Chapter 27 twenty five
failure and hope
★Missed plan
We can imagine that in the past thousands of years, humans should have had countless kinds of animals that could be raised, but perhaps the animals themselves or humans were not ready enough for the work of raising animals, or maybe the time was wrong, or there were other animals that could meet the needs of raising animals. Humans have the same needs, and they can be raised faster and easier, so humans give up raising other animals.Farming always happens when there are the right animals, the right place, the right time, and the right people waiting to capitalize on those animals.However, the first condition for establishing a husbandry relationship between humans and animals is that people have demand for this animal.
We cannot assume that any kind of husbandry is deduced step by step and correctly along the existing route.Humans must have tried and failed countless times before raising animals such as horses, aurochs, donkeys, and camels.In other words, the husbandry of every animal must have gone through the same process.In some cases, perhaps, someone will be more successful than anyone who has tried before, and thus a new breed of husbandry is slowly and deviously begun.Farming animals is a long history of trial and error.
★Zebra
Dorothy.In her book "A Natural History of the Zebra," Doras MacClintock recounts the short history of human commitment to breeding zebras.Consider the visual feast that zebras provide us with, among other factors: the overall success of humans in domesticating equids, our dependence on them, the insatiable desire to own horses and their offspring, and There are a large number of zebras readily available on the African grasslands. It is indeed very surprising to think that humans have not raised zebras.
The three species of zebra living in the wild apparently did not interbreed with each other.In the border area of northern Kenya near the Samburu River (Samburu River), I have seen savannah zebras (also known as Barrett's zebras) roaming leisurely mixed with Grevy's zebras (also known as Grevy's zebras) several times. Apparently each bred with a zebra of the same species.In South Africa, mountain zebras, the smallest number of zebras in existence, also come and go with savannah zebras, but they don't interbreed with each other either.
However, if they are kept in captivity, they may interbreed, but the offspring produced are sterile.All three species of zebras mated with horses, as described by McClintock.In a reserve in southern Russia called Askania︱Nova, a stallion of Chapman's zebra (a species of Barrett's zebra) was repeatedly mated with the same mare; the male zebra The affection for this mare is obviously far better than that of other zebra females, but in the end it still led to the death of this mare.The male zebra is such a virtue.
Raymond of Nanyuki, Kenya.Hook (Raymond Hook) routinely mated a Grevy zebra with a mare, and then produced a zebroid of docile and stoic zebra and horse.In the sloping areas near the Kenya Mountains, zebra-horse hybrids are very common cargo animals. Some local signs indicate that certain passages are restricted to horses, donkeys and hybrids.In the 1970s, I saw this sign at an elevation of 14,000 feet.Crosses of horses and zebras, donkeys and zebras have all kinds of names: zebrula, zebrule, zebret and zebryde.The Hagenbecks, a German wildlife retailer, has been involved in cross-breeding miniature horses with zebras.
In the 1700s, according to the French naturalist François.Francois Levaillant described how he had caught zebras without much trouble and bred them for riding.In the 1800s, Lord Lugard tested the value of the disease-resistant zebra, which was considered a beast in Africa.In the 1920s, a shepherd named Rattray of Archer's Post near Kenya reported that he had easily tamed and controlled a large, powerful ( And very handsome in appearance) Grevy's zebra.
In the 1890s, the Boers of South Africa were domesticating and occasionally using the now extinct quagga.In Mauritius, Africa, people also domesticated quagga to assist human work, or introduced them from outside, and then used them locally.As early as the 1800s, London's Sharif.Sheriff Parkins once owned a pair of quagga for work.At the same time, a quagga in the London Zoo was often used by people to pull carts.There are quite a lot of literature on whether zebras are suitable for livestock, and from the literature and old photos, we can find that humans have repeatedly used zebras.
Banker Ward.Walter Rothschild owned three zebras that were trained for draft use, a common occurrence in London at the time.Naturalist Richard.Sir Richard Lyddeker has written a book on the potential value of zebras.In the late 1800s, southeast of Mount Kilimanjaro in Tanzania (then called Tanganyika) and in the southeast of Mount Kilimanjaro, sixty-five miles outside Nairobi, Kenya, Near Lake Naivasha (Lake Naivasha), there are zebra farms.At that time, the price of each zebra was about ten dollars.
American naturalist and taxidermist Carl.Carl Akeley wrote that the domestication of zebras was purely a personal pastime, because zebras are not as vigorous as horses.However, his observations were too short-sighted.Vigor is an important trait that breeders want to develop in working animals, a trait that is often absent in unbred animals.
However, there are currently no domesticated zebras in the world.It is generally believed that humans first appeared in Africa, so humans had the opportunity to come into contact with zebras, and there were more zebra species than there are now.While humans have had an impressive record of domesticating equids, zebras have not been included.Humans can drive, ride, and eat zebras (their meat is delicious), and they are resistant to native African diseases (a very attractive attribute).Also, they are so good at defending themselves against predators like coyotes that they were later used to guard horses.Zebras are extremely fecund, tough, strong and handsome enough to attract attention and become a status symbol.However, they were not raised after all.Why?
