Clearly dramatic changes were happening to the endocrine system, the system responsible for the creation of hormones, in the tame foxes. But due to the limited understanding of the workings of that enormously complex system, it was impossible to say precisely what was happening and why. So complex is the endocrine system that it’s still difficult to interpret this finding today. What could be said, because of the stark differences of the effects in the tame versus the control foxes, was that simply selecting foxes for their tameness had led to profound and complex changes to their reproductive system, just as Belyaev had conjectured so many years earlier.
WHILE DMITRI AND LYUDMILA WERE conducting their investigations into hormone and serotonin levels, Dmitri was also furiously planning for the fast-approaching International Genetics Congress, to be held in Moscow in August of 1978. As the Secretary General of the Congress, he was in charge of all of the arrangements, and he wanted it to be a gala affair, showcasing the finest offerings of Russian culture as well as the very best of the newest research from around the world, and from within the Soviet Union. The meeting would bring together researchers from sixty countries—3,462 geneticists in total—almost none of whom had ever been to the Soviet Union. This was a huge coming out party for Soviet genetics, a chance to show the whole world that they were well out from under Lysenko’s boot and were doing first-class work. Dmitri wanted participants to never forget their trip to Moscow, and to come away with a vastly different impression of the Soviet Union than the one given by news broadcasts, which usually covered the latest conflict of the Cold War.
Détente had paved the way for this unprecedented opening of the doors to Western genetics, and in another sign of the seriousness of the Soviet authorities about new cooperation with the West, the USSR Academy of Science and the US National Academy of Sciences teamed up in 1977, the year before the International Genetics Congress, to conduct an assessment of the quality of Soviet research programs. They appointed John Scandalious, a senior geneticist from North Carolina State University, to visit a number of Soviet centers in genetics and evaluate them. The Institute of Cytology and Genetics in Novosibirsk was on his list, and his visit offered Dmitri a dry run at putting Russia’s best foot forward.
Scandalious was put up at the lavish hotel in Akademgorodok reserved for visiting dignitaries and wined and dined, with many evenings of free-flowing caviar and vodka toasts. Dmitri and his wife, Svetlana, had him over to their home for several of their signature dinners with the Institute researchers, featuring much storytelling by Dmitri and lots of lively debate. Scandalious was impressed by how intensely the researchers at the Institute were thirsting for knowledge, not only about the latest scientific findings in the West, but about culture and politics as well.
Belyaev proudly brought him to the fox farm for a visit and Scandalious warmly recalls how Dmitri gently took one of the tame foxes from its cage and “handled it like it was a little baby, stroking it and talking to it.” Scandalious had seen Dmitri as a somewhat stern man at first, and had then seen his warm side in spending more time with him. But even so, he was surprised to see him with the foxes, suddenly so gentle and affectionate. He was also struck over the course of his visit by how unofficious Dmitri could be when it was for the betterment of science, and how concerned he was for his researchers. One day as the two headed out of a meeting that had annoyed Dmitri, he said to Scandalious, “That guy is a pompous ass.” “When we spoke science,” Scandalious recalls, “Dmitri was very enthused, but at the same time depressed at how far back they were from the West.”16 When Dmitri learned that a number of younger scientists at the Institute had given Scandalious unpublished manuscripts to submit on their behalf to European and American genetics journals, which was still a violation of official rules, all Dmitri said to Scandalious was that it was okay and he needn’t worry about being searched on the way out of the country.
Belyaev and the Institute received high grades in Scandalious’s report, and Dmitri felt confident that was a good omen of what the International Genetics Congress would bring.
Indicative of the stature he now held in Soviet science, Dmitri had secured approval for the Congress to be officially opened at the Kremlin, the heart of Soviet power and legend. Within the imposing towered walls lay the seat of the Senate, the Great Bell Tower, the Tsar’s Cannon, the Arsenal, the Armory (treasury), and a number of exquisite churches with breathtaking gold turrets. The opening session of evening addresses was held in the cavernous main theatre of the State Kremlin Palace, which seats 6000.
The president of the International Congress of Genetics, seventy-nine-year-old botanist Nikolai Tsitsin, took the stage first and immediately assured the august assembly of the world’s leading geneticists that the Soviet Union was back in the business of serious science, beginning his speech with the welcome, “On behalf of the Soviet people, scientists, geneticists and selectionists. . . .” His use of the word “selectionists” sent an unmistakable message that Lysenko and his denialism were dead and buried and that Gregor Mendel’s genetics and Charles Darwin’s theory of natural selection were again the driving force of Soviet genetics. Dmitri Belyaev could not have been more pleased. Making that case was one of his main objectives in signing on for the massive undertaking. The president also made a special point that night of noting that Darwinian ideas on natural selection had recently been enhanced by Professor Belyaev’s powerful new theory of destabilizing selection.17 Yes, Dmitri thought, the meeting is off to a good start.
