structures that perform a similar function but are not similar in origin

remnants of once-important structures that have slowly lost all or most of their function

features found in different organisms that share structural similarities but may have very different functions

preserved remains of an organism

Homologous structure

Analogous structure

Vestigial organs

Functional adaption

The bones are analogous structures to the fins of living fish.

The bones are vestigial structures that had a function in an ancestor.

The bones are homologous structures to the wings of butterflies.

The bones are fossil structures from an extinct ancestor.

Dog & Rabbit

Rabbit & Elk

Dog & Elk