Simplify the following text for a Grade 8 native English-speaking person.
Original: A study in 2005 concluded that mothers teach the behavior to their daughters , and that all the sponge-users are closely related , suggesting that it is a fairly recent innovation .
Simplified: A study in 2005 concluded that mothers teach the behavior to their daughters , and that all the sponge-users are closely related . This suggests that it is a fairly recent innovation .