As it turns out, at least one of the island’s mammoths had a string of genetic defects. There were issues with male fertility, neurological development, insulin signalling and even the ability to smell flowers. This suggests the mammoths might have been hurt by their small population size (300 to 500) and isolation from the Siberian mainland, reducing their long-term chances of survival.

This doesn’t provide a full explanation for why woolly mammoths finally died out. Most of them (along with other species) were wiped out by a changing climate that eliminated the tundra they needed to survive. It paints a clearer picture, though, and suggests technology could help solve other prehistoric mysteries.

Company chief Anne Wojcicki didn’t have definitive explanations for the shrinking sales in a chat with CNBC, but did speculate that privacy was “top of mind” for customers and might have been a factor. Cold cases like the Golden State Killer appear to have been solved using online DNA databases — there might be a fear of sensitive genetic info falling into the wrong hands. Wojcicki also suspected that fear of a US recession might lead people to cut back on unnecessary expenses, and a home DNA test could easily be one of the first things to go.

The company isn’t the only one facing trouble. Veritas Genetics closed its US business in late 2019, while Illuminia warned that the entire market was down last summer after witnessing a drop in demand for its DNA sequencing machines. In that regard, 23andMe is acknowledging the reality that DNA testing isn’t as hot a market as it was in previous years.

How does a DNA testing service like 23andMe convince you to shell out more when the base results are the same? By rolling out the red carpet, it seems. The company has introduced a $499 VIP Health + Ancestry Service that includes two Health + Ancestry kits, faster lab processing, overnight shipping, a year of “premium” support and, crucially, a 30-minute one-on-one walkthrough of your Ancestry results. Effectively, 23andMe wants to offer a concierge for your genes.

The policy generally limits law enforcement to considering genealogy sites when a candidate sample belongs to a possible culprit, or when a likely homicide victim is unidentified. Prosecutors can greenlight the use of these sites for violent crimes beyond murder and sexual assault, but only when the circumstances create a “substantial and ongoing threat” to the public. Agencies can’t use the sites unless a sample has first been uploaded to the FBI’s DNA profile database and hasn’t produced a match. Also, the investigators in the relevant jurisdiction need to have followed “reasonable investigative leads,” and case info need to be entered into national databases for missing people and violent criminals.

There’s more even after meeting these rules. FBI lab officials have to evaluate the suitability of a sample and suggest “reasonable” alternatives to genealogy sites when possible. The investigators must then agree with prosecutors that genealogy is a suitable option. If they get the go-ahead, they have to explicitly identify themselves as law enforcement to these sites, use only sites that make clear the police have access, keep data as private as possible and obtain consent from third parties before collecting any reference samples. Any analysis on a covertly-obtained sample will require a search warrant, and samples have to be limited to the identification purposes necessary for the case.

If there’s a lead, the case holders have to turn back to conventional investigation methods.

Any genealogy profiles and account info will be treated as confidential, and there are tight controls on what happens if a suspect faces charges. If they’re charged after a genealogy profile has been entered into an open DNA database, the investigators will have to remove that profile. Samples, profiles and accounts have to be destroyed once there’s a verdict, while Department elements have to routinely document instances where genealogy sites were used, including the sites in question and the ultimate outcome.

The temporary policy takes effect November 1st, while a final policy is due in 2020. It’s safe to say there’s a clear goal at this stage — the DOJ wants law enforcement to avoid using genealogy sites as much as possible, and leave an extensive record of what happened. It might not completely alleviate privacy concerns, but it could prevent obvious abuses of sensitive genetic data.

In lab testing, this had dramatic effects on progeria, a premature aging disease. Mice treated with SATI lived about 45 percent longer while seeing reduced aging effects. That would translate to over a decade for a human affected by the same condition.

As is often the case with gene editing treatments, there’s still work to be done. The Salk team wanted to make SATI more efficient by boosting the number of cells that can incorporate the healthier DNA. The lab experiment was also a proof of concept, and there’s a long road between that and clinical trials. If it works as hoped, though, it could help doctors mitigate (or ideally, eliminate) a wide variety of mutation-based diseases.

The team found three bacteriophages that could be useful (including one from a rotting eggplant) and modified them to maximize their ability to target and wipe out the bacteria strain. Once this was ready, they gave the teen twice-daily infusions as well as surface treatments on the skin lesions resulting from the infection.

The treatment didn’t amount to a cure, but it did have dramatic (and likely life-saving) results. The infection has nearly vanished, according to NPR, and the teen is now healthy enough to resume a mostly normal life — really, the main goal. There also weren’t side effects.

