Biotech Firm Engineers ‘Woolly Mice’ in Pursuit of Woolly Mammoth Revival

In a notable development in genetic research, Colossal Biosciences, a biotechnology company based in Texas, has successfully engineered mice exhibiting traits reminiscent of the extinct woolly mammoth. This endeavor represents a preliminary step toward the ambitious goal of reviving the woolly mammoth species.​

The research team at Colossal Biosciences employed advanced gene-editing techniques to modify seven specific genes in mouse embryos. These genetic alterations resulted in mice with long, thick, woolly hair, earning them the moniker “colossal woolly mice.” The modifications also targeted genes associated with fat metabolism, potentially enhancing the rodents’ cold tolerance. ​

This experiment serves as a proof of concept, demonstrating the feasibility of introducing ancient traits into modern animals. By first applying these genetic modifications to mice, which have shorter gestation periods and are more manageable in a laboratory setting, researchers can refine their techniques before attempting to apply them to larger animals, such as elephants. ​

Colossal Biosciences envisions extending this genetic engineering approach to Asian elephants, the closest living relatives of woolly mammoths. The objective is to produce elephant-mammoth hybrids capable of thriving in cold environments, thereby contributing to ecological restoration efforts in Arctic regions. The company projects the birth of a woolly mammoth-like calf by 2028. ​

However, this initiative has elicited mixed reactions within the scientific community. Some experts caution that altering existing species does not equate to true de-extinction. Christopher Preston, a wildlife and environmental ethicist at the University of Montana, remarked, “You’re not actually resurrecting anything—you’re not bringing back the ancient past. You might be able to alter the hair pattern of an Asian elephant or adapt it to the cold, but it’s not bringing back a woolly mammoth. It’s changing an Asian elephant.”

Vincent Lynch, a biologist at the University of Buffalo, acknowledged the technological achievement but emphasized that creating a mouse with mammoth-like traits is a preliminary step and does not guarantee the feasibility of resurrecting extinct species. ​

The ethical considerations of such genetic experiments are also under scrutiny. Concerns include the welfare of genetically modified animals, potential ecological impacts, and the prioritization of resources that might be better allocated to conserving existing species facing extinction. ​

From a Torah perspective, any scientific innovation must be examined through the lens of Halacha and ethical considerations. The Torah teaches us that man was given dominion over the world (Bereishis 1:28), but this dominion comes with responsibilities and moral boundaries. The idea of altering Hashem’s creations through genetic engineering raises serious halachic and philosophical questions.

One fundamental concern is the prohibition of kilayim which applies to crossbreeding animals and altering their fundamental nature (Vayikra 19:19). While classical kilayim refers to direct interbreeding, modern genetic engineering introduces a new dimension to the discussion.

Furthermore, the concept of tikkun olam—rectifying the world—must be considered. If such scientific endeavors genuinely contribute to the betterment of creation, they may be justified. However, if they lead to ethical concerns, unintended ecological consequences, or a challenge to the natural boundaries set by Hashem, they warrant caution. The Ramban (commentary on Bereishis 1:26) explains that human dominion over the world is limited by the framework Hashem established, and it must not be abused.

Another issue is tza’ar ba’alei chayim . If these genetically modified animals experience health complications or unnatural suffering, it could pose a serious halachic concern. In addition, altering an animal’s genetics raises questions about its halachic status, particularly regarding kashrus. If an animal is significantly altered, does it retain its original halachic identity, or does it become a new category?

Ultimately, while scientific advancements can be beneficial, the Torah world must approach these innovations with wisdom and caution, ensuring that they align with halachic principles and the values of yiras Shamayim. It is essential for Gedolei Yisrael and Poskim to weigh in on these matters, offering guidance on how to navigate the complex intersection of Torah and modern science.