The Ten Most Significant Science Stories of 2021

Covid-19 dominated science coverage again in 2021, and deservedly so. The disease garnered two entries on this list of our picks for the most important science stories of the year. But other key discoveries and achievements marked the year in science too, and they deserve more attention. NASA and private companies notched firsts in space. Scientists discovered more about the existence of early humans. And researchers documented how climate change has impacted everything from coral reefs to birds. Covid-19 will continue to garner even more attention next year as scientists work to deal with new variants and develop medical advances to battle the virus. But before you let stories about those topics dominate your reading in 2022, it’s worth it to take a look back at the biggest discoveries and accomplishments of this past year. To that end, here are our picks for the most important science stories of 2021.

The Covid Vaccine Rollout Encounters Hurdles

Last year the biggest science story of the year was that scientists developed two mRNA Covid vaccines in record time. This year the biggest Covid story is that the rollout of those vaccines by Pfizer and Moderna, and one other by Johnson and Johnson, haven’t made their way into a large proportion of the United States population and a significant portion of the world. As of this writing on December 21, roughly 73 percent of the U.S. population has received one dose, and roughly 61 percent of the U.S. population has been fully vaccinated. An incomplete rollout allowed for a deadly summer surge, driven by the highly contagious Delta variant. Experts pointed out that vaccination rates lagged due to widespread disinformation and misinformation campaigns. It didn’t help that some popular public figures—like Packers’ quarterback Aaron Rodgers, musician Nick Minaj, podcast host Joe Rogan and rapper Ice Cube—chose not to get vaccinated. Luckily, by November, U.S. health officials had approved the Pfizer vaccine for children as young as five, providing another barrier against the deadly disease’s spread, and Covid rates declined. But while the wall against the disease in the U.S. is growing, it is not finished. As cases surge as the Omicron variant spreads around the country, building that wall and reinforcing it with booster shots is critically important. In much of the rest of the world, the wall is severely lacking where populations haven’t been given decent access to the vaccine. Only 8 percent of individuals in low-income countries have received at least one dose of the vaccine, and a WHO Africa report from this fall said that on that continent, less than 10 percent of countries would hit the goal of vaccinating at least 40 percent of their citizens by the end of the year. Globally, less than 60 percent of the population has been vaccinated. The holes in vaccination coverage will allow the virus to continue to kill a large number of individuals, and allow an environment where possibly other dangerous variants can emerge.

Perseverance Notches Firsts on Mars

NASA took a huge step forward in exploring the Red Planet after the rover Perseverance landed safely on Mars in February. Scientists outfitted the vehicle with an ultralight helicopter that successfully flew in the thin Martian atmosphere, a toaster-sized device called MOXIE that successfully converted carbon dioxide to oxygen, and sampling elements that successfully collected rocks from the planet’s floor. All of the achievements will lend themselves to a better understanding of Mars, and how to investigate it in the future. The flight success will give scientists clues on how to build larger helicopters, the oxygen creation will help scientists come up with grander plans for conversion devices, and the rocks will make their way back to Earth for analysis when they are picked up on a future mission. In addition to the rover’s triumphs, other countries notched major firsts too. The United Arab Emirates Hope space probe successfully entered orbit around the planet and is studying the Martian atmosphere and weather. China’s Zhurong rover landed on Mars in May and is exploring the planet’s geology and looking for signs of water. With these ongoing missions, scientists around the world are learning more and more about what the planet is like and how we might better explore it, maybe one day in person.

Is “Dragon Man” a New Species of Human?

The backstory of the skull that scientists used to suggest there was a new species of later Pleistocene human—to join Homo sapiens and Neanderthals—garnered a lot of ink. After the fossil was discovered at a construction site in China nearly 90 years ago, a family hid it until a farmer gave it to a university museum in 2018. Since then, scientists in China pored over the skull—analyzing its features, conducting uranium series dating, and using X-ray fluorescence to compare it to other fossils—before declaring it a new species of archaic human. They dubbed the discovery Homo longi, or “Dragon Man.” The skull had a large cranium capable of holding a big brain, a thick brow and almost square eye sockets—details scientists used to differentiate it from other Homo species. Some scientists questioned whether the find warranted designation as a new species. “It’s exciting because it is a really interesting cranium, and it does have some things to say about human evolution and what’s going on in Asia. But it’s also disappointing that it’s 90 years out from discovery, and it is just an isolated cranium, and you’re not quite sure exactly how old it is or where it fits,” Michael Petraglia of the Smithsonian Institution’s Human Origins Initiative told Smithsonian magazine back in June. Other scientists supported the new species designation, and so the debate continues, and likely will until more fossils are discovered that help to fill in the holes of human history.

