The Atlantic: Making Rhino Horns Out of Stem Cells

Last spring I was reporting on the last Northern white rhinos in Africa and I had an interesting conversation with a bush pilot on the veranda of my host's home on the outskirt of Nairobi. I had been explaining how in the future, stem cell technology might be used to recreate Northern white rhinos in surrogate rhinos, when he asked me, "Why don't they just use stem cells to recreate rhino horns and sell them to stop poaching?" I went home and set out to find anyone else who had the same idea and sure enough, I found the bioengineer and entrepreneur Garrett Vygantas. My piece in The Atlantic focuses on how Vygantas is launching a company to produce and sell artificial rhino horns to Asian markets, and the ethics of this endeavor. 

How Fast Can Evolution Go?

I recently returned from a reporting trip to the banks of this tiny creek on a U.S. Air Force base in White Sands, New Mexico. Called the Lost River and at times no more than a foot wide, the slow-moving water creeps for about a mile until it disappears into the gypsum dunes of the White Sands National Monument. I went to see Cyprinodon tularosa, a desert fish that has survived in the Tularosa basin since the Pleistocene era, when the basin floor was covered by a body of salt water called Lake Otero. As the climate warmed, the lake dried up and the pupfish were isolated to a handful of remaining springs and drainages. In modern times, these habitats shrank to just two: Malpais Spring and Salt Creek, and the fish were listed as threatened by the state of New Mexico. The geologist C.L. Herrick, who went to New Mexico in 1898 to try and cure his tuberculosis, was the first person to take note of the silver fish, no more than two inches long, flitting in the waters of Malpais Spring. A few years later, another geologists noted the same fish in Salt Creek. Later genetic testing shoed that a volcanic lava flow separated these two populations from each other at least 5,000 years ago. 

In 1859, Charles Darwin wrote that "We see nothing in these slow changes in progress, until the hand of time has marked the long lapse of ages." 150 years later, Darwin's belief that natural selection and evolution are slow processes that take place over eons, has been upturned by the White Sands pupfish. Biologists now believe that the fish have one of the fastest rates of evolution for a known vertebrate. This phenomenon, called “rapid” or “contemporary” evolution, has significant implications for how we think about and mitigate extinction crises. Anthropogenic disruptions like climate change don’t just reduce biodiversity and abundance, they alter the evolution of organisms and can do so over mere decades. This also means that conservation efforts themselves—moving populations of animals, captive breeding, and assisted reproduction—is not really preserving animals at all. It’s actually setting them on new evolutionary trajectories that are not “wild” in the way we typically understand that word to mean free of human interference. This is evolution directed by us.   

Biologists might never have discovered this remarkable trait of the obscure pupfish if not for a retired engineer by the name of Ralph Charles. 40 years ago, Charles' fascination with pupfish led him to do something bizarre: he stole 30 of them from Salt Creek and brought them to Lost River, where he released them into the tail end of the creek as it meets the white gypsum sand dunes. Charles was a former employee of the Bureau of Reclamation, a water management agency under the U.S. Department of Interior. For years he had requested to visit the native populations of pupfish at Salt Creek and Malpais Spring. Unfortunately for him, the fish had been under the protection of the U.S. Department of Defense since around 1945. That was when the military created a missile range and weapons testing ground on 3,200 square miles in the Tularosa Basin (still operative today) that enveloped both native pupfish habitats. Charles finally appealed to a U.S. Senator, who granted him a one day security clearance to get onto the missile range. In the late 1990s, when ecologist John Pittenger was trying to understand how exactly pupfish got to Lost River, he came across the papers of William Jacob Koster, one of the first ichthyologists to focus on New Mexico’s fish, at the Museum of Southwestern Biology in Albuquerque. Among the papers was a letter from Charles inquiring as to how the pupfish he had brought from Salt Creek to Lost River were faring. Until Pittenger found this note, no one knew whether the Lost River population had always been there or was introduced. 

