 There he spoke against the teaching of the theory of evolution in schools, arguing that it was as yet an unproven hypothesis that lacked empirical foundations and that, therefore, its teaching would negatively affect scientific studies.Ernst Haeckel, who had been Virchow's student, later reported that his former professor said that "it is quite certain that man did not descend from the apes...not caring in the least that now almost all experts of good judgment hold the opposite conviction.