Editing Common frog (section)

=== Genetic population structure ===
The common frog is a very widely distributed species, being common all throughout Europe and northwest Asia. The more peripheral subpopulations of common frogs are significantly less in number, as well as less genetically variable. There is a steep genetic decline when approaching the periphery of the common frog's distribution range.<ref name=Johansson>{{cite journal |last1=Johansson |first1=Markus |last2=Primmer |first2=Craig R. |last3=Merilä |first3=Juha |date=14 March 2006 |title=History vs. current demography: explaining the genetic population structure of the common frog (''Rana temporaria'') |doi=10.1111/j.1365-294X.2006.02866.x |journal=Molecular Ecology |volume=15 |issue=4 |pages=975–983 |pmid=16599961 |bibcode=2006MolEc..15..975J |s2cid=30974911 |ref=Demography}}</ref> Additionally, genetic differentiation of common frog subpopulations tends to decrease in relation to increasing latitude.<ref name=Johansson/> The colder climates create a strong selective pressure favoring common frog populations able to behaviorally [[Thermoregulation|thermoregulate]] at a high degree.<ref name="Ludwig-2015" />