Charles' motives for taking the fish have been lost to time, but translocating fish around the springs and drainages of southern New Mexico was not necessarily unheard of. An anonymous rancher had done the same thing in the 1960s, bringing pupfish from Salt Creek TK to a freshwater environment called Mound Spring further north in the basin, probably as a form of mosquito control. Both of these translocated fish survived. Pupfish, in fact, appear to be an extraordinarily adaptive species, capable of reproducing in waters that range from brackish to highly saline. At Lost River, for instance, the water can vary from 25 to 80 percent salt concentration. At the high end of this spectrum, the salt content of Lost River is double that of the Dead Sea.  “I like to say they are evolutionarily labile,” said Michael Collyer. “They are capable of evolving in multiple directions. They can be saline fish, freshwater fish. These changes would normally cause extinctions in most fishes but they tend to persevere.” Fresh and salt water, however, have different densities that result in different kinds of fish. Saline habitats produce fish with more slender bodies and hence less drag, whereas freshwater fish have a deep-bodied shape.

By the time Collyer, a graduate student at the North Dakota State University began studying the species in the late 1990s, he began to notice something strange about the two introduced populations of fish at Lost River and Mound Spring. "You spend enough time looking at the fish and start thinking, you know, they look different to me," he told me. "It's a lot like parents of twins, they see differences in their kids other people can't see." This single observation became the main thrust of Collyer's research. He developed a methodology for establishing morphological differences between the populations and what he found was that the Mound Spring population had evolved a deep body shape since their relocation, while the Lost River population maintained their streamlined morphology. This was not just the result of what biologists call phenotypic plasticity, the ability of an organism to change its appearance and physiology in response to changes in the environment. The differences in the Mound Spring population were genetically based. "This was contemporary evolution," said Collyer. "This population of fish was now different from its source. That was fascinating. We're talking about a couple of decades, when we're used to to seeing changes over thousands of generations." 

Banking on Latent Life

Over the last six months I've been visiting the Ambrose Monell Cryo Collection (AMCC) at the American Museum of Natural History in Manhattan, to learn about the 87,000 frozen tissue samples from thousands of species within the collection. On my last visit, I met with Julie Feinstein, the manager of the laboratory, who explained the significance of the samples for research and conservation. “These are priceless, irreplaceable specimens. They might come from places where it is politically difficult to collect. It’s not free to travel around the world to get them,” she said. “All of them are animals that died for science so in a way, they are all really priceless.” 

It was difficult to imagine the treasures inside the steel canisters and I asked whether I could look inside one. Feinstein put on plastic goggles and thick rubber gloves to protect against contact with the freezing vat. It was tall enough that Feinstein had to step onto a small platform in order to reach the top and open its lid. When she did, a thick white fog spilled over the sides.  Feinstein invited me onto the platform while warning against inhaling the toxic vapor too deeply. Inside was what looked like a giant Trivial Pursuit pie with six sections. Each of the these held nine metal racks. With a gloved hand, Feinstein turned the pie like a Lazy Susan and pulled one out. It had 13 white boxes stacked on top of each other and inside each box was one hundred, two-inch vials, all labeled with a barcode and serial number. Using forceps she picked a vial from a box at random and rattled it to show me a specimen that looked like a black-eyed pea. “This is number is 110029,” said Feinstein, reading the barcode. We walked to her office in the next room and she opened up the collection’s database on a computer. “Here it is,” she said. “110029 is a mosquito from the New York City Department of Health.” She paused for a moment, searching her own memory. “I remember this, it’s someone’s PhD work.” 