It could be a long while before you see this kind of treatment happening on a regular basis. There’s still more work to be done determining the efficacy of bacteriophages (gene-modified or otherwise) and whether or not they’re truly safe to use. However, this hints that gene tweaking could one day tackle a variety of stubborn infections, providing a second chance for people who’d otherwise be resigned to a grim fate.

Calculus has traditionally been applied in the “hard” sciences like physics, astronomy, and chemistry. But in recent decades, it has made inroads into biology and medicine, in fields like epidemiology, population biology, neuroscience, and medical imaging. We’ve seen examples of mathematical biology throughout our story, ranging from the use of calculus in predicting the outcome of facial surgery to the modeling of HIV as it battles the immune system. But all those examples were concerned with some aspect of the mystery of change, the most modern obsession of calculus. In contrast, the following example is drawn from the ancient mystery of curves, which was given new life by a puzzle about the three-dimensional path of DNA.

The puzzle had to do with how DNA, an enormously long molecule that contains all the genetic information needed to make a person, is packaged in cells. Every one of your ten trillion or so cells contains about two meters of DNA. If laid end to end, that DNA would reach to the sun and back dozens of times. Still, a skeptic might argue that this comparison is not as impressive as it sounds; it merely reflects how many cells each of us has. A more informative comparison is with the size of the cell’s nucleus, the container that holds the DNA. The diameter of a typical nucleus is about five-millionths of a meter, and it is therefore four hundred thousand times smaller than the DNA that has to fit inside it. That compression factor is equivalent to stuffing twenty miles of string into a tennis ball.

On top of that, the DNA can’t be stuffed into the nucleus haphazardly. It mustn’t get tangled. The packaging has to be done in an orderly fashion so the DNA can be read by enzymes and translated into the proteins needed for the maintenance of the cell. Orderly packaging is also important so that the DNA can be copied neatly when the cell is about to divide.

Evolution solved the packaging problem with spools, the same solution we use when we need to store a long piece of thread. The DNA in cells is wound around molecular spools made of specialized proteins called histones. To achieve further compaction, the spools are linked end to end, like beads on a necklace, and then the necklace is coiled into ropelike fibers that are themselves coiled into chromosomes. These coils of coils of coils compact the DNA enough to fit it into the cramped quarters of the nucleus.

But spools were not nature’s original solution to the packaging problem. The earliest creatures on Earth were single-celled organisms that lacked nuclei and chromosomes. They had no spools, just as today’s bacteria and viruses don’t. In such cases, the genetic material is compacted by a mechanism based on geometry and elasticity. Imagine pulling a rubber band tight and then twisting it from one end while holding it between your fingers. At first, each successive turn of the rubber band introduces a twist. The twists accumulate, and the rubber band remains straight until the accumulated torsion crosses a threshold. Then the rubber band suddenly buckles into the third dimension. It begins to coil on itself, as if writhing in pain. These contortions cause the rubber band to bunch up and compact itself. DNA does the same thing.

This phenomenon is known as supercoiling. It is prevalent in circular loops of DNA. Although we tend to picture DNA as a straight helix with free ends, in many circumstances it closes on itself to form a circle. When this happens, it’s like taking off your belt, putting a few twists in it, and then buckling it closed again. After that the number of twists in the belt cannot change. It is locked in. If you try to twist the belt somewhere along its length without taking it off, counter-twists will form elsewhere to compensate. There is a conservation law at work here. The same thing happens when you store a garden hose by piling it on the floor with many coils stacked on top of each other. When you try to pull the hose out straight, it twists in your hands. Coils convert to twists. The conversion can also go in the other direction, from twists to coils, as when a rubber band writhes when twisted. The DNA of primitive organisms makes use of this writhing. Certain enzymes can cut DNA, twist it, and then close it back up. When the DNA relaxes its twists to lower its energy, the conservation law forces it to become more supercoiled and therefore more compact. The resulting path of the DNA molecule no longer lies in a plane. It writhes about in three dimensions.

