After the second mating season in January of 1961, with the birth of the second generation of pups, her experimental population of foxes included one hundred females and thirty males. As this new generation of pups matured, some of them were so comfortable with people, like the two astonishing foxes from Kohila, Laska and Kisa, that they allowed Lyudmila and caretakers at the farm to hold them. But those were the exceptions. The rest of the pups matured to be just mildly calmer than was typical of captive silver foxes, and they often still exhibited fear or aggression. They might even bite on occasion, so that gloves still had to be worn when handling them.
Lyudmila was feeling increasingly confident, though, that the experiment was working. This was due not only to the calmer behavior of more of the foxes in the newest generation, but to the change in behavior of some of the farm workers toward those calmer foxes. A few workers at Lesnoi had been assigned to help her as caretakers of the foxes, and they had begun petting the calmest foxes when they brought them their food or came to clean their pens, spending a little extra time with them and clearly forming a bond with them. One worker in particular, named Fea, had fallen in love with the calmest foxes. She was quite poor, and could barely make ends meet by working at the farm. But Fea would bring her breakfast to the farm every day and fed most of it to her favorite foxes. She loved petting them and picking them up, even when they’d become fully grown and weighed a considerable 10–20 pounds.
This kind of affection was natural with small pups, who were so adorable and docile. But to see such a strong bond forming with mature foxes was striking to Lyudmila. As an animal lover, she felt their pull too, and she occasionally allowed herself to pet them and pick them up as she was making her measurements. But for the most part she held back. She had to remain an objective scientific observer and see that others did as well, and over the years she was obsessive about that. Yet this bond that the occasional worker like Fea was forming with the foxes was an important part of the study, she felt sure. Belyaev had conjectured that our ancient ancestors selecting animals for their tameness was one of the earliest stages in getting the process of domestication rolling, and here Fea was, in real time, doing just that. It required no stretch of the imagination to envision that naturally tamer wolves who ventured into contact with our early ancestors would have elicited a similar response.
After Lyudmila returned to the Institute of Cytology and Genetics from her second June visit to Lesnoi, Belyaev and she began to analyze all of the results, pouring through the voluminous data she had collected. They were stunned to discover a change underway in some of the foxes. By visual inspection of the female foxes’ reproductive organs, as well as by analyzing vaginal smears, Lyudmila had made meticulous note of when each of the females had gone into estrous each season, opening the short window of a few days in which she could mate them. Her data indicated that some of the tamer foxes were mating a few days earlier in the winter than is normal for silver foxes. Not only that, but their fertility was a little bit higher—they were producing, on average, slightly larger litters. A link between selection for tameness and more frequent reproduction was one of the pillars of Dmitri’s theory that somehow selecting for innate tameness kicked off all of the changes involved in domestication. Even this slight modification of a mating cycle that had been so fixed in the species for so long seemed to be a strong indication that he was right about that link, and also that a true process of domestication, not just of breeding marginally tamer foxes, was already underway.
3
Ember’s Tail
One morning in April of 1963, shortly after the fourth generation of pups was born at Lesnoi, Lyudmila was making her rounds observing them. The pups had only recently opened their eyes and left their dens. They were especially precious in these early days of exploring their world. By the time pups were three weeks old they were little bundles of energy. When they weren’t being groomed by their mother, or feeding blissfully at her belly, all snuggled up next to one another in a neat little row, they were scampering around their pens, pouncing on one another, yelping gleefully and tugging each other’s tails. Little fox pups are every bit as cute as dog puppies and kittens. Something about the neotonic features—the disproportionately large heads and eyes of all of these little creatures, along with their fuzzy fur and rounded little snouts—makes them irresistibly cute to humans, calling out for us to pick them up and cuddle them. On rare occasions Lyudmila gave in to that impulse and picked a little pup up. But she did her best to resist and simply observe the pups.
