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 .
A study in 2005 concluded that mothers teach the behaviour to their daughters , and that all the sponge-users are closely related . This suggests that it is a fairly recent innovation .
During the 1850s Courbet painted many other pictures using common folk and friends as his subjects , such as `` Village Damsels '' ( 1852 ) , the `` Wrestlers '' ( 1853 ) , `` Bathers '' ( 1853 ) , `` The Sleeping Spinner '' ( 1853 ) , and `` The Wheat Sifters '' ( 1854 ) .