A Farmer Abandoned Five Cows on a Remote Island in 1871. 130 Years Later, Scientists Opened Their DNA and Froze

Key Points:

• A genetic study published in May 2026 revealed that the feral cattle herd on Amsterdam Island, established by five animals abandoned in 1871, did not undergo rapid island dwarfism but likely arrived already small with mixed European and Indian Ocean ancestry.
• The cattle's genetic makeup included about 75% European taurine breeds, particularly Jersey cattle, and 25% Indian Ocean zebu, suggesting the founders brought diverse genetic variation that helped the population survive and expand despite extreme isolation.
• Contrary to earlier research suggesting rapid body size reduction, the new DNA analysis found no genetic evidence of selection for smaller size, indicating the animals were inherently small and resilient enough to recover from a severe population bottleneck.
• Despite heavy inbreeding with an estimated 30% individual inbreeding, the herd showed no clear signs of genetic collapse or purging of harmful mutations, likely due to a quick population rebound that maintained genetic diversity.
• Conservation efforts prioritized protecting Amsterdam Island’s unique ecosystem over preserving the feral herd, leading to the removal and eventual culling of the cattle by 2010 to safeguard endangered native species and restore native vegetation, with the area now recognized as a UNESCO World Heritage site.