Last year, I compiled this list the night Pfizer/BioNTech’s COVID-19 vaccine became the first approved vaccine for SARS-CoV-2. Feeling excited and optimistic, I wrote, “Scientists did their work to figure out which treatments would work and which would not. And now, thanks to them, it finally feels like there is a light at the end of the coronavirus tunnel.” A year later, due to a myriad of reasons, that’s unfortunately not the case. However, 2021 did see a reluctant return to “normal” life, at least more so than the quarantine-filled year prior. Scientists like yourself returned to the lab, continued to take on SARS-CoV-2, and delved into so much more. Let’s take a look at some of the most interesting scientific discoveries of this year.
1. World’s First Double Arm and Shoulder Transplant
An Icelandic man who lost both arms in a work accident 23 years ago became the world’s first recipient of a double arm and shoulder transplant in January. At the time, doctors said it would be “life-changing” if the patient, Felix Gretarsson, recovered the ability to actively bend his elbow. Nerves grow, on average, about 1 mm per day, meaning after about a year, Gretarsson’s nerves would be reaching the elbow, and in two years, may reach his hands. Less than 6 months after the surgery, Gretarsson could already flex his bicep and reported some nerve feeling in his forearms.
2. Researchers Sequence World’s Oldest DNA from 1-Million-Year-Old Mammoth
An international team led by Stockholm University researchers successfully analyzed the genomes from three ancient mammoths using DNA recovered from mammoth teeth that had been buried for 0.7 to 1.2 million years in the Siberian permafrost. Analysis showed the oldest specimen, which was approximately 1.2 million years old, belonged to a previously unknown genetic lineage of mammoth, now known as the Krestovka mammoth. The results show the Krestovka mammoth diverged from other Siberian mammoths more than 2 million years ago.
"One of the big questions now is how far back in time we can go,” said Anders Götherström, molecular archaeology professor and research leader at Stockholm University’s Centre for Palaeogenetics. “We haven’t reached the limit yet. An educated guess would be that we could recover DNA that is two million years old, and possibly go even as far back as 2.6 million.”
3. Irreversible Changes to the Climate
The Intergovernmental Panel on Climate Change (IPCC) released the first part of its Sixth Assessment Report, which summarizes the state of physical science on climate change based on over 14,000 papers and concludes that effects of human-caused climate change are now "widespread, rapid, and intensifying.” Overall, the Sixth Assessment Report indicates a faster warming Earth with every region facing changes beyond temperature, including some that are considered irreversible at this point.
“Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years,” reads the report.
Just a month prior to the release of the IPCC report, researchers from Sweden, Norway and Germany published a study that argued the current rate of global plastic pollution is nearing an irreversible tipping point. The study laid out a number of hypothetical examples of plastic pollution threats, including exacerbation of climate change because of disruption of the global carbon pump, biodiversity loss in the ocean where plastic pollution acts as additional stressor to overfishing, ongoing habitat loss caused by changes in water temperatures, nutrient supply and chemical exposure.
4. World’s First Malaria Vaccine Endorsed by WHO
Based on an ongoing pilot program of 800,000 children since 2019, the World Health Organization (WHO) recommended the widespread use of the RTS,S/AS01 malaria vaccine among children in sub-Saharan Africa and other regions with moderate to high malaria transmission. The GSK-developed vaccine has limited efficacy, preventing 39% of malaria cases and 29% of severe malaria cases among small children in Africa over four years of trials. Still, if the full series of doses is given to all kids in countries with a high incidence of malaria, modeling studies suggest the vaccine could prevent the deaths of 23,000 children a year. In 2019, 409,000 people died from malaria—and more than 270,000 of those victims were children under five.
