In recent years, there has been a lot of excitement about the potential for studying human diseases in what are called "organoids." These small patches of tissue, formed using stem cells, appear to produce many of the same cell types and at least some of the structures normally formed in actual organs, and thus can provide a better model for diseases that rely on the sometimes complex interactions among multiple specialized cell types that are a feature of the human body.

But even the most sophisticated organoids lack a lot of the features of a real human body. This is especially true for brain organoids, which don't form any of the connections with specialized brain structures needed to behave "normally." On Wednesday, a research group at Stanford University described a possible way to study brain organoids in a somewhat more natural context: They genetically wiped out a large portion of the mouse brain and replaced it with human brain organoid cells.

The replacements

Organoids, because they adopt a three-dimensional tissue structure and consist of various specialized cells, provide a much better model for an intact tissue than simply having a bunch of disassociated cells lying flat on a culture dish. But they still have a lot of limitations—they're not hooked up to a circulatory system that allows the liver to process chemicals the organoid produces and don't have immune cells moving through them, to give just a couple of examples.

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Our basic understanding of core-collapse supernovae hasn't changed in decades. Large stars burn through all the fuel at their cores and start creating heavier elements in reactions that consume energy. The lack of energy from these reactions allows gravity to pull the interior of the star in on itself, collapsing it into a neutron star or black hole. The energy released by this process then blows the remainder of the star apart.

And, generally, that's right. But there's an entire busload of devils in the details. The statistics of supernovae that we've observed indicate that the model may be seriously incomplete. And on the theoretical side, there are still plenty of uncertainties, including over some of the basics, such as whether all core collapses actually result in a supernova.

A paper being released by Physical Review D provides what might be a potential explanation for the discrepancy: flavor-changing neutrinos. Neutrinos play a key role in our current models of supernovae, and right now, those models don't take into account one of neutrinos' most striking features: their ability to change identity.

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On Tuesday, Google announced AlphaGenome Atlas, a resource that attempts to predict the consequences of every possible single-base variant in the human genome. The human genome is about 3 billion bases long, so trying the other three DNA bases that don't appear in our reference genome means sending a total of 9 billion bases through AlphaGenome software.

AlphaGenome is designed to identify potential functions of non-coding DNA, which does not encode proteins but makes up the vast majority of the human genome. Some of this non-coding DNA is essential for controlling the activity of the protein-coding portion—it tells the cell where and when to make messenger RNAs, how to process them into mature protein-coding forms, and so on. But much of it appears to be little more than the remains of viruses and other molecular parasites.

Being able to identify the functional portion is very useful, as is having all the analysis done by a single software package. But until biologists start to use it heavily (assuming they do), it won't be clear what AlphaGenome offers beyond what we could have gotten out of its training data.

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Late last week, word started leaking that the National Institutes of Health (NIH) had reached an agreement with the Department of Defense that would see part of the NIH's budget used to fund research at the Department of Defense. So, on the Friday just prior to a US holiday weekend, the Department of Defense released a copy of the agreement and confirmed that it had been signed roughly a month earlier. The move is striking for a number of reasons, ranging from the existing budget disparities between the two parties involved to the fact that the money would be used for projects that the current NIH leadership has explicitly rejected.

The agreement itself sets up a system where the NIH would transfer money to the Department of Defense to fund staff and projects that would "support the advanced development of medical countermeasures against pandemic influenza, chemical, biological, radiological, and nuclear (CBRN) threats, and emerging infectious diseases." The money would come out of the budget for the NIH's National Institute of Allergy and Infectious Diseases, or NIAID, to which Congress has allocated $6.6 billion in 2026. The agreement is set to run for a decade.

Left unspecified is just how much of the NIAID budget will be spent on Defense projects. Reporting by Nature suggests that the Department of Defense was looking for up to a third of its total budget but was being told to settle for about 10 percent. There's obviously an enormous disparity between the budgets of these two agencies, given that the 2026 Defense budget is roughly $1 trillion. That budget is under considerable strain, however, due to the open-ended nature of the conflict with Iran. The deal has also been announced at a time when the NIH has been struggling to issue sufficient grants to use the money that Congress allocated to it.

