Divers swam throughout Yucatán’s underwater caves taking samples of the different microbes that live there. Natalie Gibb/Under the Jungle The Yucatán Peninsula’s underwater caves cover over 900 miles. Its cenotes, or sinkholes, are an important drinking water resource for the region. Researchers mapped unique communities of microbes in a dozen areas of the cave system. The Sac Actun cave system on Mexico’s Yucatán Peninsula contains…