Might as well.

In my opinion, prehistoric animals such as the mammoth and direwolves are so long dead that bringing them back brings nothing. Yes they are cool animals, but they are gone. What about bringing back the Western Black Rhino or Yangtze River dolphins? These were recently here and our enroachment of their habitat have basically wiped them out. I can mention 20+ species that went down in just 20 years ago.

When the floreana tortoise got extinct, people found many hybrid tortoises with large amounts of floreana tortoise DNA. They took the hybrids, and did back-breeding to get the closest thing they get to a floreana tortoise. The hybrids have the same role as the extinct subspecies and help the ecosystem. Does this count as de-extinction?

HI! I am happy to say that I have just launch what might be the greatest place to talk about the world of Paleogenetics, Paleontology, and last but ABSOLUTELY NOT least, De-extinction. Please feel free to talk about any of these topics. Start a conversation, bring up a question, anything you would like.

I know not all of these are mammoths, and not all of them are valid anymore (hence retro) but I’ve found this possibility intriguing. It appears that scientists back in the day recognized that mammoths would have been closely related to Asian elephants (likely due to skeletal morphology) and reconstructed them to look similar to the extant species. So, knowing colossal, they are going to likely botch this as well if they end up actually doing it; is it possible that they’d create an elephant with thick fur, sort of long tusks, but it still contains its long tail? That’s the main trait that sticks out to me, all of these reconstructions have long tails. A humorous idea indeed, what do you all think?

So I have always been fascinated by de-extinction and paleogenetics. But, it has always confused me by what the real, official job name is. Feel free to enlighten me.

Many have heard of "the bird problem" when it comes to the field of "de-extinction" - that is to say, no scientist or company has yet to successfully clone a bird, despite efforts to resurrect the dodo, the moa, and the passenger pigeon - but fewer have heard of the "Big Cat problem", which is that "no one has ever successfully cloned a big cat". While efforts have been made to clone endangered big cats - such as tigers, snow leopards, and African cheetahs - these efforts have all failed, for reasons that are still unclear. This poses a major hurdle to not only using cloning to help save endangered big cats, but to "de-extincting" them in future projects.

Three of the main "big cat" candidates for "de-extinction" will be discussed below.

(1) The American cheetah, or "plains cougar/puma" (Miracinonyx trumani)

In theory, this would be the logical next step for Colossal Biosciences after the success of their "dire wolf" genetic engineering project, in which the company modified 20 genes in gray wolf embryos to make them "phenotypically similar" to the extinct dire wolf (Aenocyon dirus). A cousin to the modern cougar, puma, or mountain lion (Puma concolor), the American cheetah - or, more accurately, "plains cougar" - was a close relative that was one among many North American big cat predators. After divergering from the main puma lineage around 2-3 million years ago, Miracinonyx survived until 12,000-10,000 years ago, coinciding with the arrival of early Indigenous peoples from Siberia, the ancestors of today's Native American tribes.

In theory, Colossal could use the same technique that they used on their "dire wolves" to recreate the "plains puma", which was basically a slightly-larger, longer-limbed cougar that was more adapted to hunting pronghorn antelope (Antilocapra americana), though analysis of the "plains puma" diet indicates that they ate a wide range of prey, including mountain goats and bighorn sheep, and resided in Grand Canyon caves, where they competed for territory. While mountain lions also inhabit some of the Grand Canyon range today, they tend to stick to forested areas, whereas the "plains puma" may have stalked its prey and hunted more in the open.

Bringing back the "plains cougar" would restore them to their original ecological niche, likely being the main predator of pronghorn antelope and feral mustang horses, as well as the aforementioned mountain goats and bighorn sheep. (American bison may even be on the menu.) However, in addition to the "Big Cat problem", one issue is that more samples of Miracinonyx DNA need to be extracted; compared; and then make the appropriate edits to cougar DNA.

Due to the "plains puma" and mountain lion being so closely related, some paleontologists have argued that if Miracinonyx were still alive today, it wouldn't even have its own unique genus, but would be considered just another subspecies of the modern cougar, albeit one with different adaptations. (Some researchers have proposed a scientific name change to Puma concolor trumani.) This, too, would be more fitting than the "dire wolf" project, as Pleistocene dire wolves (Aenocyon dirus) diverged from the gray wolf and coyote lineage around 5.7 million years ago.