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On Thursday, a US District Court in Oregon ordered the US government to restart the process of approving wind projects. All new wind development in the US has been on hold since August 2025, when the Department of Defense (DoD) stopped participating in a process that allows it to compel developers to alter projects in order to limit their interference with radar equipment. The court ruled, however, that the DoD's national security claims did not allow it to opt out of a process that is legally mandated.

The Trump administration has made many attempts to block wind development, both offshore and land based. Its attempts to stop offshore wind included the same approach at issue in this case: Claim that drone developments mean that radar interference by wind turbines creates a national security risk. The courts were not sympathetic to this claim, including in cases where judges examined a classified report that the DoD was using to justify blocking offshore wind construction. As a result, the administration has turned to paying companies not to pursue wind development.

In parallel, the government was pursuing a similar approach for onshore wind. Here, a law lays out a process for the DoD to evaluate any problems posed by wind turbines and negotiate changes to planned wind farms with the developers. As laid out in the new decision, the government simply stopped participating in this process in August 2025, first by refusing to sign off on previously negotiated agreements, and later by refusing to draft agreements entirely. Eventually, it simply refused to participate in negotiations at all. This has brought a halt to all wind development in the US.

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When the history of our ancestry is written, the fact that we've interbred with some of our closest relatives, the Neanderthals and Denisovans, will have a central role. And it will be tempting to write it as a very tidy story: Once we got genomes from these other groups, it was possible to identify the sequences in our genomes that we shared with them.

But in reality, as scientists started poking large enough collections of data, there were regular hints of some strange ancestry in our genomes. It was hard to pin down, though, at least in part because the 2 percent on average of Neanderthal DNA found in many populations does not guarantee that any two individuals will have the same 2 percent. So having the genomes of those two groups made sense of some things researchers had already been seeing.

But knowing what we do about Neanderthal and Denisovan DNA is now allowing researchers to answer a somewhat different question: Is there anything else? Using recently developed analytical techniques, they find evidence of a third lineage that we apparently interbred with before any modern humans left Africa. Again, there were hints of this earlier, but so far, there's been no genome from a modern human relative to help us understand the details—the source of this DNA remains a "ghost lineage."

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In a widely expected move, a committee organized by the Food and Drug Administration (FDA) has voted to endorse removing restrictions on the manufacture of peptides for human use. Thursday's panel meeting saw a sharply divided group recommend lifting limits on four peptides; votes on three additional peptides are scheduled for today. The move comes despite a continuing lack of evidence regarding their safety and effectiveness.

The move had been telegraphed months earlier as peptide enthusiast and Health and Human Services Secretary Robert F. Kennedy Jr. took steps to ensure this outcome.

Like proteins, peptides are composed of amino acids that are chemically linked into a chain. Peptides differ merely by length; they're often 10–20 amino acids long, in contrast to proteins, which can be hundreds or thousands. Some of them, such as insulin, are specifically made by targeted processing of a protein into shorter fragments, and the resulting peptide interacts with receptors that have evolved to send signals to cells based on its levels.

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A couple of decades after the discovery of systems that could selectively target DNA, we're starting to see the first therapies based on gene editing. One challenge these developments have faced is safety. While we can make them pretty specific to the gene we want edited, the human genome is very large, and even rare DNA sequences can appear a couple of times by chance.

As a result, all the original gene-editing systems had known rates of what are called off-target effects, in which they simply edit the wrong sequence. This may be a low-probability event, but edit enough cells—and therapies generally have to edit many—and errors become inevitable.

A lot of effort has gone into finding ways to minimize or eliminate off-target edits. In a recent issue of Nature, researchers described modifying the AI protein-folding software AlphaFold to help identify key areas of gene-editing proteins responsible for off-target effects. Those areas were then modified to reduce the problems.

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Climate change is being driven largely by the greenhouse gases we've pumped into the atmosphere, which trap more of the Sun's energy there. That added energy increases the odds of extreme events: longer, more intense heat waves and droughts, interspersed with excessive precipitation. But these sorts of events have happened in the past—how can we tell if any given weather disaster has been made more likely by the climate?

It's a question with implications for everything from building codes to disaster preparedness. And there's some good news: According to a report released by the US National Academies of Science on Thursday, the field of climate attribution is growing increasingly mature and can answer some questions for us with far greater confidence than it could just a decade ago. The report also notes that there are still important limits and suggests steps to address them.

