bees that could not follow the dances of experienced bees produced dances with significantly more directional, distance and disorder errors than the dances of control novice bees.
We then tested the same bees later, when they were experienced foragers. Bees who had lacked teachers now produced significantly fewer directional and disorder errors, possibly because they had more practice or had learned by eventually following other dancers. The dances of the older control bees from colonies with teachers remained just as good as their first dances.
This finding told us that bees are therefore born with some knowledge of how to dance, but they can learn how to dance even better by following experienced bees. This is the first known example of such complex social learning of communication in insects and is a form of animal culture.
Dance dialects are about distance
A mystery remained with respect to the bees that had lacked dance teachers early on. They could never correct their distance errors. They continued to overshoot, communicating greater distances than normal. So, why is this interesting to scientists? The answer may lie in how distance communication could adapt to local conditions.
There can be significant differences in where food is distributed in different environments. As a result, different honeybee species have evolved different “dance dialects,” described as the relationship between the distance to a food source and the corresponding waggle dance duration.
Interestingly, these dialects vary, even within the same honeybee species. Researchers suspect this variation exists because colonies, even of the same species, can live in very different environments.
If learning language is a way to cope with different environments, then perhaps each colony should have a distance dialect tailored to its locale and passed on from experienced bees to novices. If so, our teacher-deprived individual bees may never have corrected their distance errors because they acquired, on their own, a different distance dialect.
Normally, this dialect would be learned from experienced bees, but could potentially change within a single generation if their environmental conditions changed or if the colony swarmed to a new location.
The complex terrain bees must navigate while doing their dances. Dong Shihao, CC BY-ND
In addition, each colony has a “dance floor,” or the space where bees dance, with complex terrain that the dancers may learn to better navigate over time or by following in the footsteps of older dancers.
These ideas remain to be tested but provide a foundation for future experiments that will explore cultural transmission between older and younger bees. We believe that this study and future studies will expand our understanding of collective knowledge and language learning in animal societies.
A new species of lizard, of the genus Proctoporus, was found in a high Andean area of a national park in Peru, authorities said Friday.
This small species was located in the Otishi National Park, in the jungle area shared by the departments of Cusco and Junin, the Peruvian authority for protected areas announced.
This is a new specimen of the genus Proctoporus that includes species that inhabit yungas forests and high mountain grasslands on the Amazon slope of the Andes," said the National Service of Natural Areas Protected by the State (Sernanp), without specifying the date of discovery in an area located between 3,241 and 3,269 meters above sea level.
Among its characteristics, "its smooth scales on the head, which lack grooves or roughness, and the eyelids with an undivided translucent disc" stand out, the agency reported.
Males have a dark gray to black neck, breast, and belly, while females have a pale gray neck, breast, and belly with a diffused dark gray.
Peruvian authorities say that there are 20 species of Proctoporus, of which 18 are found in Peru. The discovery was made by a team of five researchers.
The world's first 3D printed rocket is scheduled to blast off from Florida on Saturday on the maiden flight of an innovative spacecraft billed as being less costly to produce and fly.
Liftoff of the rocket, Terran 1, had been scheduled for Wednesday at Cape Canaveral but was postponed at the last minute because of propellant temperature issues.
The new launch window for the rocket built by California aerospace startup Relativity Space to put satellites into orbit is from 1:00 pm to 4:00 pm (1800 GMT to 2100 GMT) on Saturday.
Terran 1 is set to reach low Earth orbit eight minutes after blastoff on a voyage intended to gather data and demonstrate that it can withstand the rigors of liftoff and space flight.
If the rocket manages to attain low Earth orbit, it will be the first privately-funded vehicle using methane fuel to do so on its first try, according to Relativity.
Terran 1 is not carrying a payload for its first flight but the rocket will eventually be capable of putting up to 2,755 pounds (1,250 kilograms) into low Earth orbit.
The rocket is 110-feet (33.5 meters) tall with a diameter of 7.5 feet (2.2 meters) and 85 percent of its mass is 3D printed with metal alloys, including the engines.
