Pangenesis is the idea that traits are inherited from the parents depending what they do in their lifetimes or from the effects of their environment. Charles Darwin proposed that little particles called gemmules were circulated throughout the body and into the gonads where they are transmitted to the child. The gemmules carry the traits that the parents accumulate through the environment. An example would be that a child would have increased muscle growth if the parents had been weight lifting later in their lives but earlier, they had been sedentary. It is now known that Darwin’s pangenesis theory was wrong and that a new, better model has been proposed by Gregor Mendel.