Simplify the following text for a Grade 8 native English-speaking person.
Original: There are other eroded mountain ranges of equal or greater age to the MacDonnell Ranges , both in Australia and on other continents , so present rivers in those areas may have evolved from ancestral streams of equal and greater antiquity than the Finke .
Simplified: There are other mountain ranges of equal or greater age to the MacDonnell Ranges , both in Australia and on other continents . The rivers in those areas may have evolved from ancestral streams of of the same age or older than the Finke .