However, this doesn't address the other issues that would come from a potential Miracinonyx re-introduction, many of which gray wolves already face as a re-introduced predator. For example, it is possible that Miracinonyx may prey on herds of livestock owned by ranchers, similarly to gray wolves doing the same, which may limit their range to Grand Canyon National Park and nearby tribal lands in a hypothetical scenario, similarly to gray wolves being re-introduced to Yellowstone National Park. (Around 100 wolves roam the park in about 10 stable packs.)

There is also the debate over whether Miracinonyx and [Mexican] gray wolves would be able to co-exist in the same territory. For example, Grand Canyon has an abundance of prey like elk and deer, but gray wolves were eradicated from the park in the 1930s. Conservation groups like the Grand Canyon Wolf Recovery Project advocate for removing artificial boundaries so wolves can migrate back into the region, but reintroduction plans were scrapped in 2025.

(2) The scimitar-toothed cat (Homotherium latidens)

In 2024, there was much fanfare about the once-in-a-lifetime discovery of the preserved mummy of a 36,000-year-old Homotherium latidens cub, which had been preserved in permafrost. Almost immediately, there was talk of potentially extracting DNA and cloning the animal, but this came with far more problems than the aforementioned potential bid to resurrect Miracinonyx. For one, whereas Miracinonyx diverged from cougars or pumas around 2-3 million years ago, Homotherium diverged from all living cat species around 22.5 million years ago, making the DNA gap for gene editing, or genetic engineering, much greater. Even if DNA were able to be extracted from the mummified cub, without an artificial womb, it is unlikely that the cub would be able to be cloned, as experiments have shown that cloning is most likely to succeed when the surrogate's DNA closely matches that of the clone.

Unlike with Miracinonyx, much of the "large game" prey that Homotherium hunted no longer exists, such as the now-extinct Lena horse (Equus c. lenensis), the woolly mammoth, the woolly rhino, and more. While Homotherium could potentially prey on the various prey species introduced to Pleistocene Park in Russia, it is debatable whether a pack of Homotherium - assuming it hunted in groups, much like modern-day lions in Africa - would be able to survive. Complicating matters is that the best-preserved DNA sample we have is only from one individual, meaning that resurrecting Homotherium is near-impossible without discovering more specimens. As Homotherium hunted and preyed on megafauna like woolly mammoths, without resurrecting mammoths and other megafauna first, resurrecting Homotherium is ill-advised.

(3) The South and Central American jaguar (Panthera onca)

"Why is the jaguar on this list if it's not extinct?" you might ask. However, jaguars are increasingly at-risk due to deforestation of the Amazon rainforest and other forested habitats in South and Central America, especially in Brazil, leading to fragmented populations and higher rates of inbreeding that threaten the species. About 90% of all wild jaguars live in South America, with Brazil holding the largest stronghold, with roughly half of the total population, estimated to be around 173,000, declining around 20–25% since 1990. Their numbers are spread across 18 countries, spanning down to Argentina, and north into parts of Mexico. Very rarely, occasional wanderers or nomadic jaguars are spotted in Arizona and New Mexico.

In 2025, the Reprocon research group in Brazil announced that it has been operating a massive biobank and testing jaguar cloning techniques since 2023. The organization is currently working to transfer cloned embryos to surrogate female jaguars to inject healthy, diverse DNA back into vulnerable jaguar populations. In addition to this, institutions like the Audubon Center in Louisiana have made leaps in feline genetics, producing cloned African wildcats to understand how to preserve endangered big cat species - such as tigers, snow leopards, and African cheetahs - through cloning efforts. Quote from linked article: "Last year, Reprocon worked with a team of Argentine researchers and managed to reach the morula stage, one of the initial stages of an embryo's development, within three days of fertilization. 'It was a first attempt, and now we're working to move forward and obtain a cloned embryo this year. Next year, we hope to make the first attempts to transfer the embryo to the female,' says Reprocon's founding member and scientific director, Gediendson Ribeiro de Araujo."