It is the largest ever 3D printed object according to the Long Beach-based company whose goal is to produce a rocket that is 95 percent 3D printed.
Terran 1 is powered by Aeon engines using liquid oxygen and liquid natural gas -- the "propellants of the future," according to Relativity, capable of eventually fueling a voyage to Mars.
Vulcan rockets being developed by United Launch Alliance and SpaceX's Starship use the same fuel.
Terran 1 has nine 3D printed Aeon 1 engines on its first stage and one 3D printed Aeon Vacuum engine on its second stage.
Built in 60 days
Relativity is also building a larger rocket, Terran R, capable of putting a payload of 44,000 pounds (20,000 kgs) into low Earth orbit.
The first launch of a Terran R, which is designed to be fully reusable, is scheduled for next year from Cape Canaveral.
A satellite operator can wait for years for a spot on an Arianespace or SpaceX rocket, and Relativity Space hopes to accelerate the timeline with its 3D printed rockets.
"Long-term, a major benefit of 3D printing is the ability to more rapidly democratize space due to the incredible cost effectiveness, radical flexibility and customization," the company said.
Relativity said its 3D printed rockets use 100 times fewer parts than a traditional rocket and a Terran 1 and a Terran R can be built from raw materials in just 60 days.
Relativity has already signed commercial launch contracts worth $1.65 billion, mostly for the Terran R, according to CEO Tim Ellis, who cofounded the company in 2015.
"Medium-heavy lift is clearly where the biggest market opportunity is for the remaining decade, with a massive launch shortage in this payload class," Ellis tweeted.
Plastic pollution in the world's oceans has reached "unprecedented levels" over the past 15 years, a new study has found, calling for a legally binding international treaty to stop the harmful waste.
Ocean plastic pollution is a persistent problem around the globe -- animals may become entangled in larger pieces of plastic like fishing nets, or ingest microplastics that eventually enter the food chain to be consumed by humans.
Research published on Wednesday found that there are an estimated 170 trillion pieces of plastic, mainly microplastics, on the surface of the world's oceans today, much of it discarded since 2005.
"Plastic pollution in the world's oceans during the past 15 years has reached unprecedented levels," said the study, published in open-access journal PLOS One.
The amounts were higher than previous estimates, and the study found that the rate of plastic entering the oceans could accelerate several-fold in the coming decades if left unchecked.
Researchers took plastic samples from over 11,000 stations around the world focusing on a 40-year period between 1979 and 2019.
They found no trends until 1990, then a fluctuation in trends between 1990 and 2005. After that, the samples skyrocket.
"We see a really rapid increase since 2005 because there is a rapid increase in production and also a limited number of policies that are controlling the release of plastic into the ocean," contributing author Lisa Erdle told AFP.
The sources of plastic pollution in the ocean are numerous.
Fishing gear like nets and buoys often end up in the middle of the ocean, dumped or dropped by accident, while things like clothing, car tires and single-use plastics often pollute nearer to the coast.
They eventually break down into microplastics, which Erdle said can look like "confetti on the surface of the ocean".
'Flood of toxic products'
On current trends, plastic use will nearly double from 2019 across G20 countries by 2050, reaching 451 million tonnes each year, according to the report, jointly produced by Economist Impact and The Nippon Foundation.
In 1950, only two million tonnes of plastic were produced worldwide.
Recycling, even in countries with advanced waste management systems, has done little to help the pollution problem since just a small percentage of plastics are properly recycled and much often ending up in landfills instead.
If landfills are not properly managed, plastic waste can leech into the environment, eventually making its way to oceans.
"We really see a lack of recycling, a flood of toxic products and packaging," Erdle said.
The rates of plastic waste were seen to recede at some points between 1990 and 2005, in part because there were some effective policies in place to control pollution.
That includes the 1988 MARPOL treaty, a legally binding agreement among 154 countries to end the discharge of plastics from naval, fishing and shipping fleets.
