President John F. Kennedy gave Dr. Frances Oldham Kelsey the nation's highest federal civilian service award in 1962, saying she had "prevented a major tragedy of birth deformities."
The White House
By 1960, Thalidomide was being sold in countries throughout the world, and the United States was expected to soon follow suit. Dr. Frances Oldham Kelsey, a pharmacologist and physician, was hired by the Food and Drug Administration (FDA) in September of that year to review and approve drugs for the administration. Immediately, Kelsey was tasked with approving thalidomide for commercial use in the United States under the name Kevadon. Kelsey's approval was supposed to be a formality, since the drug was so widely used in other countries.
But Kelsey did something that few people expected – she paused. Rather than approving the drug offhand as she was expected to do, Kelsey asked the manufacturer – William S. Merrell Co., who was manufacturing thalidomide under license from Chemie Grünenthal – to supply her with more safety data, noting that Merrell's application for approval relied mostly on anecdotal testimony. Kelsey – along with her husband who worked as a pharmacologist at the National Institutes of Health (NIH) — was highly suspicious of a drug that had no lethal dose and no side effects. "It was just too positive," Kelsey said later. "This couldn't be the perfect drug with no risk."
At the same time, rumors were starting to swirl across Europe that thalidomide was not as safe as everyone had initially thought: Physicians were starting to notice an "unusual increase" in the birth of severely deformed babies, and they were beginning to suspect thalidomide as the cause. The babies, whose mothers had all taken thalidomide during pregnancy, were born with conditions like deafness, blindness, congenital heart problems, and even phocomelia, a malformation of the arms and legs. Doctors and midwives were also starting to notice a sharp rise in miscarriages and stillbirths among their patients as well.
Kelsey's skepticism was rewarded in November 1961 when thalidomide was yanked abruptly off the market, following a growing outcry that it was responsible for hundreds of stillbirths and deformities.
Kelsey had heard none of these rumors, but she did know from her post-doctoral research that adults could metabolize drugs differently than fetuses – in other words, a drug that was perfectly safe for adults could be detrimental to a patient's unborn child. Noting that thalidomide could cross the placental barrier, she asked for safety data, such as clinical trials, that showed specifically the drug was non-toxic for fetuses. Merrell supplied Kelsey with anecdotal data – in other words, accounts from patients who attested to the fact that they took thalidomide with no adverse effects – but she rejected it, needing stronger data: clinical studies with pregnant women included.
The drug company was annoyed at what they considered Kelsey's needless bureaucracy. After all, Germans were consuming around 1 million doses of thalidomide every day in 1960, with lots of anecdotal evidence that it was safe, even among pregnant women. As the holidays approached – the most lucrative time of year for sedative sales – Merrell executives started hounding Kelsey to approve thalidomide, even phoning her superior and paying her visits at work. But Kelsey was unmovable. Kelsey's skepticism was solidified in December 1960, when she read a letter published in the British Medical Journal from a physician. In the letter, the author warned that his long-term thalidomide patients were starting to report pain in their arms and legs.
"The burden of proof that the drug is safe … lies with the applicant," Kelsey wrote in a letter to Merrell executive Joseph F. Murray in May of 1961. Despite increasing pressure, Kelsey held fast to her insistence that more safety data – particularly for fetuses – was needed.
Kelsey's skepticism was rewarded in November 1961 when Chemie Grünenthal yanked thalidomide off the market overseas, following a growing outcry that it was responsible for hundreds of stillbirths and deformities. In early 1962, Merrell conceded that the drug's safety was unproven in fetuses and formally withdrew its application at the FDA.
Thanks to Kelsey, the United States was spared the effects of thalidomide – although countries like Europe and Canada were not so lucky. Thalidomide remained in people's homes under different names long after it was pulled from the market, and so women unfortunately continued to take thalidomide during their pregnancies, unaware of its effects. All told, thalidomide is thought to have caused around 10,000 birth defects and anywhere from 5,000 to 7,000 miscarriages. Many so-called "thalidomide babies" are now adults living with disabilities.
Niko von Glasow, born in 1960, is a German film director and producer who was born disabled due to the side effects of thalidomide.