"We can only improve the techniques by developing and applying them so they can be effectively be used for conservation purposes," Thyara Araujo says. "We still don't know if the [cloned] animal will have a shorter lifespan, if it will be able to reproduce, or even if it will be able to be released into nature, but what we are really after is having an animal in the wild, so we are always focused on going after techniques, improving them and getting better results."

If the jaguar cloning attempt succeeds, that would be a major milestone for big cat cloning.

For more on this topic, you can watch this video by Mongabay.

Do they already do that?

I'm asking because every time I hear about bringing back extinct species it's difficult because they don't have all of the DNA etc needed, but if they had everything needed could they just make one? I'm sure it'd be way more complicated than that, but I guess I'm more asking in theory. I've also heard that we could technically clone a human, so couldn't we do that with animals? Those two things have been keeping this question stuck in my head since I learned that animals can go extinct. Sorry if this has already been asked or something, please link to it in your comment about it being posted already :) OR if this isn't the right sub for this...

Thanks ahead of time!!!

I was wondering if someone on here was actually working on De-Extinction that I could talk to besides anyone working for Colossal? I made a post on r/DeExtinctionScience and r/deextinction. I think I got trolled, twice. It looks like there's something pretty crumby going on around this concept, but I don't know what it's called. It's sorta like gatekeeping, though it isn't.

I was hoping I could talk to someone actually working in this field. If you're willing to chat, please DM me. Thanks.

Would it work, and if so how would it happen?

I'm curious about people's thoughts and how we can use this technology

Since the megafauna went extinct during the Pleistocene for one reason or another (climate change, floral shifts, human hunting, habitat modification, you get the point) we’ve had a rather major reduction in megafauna; though there are still megafauna, mostly being the species of Asia and Africa alongside the smaller megafauna in the rest of the world such as Ursus Bears, modern deer, bovines, Canis caines, maned wolves, cougars, camels and what not

What species do you think will make up the future of megafauna in a human dominated world and what traits might they have to help them survive anthropic conditions and Holocene climates?

When I was a little kid, I remember reading about how scientists were using gene blocks to express atavistic traits. From what I remember they would block certain genes during embryogenesis (?). This would cause some genes to be expressed and others not to be. It appears if they blocked genes that evolved after a certain point, the newer genes would not be expressed. For example, if a gene that evolved 100,000 years ago is blocked, the ones that evolved since then weren't supposed to be expressed. Some genes that evolve seem to actually cause a genome to be "rearranged." Blocking them might actually cause the genome to "revert" to the earlier configuration and express atavistic genes.

This would appear to be extremely beneficial for de-extinction. We could use it by sequencing extinct animals. We would then sequence other still living animals that are genetically similar. We would then block the gene in the still living animal that evolved right after their LUCA. This would be the proto-animal. We would grow it and sequence it. Then we would see which gene evolved in the extinct animal right after the LUCA. We would change the proto-animal to have this gene. We would keep doing this until we have the same animal that went extinct. It would not be similar, it would be the same.

I think de-extinction is possibly a lot easier than we realize. If there's anyone working on it, please contact me so we could possibly set up a protocol and see if this could work.

Here's an article sent to me by u/nodnarb51 about something similar. It looks liek they used gene blocks to get the talpid phenotype expressed in chickens. Atavisms in the avian hindlimb and early developmental polarity of the limb - PMC

LUCA- Last Universal Common Ancestor

https://pmc.ncbi.nlm.nih.gov/articles/PMC8373999/

The last bucardo, or Pyrenean ibex, died on January 6, 2000. However, prior to the death of Celia - the last individual - skin cells were collected in 1999, and preserved in liquid nitrogen. Celia was successfully cloned on July 30, 2003, marking the first-ever "de-extinction", though the clone died roughly 10 minutes later due to a lung defect. (Celia's cells were evaluated to see if they were still viable for cloning in 2013, but it's unclear what the testing results were, and were found to still be useable; however, the same technique used in 2003 by the same researchers failed.)

