We’re Cloning Animals From The “Frozen Zoo”; Like A Seed Bank But For Animals

Seed banks are facilities of great value to biodiversity and agriculture around the world. These facilities are used to house stocks of seeds of a wide variety, helping to maintain genetic diversity and avoid the permanent loss of various plant species. While there are some challenges, the basic requirements to run a simple seed bank are to keep a selection of seeds at low temperature and humidity to maximise their viable lifespan.

When it comes to animals, things become more difficult — one can’t simply plant an old seed in the ground and grow a fresh new meerkat, for example. Preservation of animal genetic material poses its own unique set of challenges — ones that the San Diego “Frozen Zoo” don’t shy away from. They’ve recently shown the viability of the program with the healthy birth of a ferret cloned from an animal that died in 1988.

Long-Term Storage

There are less than a dozen frozen zoos around the world, with the first being established at San Diego Zoo by Kurt Benirschke in 1972. While the available biological technology was limited at the time, it was hoped that by cryopreserving samples of animal tissues and reproductive material, they might later be used for research or reproduction purposes. The idea has since spread, with a smattering of other facilities opening up around the world. Such facilities necessarily store a wide variety of material, depending on the species in question. Obviously, viable gametes, or reproductive cells, are of high priority. Eggs and sperm cells from sexually mature animals can readily be secured from both live and deceased specimens, and used to produce embryos for implantation.

Alternatively, fluids such as blood or milk may be saved, as well as muscle tissue, bone, hair or skin samples. With cloning techniques pioneered in the 1990s, DNA extracted from these non-reproductive cells can be inserted into an egg with its nucleus removed. This egg can then be implanted in a surrogate mother like any other embryo, and the pregnancy carried to term. With in vitro fertilization (IVF) techniques in their infancy in the 1970s and cloning a distant blip on the horizon, Dr. Benirschke’s decision to establish the first frozen zoo at the time shows considerable foresight.

Elizabeth Ann was born in late 2020 – the first clone of a US endangered species. This is a screenshot from a video from the US Fish and Wildlife Service.

With decades of advancements in genetic sequencing and techniques like in vitro fertilization now available, these libraries of genetic material are starting to bear fruit. Although other species have already been successfully cloned, this is the first clone of a US endangered species — a black-footed ferret by the name of Elizabeth Ann. Born to a domestic ferret serving as a foster mother on December 10th of last year, her genes are a duplicate of a ferret named Willa who passed away in 1988 and was frozen at the San Diego facility.

The black-footed ferret has long been a focus of conservationists, who have been working to re-establish the species since it was thought to be extinct in the mid-20th century. When a dead specimen was found on a ranch in the 1980s, breeding work began in earnest, with thousands of ferrets reintroduced into the wild. As for Elizabeth Ann and any potential future clones, however, there aren’t yet plans to release them from captivity.

The Challenge of Genetic Diversity

Both breeding programs and cloning experiments highlight a limitation of this work, however. Genetic diversity is key to maintaining a thriving population over many generations, but the ferrets bred as part of the program all trace their lineage to just 7 individuals. Similarly, a cloning program can produce theoretically unlimited offspring from a single DNA sample, but inbreeding depression will make such a cohort unlikely to thrive in the long term. Thus, any frozen zoo aiming to serve as a potential backup against possible extinctions needs to collect as broad a spectrum of genetic samples as possible.

Kurt is the world’s first Przewalski’s horse clone, born to a domestic horse surrogate mother. It’s hoped that Kurt will grow up to breed with others of his species, increasing the genetic diversity of the herd.

The San Diego facility has had other success stories, too. In partnership with Viagen, a company perhaps best known for offering cloning services for domestic pets, scientists were able to clone Kurt, a Przewalski’s Horse, from forty-year old frozen skin samples. Similarly to the methods used to create Elizabeth Ann, Kurt’s genetic material was used to fertilise an egg which was then implanted into a domestic horse serving as a surrogate mother. Sequencing revealed the donor tissue featured many unique genes not found in the currently-alive population, all of which come from lines of just 12 former individuals. It’s hoped that when Kurt comes of age, breeding with others will significantly increase the genetic diversity of the endangered species.

The need for similar species to carry pregnancies means that it’s unlikely we’ll see frozen zoos churning out wooly mammoths or Tasmanian tigers for some time yet. Having the genetic material alone isn’t enough; a suitably close living relation is key, along with the aforementioned need for genetic diversity if repopulation is the goal. However, the technologies and techniques that have been developed will be crucial to maintaining biodiversity of existing species well into the future, especially given that habitat destruction and other existential threats remain around the world. And, as science continues to progress, it’s likely that frozen zoos will be the first to invite you to see their new dodo exhibit in the future!