After the opening speeches, the guests headed to a lavishly laid out banquet hall in the Kremlin State Palace, where as one of the attendees recalls, “champagne and black caviar were not limited.”18 On other nights, Dmitri and Svetlana hosted late night cocktail parties in their luxurious suite at the Rossiya Hotel, which was listed in the Guinness Book of World Records as the world’s largest hotel. With 3,200 rooms, the finest of which overlooked the Kremlin, it was equipped with its own police station. John Scandalious made sure to attend one of these fêtes, and his wife Penelope, who’d come along for this exotic trip, fondly remembers the spirit of international camaraderie in the room, the plentiful caviar, sturgeon and top-quality cognac, which was served with sugared lemon slices as chasers, and the many toasts to friendship and genetics.
As the Secretary General of the Congress, Dmitri was slated to give one of the evening keynote addresses, and naturally chose to discuss the fox experiment. After introducing all of the latest findings, he presented a short film that showed the foxes in action. He had hired a professional film crew to come to the farm, and Lyudmila and her assistants had brought them all around, showing them the tame foxes and how they responded so gleefully to attention, and also the aggressive foxes and how fierce they were. Lyudmila also brought the crew over to Pushinka’s house to meet the current brood living there and how they came trotting right into the house from the yard when they were called.
The lights went down and as stock footage of cows grazing, horses prancing, and puppies frolicking around in a field rolled, a narrator announced in crisp English, “Domesticated animals have been bred by man for about fifteen thousand years.” Then a little charcoal-colored fox appeared on the screen, prancing happily along a country road, off leash, accompanied by a woman in a white lab coat—one of the Institute researchers. The fox was sniffing the grass by the side of the road, wagging its curly tail, and glancing up at the woman repeatedly to make sure she was keeping pace—looking exactly like a dog. As the camera toured the farm, fox pups nibbled playfully at a researcher’s fingers, adults wagged their tails excitedly as Lyudmila and her assistant Tamara walked by their cages saying hello, and the family of foxes living in Pushinka’s house followed Lyudmila out the door and into the back yard, gathering around her and competing for her attention. As the lights came back up, the room was abuzz with whispered comments about these amazing animals.
Dmitri completed his talk by informing the crowd that after the twenty years the experiment ha
d been running, the farm now housed 500 domesticated adult female foxes, 150 adult males, and 2,000 young foxes, many of whom displayed the domestication traits. He closed by offering a tantalizing thought: that his theory of destabilizing selection and domestication “can also, of course, apply to human beings.” He said nothing more on the subject, and discussion as the crowd streamed out of the auditorium was rife with speculation about what he was suggesting.
THE IDEA THAT HUMAN EVOLUTION MIGHT have followed essentially the same course as the domestication of dogs, goats, sheep, cows, and pigs was provocative to say the least. Were we humans really, in essence, domesticated apes? Some astonishing genetic analysis of humans published only a few years before the Moscow congress had proved that we were extremely closely related to the primates thought to be our closest relatives, chimpanzees. In fact, this work suggested that we were so closely related that genes alone could not explain all of the substantial differences in our physiology, not to mention our cognitive abilities.
In 1975, Mary-Claire King and A. C. Wilson published a Science paper where they note that “the sequences of human and chimpanzee polypeptides examined to date are, on the average, more than 99 percent identical.” They hypothesized that this meant that the differences between the two species must be due primarily to changes in the regulation of the activity of genes, rather than to a series of new mutations that selection had acted on.19 This argument fit nicely with Dmitri’s theory of destabilizing selection. Dmitri had asserted that the dramatic changes involved in domestication were not due primarily to an accumulation of new genetic mutations favored by selection—though he knew that these surely played some role—but rather to alterations in the expression of existing genes that caused them to produce different results. Belyaev’s core insight that the activity of genes could be turned on and off, or altered somehow, so that the same genes produced different results, such as tame behavior, curly tails, and the emergence of new coat colors, was being confirmed.
The term gene expression had begun gaining currency as researchers discovered more about just what a complex process the translation of the coding of a gene into a biological product, like hormones, is. As sequencing techniques improved and the elaborate workings of cells became better understood, researchers began to discover that gene expression was not a matter of a lock-step, computer-like “reading” of the genetic code by the cell. The code could be modified and production could be either stopped or increased. Cell biologists had determined that the manufacturing of the proteins, hormones, enzymes, and the other chemicals that genes code for, conducted by the little structure in the cell called the ribosome, could be interfered with to produce more or less of any given chemical product. The expression of a gene came to be understood as, essentially, the process by which the gene led to the production of more or less of a protein, hormone, enzyme, or other chemical by cells. And small changes in expression could produce large effects in an animal’s physiology and life functioning. Some change or set of changes in gene expression, Dmitri thought, might explain why the pineal glands of the tame foxes were now producing so much more melatonin, and also why, even though that melatonin wasn’t making it out into their blood systems, it seemed to be dramatically affecting the foxes’ reproductive behavior.
Subsequent research has revealed that the expression of genes can be interfered with in a host of ways, and by multiple culprits, including environmental factors. The action of light in regulating the production of melatonin is only one of a multitude of examples.