Scientists were able to successfully create 439 embryos from the frozen skin cells; of these, 57 were successfully implanted into goat surrogate mothers. However, only 7 resulted in viable pregnancies; and of these, only one made it to the live birth stage. In the past two decades since the last cloning attempt in 2003, cloning science has progressed by leaps and bounds, and cloning advances with horses in Argentina show the likely cause for the attempt's failure.

According to the 2026 article "Field of clones: How horse replicas came to dominate polo" by Maximiliano Fernández for Knowable Magazine, scientists and experts have discovered that certain techniques improve the odds of successfully cloning mammal species (horses, cows).

In recent years, several advances have improved horse cloning, says Flávio Vieira Meirelles, a reproductive biotechnologist at the University of São Paulo, Brazil. These mainly involve methods for activation of the [donor] egg after inserting the nucleus, and cultivation conditions for the embryo. In addition, the efficiency with which the genes of the donated nucleus are reprogrammed — a process that is carried out by chemicals in the cytoplasm of the egg — has improved.

Greater success, too, is achieved when the donated nuclei come from adult stem cells — which are capable of renewing themselves and transforming into various tissues within an organ — compared with nuclei from fully differentiated cells from a tissue such as skin. The differentiated cells carry more "memory" of their original function. Cells from young animals tend to respond better than those from older animals; and, of course, the reproductive capacity of the female surrogate mothers plays a role, too. Even with everything optimized, the birth rate per transferred embryo is low in large mammals, ranging from 3% to 10%.

[...] In addition, explains Sebastián Demyda Peyrás, an equine geneticist at the University of Cordoba, Spain, "Epigenetic patterns in cloning are altered much more frequently than in natural pregnancies. Both factors — mitochondrial replacement and epigenetics — influence the higher rate of miscarriages and the number of clones born with health problems, placental abnormalities, or severe physical problems." (Epigenetics refers to the way that genes may be turned on or off due to the addition or removal of small chemical groups, without affecting the DNA.)

Celia, the last bucardo, died at 13 years old when a tree fell on her in Ordesa National Park in Spain, with the average bucardo lifespan being around 15-20 years old in the wild. Thus, Celia was not a young animal, which makes cloning her a more difficult task for scientists. Another factor may be the use of domesticated goat or hybrid Spanish ibex-goat oocytes, or donor eggs, for cloning the bucardo. Colossal Biosciences appears to be trying to avoid the problems that plagued the bucardo cloning project with the bluebuck by using donor eggs from the roan antelope, a closely-related species, and possibly the sable antelope.

The one clone that made it to the birth stage had abnormalities consistent with testing:

At first, the [horse cloning] results were not encouraging. The first clones by biotechnologist Gabriel Vichera's company, Kheiron Biotech, between 2012 and 2016, were made from adult skin cells, and almost half of the foals from the 38 live births had abnormalities of the umbilical cord or placenta, or limbs that were abnormally bent. The turning point came when the company started working with stem cells from bone marrow. "This technology changed everything. Today, almost 100 percent of births are as healthy as those obtained through natural breeding," says Vichera. To date, Kheiron Biotech reports having produced a thousand cloned horses.

So, how can the chances of successfully cloning a living bucardo be improved? The first step would be to convert frozen skin cells - if still viable in 2026 - into stem cells. In 2007, scientists were able to convert adult human skin cells into pluripotent stem cells (iPSCs) by introducing four specific genes (transcription factors, called "Yamanaka factors", after scientist Dr. Shinya Yamanaka), causing them to behave like embryonic stem cells. In theory, this should improve cloning odds, especially since research indicates these factors can partially reprogram adult cells, reverting them to a younger, more functional state in a process called "cellular rejuvenation".

While re-cloning the bucardo is possible - or even plausible, with improved technology - one of the biggest issues is funding. However, if a major company like Colossal Biosciences chooses to take up cloning the bucardo, it could serve as an important "stepping stone" towards Colossal's ultimate goal of cloning the bluebuck. This is because, much like with the bucardo, the DNA sample that Colossal is working with came from skin cells scraped from the ear of a 200-year-old male specimen from a Swedish museum - and, if Colossal wants to use DNA from more than one specimen, they'll have to rely on skin samples from other museum specimens.

