Simplify the following text for a Grade 16 native English-speaking person.
Original: There was also the problem of an ever-expanding number of known species : for Kircher and earlier natural historians , there was little problem finding room for all known animal species in the Ark , but by the time John Ray ( 1627 â `` 1705 ) was working , just several decades after Kircher , their number had expanded beyond biblical proportions .
Simplified: There was also the problem of an ever-expanding number of known species : for Kircher and earlier natural historians , there was little problem finding room for all known animal species in the Ark , but by the time John Ray ( 1627 â `` 1705 ) was working , just several decades after Kircher , their number had increased dramatically .