Overall, this makes it clear that climate attribution is normal, mainstream science. And the fossil fuel industry views that as a problem, as it could make it easier to hold companies liable for damages. This has triggered a backlash that has Republicans in Congress and state governments threatening the National Academies' funding.

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Over decades, researchers in the US government and programs it sponsored built up a tremendous number of climate resources, from comprehensive analyses to massive datasets to basic explainers meant to inform the public. And people within the government built the climate.gov website to make it all accessible. But if you try to navigate there today, you get redirected to the climate page of the National Oceanic and Atmospheric Administration, and are greeted with the following message:

In compliance with Executive Order 14303 (“Restoring Gold Standard Science”), the White House Office of Science and Technology Policy’s June 23, 2025 Memorandum (“Agency Guidance for Implementing Gold Standard Science in the Conduct & Management of Scientific Activities”), 15 USC § 2904 (“National Climate Program”), 15 USC § 2934 (“National Global Change Research Plan”), and 33 USC § 893a (“NOAA Ocean and Atmospheric Science Education Programs”), you have been redirected to NOAA.gov. Future research products previously housed under Climate.gov will be available at NOAA.gov/climate and its affiliate websites.

Climate.gov was essentially gone, and the team that deleted implied that it happened because climate research somehow failed to uphold what the administration was calling "gold standard science."

But the people who put together climate.gov didn't go away. While the government didn't hesitate to delete inconvenient climate information, dedicated volunteers outside the government managed to preserve copies of much of the material, which the federal government is prohibited from copyrighting. The volunteers and former climate.gov admins got together and launched climate.us. On Tuesday, the team announced that it had completed the project to restore everything lost when climate.gov shut down.

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In May, the federal government announced without warning that it would take apart a network of ocean monitoring systems that it had spent over $350 million to build. No reason was given for the decision to shut down the Ocean Observatories Initiative (OOI), but suspicion immediately focused on the network's role in tracking climate change.

But the OOI also provides data that's useful for weather forecasting and fisheries management, leading to widespread opposition. Today, it appears that the opposition has won, as the government will announce that it's reversing the decision. The big remaining question is how much damage the OOI took during the intervening month.

As of now, there is no formal statement available from the federal government. However, The New York Times reports that the decision will be announced later today, and Ars received a statement from Zoe Lofgren, the ranking Democrat on the House Science Committee, indicating that the decision has been made.

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Quantum computing news usually picks up near the end of the year, as companies try to provide evidence that they are hitting benchmarks on time. However, there have been interesting announcements as the summer starts this year, from incremental progress to attention-grabbing promises. As we did earlier this month, Ars has a rundown of some of the most significant announcements.

These include a promise of useful, error-corrected quantum computing as soon as 2028, details on an updated trapped ion processor, and a case in which claims of quantum supremacy have been cut back a bit thanks to advances in more traditional algorithms.

2028 is remarkably soon

Many people in the field expect that useful quantum computers are still about five to 10 years away. While there may be a few useful algorithms that can be run on existing error-prone hardware, almost all of the interesting problems that quantum computing can be applied to will require some form of error correction enabled by linking a small collection of hardware qubits together into what's called a logical qubit. Logical qubits include the redundant storage of information along with neighboring qubits that can be measured to determine when errors occur and how to fix them.

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Last week, we looked at a new study of the origin of complex cells, one that showed that our ancestors' genomes were pieced together from bits and pieces of multiple species. It put a spotlight on a phenomenon called horizontal gene transfer, in which a gene from one species is incorporated into the genome of a distantly related species. The frequency of horizontal gene transfer means that, in addition to the neatly branching trees that relate species by common descent, there are small threads connecting distant branches of the tree of life.

It's easy to see why horizontal gene transfer would be common among microbes. They often live in complex communities that are likely awash in the DNA of dead and damaged cells. Plus, bacteria and archaea lack a membrane between their DNA and the rest of the cell, making it easier for environmental DNA to find its way to the genome.

However, a new study this week shows that horizontal gene transfers are remarkably common even in multicellular animals. And it does so by examining the genomes of multiple cockroach species, which have had bits of bacterial DNA for millions of years.

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