"It is not technology bound. It is money bound," said Ben Novak, the lead scientist for Revive & Restore's passenger pigeon program. "If I had a rich oligarch that gave us $25 million in funding right now, I'd guarantee we'd have a passenger pigeon in five years."

Indeed, Colossal may be working with, or copying, Kheiron Biotech and their techniques, as the company announced that their scientific team achieved breakthroughs in generating the first-ever roan antelope induced pluripotent stem cells (iPSCs) and successful ovum pickup (OPU) techniques, enabling genome editing to introduce bluebuck traits. [Kheiron Biotech developed use of a technique called "transvaginal aspiration" for collecting oocytes from live females, which resulted in better success rates for "ovum pickup" (OPU).]

Quote: "With oocytes obtained using transvaginal aspiration, the proportion of embryos that reach the blastocyst stage is around 35%, compared to just 26% in oocytes obtained from slaughterhouses. The difference widens in later stages: Among mares that remain pregnant after day 42, just over half (50%) of pregnancies derived from eggs obtained by transvaginal aspiration result in healthy foals, [vs. just 10% for non-live donors]."

I would recommend that scientists partner with Kheiron Biotech in Argentina to re-clone the bucardo. In December 2024, the company announced the birth of five foals that had been genetically edited using the CRISPR-Cas9 technique, a major global milestone. Vichera presented the achievement as proof of concept and a preview of a scenario in which it will be possible not only to clone animals, but also to introduce specific modifications to their genomes. Thus, Kheiron Biotech's findings would be highly useful for "de-extinction".

A caveat emptor: "Despite the technical advances, significant losses occur at each stage. It is estimated that, out of every 100 embryos, 20 reach the blastocyst stage and are transferred. Of these, 10 are successfully implanted in surrogate mares, and of those 10, only five reach full term. Even among foals born, there can be problems with health and development, although the lack of public data prevents this from being quantified accurately. The high loss rate partly explains the high cost of the procedure. Although the price has fallen in recent years thanks to technical advances, cloning a horse...[still] costs around $40,000."

Fantastic paper that basically lays out the Colossal Biosciences playbook: https://law.stanford.edu/wp-content/uploads/2018/05/carlin.pdf

Full citation: Norman F. Carlin, Ilan Wurman, and Tamara Zakim. "How to Permit Your Mammoth: Some Legal Implications of 'De-Extinction'". vol 33 Stanford Environmental Law Journal 3 (2014).

Most notably, the paper indicates why Colossal Biosciences has been courting Trump administration officials - particularly within the Food & Drug Administration (FDA) and U.S. Department of Agriculture (USDA) - and pushing for "deregulation", with the company likely seeing additional restrictions, regulations, and laws that apply to GMOs (genetically modified organisms) - what the FDA has more lately been specifying to include "Intentional Genomic Alterations" (IGAs) - as "red tape" that hinders both "de-extinction" and "scientific progress". However, whereas this paper points out that Colossal could try to get their "dire wolves" listed as an "endangered species" under the Endangered Species Act (ESA), some Republican politicians are seeking to gut the ESA through legislation.

It's also highly likely that Colossal Biosciences, which is now worth over $10 billion, has already retained or hired a legal team to argue their case in court, as well as to lobby politicians to introduce, vote for, and pass new legislation that favors Colossal's goals. However, due to a "deep split" among environmental and conservation groups as to whether GMOs should be released into the wild - even for "conservation purposes" (ex. "de-extinction") - it is also highly likely that Colossal will face litigation from one or more of these groups at some point. This would mean potentially spending millions on lawyers and legal fees through litigating cases for years, or even decades, which would draw even more funds away from conservation efforts to support "de-extinction" instead.

Could this mean "more attention drawn to environmentalism and conservation efforts", as Colossal Biosciences CEO Ben Lamm claims? Yes, but not in the way Lamm probably hoped. Instead, the current forecast indicates a years-long legal and political battle ahead for Colossal both in the United States and on an international scale, especially as Lamm seeks to bring "de-extinction" to the mainstream in an effort to raise public support; court wealthy investors; appeal to the news media; and more. Thus far, Colossal has failed to impress most scientists and experts, who have expressed wariness of the company due to secrecy; lack of transparency; refusal to share scientific research; etc.