 Among the most significant were the voyages of where Charles Darwin came up with his theories of evolution and on the formation of coral reefs.Another important expedition was undertaken by HMS "Challenger", where findings were made of unexpectedly high species diversity among fauna stimulating much theorizing by population ecologists on how such varieties of life could be maintained in what was thought to be such a hostile environment.This era was important for the history of marine biology but naturalists were still limited in their studies because they lacked technology that would allow them to adequately examine species that lived in deep parts of the oceans.