Staying well in the 21st century is like playing a game of chess
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.
This article originally appeared in One Health/One Planet, a single-issue magazine that explores how climate change and other environmental shifts are increasing vulnerabilities to infectious diseases by land and by sea. The magazine probes how scientists are making progress with leaders in other fields toward solutions that embrace diverse perspectives and the interconnectedness of all lifeforms and the planet.
On July 30, 1999, the Centers for Disease Control and Prevention published a report comparing data on the control of infectious disease from the beginning of the 20th century to the end. The data showed that deaths from infectious diseases declined markedly. In the early 1900s, pneumonia, tuberculosis and diarrheal diseases were the three leading killers, accounting for one-third of total deaths in the U.S.—with 40 percent being children under five.
Mass vaccinations, the discovery of antibiotics and overall sanitation and hygiene measures eventually eradicated smallpox, beat down polio, cured cholera, nearly rid the world of tuberculosis and extended the U.S. life expectancy by 25 years. By 1997, there was a shift in population health in the U.S. such that cancer, diabetes and heart disease were now the leading causes of death.
The control of infectious diseases is considered to be one of the “10 Great Public Health Achievements.” Yet on the brink of the 21st century, new trouble was already brewing. Hospitals were seeing periodic cases of antibiotic-resistant infections. Novel viruses, or those that previously didn’t afflict humans, began to emerge, causing outbreaks of West Nile, SARS, MERS or swine flu.In the years that followed, tuberculosis made a comeback, at least in certain parts of the world. What we didn’t take into account was the very concept of evolution: as we built better protections, our enemies eventually boosted their attacking prowess, so soon enough we found ourselves on the defensive once again.
At the same time, new, previously unknown or extremely rare disorders began to rise, such as autoimmune or genetic conditions. Two decades later, scientists began thinking about health differently—not as a static achievement guaranteed to last, but as something dynamic and constantly changing—and sometimes, for the worse.
What emerged since then is a different paradigm that makes our interactions with the microbial world more like a biological chess match, says Victoria McGovern, a biochemist and program officer for the Burroughs Wellcome Fund’s Infectious Disease and Population Sciences Program. In this chess game, humans may make a clever strategic move, which could involve creating a new vaccine or a potent antibiotic, but that advantage is fleeting. At some point, the organisms we are up against could respond with a move of their own—such as developing resistance to medication or genetic mutations that attack our bodies. Simply eradicating the “opponent,” or the pathogenic microbes, as efficiently as possible isn’t enough to keep humans healthy long-term.
Instead, scientists should focus on studying the complexity of interactions between humans and their pathogens. “We need to better understand the lifestyles of things that afflict us,” McGovern says. “The solutions are going to be in understanding various parts of their biology so we can influence how they behave around our systems.”
Genetics and cell biology, combined with imaging techniques that allow one to see tissues and individual cells in actions, will enable scientists to define and quantify what it means to be healthy at the molecular level.
What is being proposed will require a pivot to basic biology and other disciplines that have suffered from lack of research funding in recent years. Yet, according to McGovern, the research teams of funded proposals are answering bigger questions. “We look for people exploring questions about hosts and pathogens, and what happens when they touch, but we’re also looking for people with big ideas,” she says. For example, if one specific infection causes a chain of pathological events in the body, can other infections cause them too? And if we find a way to break that chain for one pathogen, can we play the same trick on another? “We really want to see people thinking of not just one experiment but about big implications of their work,” McGovern says.
Jonah Cool, a cell biologist, geneticist and science officer at the Chan Zuckerberg Initiative, says that it’s necessary to define what constitutes a healthy organism and how it overcomes infections or environmental assaults, such as pollution from forest fires or toxins from industrial smokestacks. An organism that catches a disease isn’t necessarily an unhealthy one, as long as it fights it off successfully—an ability that arises from the complex interplay of its genes, the immune system, age, stress levels and other factors. Modern science allows many of these factors to be measured, recorded and compared. “We need a data-driven, deep-phenotyping approach to defining healthy biological systems and their responses to insults—which can be infectious disease or environmental exposures—and their ability to navigate their way through that space,” Cool says.
Genetics and cell biology, combined with imaging techniques that allow one to see tissues and individual cells in actions, will enable scientists to define and quantify what it means to be healthy at the molecular level. “As a geneticist and cell biologist, I believe in all these molecular underpinnings and how they arise in phenotypic differences in cells, genes, proteins—and how their combinations form complex cellular states,” Cool says.
