inherited characteristics are passed down from ancestor to descendant & some characteristics of animals are inherited ->  some characteristics are passed down from ancestor to descendant  some characteristics are passed down from ancestor to descendant & two or more animals have similar characteristics ->  animals with similar characteristics might share a common ancestor  evolution causes significant trait changes in a species & evolution occurs over a long period of time ->  evolution causes  significant trait changes over a long period of time  evolution causes  significant trait changes over a long period of time & recent geological history means a relatively short period of time ->  if an animal evolved from another animal in recent geological history then the changes in traits will be less significant  animals with similar characteristics might share a common ancestor & if an animal evolved from another animal in recent geological history then the changes in traits will be less significant ->  animals with similar characteristics might have evolved from a common ancestor in recent geological history  an inherited characteristic is a kind of characteristic & bone structure is a kind of inherited characteristic of an animal ->  bone structure is a kind of characteristic of an animal  animals with similar characteristics might have evolved from a common ancestor in recent geological history & bone structure is a kind of characteristic of an animal -> animals with similar bone structure probably evolved from a common ancestor in recent geological history