30 thoughts on “We’re Cloning Animals From The “Frozen Zoo”; Like A Seed Bank But For Animals

    1. It’s just my opinion but I believe that issue is closely related to the same issue that is affecting lower life forms such as turtles and frogs and many other species. We have polluted our planet to the point those species are disappearing. Amphibians are having a harder time reproducing or at least that’s what I remember reading some years ago, due to hormone changes brought about from chemicals getting into the water they live in. Reptiles are having issues as well, at least the ones that spend a large part of their lives in that water.

      1. Guessing most likely intentionally with a causation that appears to be ecclesiastical provinces along with other narcissist aligned cults, best at worst and only really designed to compel with limited development of survival resources for the masses and projected growth since isn’t in their books. Noting also their sacking of greatest libraries of the World and secretly keeping their works they wanted… I’m guessing related to death since is easier for the Pan Troglodyte’d dominate trait’d groups. They are compelling population control, division, confusion and depopulation with hardcore efforts brought to the World in modern times by the Marxists States, Axis States and new owners Ecclesiastical Provinces Government fronts Military Orders Religiously that continued and created the latest and greatest Clandestine and Covert Chemical and Bioweapons labs. Like some communications devices… for periods bought into like a religion to slow kill.

  1. “one can’t simply plant an old seed in the ground and grow a fresh new meerkat”.

    Obviously you have never heard of the vegetable lamb of Tartary! Anyway I look forward to Mammoths and Passenger Pigeons coming back. (Elephants could probably carry Mammoth clones to term.)

  2. I have no idea why, but for some reason I woke up this morning before I even read this post, thinking about loosing certain animals just within the last 125 years. One was the Thyloziene ( misspelled because I don’t know how it is spelled) also known as the Tasmanian Wolf. I think it is our responsibility to find a way to restore that which we have been responsible for destroying! There have been numerous extinctions through out history but the human race has not been responsible for all of them. We were given the chore of caring for the planet because of the higher level of consciousness we SHOULD be capable of. Animals never had that option.

    1. The Tasmanian Tiger, AKA the Thylacine is an extinct carnivorous marsupial. It was just one of thousands of species that went extinct or where in serious decline *before* European settlement. Go and look up the extinct megafauna of Australia and cross reference the timing with the arrival of the first waves of migrating humans entering the north of the continent from southeast asia.

      1. They don’t need women at all, the Japanese gestated a goat in a synthetic womb back in 1992, since then we have made GM “humanised” pigs that could potentially be used as incubators for human fetuses, as well as their intended organ donation function. So all they need to send is a few of those pigs and a whole lot of human embryos on ice., plus all the support tech and crew. First they scale up the pig numbers then they start making human clones. Far easier than moving 1 million actual individual humans to Mars.

        1. @𐂀 𐂅 says , et.al., I didn’t realize there was a synthetic womb demonstration. Last left off researching that the synthetic womb was the last gap and all the other developments for a full life cycle life, even human, have been demonstrated.

          Do you have any references?

      2. Technically, males carry the X and Y chromosomes. Females only carry X chromosomes. Takes more mutation efforts to create Y from the females two X’s unless I suspect from a female with XY gonadal dysgenesis. Then, with the XY gonadal dysgenesis genetics Y chromosome there is another cause for concerns and risks.

        In regards to Mars, other than advancing technology and World more humane vision projects that are unifying, I assume is just a modern day overt Discoverer Program that has a more covert and clandestine Corona Program operational intent.

    1. No, not exactly, see my other comment, plus human evolution stopped a while ago, it is no longer the natural selection from random mutations, life is now sentient and able to engineer itself based on anticipated future requirements, this is fundamentally new and different from evolution.

          1. Is more of a beyond phenotypical like process, that I refer to as “creation,” that is far more than the gentotypical like process left to natural processes due to the nurturing required.

  3. what i’ve been thinking about recently is evolution. If animals are going extinct shouldn’t we also see animals coming into existence? Besides crossbreeding dogs etc. Why dont we see new creatures form? shouldn’t this be a thing? We get new virusus all the time why not cool new animals.

    1. It is a thing, observed in plants, butterflies, insects, fish, but larger mammals have decade+ breeding cycles though so relatively few generations have been observed closely enough to see meaningful changes.

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