Editing Common name (section)

== Constraints and problems ==
Common names are used in the writings of both [[professional]]s and [[Layman|laymen]]. Lay people sometimes object to the use of scientific names over common names, but the use of scientific names can be defended, as it is in these remarks from a book on marine fish:<ref name="isbn1-86812-032-5">{{cite book |last1=Heemstra |first1=Phillip C. |last2=Smith |first2=Margaret |title=Smith's Sea Fishes |publisher=Southern Book Publishers |year=1999 |isbn=1-86812-032-5 }}</ref>
* Because ''common names often have a very local distribution'', the same fish in a single area may have several common names.
* Because of ''ignorance of relevant biological facts among the lay public'', a single species of fish may be called by several common names, because individuals in the species differ in appearance depending on their maturity, gender, or can vary in appearance as a morphological response to their natural surroundings, i.e. [[ecophenotypic variation]].
* In contrast to common names, formal [[Biological classification|taxonomic]] names imply ''biological relationships between similarly named creatures''.
* Because of ''incidental events, contact with other languages, or simple confusion'', common names in a given region will sometimes ''change with time''.
* In a book that lists over 1200 species of fishes<ref name="isbn1-86812-032-5"/> ''more than half have no widely recognised common name''; they either are too nondescript or too rarely seen to have earned any widely accepted common name.
* Conversely, a ''single common name often applies to multiple species'' of fishes. The lay public might simply not recognise or care about subtle differences in appearance between only very distantly related species.
* Many species that are rare, or lack economic importance, do not have a common name.<ref>{{cite book |first1=Walter S. |last1=Judd |first2=Christopher S. |last2=Campbell |first3=Elizabeth A. |last3=Kellog |first4=Peter F. |last4=Stevens |first5=Michael J. |last5=Donoghue |date=2008 |title=Plant Systematics: A Phylogenetic Approach |edition=3rd |publisher=Sinauer Associates, Inc. |location=Sunderland, MA |isbn=978-0878934072}}</ref>