In the early 1970s an American mathematician named Brock Fuller gave the first mathematical description of this three-dimensional contortion of DNA. He invented a quantity that he dubbed the writhing number of DNA. He derived formulas for it using integrals and derivatives and proved certain theorems about the writhing number that formalized the conservation law for twists and coils. The study of the geometry and topology of DNA has been a thriving industry ever since. Mathematicians have used knot theory and tangle calculus to elucidate the mechanisms of certain enzymes that can twist DNA or cut it or introduce knots and links into it. These enzymes alter the topology of DNA and hence are known as topoisomerases. They can break strands of DNA and reseal them, and they are essential for cells to divide and grow. They have proved to be effective targets for cancer-chemotherapy drugs. The mechanism of action is not completely clear, but it is thought that by blocking the action of topoisomerases, the drugs (known as topoisomerase inhibitors) can selectively damage the DNA of cancer cells, which causes them to commit cellular suicide. Good news for the patient, bad news for the tumor.

In the application of calculus to supercoiled DNA, the double helix is modeled as a continuous curve. As usual, calculus likes to work with continuous objects. In reality, DNA is a discrete collection of atoms. There’s nothing truly continuous about it. But to a good approximation, it can be treated as if it were a continuous curve, like an ideal rubber band. The advantage of doing that is that the apparatus of elasticity theory and differential geometry, two spinoffs of calculus, can then be applied to calculate how DNA deforms when subjected to forces from proteins, from the environment, and from interactions with itself.

The larger point is that calculus is taking its usual creative license, treating discrete objects as if they were continuous to shed light on how they behave. The modeling is approximate but useful. Anyway, it’s the only game in town. Without the assumption of continuity, the Infinity Principle cannot be deployed. And without the Infinity Principle, we have no calculus, no differential geometry, and no elasticity theory.

I expect in the future we will see many more examples of calculus and continuous mathematics being brought to bear on the inherently discrete players of biology: genes, cells, proteins, and the other actors in the biological drama. There is simply too much insight to be gained from the continuum approximation not to use it. Until we develop a new form of calculus that works as well for discrete systems as traditional calculus does for continuum ones, the Infinity Principle will continue to guide us in the mathematical modeling of living things.

Excerpted from INFINITE POWERS by Steven Strogatz. Copyright © 2019 by Steven Strogatz. Reprinted by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.

It’s not certain how effective the treatment has been, and you won’t find out for a while when the trial has been cleared to treat a total of 18 patients. You won’t hear more about it until there’s been a presentation or a peer-reviewed paper, the university said. Other trials, such as ones for blood disorders in the Boston area, have yet to get underway.

No matter what, any practical uses could take a long time. There are widespread concerns that CRISPR editing could have unanticipated effects, and scientists have yet to try editing cells while they’re still in the body (a blindness trial in Cambridge, MA may be the first instance). There’s also the not-so-small matter of ethical questions. Chinese scientist He Jiankui raised alarm bells when he said he edited genes in human embryos — politicians and the scientific community will likely want to address practices like that before you can simply assume that CRISPR is an option.

The pup was reportedly cloned by plucking somatic cells (used relatively often in cloning) from the skin of the adult dog, creating a cloned embryo and implanting that into a beagle for birth.

Researcher Wan Jiusheng said that Kunxun was promising — there’s “good aptitude” for sniffing and other skills needed in a police dog. He might enter service as soon as 10 months after training. This is an experiment for now, Wan added, but the ultimate plan is to “mass produce” cloned police dogs sometime within the next 10 years. There would even be a cell bank to help quickly breed a collection of dogs.

The move could raise further ethical questions about cloning animals, including issues specific to police forces. Not everyone is likely to relish the thought of a unit full of virtually identical dogs, and there are associated risks. If there are any genetic weaknesses, a large portion of the force could be vulnerable to diseases or other hard-to-predict issues. As it stands, you’re unlikely to see other police forces (at least, outside of China) rush to embrace this concept even if it works as hoped.

FDA Commissioner Scott Gottlieb stressed that the genetic changes had been deemed safe for the animal, safe to eat and wouldn’t have a “significant” impact on the environment. AquaBounty’s modifications use DNA from other fish to grow salmon at a faster rate, raising concerns about contamination. However, they’re also bred to be female and sterile, theoretically eliminating he possibility that they’ll breed with wild salmon.

The salmon will take a while to reach the market if everything goes according to plan. Aquabounty chief Sylvia Wulf told the AP she expected certification for an Indiana growing facility in “weeks” and could receive eggs soon afterward, but it would take about 18 months for the salmon to reach their target weight.

Whether or not that happens still isn’t completely certain. An alliance of public interest, environmental and pro-fishing groups is in the midst of suing the FDA to overturn the approval on safety grounds. Groups like the Center for Food Safety have argued that regulators haven’t properly assessed the ecological and health risks of the salmon, and have pointed to problems with AquaBounty’s environmental record. If those objections hold in court, the FDA and AquaBounty could go back to square one.