Laika, a gene-edited pig, was named in honor of the first living creature to orbit the earth, a stray dog named Laika.
Untold numbers of animals have contributed to science, in ways big and small. Studying cows and cowpox helped English doctor Edward Jenner create a smallpox vaccine; Ivan Pavlov's experiments on dogs' reactions to external stimuli heavily influenced modern behavioral psychology.
We have these five animals to thank for some of our most important scientific advancements, from space travel to better organ replacement options.
Scientists still work with rats, rabbits, and other mammals to test cosmetics and pharmaceuticals and to conduct infectious disease research. Most of these animals remain nameless and unknown to the public, but over the years, certain individuals have had an outsize effect. We have these five animals to thank for some of our most important scientific advancements, from space travel to better organ replacement options.
1) LAIKA THE DOG
Laika was the first living creature ever to orbit the Earth. In October 1957, the Soviet Sputnik I ship had made history as the first man-made object sent into Earth's orbit; Premier Nikita Khrushchev was keen to gain another Space Race victory by sending up a canine cosmonaut.
Laika ("barker" in Russian), was a stray dog, reportedly a husky-spitz mix, recruited among several other female strays for the trip. Although the scientists put extensive work into preparing Laika and the other canine finalists—evaluating their reactions to air-pressure variations, training them to adapt to pelvic sanitation devices meant to contain waste, and eventually having them live in pressurized capsules for weeks—there was no expectation that the dog would return to Earth, and only one meal's worth of food was sent up with her.
Sputnik II, six times heavier than its predecessor, launched on November 3, 1957. Soviet broadcasts reported that Laika, fitted out with surgically implanted devices to monitor her heart rate, blood pressure, and breathing rates, survived until November 12; the spacecraft stayed in orbit for five more months, burning up when it re-entered the atmosphere.
At the time, the Sputnik II team reassured the world that Laika had died painlessly of oxygen deprivation. It was only decades later, in the 1990s, that Oleg Gazenko—one of the scientists and dog trainers assigned to the mission—revealed that Laika had died 5 to 7 hours after launch from a combination of heat and stress. The capsule had overheated, probably as a result of the rushed preparation; after the fourth orbit, the temperature inside Sputnik was over 90 degrees, and it's doubtful she could have survived much past that. "The more time passes, the more I'm sorry about it. We shouldn't have done it," Gazenko said. "We did not learn enough from the mission to justify the death of the dog."
Yet even the four or five orbits that Laika did complete were enough to spur scientists to press on in the effort to send a human into space.
2) HAM THE CHIMP
Four years after Laika's ill-fated flight, a chimpanzee named Ham entered suborbital flight in the American Project Mercury MR-2 mission on January 31, 1961, becoming the first hominid in space—and unlike Laika, he returned to Earth, alive, after a 16-minute flight.
Even though Ham's flight was not destined for orbit, the spacecraft and booster used on his trip were the same combination intended for the first (human) American's trip later that year. If he came back unharmed, NASA's medical team would be prepared to okay astronaut Alan Shepard's flight.
For approximately 18 months before liftoff, Ham was trained to perform simple tasks, like pushing levers, in response to visual and auditory cues. (If he failed, he received an electric shock; correct performance earned him a treat. Pavlov would have been pleased.)
At 37 pounds, Ham was also the heaviest animal to ever make it to space. His vital signs and movements were monitored from Earth, and after a light electric shock from the ground team reminded him of his tasks, he performed his lever-pushing just a bit slower than he had on Earth, verifying that motion would not be seriously impaired in space.
Less than three months after Ham returned to Earth, on April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first human to complete an orbital flight; Shepard was close behind, successfully crewing the MR-3 mission on May 5. For his part, Ham "retired" to the National Zoo in Washington D.C. for 17 years, before being transferred to the North Carolina Zoological Park; he died of liver failure in 1983 at age 26. His grave is at the International Space Hall of Fame in New Mexico.