But with so much more plastic being produced today, the study's authors said a new, wide-ranging treaty is needed to not only reduce plastic production and use but also better manage its disposal.
"Environmental recovery of plastic has limited merit, so solution strategies must address those systems that restrict emissions of plastic pollution in the first place," the study said.
Last year, 175 nations agreed to end plastic pollution under a legally binding United Nations agreement that could be finalized as soon as next year.
Among the key actions under negotiation are a global ban on single-use plastics, a "polluter pays" scheme, and a tax on new plastic production.
The total weight of the plastic pollution detected in the ocean today is estimated at 2.3 million tonnes, the PLOS study said.
It examined samples in the North Atlantic, the South Atlantic, the North Pacific, the South Pacific, the Indian and Mediterranean oceans.
With his mustache caked in icicles and frozen droplets, glaciologist Peter Neff shows his 220,000 TikTok followers a sample of old ice excavated from Antarctica's Allan Hills.
The drop-shaped fragment encapsulates tiny air bubbles, remnants of 100,000-year-old atmosphere.
The greenhouse gases trapped inside carry precious information on Earth's past climate, explains @icy_pete as he brings the translucid nugget closer to the camera.
A growing number of scientists are leveraging the short-form video app TikTok to boost literacy on climate change, campaign for action or combat rampant disinformation online.
Some have gone viral on one of Gen Z's favourite platforms.
"TikTok allows me to give people a lens through which they can embody the experience of being a climate scientist in Antarctica," Neff told AFP.
"I share my insider perspective on how we produce important records of past climate without having to spend too much time on editing and playing all the games to make perfect content."
Neff is one of 17 tiktokers and instagrammers listed in the 2023 Climate Creators to Watch, a collaboration between startup media Pique Action and the Harvard School of Public Health.
'We have a responsibility'
Some experts are also using the platform as a megaphone for climate action.
NASA climate scientist Peter Kalmus started posting videos on the platform after he was arrested in a civil disobedience action organized by the Scientist Rebellion group in Los Angeles in April 2022.
"When you engage in civil disobedience, you're taking a risk in order to try to have a positive benefit on society," Kalmus told AFP.
"So you want that civil disobedience action to be seen by as many people as possible."
Kalmus's most viral video to date shows him locked to the gates of the Wilson Air Center in Charlotte, North Carolina, delivering a speech to protest about carbon dioxide (CO2) emissions from private jets.
The researcher sees his @climatehuman channel as a way to motivate people, especially younger demographics, to become activists.
He also wants to ensure the spread of accurate information on the climate emergency.
Bringing climate literacy on TikTok is crucial to counterbalancing climate-related misinformation, according to Doug McNeall, a climate scientist at the UK Met Office and lecturer at the University of Exeter.
"Climate scientists need to show up," said McNeall, active on TikTok under the username @dougmcneall.
"We have a responsibility to make sure that the people promoting climate misinformation on purpose don't get a free header," he said, using a football metaphor.
An analysis by US-based public interest think tank Advance Democracy found the number of views of TikTok videos using seven hashtags associated with climate change denialism such as "#ClimateScam" and "#FakeClimateChange" increased by more than 50 percent over the course of 2022, to 14 million views.
In February this year, Doug McNeall and other experts such as Alaina Woods (@thegarbagequeen) posted videos flagging unfounded theories flourishing on the platform about so-called "15-minute cities".
'Normal people'
The concept is simple -- an urban setting in which all amenities such as parks and grocery are accessible within a quarter of an hour's walk or bike ride from a person's home, reducing CO2 emissions from urban car commutes.
But searching for "15-minute city" on TikTok turns up mostly scornful videos claiming the schemes will restrict residents' movements and fine people for leaving their neighborhoods.
To push back against misinformation on TikTok, scientists say they must first grab the users' attention.
"My strategy to interest young people on TikTok is similar to my approach to teaching," said Jessica Allen, a lecturer in renewable energy engineering at Australia's Newcastle University.