Julie Graves, a physician, public health consultant, former adjunct professor of management, policy and community health at the University of Texas Health Science Center in Houston, stresses the necessity of nutritious diets. According to the Rockefeller Food Initiative, “poor diet is the leading risk factor for disease, disability and premature death in the majority of countries around the world.” Adequate nutrition is critical for maintaining human health and life. Yet, Western diets are often low in essential nutrients, high in calories and heavy on processed foods. Overconsumption of these foods has contributed to high rates of obesity and chronic disease in the U.S. In fact, more than half of American adults have at least one chronic disease, and 27 percent have more than one—which increases vulnerability to COVID-19 infections, according to the 2018 National Health Interview Survey.
Further, the contamination of our food supply with various agricultural and industrial toxins—petrochemicals, pesticides, PFAS and others—has implications for morbidity, mortality, and overall quality of life. “These chemicals are insidiously in everything, including our bodies,” Graves says—and they are interfering with our normal biological functions. “We need to stop how we manufacture food,” she adds, and rid our sustenance of these contaminants.
According to the Humane Society of the United States, factory farms result in nearly 40 percent of emissions of methane. Concentrated animal feeding operations or CAFOs may serve as breeding grounds for pandemics, scientists warn, so humans should research better ways to raise and treat livestock. Diego Rose, a professor of food and nutrition policy at Tulane University School of Public Health & Tropical Medicine, and his colleagues found that “20 percent of Americans’ diets account for about 45 percent of the environmental impacts [that come from food].” A subsequent study explored the impacts of specific foods and found that substituting beef for chicken lowers an individual’s carbon footprint by nearly 50 percent, with water usage decreased by 30 percent. Notably, however, eating too much red meat has been associated with a variety of illnesses.
In some communities, the option to swap food types is limited or impossible. For example, “many populations live in relative food deserts where there’s not a local grocery store that has any fresh produce,” says Louis Muglia, the president and CEO of Burroughs Wellcome. Individuals in these communities suffer from an insufficient intake of beneficial macronutrients, and they’re “probably being exposed to phenols and other toxins that are in the packaging.” An equitable, sustainable and nutritious food supply will be vital to humanity’s wellbeing in the era of climate change, unpredictable weather and spillover events.
A recent report by See Change Institute and the Climate Mental Health Network showed that people who are experiencing socioeconomic inequalities, including many people of color, contribute the least to climate change, yet they are impacted the most. For example, people in low-income communities are disproportionately exposed to vehicle emissions, Muglia says. Through its Climate Change and Human Health Seed Grants program, Burroughs Wellcome funds research that aims to understand how various factors related to climate change and environmental chemicals contribute to premature births, associated with health vulnerabilities over the course of a person’s life—and map such hot spots.
“It’s very complex, the combinations of socio-economic environment, race, ethnicity and environmental exposure, whether that’s heat or toxic chemicals,” Muglia explains. “Disentangling those things really requires a very sophisticated, multidisciplinary team. That’s what we’ve put together to describe where these hotspots are and see how they correlate with different toxin exposure levels.”
In addition to mapping the risks, researchers are developing novel therapeutics that will be crucial to our armor arsenal, but we will have to be smarter at designing and using them. We will need more potent, better-working monoclonal antibodies. Instead of directly attacking a pathogen, we may have to learn to stimulate the immune system—training it to fight the disease-causing microbes on its own. And rather than indiscriminately killing all bacteria with broad-scope drugs, we would need more targeted medications. “Instead of wiping out the entire gut flora, we will need to come up with ways that kill harmful bacteria but not healthy ones,” Graves says. Training our immune systems to recognize and react to pathogens by way of vaccination will keep us ahead of our biological opponents, too. “Continued development of vaccines against infectious diseases is critical,” says Graves.
With all of the unpredictable events that lie ahead, it is difficult to foresee what achievements in public health will be reported at the end of the 21st century. Yet, technological advances, better modeling and pursuing bigger questions in science, along with education and working closely with communities will help overcome the challenges. The Chan Zuckerberg Initiative displays an optimistic message on its website: “Is it possible to cure, prevent, or manage all diseases by the end of this century? We think so.” Cool shares the view of his employer—and believes that science can get us there. Just give it some time and a chance. “It’s a big, bold statement,” he says, “but the end of the century is a long way away.”Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.
Massive benefits of AI come with environmental and human costs. Can AI itself be part of the solution?
The recent explosion of generative artificial intelligence tools like ChatGPT and Dall-E enabled anyone with internet access to harness AI’s power for enhanced productivity, creativity, and problem-solving. With their ever-improving capabilities and expanding user base, these tools proved useful across disciplines, from the creative to the scientific.
