This is an updated version of a story first published on Sept. 21, 2025. The original video can be viewed here. Biologist Charles Darwin began crafting his theory of evolution on a trip to the Galapagos Islands, where he discovered animals had developed unique traits that varied from island to island. Nearly two centuries later, on a different island, scientists aren't just observing evolution, they now have the technology to shape it. We met a team of modern-day Darwins on Nantucket, where, as we first told you last fall, they're hoping to use genetic engineering to reduce the transmission of Lyme disease - a tick-borne illness found primarily in the Northeast and Upper Midwest, but also throughout the United States. The scientists' target may surprise you. It's not the deer often associated with the disease, or even the ticks, but wild mice - the main carriers of Lyme. With the rate of emergency room visits for tick bites at a record high in some regions, this could be the summer Americans consider a new strategy to fight disease: sculpting evolution.Thirty miles off the coast of Cape Cod, Massachusetts, is the island of Nantucket: a 14-mile-long, 3-mile-wide oasis known for its natural beauty, pristine shorelines, and protected landscape.But hidden is a scourge that's afflicted 15% of its residents.Kevin Esvelt: The natural disaster in our area is not hurricanes, or tornadoes, or earthquakes; it is Lyme disease. It is the one plague that might be severe enough that communities might want to engineer a wild organism in order to get rid of it, or, at least, reduce the level, a lot. Deep in the island's brush, in 2024, we found MIT associate professor Kevin Esvelt, a pioneer in genetic engineering, waving a white flag in search of ticks.