"I try to engage my audience with memes or other funny things rather than just delivering dry information," she told AFP.
On TikTok, Allen tries to popularize the chemistry behind renewable energy, which is essential to achieving carbon neutrality.
When she isn't sharing clips breaking down complex chemical reactions, @drjessallen may be posting TikTok dances in her lab.
"Scientists are normal people who can have fun," she said.
Indeed, deconstructing the image of scientists stuck in their ivory towers can help climate experts reach a larger audience.
"We often make the mistake of trying to make science seem perfect and not flawed like we all are," Neff said.
"On TikTok, we show the human foundation of our research."
NASA will announce the names next month of the four astronauts -- three Americans and one Canadian -- who will fly around the Moon next year, the head of the US space agency said Thursday.
NASA administrator Bill Nelson said the crew members of the mission known as Artemis 2 would be revealed on April 3.
"Astronauts -- three from America and one from Canada -- will fly around the moon and they'll test NASA's Space Launch System, which is our rocket, and the spacecraft called Orion," Nelson said.
The first Artemis mission wrapped up in December with an uncrewed Orion capsule returning safely to Earth after a 25-day journey around the Moon.
Artemis 2, scheduled to take place in late November 2024, will take a four-person crew around the Moon but without landing on it.
The ambitious program aims to return humans to the Moon for the first time since the historic Apollo missions ended in 1972.
Artemis 3, scheduled for about 12 months after Artemis 2, will see astronauts land for the first time on the south pole of the Moon.
NASA hopes to establish a lasting human presence on the lunar surface and later launch a years-long trip to Mars.
As part of the Artemis missions, NASA is planning to send a woman and a person of color to the Moon for the first time.
Only 12 people -- all of them white men -- have set foot on the Moon.
The space agency also announced Thursday that it will unveil a prototype in Houston on March 15 of the next generation spacesuits being made by Axiom Space that the NASA astronauts will wear on the Moon's surface.
Nelson welcomed the $27.2 billion requested for NASA in President Joe Biden's 2024 budget on Thursday and noted it was a 7.1 percent increase over the previous fiscal year.
"This budget request reflects the administration's confidence in NASA and its faith in the world's finest workforce," he said.
The Third International Summit on Human Genome Editing, a three-day conference organized by the Royal Society, the U.K. Academy of Medical Sciences, the U.S. National Academies of Sciences and Medicine and The World Academy of Sciences, was held this week in March 2023 at the Francis Crick Institute in London. Scientists, bioethicists, physicians, patients and others gathered to discuss the latest developments on this technology that lets researchers modify DNA with precision. And a major topic at the summit was how to enforce research policies and ethical principles for human genome editing.
One of the first agenda items was how to regulate human genome editing in China in light of its misuse in 2018, when scientists modified the DNA of two human embryos before birth to have resistance against HIV infection. The controversy stems from the fact that because the technology is relatively early in its development, and its potential risks have not been reduced or eliminated, editing human embryos in ways they could pass on to their own offspring could lead to a variety of known and unknown adverse complications. The summit speakers noted that while China has updated its guidelines and laws on human genome editing, it failed to address privately funded research – an issue other countries also face. Many countries, including the U.S., do not have sufficiently robust regulatory frameworks to prevent a repeat of the 2018 scandal.
We are a biochemist and a geneticist who teach and conduct research in genomics and ethics at the Rochester Institute of Technology. As in our classrooms, debate about genome editing continues in the field.
Listening to different perspectives about CRISPR could lead to more balanced discussions about how to regulate it.
What is genome editing?
The human genome typically consists of 23 pairs of chromosomes made of approximately 3.2 billion nucleotides – the building blocks of DNA. There are four nucleotides that make up DNA: adenine (A), thymine (T), guanine (G) and cytosine (C). If the genome were a book, each chromosome would be a chapter, each gene on a particular chromosome would be a paragraph and each paragraph would be made of individual letters (A, T, G or C).
One can imagine a book with over 3 billion characters might need editing to correct mistakes that occurred during the writing or copying processes.