But beneath the technological wonders of human-like conversation and creative expression lies a dirty secret—an alarming environmental and human cost. AI has an immense carbon footprint. Systems like ChatGPT take months to train in high-powered data centers, which demand huge amounts of electricity, much of which is still generated with fossil fuels, as well as water for cooling. “One of the reasons why Open AI needs investments [to the tune of] $10 billion from Microsoft is because they need to pay for all of that computation,” says Kentaro Toyama, a computer scientist at the University of Michigan. There’s also an ecological toll from mining rare minerals required for hardware and infrastructure. This environmental exploitation pollutes land, triggers natural disasters and causes large-scale human displacement. Finally, for data labeling needed to train and correct AI algorithms, the Big Data industry employs cheap and exploitative labor, often from the Global South.
Generative AI tools are based on large language models (LLMs), with most well-known being various versions of GPT. LLMs can perform natural language processing, including translating, summarizing and answering questions. They use artificial neural networks, called deep learning or machine learning. Inspired by the human brain, neural networks are made of millions of artificial neurons. “The basic principles of neural networks were known even in the 1950s and 1960s,” Toyama says, “but it’s only now, with the tremendous amount of compute power that we have, as well as huge amounts of data, that it’s become possible to train generative AI models.”
Though there aren’t any official figures about the power consumption or emissions from data centers, experts estimate that they use one percent of global electricity—more than entire countries.
In recent months, much attention has gone to the transformative benefits of these technologies. But it’s important to consider that these remarkable advances may come at a price.
AI’s carbon footprint
In their latest annual report, 2023 Landscape: Confronting Tech Power, the AI Now Institute, an independent policy research entity focusing on the concentration of power in the tech industry, says: “The constant push for scale in artificial intelligence has led Big Tech firms to develop hugely energy-intensive computational models that optimize for ‘accuracy’—through increasingly large datasets and computationally intensive model training—over more efficient and sustainable alternatives.”
Though there aren’t any official figures about the power consumption or emissions from data centers, experts estimate that they use one percent of global electricity—more than entire countries. In 2019, Emma Strubell, then a graduate researcher at the University of Massachusetts Amherst, estimated that training a single LLM resulted in over 280,000 kg in CO2 emissions—an equivalent of driving almost 1.2 million km in a gas-powered car. A couple of years later, David Patterson, a computer scientist from the University of California Berkeley, and colleagues, estimated GPT-3’s carbon footprint at over 550,000 kg of CO2 In 2022, the tech company Hugging Face, estimated the carbon footprint of its own language model, BLOOM, as 25,000 kg in CO2 emissions. (BLOOM’s footprint is lower because Hugging Face uses renewable energy, but it doubled when other life-cycle processes like hardware manufacturing and use were added.)
Luckily, despite the growing size and numbers of data centers, their increasing energy demands and emissions have not kept pace proportionately—thanks to renewable energy sources and energy-efficient hardware.
But emissions don’t tell the full story.
AI’s hidden human cost
“If historical colonialism annexed territories, their resources, and the bodies that worked on them, data colonialism’s power grab is both simpler and deeper: the capture and control of human life itself through appropriating the data that can be extracted from it for profit.” So write Nick Couldry and Ulises Mejias, authors of the book The Costs of Connection.
The energy requirements, hardware manufacture and the cheap human labor behind AI systems disproportionately affect marginalized communities.
Technologies we use daily inexorably gather our data. “Human experience, potentially every layer and aspect of it, is becoming the target of profitable extraction,” Couldry and Meijas say. This feeds data capitalism, the economic model built on the extraction and commodification of data. While we are being dispossessed of our data, Big Tech commodifies it for their own benefit. This results in consolidation of power structures that reinforce existing race, gender, class and other inequalities.
“The political economy around tech and tech companies, and the development in advances in AI contribute to massive displacement and pollution, and significantly changes the built environment,” says technologist and activist Yeshi Milner, who founded Data For Black Lives (D4BL) to create measurable change in Black people’s lives using data. The energy requirements, hardware manufacture and the cheap human labor behind AI systems disproportionately affect marginalized communities.
AI’s recent explosive growth spiked the demand for manual, behind-the-scenes tasks, creating an industry described by Mary Gray and Siddharth Suri as “ghost work” in their book. This invisible human workforce that lies behind the “magic” of AI, is overworked and underpaid, and very often based in the Global South. For example, workers in Kenya who made less than $2 an hour, were the behind the mechanism that trained ChatGPT to properly talk about violence, hate speech and sexual abuse. And, according to an article in Analytics India Magazine, in some cases these workers may not have been paid at all, a case for wage theft. An exposé by the Washington Post describes “digital sweatshops” in the Philippines, where thousands of workers experience low wages, delays in payment, and wage theft by Remotasks, a platform owned by Scale AI, a $7 billion dollar American startup. Rights groups and labor researchers have flagged Scale AI as one company that flouts basic labor standards for workers abroad.