3) KOKO THE GORILLA
A western lowland gorilla born at the San Francisco Zoo, Hanabi-ko, or "Koko," became famous in the 1970s for her cognitive and communicative abilities. Psychologist Francine "Penny" Patterson, then a doctoral student at Stanford, chose Koko to work on a language research project, teaching her American Sign Language; by age four, Koko demonstrated the ability both to make up new words and to combine known words to express herself creatively, as opposed to simply mimicking her trainer.
Koko's work with Patterson reflected levels of cognition that were higher than non-human primates had previously been thought to have; by the end of her life, her language skills were roughly equivalent to a young child's, with a vocabulary of around 1,000 signs and the ability to understand 2,000 words of spoken English.
An especially impactful study in 2012 showed that Koko had learned to play the recorder, revealing an ability for voluntary breath control that scientists had previously thought was linked closely to speech and could only be developed by humans. Barbara J. King, a biological anthropologist, suggested that Koko's immersion in a human environment may have helped her develop such a skill, and that it might be misleading to consider similar abilities "innate" or lacking in either humans or non-human primates.
Koko's displays of emotions also fascinated the public, especially those that seemed to closely mirror humans': she cared for pet kittens; appeared on Mr. Rogers' Neighborhood and untied the host's shoes for him; acted playfully with Robin Williams during a visit from him, and later expressed grief when told about the comedian's death. Koko died in her sleep in June 2018, at age 46. Patterson continues to run The Gorilla Foundation, which is dedicated to using inter-species communication to motivate conservation efforts.
4) DOLLY THE SHEEP
Dolly—named after country singer Dolly Parton—was the first mammal ever to be cloned from an adult somatic cell, using the process of nuclear transfer. She was born in 1996 as part of research by scientists Keith Campbell and Ian Wilmut of the University of Edinburgh.
By taking a donor cell from an adult sheep's mammary gland, using it to replace the cell nucleus of an unfertilized, developing egg cell, and then bringing the resultant embryo to term, Campbell and Wilmut proved that even a mature cell (one that had developed to perform mammary gland functions) could revert to an embryonic state and go on to develop into any and all parts of a mammal.
Although cloned livestock are legal in the U.S.—the FDA approved the practice in 2008, after determining that there was no difference between the meat and milk of cattle, pigs, and goats—Dolly has had an even bigger impact on stem cell research. The successful test of nuclear transfer proved that it was possible to change a cell's gene expression by changing its nucleus.
Japanese stem cell biologist Shinya Yamanaka, inspired by the birth of Dolly, won the Nobel Prize in 2012 for his adaptation of the technique. He developed induced pluripotent stem cells (iPS cells) by chemically reverting mature cells back to an embryonic-like blank state that is highly desirable for disease research and treatment. This technique allows researchers to work with such stem cells without the ethically charged complication of having to destroy a human embryo in the process.
5) LAIKA THE PIG
Named in honor of the dog who made it to space, the second science-famous Laika was a genetically engineered pig born in China in 2015 as a result of gene editing carried out by Cambridge, MA startup eGenesis and collaborators.* eGenesis aims to create pigs whose organs—hearts, kidneys, lungs, and more—are safe to transplant into people.
Using animal organs in humans (xenotransplantation) is tricky: the immune system is very good at recognizing interlopers, and the human body can start to reject an organ from another species in as little as five minutes. But pigs are otherwise exceptionally good potential donors for humans: their organs' sizes and functions are very similar, and their quick gestation and maturation make them attractive from an efficiency standpoint, given that twenty Americans die every day waiting for organ donors.
Perhaps unsurprisingly, Dolly the sheep helped move xenotransplantation forward. In the 1990s, immunologist David Sachs was able to use a similar cloning method to eliminate alpha-gal, an enzyme that is produced by most animals with immune systems, including pigs—but not humans. Since our immune systems don't recognize alpha-gal, attacks on that enzyme are a major cause of organ rejection. Sachs' experiments increased the survival time of pig organs in primates to weeks: a huge improvement, but not nearly enough for someone in need of a liver or heart.
