San Antonio College Library

The intriguing theory of a land bridge periodically linking Siberia and Alaska during the coldest pulsations of the Ice Ages had been much debated since Jose de Acosta, a Spanish missionary working in Mexico and Peru, first proposed the idea of a connection between the continents in 1590. But proof of the land bridge -- now named Beringia, after eighteenth-century Danish explorer Vitus Bering -- eluded scientists until an inquiring geologist named...