It is possible to draw a parallel with chattel slavery—the most significant economic event that continues to shape the modern world—to see the business structures that allow for the massive exploitation of people, Milner says. Back then, people got chocolate, sugar, cotton; today, they get generative AI tools. “What’s invisible through distance—because [tech companies] also control what we see—is the massive exploitation,” Milner says.
“At Data for Black Lives, we are less concerned with whether AI will become human…[W]e’re more concerned with the growing power of AI to decide who’s human and who’s not,” Milner says. As a decision-making force, AI becomes a “justifying factor for policies, practices, rules that not just reinforce, but are currently turning the clock back generations years on people’s civil and human rights.”
Ironically, AI plays an important role in mitigating its own harms—by plowing through mountains of data about weather changes, extreme weather events and human displacement.
Nuria Oliver, a computer scientist, and co-founder and vice-president of the European Laboratory of Learning and Intelligent Systems (ELLIS), says that instead of focusing on the hypothetical existential risks of today’s AI, we should talk about its real, tangible risks.
“Because AI is a transverse discipline that you can apply to any field [from education, journalism, medicine, to transportation and energy], it has a transformative power…and an exponential impact,” she says.
AI's accountability
“At the core of what we were arguing about data capitalism [is] a call to action to abolish Big Data,” says Milner. “Not to abolish data itself, but the power structures that concentrate [its] power in the hands of very few actors.”
A comprehensive AI Act currently negotiated in the European Parliament aims to rein Big Tech in. It plans to introduce a rating of AI tools based on the harms caused to humans, while being as technology-neutral as possible. That sets standards for safe, transparent, traceable, non-discriminatory, and environmentally friendly AI systems, overseen by people, not automation. The regulations also ask for transparency in the content used to train generative AIs, particularly with copyrighted data, and also disclosing that the content is AI-generated. “This European regulation is setting the example for other regions and countries in the world,” Oliver says. But, she adds, such transparencies are hard to achieve.
Google, for example, recently updated its privacy policy to say that anything on the public internet will be used as training data. “Obviously, technology companies have to respond to their economic interests, so their decisions are not necessarily going to be the best for society and for the environment,” Oliver says. “And that’s why we need strong research institutions and civil society institutions to push for actions.” ELLIS also advocates for data centers to be built in locations where the energy can be produced sustainably.
Ironically, AI plays an important role in mitigating its own harms—by plowing through mountains of data about weather changes, extreme weather events and human displacement. “The only way to make sense of this data is using machine learning methods,” Oliver says.
Milner believes that the best way to expose AI-caused systemic inequalities is through people's stories. “In these last five years, so much of our work [at D4BL] has been creating new datasets, new data tools, bringing the data to life. To show the harms but also to continue to reclaim it as a tool for social change and for political change.” This change, she adds, will depend on whose hands it is in.
DNA gathered from animal poop helps protect wildlife
On the savannah near the Botswana-Zimbabwe border, elephants grazed contentedly. Nearby, postdoctoral researcher Alida de Flamingh watched and waited. As the herd moved away, she went into action, collecting samples of elephant dung that she and other wildlife conservationists would study in the months to come. She pulled on gloves, took a swab, and ran it all over the still-warm, round blob of elephant poop.
Sequencing DNA from fecal matter is a safe, non-invasive way to track and ultimately help protect over 42,000 species currently threatened by extinction. Scientists are using this DNA to gain insights into wildlife health, genetic diversity and even the broader environment. Applied to elephants, chimpanzees, toucans and other species, it helps scientists determine the genetic diversity of groups and linkages with other groups. Such analysis can show changes in rates of inbreeding. Populations with greater genetic diversity adapt better to changes and environmental stressors than those with less diversity, thus reducing their risks of extinction, explains de Flamingh, a postdoctoral researcher at the University of Illinois Urbana-Champaign.
Analyzing fecal DNA also reveals information about an animal’s diet and health, and even nearby flora that is eaten. That information gives scientists broader insights into the ecosystem, and the findings are informing conservation initiatives. Examples include restoring or maintaining genetic connections among groups, ensuring access to certain foraging areas or increasing diversity in captive breeding programs.
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.”