Hence, the structure of each part of each species, for whatever purpose it may serve, is the sum of many inherited changes, through which the species has passed during its successive adaptations to changed habits and conditions of life.
Horregatik espezie bakoitzeko atal bakoitzaren egitura, bete dezakeen xedea zeinahi delarik ere, espezieak aztura eta bizi-baldintzen aldaketara behin eta berriz moldatzeko pasa dituen aldaketa heredatu ugarien metaketa da.