Wikimedia Commons
Just two years after joining the FDA, Kelsey was presented with the President's Award for Distinguished Federal Civilian Service and was appointed as the head of the Investigational Drug Branch at the FDA. Not only did Kelsey save the U.S. public from the horrific effects of thalidomide, but she forever changed the way drugs were developed and approved for use in the United States: Drugs now need to not only be proven safe and effective, but adverse drug reactions need to be reported to the FDA and informed consent must be obtained by all participants before they volunteer for clinical trials. Today, the United States is safer because of Frances Kelsey's bravery.
Alida de Flamingh and her team are collecting elephant dung. It holds a trove of information about animal health, diet and genetic diversity.
Courtesy Alida de Flamingh
Approximately 27 percent of mammals and 28 percent of all assessed species are close to dying out. The IUCN Red List of threatened species, simply called the Red List, is the world’s most comprehensive record of animals’ risk of extinction status. The more information scientists gather, the better their chances of reducing those risks. In Africa, populations of vertebrates declined 69 percent between 1970 and 2022, according to the World Wildlife Fund (WWF).
“We put on sterile gloves and use a sterile swab to collect wet mucus and materials from the outside of the dung ball,” says Alida de Flamingh, a postdoctoral researcher at the University of Illinois Urbana-Champaign.
“When people talk about species, they often talk about ecosystems, but they often overlook genetic diversity,” says Christina Hvilsom, senior geneticist at the Copenhagen Zoo. “It’s easy to count (individuals) to assess whether the population size is increasing or decreasing, but diversity isn’t something we can see with our bare eyes. Yet, it’s actually the foundation for the species and populations.” DNA analysis can provide this critical information.
Assessing elephants’ health
“Africa’s elephant populations are facing unprecedented threats,” says de Flamingh, the postdoc, who has studied them since 2009. Challenges include ivory poaching, habitat destruction and smaller, more fragmented habitats that result in smaller mating pools with less genetic diversity. Additionally, de Flamingh studies the microbial communities living on and in elephants – their microbiomes – looking for parasites or dangerous microbes.
Approximately 415,000 elephants inhabit Africa today, but de Flamingh says the number would be four times higher without these challenges. The IUCN Red List reports African savannah elephants are endangered and African forest elephants are critically endangered. Elephants support ecosystem biodiversity by clearing paths that help other species travel. Their very footprints create small puddles that can host smaller organisms such as tadpoles. Elephants are often described as ecosystems’ engineers, so if they disappear, the rest of the ecosystem will suffer too.
There’s a process to collecting elephant feces. “We put on sterile gloves (which we change for each sample) and use a sterile swab to collect wet mucus and materials from the outside of the dung ball,” says de Flamingh. They rub a sample about the size of a U.S. quarter onto a paper card embedded with DNA preservation technology. Each card is air dried and stored in a packet of desiccant to prevent mold growth. This way, samples can be stored at room temperature indefinitely without the DNA degrading.
Earlier methods required collecting dung in bags, which needed either refrigeration or the addition of preservatives, or the riskier alternative of tranquilizing the animals before approaching them to draw blood samples. The ability to collect and sequence the DNA made things much easier and safer.
“Our research provides a way to assess elephant health without having to physically interact with elephants,” de Flamingh emphasizes. “We also keep track of the GPS coordinates of each sample so that we can create a map of the sampling locations,” she adds. That helps researchers correlate elephants’ health with geographic areas and their conditions.
Although de Flamingh works with elephants in the wild, the contributions of zoos in the United States and collaborations in South Africa (notably the late Professor Rudi van Aarde and the Conservation Ecology Research Unit at the University of Pretoria) were key in studying this method to ensure it worked, she points out.
Protecting chimpanzees
Genetic work with chimpanzees began about a decade ago. Hvilsom and her group at the Copenhagen Zoo analyzed DNA from nearly 1,000 fecal samples collected between 2003 and 2018 by a team of international researchers. The goal was to assess the status of the West African subspecies, which is critically endangered after rapid population declines. Of the four subspecies of chimpanzees, the West African subspecies is considered the most at-risk.
In total, the WWF estimates the numbers of chimpanzees inhabiting Africa’s forests and savannah woodlands at between 173,000 and 300,000. Poaching, disease and human-caused changes to their lands are their major risks.
By analyzing genetics obtained from fecal samples, Hvilsom estimated the chimpanzees’ population, ascertained their family relationships and mapped their migration routes.
