Researchers attempting to clone clones across multiple successive generations have encountered what appears to be a fundamental biological barrier, according to findings reported by Gizmodo. The study explored whether somatic cell nuclear transfer (SCNT) — the cloning technique used to create Dolly the sheep — could be repeated indefinitely by using cloned animals as the source material for subsequent clones. The results suggest it cannot, at least with current technology.

Scientists observed that successive generations of clones exhibited increasing developmental failures, reduced viability, and accumulating biological problems, effectively making the indefinite reproduction of clones a 'reproductive dead end,' as described in the report. The findings raise significant questions about the stability of epigenetic reprogramming — the biological reset that occurs when a nucleus is transferred into an egg cell — and whether that process can be reliably repeated across multiple cloning generations without compounding errors.

The research underscores long-standing concerns in cloning science about epigenetic drift, telomere shortening, and the fidelity of nuclear reprogramming. Each round of cloning may introduce or amplify molecular abnormalities that eventually prevent viable offspring from being produced.

IMPORTANT METHODOLOGY NOTE: The primary source for this article is a secondary news report from Gizmodo (https://gizmodo.com/how-many-times-can-you-clone-a-clone-science-finally-hits-the-wall-2000737412). The original peer-reviewed study, its journal of publication, sample size, species studied, and full methodology could not be independently verified from the available source material. Readers should consult the original research paper for complete scientific details. It is unclear from the available information whether the underlying study has undergone full peer review or remains a preprint.