section_path: Science and development
section_name: Science and development
paragraph_text: Science and development
  
  Because the woolly mammoth and Asian elephant share 99.6% of the same DNA, Colossal aimed to develop a proxy species by swapping enough key mammoth genes into the Asian elephant genome. Key mammoth genetic traits include a 10-centimeter layer of insulating fat, five different types of shaggy hair, and smaller ears to help the hybrid tolerate cold weather.
  
  Colossal's lab pairs CRISPR/Cas9 with other DNA-editing enzymes, such as integrases, recombinases, and deaminases, to splice woolly mammoth genes into the Asian elephant, and has "used 65 different mammoth genomes across about 700,000 years to create an assembled ancient DNA genome". The company plans on sequencing both elephant and mammoth samples in order to identify key genes in both species to promote population diversification. By doing so, Colossal hopes to prevent any rogue mutations within the hybrid herd. Colossal set a goal for the company to grow a woolly mammoth calf by 2028.
  
  The company plans to use African and Asian elephants as potential surrogates and largely plans to develop artificial elephant wombs lined with uterine tissue as a parallel path to gestation. In 2021, it was reported that Colossal scientists planned on creating these embryos by taking skin cells from Asian elephants and reprogramming them into induced pluripotent stem cells which carry mammoth DNA. Lamm stated that Colossal will use both induced pluripotent stem cells (iPSC) as well as somatic cell nuclear transfer in the process.
  
  In July 2022, VGP and Colossal announced that they successfully sequenced the entire Asian elephant genome; this was the first time that mammalian genetic code had been fully sequenced to a detailed level since the Human Genome Project was completed in the early 2000s.
  
  In August 2022, Colossal announced that they would launch a thylacine research project, in hopes of "de-extincting" the Tasmanian tiger. Colossal planned to reintroduce the thylacine proxy to selected areas in Tasmania and broader Australia and claimed that, by doing so, this would re-balance ecosystems that have suffered biodiversity loss and degradation since the species disappeared. A successful thylacine proxy birth could also introduce new marsupial-assisted reproductive technology, which could aid in other marsupial conservation efforts. Colossal partnered with the University of Melbourne for the project, led by Andrew Pask. The Tasmanian Thylacine Advisory Committee was launched in December 2023.
  
  In January 2023, Colossal announced the formation of its Avian Genomics Group, which would be dedicated to reconstructing the DNA of the dodo bird, which went extinct in the 1600s. Led by Beth Shapiro, who serves as Chief Science Officer to Colossal, this research group aims to create a hybrid composed of specific traits most commonly associated with the dodo and plans to reintroduce these hybrids into their respective environments. Colossal will be working with primordial germ cells to pair dodo DNA with the genome of the Nicobar pigeon, the extinct dodo's closest living relative, and develop chimeric chicks as surrogates for future dodo restoration.
  
  Breaking, a plastic degradation and synthetic biology startup, was developed inside Colossal and launched in April 2024. The startup discoveted X-32, a microbe that is capable of breaking down various plastics in as little as 22 months while leaving behind carbon dioxide, water and biomass.
  
  It was reported in 2024 that Colossal successfully produced the first-ever elephant and dunnart iPSCs.
  
  In October 2024, the company announced that it had rebuilt a 99.9% accurate genome of the thylacine, using a "pickled" 110-year-old fossilized Tasmanian tiger skull. This marks "the most complete ancient genome of any species known to date" and provides a full DNA blueprint to potentially bring back the Tasmanian tiger. Three months later, in January 2025, the company sequenced the complete genome of the Tasmanian tiger; Colossal also made a prototype for an artificial uterus and used that to culture fertilized single-cell marsupial embryos to over halfway through pregnancy.
  
  In March 2025, Colossal announced the creation of gene-edited " woolly mice " with mutations inspired by woolly mammoths, touting it as a step toward engineering mammoth-like Asian elephants. The mice, which exhibit long, shaggy, tawny-toned fur, were developed using a mix of mammoth-like and known mouse hair-growth mutations. Some experts expressed skepticism, arguing that the experiment was more about mouse genetics than a breakthrough in de-extinction. The company stated that it planned further studies on the mice's cold tolerance and long-term health but had no commercial breeding plans.
  
  In April 2025, the Colossal Biosciences Dire Wolf Project was announced, which used cloning and gene-editing to birth three genetically modified wolf pups: six-month-old males Romulus and Remus and two-month-old female Khaleesi. In-house scientists analyzed the dire wolf genome, extracted from two ancient samples – a 13,000-year-old tooth and a 72,000-year-old ear bone. After comparing the genomes of gray wolves and dire wolves to identify the genetic differences responsible for the dire wolf's distinctive features, Colossal isolated EPC cells from gray wolf blood samples before rewriting 14 key genes in the cell's nucleus to express 20 traits claimed to represent the dire wolf phenotype. Overall, the work was less invasive than the typical cloning process. Colossal scientists produced 45 engineered ova, which developed into embryos and inserted into the wombs of two surrogate hound mixes. Colossal claims that these minor genetic modifications effectively revived dire wolves as a species, though "no ancient dire wolf DNA was actually spliced into the gray wolf's genome".
  
  Independent experts disagreed with Colossal Biosciences' claim that these animals are revived dire wolves, stating that they are "not a dire wolf under any definition of a species ever". The IUCN Species Survival Commission Canid Specialist Group officially declared that the three animals are neither dire wolves nor proxies of the dire wolves based on the IUCN SSC guiding principles on creating proxies of extinct species for conservation benefit. They commented that creating phenotypic proxies doesn't change the conservation status of an extinct species and may instead threaten the extant species such as grey wolves. Therefore, since the claimed proxies do not conform with the IUCN SSC guidelines, have no ecological niche left today and "will not restore ecosystem function", they concluded that the Colossal Biosciences' project "does not contribute to conservation." Colossal Biosciences released a clarifying document Alignment of Colossal’s Dire Wolf De-Extinction Project with IUCN SSC Guiding Principles in response.
  
  In May 2025, the company's chief scientist Beth Shapiro stated that the three animals are merely "grey wolves with 20 edits" as purportedly stated by the company "from the very beginning", acknowledging that it is impossible to bring back an extinct organism, or at least an organism "identical to a species that used to be alive". She admitted that the term "dire wolves" applied to the pups are a colloquialism, not scientific terminology. This is a "major departure from what Colossal had said previously".
  
  In the same month, Colossal along with University of Melbourne announced that they have successfully created vital stem cells for the thylacine, with researchers estimating they could be re-introduced in the wilderness as little as 8 years.