A new study published in Nature challenges long-held theories about the origins of bats, suggesting they first appeared in Europe around 65 million years ago, rather than in Asia, Africa, or North America as previously thought. Conducted by an international team of 137 researchers from 64 countries as part of the Bat1K consortium, the study combined genomic data and fossil evidence to trace the evolutionary history of bats, the only mammals capable of powered flight. This research examined 103 bat species, representing all 21 recognized bat families, and assembled the largest collection of high-quality bat genomes to date. Using advanced DNA sequencing and computational tools, scientists compared these genomes to identify the genes involved and reconstruct the evolutionary relationships among bat species. To map the history of bat evolution, researchers combined the genomic data with 44 fossil specimens from around the world. This allowed them to determine when key traits, such as echolocation and flight, first appeared. The study found that echolocation evolved early in bat history, before the diversification of modern bat species. Fossil evidence, including the placement of the ancient bat Vielasia in the oldest branch of the bat family tree, supports this conclusion. The findings suggest that two of the most defining features of bats—echolocation and powered flight—were established near the origin of the group, contributing to their evolutionary success over millions of years. The research also reconstructed the genome of the earliest bat ancestor, providing a detailed blueprint of the first mammal capable of flight. This genomic map offers insights into how a lineage of mammals evolved traits such as advanced biosonar, exceptional longevity, and disease resistance. Scientists hope this work will inform future studies on human aging, immunity, and disease resistance. For example, a 2025 study based on this genomic data found that early bat ancestors had unique immune gene adaptations, which may explain why bats can host dangerous viruses like Ebola, Nipah, and Marburg without getting sick themselves. Additionally, bats are among the longest-living mammals for their size, showing few signs of aging or cancer. Despite their ecological importance, many bat species are under threat. Around half of known bat species have declining populations, with 18% classified as threatened by the International Union for Conservation of Nature. Bats face challenges such as climate change, habitat loss, and human persecution. Their low reproductive rates—most species give birth to only one or two pups—make it difficult for their populations to recover from sudden losses. In North America, millions of bats have died from white nose syndrome, a fungal disease that affects hibernating bats. This study may help scientists better understand why certain bat species, like the Myotis genus, are more vulnerable to such diseases, potentially leading to new conservation strategies.