Lamarckism fell from favour after August Weismann's research in the 1880s indicated that changes from use (such as lifting weights to increase muscle mass) and disuse (such as being lazy and becoming weak) were not heritable.
O lamarckismo deixou de aceptarse a partir das investigacións de August Weismann na década de 1880 que indicaban que os cambios relacionados con usar (como levantar pesos para incrementar a masa muscular) ou non usar (como ser preguiceiro e quedar esmirrado) non eran herdables.