Frequency of migrants and migratory activity are genetically correlated in a bird population: Evolutionary implications

TY - JOUR

T1 - Frequency of migrants and migratory activity are genetically correlated in a bird population: Evolutionary implications

AU - Pulido, F.

AU - Berthold, P.

AU - Van Noordwijk, A.J.

N1 - Reporting year: 1996 Metis note: 2210; CTE; PVD ; AnE; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs1996/Pulido_ea_2210.pdf

PY - 1996

Y1 - 1996

N2 - Most migratory bird populations are composed of individuals that migrate and individuals that remain resident, While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not yet been considered. Drawing on the recorded migratory activities of 775 blackcaps (Sylvia atricapilla) from a partially migratory population in southern France, He tested two alternative genetic models about the relationship between incidence and amount of migratory activity. The amount of migratory activity could be the continuous variable ''underlying'' the phenotypic expression of migratory urge, or, alternatively, the expression of both traits could be controlled by two separate genetic systems, The distributions of migratory activities in five different cohorts and the inheritance pattern derived from selective breeding experiments both indicate that incidence and amount of migratory activity are two aspects of one trait, Thus, all birds without measurable activity have activity levels at the low end of a continuous distribution. below the limit of expression or detection, The phenotypic dichotomy ''migrant-nonmigrant'' is caused by a threshold which may not be fixed but influenced both genetically and environmentally. This finding has profound implications for the evolution of migration: the transition from migratoriness to residency should not only be driven by selection favoring resident birds but also by selection for lower migratory activity. This potential for selection on two aspects, residency and migration distance, of the same trait may enable extremely rapid evolutionary changes to occur in migratory behavior. [KEYWORDS: Sylvia atricapilla; blackcap; threshold trait; selection response; partial migration Ringing recoveries; european warblers; behavior; selection]

AB - Most migratory bird populations are composed of individuals that migrate and individuals that remain resident, While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not yet been considered. Drawing on the recorded migratory activities of 775 blackcaps (Sylvia atricapilla) from a partially migratory population in southern France, He tested two alternative genetic models about the relationship between incidence and amount of migratory activity. The amount of migratory activity could be the continuous variable ''underlying'' the phenotypic expression of migratory urge, or, alternatively, the expression of both traits could be controlled by two separate genetic systems, The distributions of migratory activities in five different cohorts and the inheritance pattern derived from selective breeding experiments both indicate that incidence and amount of migratory activity are two aspects of one trait, Thus, all birds without measurable activity have activity levels at the low end of a continuous distribution. below the limit of expression or detection, The phenotypic dichotomy ''migrant-nonmigrant'' is caused by a threshold which may not be fixed but influenced both genetically and environmentally. This finding has profound implications for the evolution of migration: the transition from migratoriness to residency should not only be driven by selection favoring resident birds but also by selection for lower migratory activity. This potential for selection on two aspects, residency and migration distance, of the same trait may enable extremely rapid evolutionary changes to occur in migratory behavior. [KEYWORDS: Sylvia atricapilla; blackcap; threshold trait; selection response; partial migration Ringing recoveries; european warblers; behavior; selection]

U2 - 10.1073/pnas.93.25.14642

DO - 10.1073/pnas.93.25.14642

M3 - Article

SN - 0027-8424

VL - 93

SP - 14642

EP - 14647

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 25

ER -