Climate Change Wreaks Havoc on Coral Reefs

Increasing natural disasters—forest fires, droughts and heat waves—may be the most noticeable events spurred by climate change; a warming Earth has helped drive a five-fold uptick in such weather-related events over the last 50 years according the a 2021 report by the World Meteorological Organization. But one of the biggest impacts wrought by climate change over the past decade has occurred underwater. Warming temps cause coral reefs to discard the symbiotic algae that help them survive, and they bleach and die. This year a major report from the Global Coral Reef Monitoring Network announced that the oceans lost about 14 percent of their reefs in the decade after 2009, mostly because of climate change. In November, new research showed that less than 2 percent of the coral reefs on the Great Barrier Reef—the world’s largest such feature—escaped bleaching since 1998. That news came just two months after a different study stated that half of coral reefs have been lost since the 1950s, in part due to climate change. The reef declines impact fisheries, local economies based on tourism and coastal developments—which lose the offshore buffer zone from storms the living structures provide. Scientists say if temperatures continue to rise, coral reefs are in serious danger. But not all hope is lost—if humans reduce carbon emissions rapidly now, more reefs will have a better chance of surviving.

The Space Tourism Race Heats Up

This year the famous billionaires behind the space tourism race completed successful missions that boosted more than just their egos. They put a host of civilians in space. Early in July, billionaire Richard Branson and his employees flew just above the boundary of space—a suborbital flight—in Virgin Galactic’s first fully crewed trip. (But Virgin Galactic did delay commercial missions until at least late next year.) Just over a week after Branson’s mission, the world’s richest person, Jeff Bezos, completed Blue Origin’s first crewed suborbital flight with the youngest and oldest travelers to reach space. In October, his company Blue Origin repeated the feat when it took Star Trek actor William Shatner up. A month before that, a crew of four became the first all-civilian crew to circle the Earth from space in Elon Musk’s SpaceX Dragon capsule Resilience. More ambitious firsts for civilians are in the works. In 2022, SpaceX plans to send a retired astronaut and three paying passengers to the International Space Station. And beyond that, Bezos announced Blue Origin hopes to deploy a private space station fit for ten—called “Orbital Reef”—sometime between 2025 and 2030.

WHO Approves First Vaccine Against Malaria

In October, the World Health Organization approved the first vaccine against malaria. The approval was not only a first for that disease, but also for any parasitic disease. The moment was 30 years in the making, as Mosquirix—the brand name of the drug—cost more than $750 million since 1987 to develop and test. Malaria kills nearly a half million individuals a year, including 260,000 children under the age of five. Most of these victims live in sub-Saharan Africa. The new vaccine fights the deadliest of five malaria pathogens and the most prevalent in Africa, and is administered to children under five in a series of four injections. The vaccine is not a silver bullet; it prevents only about 30 percent of severe malaria cases. But one modeling study showed that still could prevent 5.4 million cases and 23,000 deaths in children under five each year. Experts say the vaccine is a valuable tool that should be used in conjunction with existing methods—such as drug combination treatments and insecticide-treated bed nets—to combat the deadly disease.