She visited all three dozen or so pups born to the calmest mothers several times a day, closely observing their reactions to her, how timid or bold they were, whether they were frightened if she reached in to touch them, or stayed calm, and taking detailed notes about each one on their length, size, coat color, anatomical features, and general health. As she walked up to the pen of one litter that day, one little male pup, named Ember, began vigorously wagging his tiny tail. Lyudmila felt overcome with joy. He looked just like a little dog puppy wagging his tail at her. It’s really true, she thought, the foxes are becoming more like dogs! Ember was the only pup in his litter with his tail wagging, and she felt as though he were calling out to her, bursting with excitement to see her.
Wagging their tails in response to humans is one of the signature behaviors of dogs, and until that day, they were the only animals observed to do so. None of the other pups she tested had ever done this. The behavior was unheard of in foxes, either in captivity or in the wild. Foxes do wag their tails towards each other, or to rid themselves of fleas or other pests, but fox pups had not been observed to do so in response to a person approaching.
Lyudmila quickly checked her emotions. She mustn’t make too much of this, she told herself, not yet. It seemed clear that Ember had started wagging his tail in response to her, but she’d have to verify that to know for sure, carefully observing whether or not he began wagging his tail again the next time she came to check on him and his siblings. Still, this was exciting. Tail wagging might be the first sign of the emergence of distinctively dog-like behavior in the foxes, and she hoped that some other pups would also wag their tails at her as she continued her rounds that morning. Not one other pup did so. Not that day, or any other day as she continued to observe them in the next couple of weeks. But Ember did keep wagging his tail, and there was no question that he started doing so when she came close to him. He also wagged his tail in response to attention from the caretakers.
Was Ember just an anomaly? Or might Belyaev and she have already found important evidence about the genetic origins of behavior in animals? Ivan Pavlov and many who had followed in the behaviorist vein of research argued that dog behaviors toward humans, including tail wagging, were the product of conditioning, which Pavlov had demonstrated with the dogs he’d conditioned to salivate at the sound of a bell. But for a new behavior to be picked up that way, an animal had to be subjected many times to a stimulus associated with the behavior. The American psychologist B.F. Skinner, one of Pavlov’s most influential followers, had demonstrated a different kind of conditioning, which he called operant conditioning. This involves rewarding an animal whenever it performs a certain behavior, such as in famous experiments Skinner conducted in which he rewarded rats with a pellet of food whenever they pressed a lever with their feet. At first the rats would press the lever only by chance, but after the pellets of food appeared a number of times, they began intentionally pressing the lever. This method is used to train all sorts of animals, from dogs to seals, dolphins, and elephants. But neither type of conditioning was involved with Ember wagging his tail toward her. He had simply spontaneously started doing so. This little pup might be leading the way in the foxes displaying a newly innate dog-like trait, just as Belyaev had predicted would begin to happen. But a single animal performing a new behavior, even over and over, might just be a quirk. It would be fascinating to see if any of Ember’s pups in the next generation, or any of the other pups
next spring, would be tail waggers.
Lyudmila observed no other striking new behaviors in Ember’s generation, but she did note that many more of the pups were markedly calmer when tested than in the prior generations. And more tame females also went into estrous a few days earlier than the normal timing for wild females, which was another good sign that the experiment was continuing to produce notable results.
She would have loved to share this news with Dmitri right away, but she’d have to wait until she returned to the Institute of Cytology and Genetics. She always had a meeting with him shortly after she got back from Lesnoi, and these meetings were special to her because they offered the rare opportunity for the two of them to discuss their findings in depth and share notions about what the results were telling them. Belyaev wished he could spend more time with Lyudmila on the fox experiment, and that he could visit the foxes regularly. But he was so busy with his work running the Institute that he had been able to sneak in only a couple of quick trips to Lesnoi so far. These meetings when she came back to the Institute with the latest news were also special to him.