The zebra would have been the most useful animal ever before people bred and domesticated horses and donkeys, but the native Africans hadn't developed the techniques or traditions of herding.Whatever happened in the southern part of the Sahara, the natives never owned any domestic animals.Until they did have a tradition of livestock (whether that tradition came from immigrants from other areas that were more advanced in the use of animals, or explorers and land users who brought livestock to their culture), at which point people Zebras are no longer needed.Looking at those human cultures that shared the same land with zebras, we can see that the appropriate animal, the zebra, was in the right place but at the wrong time.
★Other failures
In addition to getting off to a bad start with zebra husbandry, there have been many other failed attempts, but we don't know as much about these processes as we do about the failures of humans to raise zebras.Although coyotes (particularly striped coyotes) are extremely difficult animals, the Egyptians kept them as pets and food animals.The European fallow deer and Persian fallow deer in the Middle East, as well as the Dorcas gazelle and mountain gazelle in the same region, were once in the hands of humans.In addition, humans have also tried to domesticate bent-horned oryx, and a small ibex.In addition, Europeans also herded and hunted red deer.
While there are other attempts at husbandry that humans have tried and failed to do, it's getting harder and harder to explore the list of failed animals based solely on the evidence provided by animal bones and artwork.It is impossible to determine from this evidence when humans began to control wild herds and when they began to raise them in captivity.Those herds that were kept in captivity are the progenitors of the new breeds we now appropriate; and those wild herds that we managed leave behind nothing but a dubious history.
All in all, the history of animals in human care is a long and eventful one.From natural selection to artificially manipulated breeding, we are now on the verge of a startling and dazzling ray that may represent humanity's last scientific achievement; or, it may just be the first step into an unforeseen future. Just one step.At the same time, this ray holds the final fate of domesticated animals and the unfolding of a new beginning.
★Bioengineering
In 1953 AD, a scientist at Oxford University, France.Crick (Francis Crick) and James.James Watson discovered an intricate organic chemical substance, now known as deoxyribonucleic acid or DNA, which contains the genetic code necessary for organisms to reinvent themselves.In the fields of organic chemistry, biology or molecular science, DNA is the key to everything.As early as the late 1880s, an Austrian monk named GregGregor Mendel confirmed the existence of genes and chromosomes, and briefly described their role in reproduction and breeding, but he could not prove how this process works.When it came to Crick and Watson, they did it, and they were awarded the Nobel Prize in Medicine, granting them immortality in the scientific community.However, there is a British female X-ray crystallographer who has been ignored by people. She is Rosalind, who is as smart and stubborn as Watson and Crick.Rosalind Franklin, who made great contributions to the discovery of the DNA double helix structure, died of cancer just before people discovered that she was neglected.
DNA and the later discovered RNA not only contain all the information of organisms, but can also be manipulated, transformed, or subjected to surgery and transplantation by humans. Therefore, the information they carry can be changed, and the organisms they dominate themselves have Sometimes there will be small changes, and sometimes there will be large changes.The biological protein formed by the self-controlled combination of DNA will become a tool due to the change of the genetic code.Like a surgeon's scalpel, engineered proteins can be used to interact with faulty or defective genes and replace them with normal, healthy ones.Conversely, and unfortunately, these proteins can also knock out good genes for health and thus produce unimaginable changes that make the situation worse.There is no way for such chemical tools to know whether they were manipulated by malicious intent or just a moment of inattention.What they ultimately reflect is the manipulator's view of how things should be done.People's use of bioengineering is subjective and susceptible to errors in judgment.There is no definition of whether the future will be better or worse, and no life form will be spared.
In 1976, a group of scientists working at the Massachusetts Institute of Technology in Cambridge announced that they had finally synthesized a gene of their own design, and that when they injected the gene into a living cell, the cell continued to function .Now, people can turn on and modify genes at will.In addition, one can easily open up chromosomes and inject genes into them.Although a gene is a small substance, there may be a small element in this small mass, which is responsible for sending a signal to the master, informing him to produce certain substances or make certain reactions.Once these basic information transmission routes are discovered and identified by humans, they are vulnerable to human interference.
The U.S. Department of Agriculture's top secret and taboo disease laboratory is located on remote Plum Island at the tip of New York's Long Island.Scientists have discovered an important viral gene that causes foot-and-mouth disease on the island.This gene sends the message for the virus to make the protein that kills the infected animal.Scientists took the gene out of the virus and put it back into E. coli, and the same gene continued to signal, but the E. coli made a protein that was not toxic; just injecting the protein into the animal stimulated it Antibodies are produced so that the disease cannot be transmitted.This is just a small example of bioengineering.
Interfering with existing life forms may be a temptation for bioengineers (the so-called bioengineering is a new science about life engineering).So far, the bioengineering community has shown great self-control.Although the tools of bioengineering have been designed and built, and the required technology has evolved, as far as we know, no experiment has been performed in which we were not prepared.
Whether applied for bad or good, this new science clearly has great potential.We can almost be sure that the progress of bioengineering and reproductive physiology will have a great impact on the current human animal husbandry and the future evolution of domesticated animals.With artificial insemination, storage of sperm and zygotes, and the well-established techniques of interspecies and intraspecies embryo transfer, the reproductive rates of our most beloved species have long been completely under human control.The hurdle we are currently facing is whether humans can decide with increasing accuracy which characteristics of domestic animals should be inherited. At present, the future seems to have unlimited potential.However, if we make any mistakes in choosing to apply and utilize this new science, it will be the greatest mistake ever made by mankind.
【Note】Fusion of two gametes.