Genome editing is a way for scientists to make specific changes to the DNA in a cell or in an entire organism by adding, removing or swapping in or out one or more nucleotides. In people, these changes can be done in somatic cells, those with DNA that cannot be inherited by offspring, or in gamete cells, those containing DNA that can be passed on to offspring. Genome editing of gamete cells, which includes egg or sperm, is controversial, as any changes would be passed on to descendants. Most existing guidelines and policies prohibit its use at this time.
Geneticist Jennifer Doudna is one of the co-inventors of CRISPR/Cas9.
How CRISPR works
In 2012, scientists published a groundbreaking study demonstrating how CRISPR, or Clustered Regularly Interspaced Short Palindromic Repeats, can be used to accurately change specific DNA sequences.
CRISPR’s natural origins are as a kind of immune response for bacteria. Bacteria that can be infected with viruses have evolved mechanisms to combat them. When a bacterium is infected with a particular virus, it keeps a small piece of the viral DNA sequence called a “spacer” in its own genome. This spacer is an exact match to the viral DNA. Upon subsequent infection, the bacterium is able to use the spacer to recruit a scissorlike protein called Cas9 that can sever new viral DNA attempting to integrate into the bacterium’s genome. This cut to the genetic material prevents the virus from replicating and killing its bacterial host.
After this discovery, scientists were able to fine-tune the system in the lab to be highly precise. They can sever DNA from a variety of cells, including human cells, at a specific location in the genome and subsequently edit it by adding, removing or swapping nucleotides. This is similar to adding or removing letters and words from a book.
This technology has the potential to treat diseases that have genetic origins. One of the summit’s sessions covered CRISPR’s ongoing experimental use to treat patients with sickle cell anemia and beta-thalassemia, two blood disorders caused by mutations in the genes. Notably, genetic modification to treat sickle cell anemia and beta-thalassemia involves editing somatic cells, not germline cells. But as the summit speakers noted, whether these likely expensive therapies will be accessible to the people who need them most, especially in low- and middle-income countries, is a problem that requires changes to how treatments are sold.
Scientists have been testing ways to use CRISPR/Cas9 to treat sickle cell anemia.
Ethics of human genome editing
Many questions remain concerning the safety of genome editing, along with its potential to promote eugenics and exacerbate inequities and inequality.
A number of the summit’s sessions involved discussion on the ethics and regulation of the use of this tool. While the landmark 1979 Belmont Report outlined several ethical pillars to guide human research in the U.S., it was published before human genome editing was developed. In 2021, the World Health Organization issued recommendations on human genome editing as a tool to advance public health. There is no current international law governing human genome editing.
There is still a debate regarding how to use this technology. Some people equate genome editing to interfering with the work of God and argue that it shouldn’t be used at all, while others recognize its potential value and weigh that against its potential risks. The latter focuses on the fundamental question of where to draw the line between which applications are considered acceptable and which are not. For example, some people will agree that using genome editing to modify a defective gene that may lead to an infant’s death if untreated is acceptable. But these same people may frown upon the use of genome editing to ensure that an unborn child has specific physical features such as blue eyes or blond hair.
Nor is there consensus about what diseases are desirable targets. For example, it may be acceptable to modify a gene to prevent an infant’s death but not acceptable to modify one that prevents a disease later in life, such as the gene responsible for Huntington’s disease.
The potential for positive applications of human genome editing is both numerous and tantalizing. But establishing informed regulatory legislation everyone can agree on is and will continue to be a challenge. Conferences such as the human genome editing summit are one way to continue important discussions and educate the scientific community and the public on the benefits and risks of genome editing.
NASA recently announced the discovery of a new, Earth-sized planet in the habitable zone of a nearby star called TOI-700. We aretwo of the astronomers who led the discovery of this planet, called TOI-700 e. TOI-700 e is just over 100 light years from Earth – too far away for humans to visit – but we do know that it is similar in size to the Earth, likely rocky in composition and could potentially support life.