Discoveries Move Key Dates Back for Humans in the Americas

Two very different papers in two of the world’s most prestigious scientific journals documented key moments of human habitation in the Americas. In September, a study in Science dated footprints found at White Sands National Park to between 21,000 and 23,000 years ago. Researchers estimated the age of the dried tracks known as “ghost prints” using radiocarbon dating of dried ditchgrass seeds found above and below the impressions. Previously, many archaeologists placed the start of human life in the Americas at around 13,000 years ago, at the end of the last Ice Age, based on tools found in New Mexico. The new paper, whose results have been debated, suggests humans actually lived on the continent at the height of the Ice Age. A month after that surprising find, a study in Nature published evidence showing that Vikings lived on North America earlier than previously thought. Researchers examined cut wood left by the explorers at a site in Newfoundland and found evidence in the samples of a cosmic ray event that happened in 993 C.E. The scientists then counted the rings out from that mark and discovered the wood had been cut in 1021 C.E. The find means that the Norse explorers completed the first known crossing of the Atlantic from Europe to the Americas.

Humans Are Affecting the Evolution of Animals

New research published this year shows that humans have both directly and indirectly affected how animals evolve. In probably the starkest example of humans impacting animal evolution, a Science study found a sharp increase in tuskless African elephants after years of poaching. During the Mozambican Civil War from 1977 to 1992, poachers killed so many of the giant mammals with tusks that those females without the long ivory teeth were more likely to pass on their genes. Before the war, 20 percent were tuskless. Now, roughly half of the female elephants are tuskless. Males who have the genetic make-up for tusklessness die, likely before they are born. And killing animals isn’t the only way humans are impacting evolution. A large study in Trends in Ecology and Evolution found that animals are changing shape to deal with rising temps. For example, over various time periods bats grew bigger wings and rabbits sprouted longer ears—both likely to dissipate more heat into the surrounding air. More evidence along those lines was published later in the year in Science Advances. A 40-year-study of birds in a remote, intact patch of Amazon rainforest showed 77 species weighed less on average, and many had longer wings, than they used to. Scientists said the changes likely occurred due to rising temperatures and changes in rainfall.

Antiviral Pills That Fight Covid Show Promising Results

Almost a year after scientists released tests showing the success of mRNA vaccines in fighting Covid, Merck released promising interim test results from a Phase III trial of an antiviral pill. On October 1, the pharmaceutical giant presented data that suggested molnupiravir could cut hospitalizations in half. Ten days later, the company submitted results to the FDA in hopes of gaining emergency use. In mid-November, the U.K. jumped ahead of the U.S. and granted approval for the treatment. By late November, advisers to the FDA recommended emergency authorization of the pill, though it was shown by this time to reduce death or disease by 30—not 50—percent. The drug should be taken—four pills a day for five days—starting within five days of the appearance of symptoms. It works by disrupting SARS-CoV-2’s ability to replicate effectively inside a human cell.

Molnupiravir isn’t the only viral drug with positive results. In November, Pfizer announced its antiviral pill, Paxlovid, was effective against severe Covid. By December, the pharmaceutical giant shared final results that it reduced the risk of hospitalization and death by 88 percent in a key group. News about both pills was welcome, as they are expected to work against all versions of the virus, including Omicron. Though the drugs aren’t as big of a breakthrough as the vaccines, a doctor writing for the New Yorker called them “the most important pharmacologic advance of the pandemic.” Many wealthy countries have already agreed to contracts for molnupiravir, and the Gates Foundation pledged $120 million to help get the pill to poor countries. If approved and distributed fast enough, the oral antivirals can be prescribed in places, like Africa, where vaccines have been lacking. The pills represent another crucial tool, in addition to masks and vaccines, in the fight against Covid.

The James Webb Space Telescope May Finally Launch

The James Webb Space Telescope, the most powerful space telescope ever constructed, is supposed to launch in late December—pending yet another delay. If this news seems like a long time coming, that’s because it is. NASA, the Canadian Space Agency and the European Space Agency started working on the craft in 1996, and it was expected to launch in 2007 and come in at a cost of $500 million. The craft has been delayed numerous times, including several times this year, and the final cost will be more than $9 billion over budget. But many scientists say the telescope is worth the wait and the money, as it will be able to do things the Hubble Space Telescope can’t. It will help astronomers discover how early galaxies formed, detect possible signs of life on other planets and watch the birth of stars. With the date of the launch so close, the astronomy community is extremely excited, though their wait won’t be quite over. It will take the telescope six months in space to prepare itself to work.