The advent of CRISPR technology, and the ability to edit genes, has allowed another leap. In 2015, researchers at eGenesis used targeted gene-editing to eliminate the genes for porcine endogenous retroviruses from pig kidney cells. These viral elements are part of all pigs' genomes and pose a potentially high risk of infecting human cells. (After the HIV/AIDS crisis especially, there was a lot of anxiety about potentially introducing a new virus into the human population.)
The eGenesis lab used nuclear transfer to embed the edited nuclei into egg cells taken from a normal pig; and Laika was born months later—without the dangerous viral genes. eGenesis is now working to make the organs even more humanlike, with the goal of one day providing organs to every human patient in need.
*[Disclosure: In 2019, eGenesis received a series B investment from Leaps By Bayer, the funding sponsor of leapsmag. However, leapsmag is editorially independent of Bayer and is under no obligation to cover companies they invest in.]
[Correction, March 3, 2020: Laika the gene-edited pig was born in China, not Cambridge, and eGenesis is pursuing xenotransplant programs that include heart, kidney, and lung, but not skin, as originally written.]
A recent study in The Lancet Oncology showed that AI found 20 percent more cancers on mammogram screens than radiologists alone.
Published in The Lancet Oncology, the study analyzed the scans of 80,000 Swedish women with a moderate hereditary risk of breast cancer who had undergone a mammogram between April 2021 and July 2022. Half of these scans were read by AI and then a radiologist to double-check the findings. The second group of scans was read by two researchers without the help of AI. (Currently, the standard of care across Europe is to have two radiologists analyze a scan before diagnosing a patient with breast cancer.)
The study showed that the AI group detected cancer in 6 out of every 1,000 scans, while the radiologists detected cancer in 5 per 1,000 scans. In other words, AI found 20 percent more cancers than the highly-trained radiologists.
Scientists have been using MRI images (like the ones pictured here) to train artificial intelligence to detect cancers earlier and with more accuracy. Here, MIT's AI system, MIRAI, looks for patterns in a patient's mammograms to detect breast cancer earlier than ever before. news.mit.edu
But even though the AI was better able to pinpoint cancer on an image, it doesn’t mean radiologists will soon be out of a job. Dr. Laura Heacock, a breast radiologist at NYU, said in an interview with CNN that radiologists do much more than simply screening mammograms, and that even well-trained technology can make errors. “These tools work best when paired with highly-trained radiologists who make the final call on your mammogram. Think of it as a tool like a stethoscope for a cardiologist.”
AI is still an emerging technology, but more and more doctors are using them to detect different cancers. For example, researchers at MIT have developed a program called MIRAI, which looks at patterns in patient mammograms across a series of scans and uses an algorithm to model a patient's risk of developing breast cancer over time. The program was "trained" with more than 200,000 breast imaging scans from Massachusetts General Hospital and has been tested on over 100,000 women in different hospitals across the world. According to MIT, MIRAI "has been shown to be more accurate in predicting the risk for developing breast cancer in the short term (over a 3-year period) compared to traditional tools." It has also been able to detect breast cancer up to five years before a patient receives a diagnosis.
The challenges for cancer-detecting AI tools now is not just accuracy. AI tools are also being challenged to perform consistently well across different ages, races, and breast density profiles, particularly given the increased risks that different women face. For example, Black women are 42 percent more likely than white women to die from breast cancer, despite having nearly the same rates of breast cancer as white women. Recently, an FDA-approved AI device for screening breast cancer has come under fire for wrongly detecting cancer in Black patients significantly more often than white patients.
As AI technology improves, radiologists will be able to accurately scan a more diverse set of patients at a larger volume than ever before, potentially saving more lives than ever.