You’ve probably heard about some of the manyotherexoplanetdiscoveries in recent years. In fact, TOI-700 e is one of two potentially habitable planets just in the TOI-700 star system.
Habitable planets are those that are just the right distance from their star to have a surface temperature that could sustain liquid water. While it is always exciting to find a new, potentially habitable planet far from Earth, the focus of exoplanet research is shifting away from simply discovering more planets. Instead, researchers are focusing their efforts on finding and studying systems most likely to answer key questions about how planets form, how they evolve, and whether life might exist in the universe. TOI-700 e stands out from many of these other planet discoveries because it is well suited for future studies that could help answer big question about the conditions for life outside the solar system.
Specific methods for detecting exoplanets, like the transit method, which looks for a dip in the light coming from a distant star as a planet passes in front of it, have led to an explosion in the number of known exoplanets.
From 1 to 5,000
Astronomers discovered the first exoplanet around a Sun-like star in 1995. The field of exoplanet discovery and research has been rapidly evolving ever since.
At first, astronomers were finding only a few exoplanets each year, but the combination of new cutting-edge facilities focused on exoplanet science with improved detection sensitivity have led to astronomers’ discovering hundreds of exoplanets each year. As detection methods and tools have improved, the amount of information scientists can learn about these planets has increased. In 30 years, scientists have gone from barely being able to detect exoplanets to characterizing key chemical clues in their atmospheres, like water, using facilities like the James Webb Space Telescope.
Today, there are more than 5,000 known exoplanets, ranging from gas giants to small rocky worlds. And perhaps most excitingly, astronomers have now found about a dozen exoplanets that are likely rocky and orbiting within the habitable zones of their respective stars.
Astronomers have even discovered a few systems – like TOI-700 – that have more than one planet orbiting in the habitable zone of their star. We call these keystone systems.
The TOI-700 system has a large habitable zone, and the newly discovered TOI-700 e, not shown in this image, orbits the star along the inner edge of the habitable zone.
By taking precise measurements of the changes in light, we were able to determine that at least three small planets are in the TOI-700 system, with hints of a possible fourth. We could also determine that the third planet from the star, TOI-700 d, orbits within its star’s habitable zone, where the temperature of the planet’s surface could allow for liquid water.
The Transiting Exoplanet Surveying Satellite observed TOI-700 for another year, from July 2020 through May 2021, and using these observations our team found the fourth planet, TOI-700 e. TOI-700 e is 95% the size of the Earth and, much to our surprise, orbits on the inner edge of the star’s habitable zone, between planets c and d. Our discovery of this planet makes TOI-700 one of only a few known systems with two Earth-sized planets orbiting in the habitable zone of their star. The fact that it is relatively close to Earth also makes it one of the most accessible systems in terms of future characterization.
New tools, like the James Webb Space Telescope, can provide clues about life on distant planets, but with thousands of scientific questions to answer, efficient use of time is key.
With the successful launch of the James Webb Space Telescope, astronomers are now able to start characterizing the atmospheric chemistry of exoplanets and search for clues about whether life exists on them. In the near future, a number of massive, ground-based telescopes will also help reveal further details about the composition of planets far from the solar system.
But even with powerful new telescopes, collecting enough light to learn these details requires pointing the telescope at a system for a long period of time. With thousands of valuable scientific questions to answer, astronomers need to know where to look. And that is the goal of our team, to find the most interesting and promising exoplanets to study with the Webb telescope and future facilities.
Earth is currently the only data point in the search for life. It is possible alien life could be vastly different from life as we know it, but for now, places similar to the home of humanity with liquid water on the surface offer a good starting point. We believe that keystone systems with multiple planets that are likely candidates for hosting life – like TOI-700 – offer the best use of observation time. By further studying TOI-700, our team will be able to learn more about what makes a planet habitable, how rocky planets similar to Earth form and evolve, and the mechanisms that shaped the solar system. The more astronomers know about how star systems like TOI-700 and our own solar system work, the better the chances of detecting life out in the cosmos.