5. Supercomputers Outwit Antibiotic Resistance
About 700,000 people die every year because of antibiotic-resistant bacteria, and that number is projected to rise into the millions. Some studies predict that, without effective antibiotics, life expectancy will drop by 20 years. Researchers from the University of Portsmouth recently took a giant leap toward combatting this public health threat—they are the first to use a multi-pronged computer-guided strategy to make a new antibiotic from an existing one that bacteria have outwitted. Their best drug candidate, which is yet to undergo clinical trials, is up to 56 times more active for the tested bacterial strains than two antibiotics on the World Health Organisation’s list of essential medicines, erythromycin and clarithromycin.
6. Human Cells Can Write RNA Sequences into DNA
In a study published this summer, Thomas Jefferson University researchers provided the first evidence that RNA segments can be written back into DNA, which potentially challenges the central dogma in biology and could have wide implications affecting many fields of biology. In a series of experiments, the researchers tested polymerase theta against the reverse transcriptase from HIV, which is one of the best studied of its kind. They showed that polymerase theta was capable of converting RNA messages into DNA, which it did as well as HIV reverse transcriptase, and that it actually did a better job than when duplicating DNA to DNA. Polymerase theta was more efficient and introduced fewer errors when using an RNA template to write new DNA messages, than when duplicating DNA into DNA, suggesting that this function could be its primary purpose in the cell.
7. E.T. Phone Home?
For the first time ever, the U.S. government released a report on extraterrestrials, or the possibility of extraterrestrial life. In reviewing 144 sightings of aircraft or other devices apparently flying at mysterious speeds or trajectories, investigators did not find extraterrestrial links. But, they did highlight the need for better data collection. To that point, Harvard’s Avi Loeb launched the Galileo Project, to "bring the search for extraterrestrial technological signatures from accidental or anecdotal observations and legends to the mainstream of transparent, validated and systematic scientific research." The research group will aim to identify the nature of unidentified aerial phenomena and other interstellar objects using the standard scientific method based on an analysis of open scientific data collected using optimized instruments.
8. Green Coffee and Starch
Scientists at VTT in Finland successfully produced batches of coffee that smell and taste like the real thing using coffee cell cultures and bioreactors. Startup companies Compound Foods and Atomo are also working toward more sustainable coffee production. These synthetic versions of coffee use less water, generate less carbon emissions, require less labor, and—most importantly—cause no deforestation. Around the same time, scientists in China published a study on a novel technology that can turn CO2 into starch in a highly efficient manner. Essential for many products and the most common carbohydrate in human diets, sustainable production could reduce land, pesticide and water use, as well as greenhouse gas emissions, all while increasing food security.
9. First Sample from Another Planet
NASA’s Perseverance rover successfully completed the collection of the first sample of Martian rock, a core from Jezero Crater, slightly thicker than a pencil. The sample-taking process began when the rotary-percussive drill at the end of Perseverance’s robotic arm cored into a flat, briefcase-size Mars rock nicknamed “Rochette.” After completing the coring process, the arm maneuvered the corer, bit, and sample tube so the rover’s Mastcam-Z camera instrument could image the contents of the still-unsealed tube and transmit the results back to Earth. After mission controllers confirmed the cored rock’s presence in the tube, they sent a command to complete processing of the sample. Perseverance then transferred sample tube serial number 266 and its Martian cargo into the rover’s interior to measure and image the rock core. It then hermetically sealed the container, took another image, and stored the tube. These samples would be the first set of scientifically identified and selected materials returned to Earth from another planet.
10. Long-term COVID-19 Research, including Long COVID
Dogs have long been used for the detection of drugs and bombs, so why not turn to them again in a pandemic-driven time of need? Both Florida International University and the University of Pennsylvania launched successful programs to train dogs to detect the smell of COVID-19 on humans. FIU researchers demonstrated the dogs achieved greater than 90 percent accuracy with low false positives, while Penn researchers showed the dogs were even able to detect asymptomatic patients and those who already cleared the virus from their system. Additionally, start-up companies InsectSense and Wageningen Bioveterinary Research successfully trained bees to extend their tongues when they smell the coronavirus. Bees, like dogs, can learn to detect volatiles and odors, but with just a few minutes of training. The research was conducted with more than 150 bees with different training setups to determine the most optimum training protocol.