The timing of when genes become activated can also be modified. For example, small bits of “noncoding DNA” that produce no product of their own can tinker with gene expression, causing certain genes to become activated either earlier or later in the development process. Some such change in the timing of activation probably explains one of the physical changes that had begun appearing in more and more of the foxes during the course of the 1970s. The white star that had appeared on the head of only one male pup in 1969 started showing up on the heads of more foxes with each new generation. Advances in embryology allowed researchers in that field who worked at the Institute of Cytology and Genetics to explain how the stars were emerging. By analyzing the hair that constituted the stars closely, Dmitri and Lyudmila had found that the stars were made up of only three to five white hairs. Their ongoing pedigree analysis had shown that the pattern of inheritance by which the stars were appearing indicated they were not due to new genetic mutations; the number of stars was increasing much too rapidly for that to be the case. Something else was going on, and the embryologists figured out that it had to do with a change in timing in one aspect of the development of the fox embryos.
By this time, embryologists had worked out ways to track the migration of cells to different parts of the body as an embryo develops. Some migrate to the top of the spinal column and become brain cells, some migrate to become lung cells, some heart cells, and so on. The embryologists at the Institute were able to determine that the white coloring of the few hairs creating the stars was due to the timing of when the cells responsible for the coloration of hair were being instructed to migrate and become skin cells. While these cells normally migrate during the period from 28 to 31 days of development, in the foxes with the stars on their forehead, the movement was delayed by two days. This delay caused an error in their production of hair color, leading the hairs of these cells to be white.
The timing of the cell migration must be governed, Dmitri and Lyudmila concluded, by a chemical produced by a gene, and it seemed that the expression of that gene had been affected by the destabilization brought about by the selection for tameness. One small example of what a delicate operation the functioning of genes is.
Much subsequent research has shown that gene expression is an extraordinarily complex affair. So complex and unpredictable are the processes by which gene expression is regulated that learning how to take charge of the process, in order to fight diseases and harness the body’s healing powers, is a quest we’ll be on for many years to come.
Dmitri and Lyudmila were to experience a sad truth of the mystifying complexities of these elaborate operations when they decided to try again to mate some of the tame foxes before the normal January mating period. Lyudmila had discovered that some of the elite males in addition to females were sexually active and prepared for mating in the fall as well as in the winter mating window. This was without any manipulation of their exposure to light. The change had emerged, as with the females, from the continuing selection for tameness. In the fall of that year, she and Dmitri decided to see whether some of these foxes would mate if they were put together, and whether the tame females would now become pregnant. A number of them did, and though some of them miscarried, a few of them gave birth successfully. This was another huge step for the experiment. The question whether or not, if foxes were bred to be domesticated, they would be able to mate more than once a year, as almost all domesticated animals do, was answered.
Everyone, especially Dmitri Belyaev, was thrilled. Lyudmila recalls that “when we produced the pups, Belyaev went to the Institute and arranged an emergency meeting in the conference hall.” Dmitri enthusiastically told the staff, “Here are results you should be proud of. Here are results you can boast about.”
But the sad truth was that being able to give birth outside of the normal cycle did not also include being able to nurture the newborn pups. The mothers were not producing enough milk to sustain their pups, and the little they did produce, they were reluctant to dispense. For the most part, they ignored their pups. Lyudmila and her team did all they could to care for the helpless little creatures, feeding them on a rigorous schedule with a dropper. But that was not enough. None of them survived.
As Dmitri had hypothesized so many years earlier, destabilizing selection had substantially altered the genetic systems of the foxes, but some components of the delicate cycle of reproductive readiness were now out of sync with one another. With dogs and cats and
cows and pigs, over the longer sweep of evolutionary time in which their domestication unfolded, changes in the selection pressures they were living under, due to living in close proximity to humans, had recalibrated their reproductive systems so that mothers could produce more milk and developed nurturing impulses more than once per year. It made perfect sense that the new selection conditions would have produced this new calibration; giving birth more than once a year would be selected for by natural selection once more offspring could be fed and protected. And the breeders of the animals would also have selected for the ability. In the foxes, selection for tameness had progressed to the stage where the animals could reproduce more than once in a year, but not yet care for their young. In principle, the ability to produce milk and to be a good mother would be the next step. But, as Lyudmila says, the reproductive system “cannot just be changed overnight.”
THE EARLY 1980S WAS AN EXTREMELY PRODUCTIVE PERIOD for the fox experiment in beginning to solve the mysteries of the deep biological changes going on with the foxes, but the decade would evolve into a very challenging time for the experiment.
With the Soviet invasion of Afghanistan in 1979, renewed tension developed between the Soviet Union and the Western alliance of nations, reversing the thawing of détente. President Jimmy Carter sent covert support to the Afghan rebels fighting the Soviet military, which was stepped up after the election of President Ronald Reagan in 1981, who also put new emphasis on building up US military might. The administration implemented the Reagan Doctrine, which involved the support of other resistance movements against Soviet influence in Latin America, Africa, and Asia as well as political and economic measures to undermine Soviet power.
How to Tame a Fox (and Build a Dog) Page 14
