Question

Give an example of characteristics being used to determine how close two species are in evolutionary terms

Answer 1

We basically catagorise them on basis of their anatomy. Arachaeopteryx is the best example which is closely related to reptiles as Well as aves it has feathers forelimbs are modified into wings nd beaks are also present while reptalian characters are presence of tail pneumatic bones nd weak sternum on this basis its called missing link.

Answer 2

homologous organs
analogus organs
and vestigial organs