Feinstein’s job at the Cryo Collection is to impose order on a vast amount of data associated with the samples, making sure that each one is properly catalogued and available for any scientist around the world who might request them for research. She’s like the librarian of a lending library, if librarians were expert molecular biologists whose collections are filled with irreplaceable books that would be unintelligible and meaningless if cataloged or preserved incorrectly. Freezing tissue samples is not an easy task, or at least doing so in a way that preserves the integrity of their DNA for posterity. “It’s hard to store tissues because they are filled with entropy and disorder. They are cold and hard to handle. People store them in appropriate ways that are undependable,” she said. This is a job that requires tremendous capacity and patience for practical detail. She takes raw samples that are often collected under difficult conditions in the field and conforms them to laboratory standards designed to last hundreds of years. It’s a process that she described as rife with difficulty, the first challenge being that the samples are gathered by idiosyncratic scientists. She told me how one time a biologist dropped off a black trash bag filled with irreplaceable herbs from the mountains of Mexico, and a handful of xeroxed field notes; it took a year and a half to catalog the 850 samples inside the bag.  

Conserving at the Evolutionary Scale

I've been writing about one of the first individuals to recognize the need for centralized repositories of the planet’s genetic biodiversity, an Austrian-born geneticist and plant breeder by the name of Otto Frankel. Born in 1900, Frankel was a young communist  who wanted to dedicate himself to the fight against hunger and chose to study agriculture. His early research included counting chromosomes of the Jaffa Orange and understanding the evolution of wheat. In the 1960s, Frankel became what some have called the high-prophet of genetic resources conservation, beginning with his involvement in the International Biological Program and its 1st General Assembly in Paris in 1964. Otto saw firsthand through his research that we were losing genetic diversity among plant species, and he believed that institutions needed to respond with long-term seed storage, computerized data cataloging, and the creation of a global network of genetic resource collections. A few years after the Biological Program assembly, Otto helped to organize a conference on “The Exploration, Utilization and Conservation of Plant Genetic Resources,” now considered a landmark moment in the timeline of conservation biology. He argued that humankind’s impact on genetic diversity of other organisms was on so great a scale that we had “acquired evolutionary responsibility and must develop an ‘evolutionary ethic.’” An evolutionary ethic, said Frankel, is one in which civilized man recognizes the continued existence and evolution of other species as integral to his own existence. In 1974 Otto went to Berkeley, California for the International Congress of Genetics and presented his paper “Genetic Conservation: our evolutionary responsibility,” a moment that according to subsequent leaders in the field of conservation biology, was groundbreaking for its presentation of a conceptual and moral agenda for conservation. Here is a quote from that paper: 

    “Neither our pre-agricultural ancestor, nor the peasant farmer who succeeded him had cause for concern beyond the next meal or the next crop, the former because he used a pool of great species diversity, the latter a pool of self-renewing intraspecific diversity. This came to an end with the advent of scientific selection. Today’s concern is with preserving and broadening the genetic base. The time perspective for gene pool conservation might be the next 50 or 100 years—which is merely an acknowledgement of the unparalleled technological transcience of our age; we cannot foresee even what kinds of crops will be used at that time. For wildlife conservation the position is altogether different. Concern for its preservation is new, a consequence of our destructive age. Nature conservation is fighting for reserves and for legal recognition. The sights often are set for the short term, although perpetuity is its ultimate objective. Genetic wildlife conservation makes sense only in terms of an evolutionary scale. Its sights must reach into the distant future.”

Birds of a Feather

Hummingbirds, owls and finches are some of the 130,000 bird specimens preserved at University of Washington's Burke Museum of Natural History and Culture. The 125-year-old museum continues to preserve whole specimens but it increasingly focuses on its Genetic Resources Collection, one of the largest in the country. Today the museum maintains tissue samples from some 50,000 birds that are cryogenically frozen and kept in deep freezers. I've been visiting, reading and researching "frozen zoo" initiatives around the world and one of the best perspectives I've found on them comes from the anthropologist Tracey Heatherington. Here's an quick excerpt from her essay, "From Ecocide to Genocide: Can Technoscience Save the Wild?"

"Mundane monitoring of population health and protection of habitats is necessarily the mainstay of wildlife management for most biodiversity conservation programs. Yet the moral terrain of extinction is tremendously evocative for the genetic imagination, defining the frontiers of capital investment in both technoscience and biodiversity."