The tripeptide Arginyl-Glycyl-Aspartic acid (RGD) is a common cell recognition site of many adhesive proteins contained in extracellular matrices and in the blood .
Davidson overthrows this conventionalist view of communication by language in the light of his original ideas as to the essence of linguistic communication.
The branching points of the cladogram may be regarded either as an ancestral species (as in an evolutionary tree) or solely as representing shared characteristics.