He would invite Lyudmila to his office and order some of his favorite brew of tea—a special blend of Indian and Ceylon with 1.5 lumps of sugar, “every time, without exception,” recalls his secretary. He’d first ask Lyudmila how her husband, daughter, and mother were faring, sensitive that her time away at Lesnoi had been hard on her family. He’d then ask how she was doing. Though Belyaev was an intensely driven man who worked at a feverish pace, he took the time to check in this way with those who worked for him, and he understood how difficult the long trips away had been for Lyudmila, and that she especially was missing time with young Marina, who was now a lively toddler. Lyudmila recalls how “At times when there was something wrong in my soul he [Dmitri] would feel it. And if I started to talk, well, I wouldn’t even complete a word before he understood what I wanted to say.”
For their meeting this time, she was delighted that she had particularly intriguing news for him. She filled him in on how calm some of the foxes were compared with earlier generations and that more females were displaying a slightly longer reproductive period. Then Lyudmila told him about Ember and his tail wagging. Dmitri agreed it could be important. Ember appeared to be wagging his tail due to a new emotional response to people, and if other pups also began to do so, that might prove to be a big step in the process of domestication. Though they’d have to wait to discover whether that was the case, the results they’d already recorded in sum were substantial enough that Belyaev decided it was time to announce them to the world genetics community. He would have the perfect opportunity for doing so, having secured a slot for a presentation at the 1963 International Congress of Genetics, which was being held at The Hague, in the Netherlands. For the first time since Lysenko had wormed his way into power decades earlier, the government was allowing a delegation of Soviet geneticists to attend this meeting, a clear sign that Lysenko was losing the power struggle. Held only once every five years, the Congress was the most important conference in genetics in the world; the one “don’t miss” genetics meeting. Dmitri made sure he was on the list.
Over the past several years, the Russian genetics community had continued to wage its fight against Lysenko, and the wider scientific community had also taken up the cause. In 1962, three of the most respected physicists in the Soviet Union had joined in a public excoriation of Lysenko’s work. He remained the director of the Institute of Genetics for another two years, but after physicist Andrei Sakharov lambasted Lysenko in 1964 in a speech to the General Assembly of the Academy of Science, blaming him for the “shameful backwardness of Soviet biology . . . for the defamation, arrest, and even death of many genuine scientists,” Lysenko was deposed from his position. Shortly thereafter, the government officially denounced him and repudiated his work. Belyaev, his wife recalls, was thrilled. Soviet genetics could at last begin making up for lost time.
For his presentation at the Congress of Genetics at the Hague, Dmitri introduced the hypothesis guiding the fox experiment, about selection for tameness leading to domestication, and explained exactly how the experiment was being conducted, walking his listeners through the findings of the pilot study and then all of their latest results. The crowd was impressed; no one had heard of any domestication experiment of this kind. It was audacious. One of those who attended the talk was Michael Lerner, from the University of California at Berkeley, who was widely regarded as one of the world’s leading geneticists. He introduced himself to Belyaev afterwards and the two discussed the experiment further. Lerner was struck by the scope and originality of the work, and he and Belyaev began a correspondence to keep up with one another’s research. One of Dmitri’s main aims in attending the Congress was to spread the word about the experiment to geneticists in the West, and Lerner couldn’t have been a better man for the job. A few years later, Lerner wrote about the experiment’s results in his textbook about animal breeding, one of the major works on the subject. Dmitri wrote to his friend, “I was very pleased to find references to my work.”1
Garnering such recognition for their research outside of the Soviet block was still nearly impossible for Soviet scientists. Though they could now openly keep up with the research being done in the West, and a select number were allowed to attend some conferences abroad, the Cold War was raging and the Soviet government made submitting their work to research journals outside the Soviet block very difficult. They could sometimes sneak papers out with visitors from the West, but for the most part their work was not known there.
Belyaev was acutely sensitive to the frustration his research staff felt about this isolation. Great advances in genetics had been made in the West in recent years. Dmitri couldn’t do much to help his people get their work published in the West, but at least he could facilitate their doing cutting-edge work. He worked hard to build the Institute of Cytology and Genetics into a first-rate research center, and as Dubinin had anticipated when he selected Belyaev as his right-hand man, he proved to be a strong leader who knew how to recruit top talent. The fox experiment was only one of many important ongoing projects at the Institute. Other researchers were working on basic genetics studies, such as a major project to compile an archive of the chromosomes of a host of species. Some were studying how cells function and are built. Still another group was working on crop breeding.