“One of the threats is mining near the Nimba Mountains in Guinea,” a stronghold for the West African subspecies, Hvilsom says. The Nimba Mountains are a UNESCO World Heritage Site, but they are rich in iron ore, which is used to make the steel that is vital to the Asian construction boom. As she and colleagues wrote in a recent paper, “Many extractive industries are currently developing projects in chimpanzee habitat.”
Analyzing DNA allows researchers to identify individual chimpanzees more accurately than simply observing them, she says. Normally, field researchers would install cameras and manually inspect each picture to determine how many chimpanzees were in an area. But, Hvilsom says, “That’s very tricky. Chimpanzees move a lot and are fast, so it’s difficult to get clear pictures. Often, they find and destroy the cameras. Also, they live in large areas, so you need a lot of cameras.”
By analyzing genetics obtained from fecal samples, Hvilsom estimated the chimpanzees’ population, ascertained their family relationships and mapped their migration routes based upon DNA comparisons with other chimpanzee groups. The mining companies and builders are using this information to locate future roads where they won’t disrupt migration – a more effective solution than trying to build artificial corridors for wildlife.
“The current route cuts off communities of chimpanzees,” Hvilsom elaborates. That effectively prevents young adult chimps from joining other groups when the time comes, eventually reducing the currently-high levels of genetic diversity.
“The mining company helped pay for the genetics work,” Hvilsom says, “as part of its obligation to assess and monitor biodiversity and the effect of the mining in the area.”
Of 50 toucan subspecies, 11 are threatened or near-threatened with extinction because of deforestation and poaching.
Identifying toucan families
Feces aren't the only substance researchers draw DNA samples from. Jeffrey Coleman, a Ph.D. candidate at the University of Texas at Austin relies on blood tests for studying the genetic diversity of toucans---birds species native to Central America and nearby regions. They live in the jungles, where they hop among branches, snip fruit from trees, toss it in the air and catch it with their large beaks. “Toucans are beautiful, charismatic birds that are really important to the ecosystem,” says Coleman.
Of their 50 subspecies, 11 are threatened or near-threatened with extinction because of deforestation and poaching. “When people see these aesthetically pleasing birds, they’re motivated to care about conservation practices,” he points out.
Coleman works with the Dallas World Aquarium and its partner zoos to analyze DNA from blood draws, using it to identify which toucans are related and how closely. His goal is to use science to improve the genetic diversity among toucan offspring.
Specifically, he’s looking at sections of the genome of captive birds in which the nucleotides repeat multiple times, such as AGATAGATAGAT. Called microsatellites, these consecutively-repeating sections can be passed from parents to children, helping scientists identify parent-child and sibling-sibling relationships. “That allows you to make strategic decisions about how to pair (captive) individuals for mating...to avoid inbreeding,” Coleman says.
Jeffrey Coleman is studying the microsatellites inside the toucan genomes.
Courtesy Jeffrey Coleman
The alternative is to use a type of analysis that looks for a single DNA building block – a nucleotide – that differs in a given sequence. Called single nucleotide polymorphisms (SNPs, pronounced “snips”), they are very common and very accurate. Coleman says they are better than microsatellites for some uses. But scientists have already developed a large body of microsatellite data from multiple species, so microsatellites can shed more insights on relations.
Regardless of whether conservation programs use SNPs or microsatellites to guide captive breeding efforts, the goal is to help them build genetically diverse populations that eventually may supplement endangered populations in the wild. “The hope is that the ecosystem will be stable enough and that the populations (once reintroduced into the wild) will be able to survive and thrive,” says Coleman. History knows some good examples of captive breeding success.
The California condor, which had a total population of 27 in 1987, when the last wild birds were captured, is one of them. A captive breeding program boosted their numbers to 561 by the end of 2022. Of those, 347 of those are in the wild, according to the National Park Service.
Conservationists hope that their work on animals’ genetic diversity will help preserve and restore endangered species in captivity and the wild. DNA analysis is crucial to both types of efforts. The ability to apply genome sequencing to wildlife conservation brings a new level of accuracy that helps protect species and gives fresh insights that observation alone can’t provide.
“A lot of species are threatened,” Coleman says. “I hope this research will be a resource people can use to get more information on longer-term genealogies and different populations.”