Dmitri was also intent to foster a spirit of camaraderie among both the staff and students at the Institute. That was made difficult by the fact that the construction of a building meant to house the Institute had been stalled for years, and the 342 staff, scientists, and students of the Institute of Cytology and Genetics had been scattered all over the grounds in five different buildings.2 In 1964, he was at last able to bring them all together, making good use of his shrewd sense of how to negotiate political waters. When construction of a new building finally began moving forward, the increasingly powerful Computing Center at Akademgorodok lobbied hard that they deserved a nice new home more than the Institute of Cytology and Genetics, but Belyaev beat them to the punch. As soon as the building was finished, even before the ribbon cutting, he told the staff to start setting up shop in it. They moved in so quickly—in a single weekend—that before the Computing Center heads got the word, it was a fait accompli.3
Dmitri savored the evening, when he’d finished with his loads of administrative work and could finally turn to science. He would often invite a group of researchers or students to join him in discussions of their research. Exclaiming to his secretary, “Ok, tonight is the night, now I can do some science!,” he’d have her call people to his office for a working session. This required them to work long hours, but he made it well worth their while, conducting discussions that were lively affairs. They could get quite animated, and his secretary recalls lots of shouting but also lots of laughter erupting from his office. This was exactly the way he felt scientific discussion should be conducted, reminiscent of the “yelling meetings” he
attended with his brother Nicholai and the Chetverikov science group as a child.
Many of these sessions also took place at the Belyaev home, which was a short walk from the Institute. His wife Svetlana would cook a scrumptious dinner and they’d eat at about 9:00 p.m., over a heated discussion about current events. Dmitri, who was now out of his standard dark suit and tie and dressed causally, would sometimes hold forth with a story. “He was an excellent storyteller and an actor,” his student, and later colleague, Pavel Borodin, recalls. “He would never just tell a story; he would play the role of the hero,” doing a lively imitation. After dinner, they’d head upstairs with Dmitri to his study to talk more science and work on journal papers.
Lyudmila immensely enjoyed these sessions, and the intense debates with her colleagues about the significance of the fox experiments’ intriguing findings. They were fascinated by the early results, and they shot ideas back and forth about what might be causing these changes so quickly. Soon, she would have an astonishing new set of findings to share with them.
IN 1964, LYDUMILA OBSERVED NO BIG NEW changes in the new [fifth] generation of pups. She had mated Ember to a tame female that January, in hopes that some of his pups would also wag their tails, but none did. No pups born to other females that year wagged their tails either. An increasing number of pups were markedly tamer, however.
The next generation of pups was a very different story. On her April trip to Lesnoi in 1965, to observe the newborns of the sixth generation, she discovered that they displayed a set of exciting new dog-like behaviors. These pups pressed themselves up against the front of their pens when Lyudmila approached, trying to nuzzle up against her, and rolled over on their backs, clearly inviting her to rub their bellies. They also licked her hand when she reached in to test them. When she walked away from them, these pups would whine with a sound of distress: they seemed to want her to stay. They also behaved in all of these ways with the caretakers. Just as with Ember’s tail wagging, no one had ever observed these behaviors towards humans in foxes before, whether in nature or in captivity. Pups whine for food and attention from their mothers, but never had they been known to whine to solicit human attention. Nor had a fox ever been recorded to have licked the hands of caretakers. So moving were these pups’ protestations that Lyudmila had a hard time disappointing them, and she often now found herself stepping back to a cage to spend a little more time before leaving. There seemed to be no doubt at all that these pups, from as early as they could walk, eagerly sought contact with humans.4
How to Tame a Fox (and Build a Dog) Page 6
