title: Difference in evolutionary patterns of strongly or weakly selected characters among ant populations.
abstract: Despite being a central issue in evolutionary biology, few studies have examined the stasis of characters in populations with no gene flow. A possible mechanism of such stasis is stabilizing selection with similar peaks in each population. This study examined the evolutionary patterns of morphological characters with and without strong selection in ant populations. We show that compared to a character that seems to be less important, characters that are more important were less variable within and among populations. Microsatellite analyses showed significant genetic differences between populations, implying limited gene flow between them. The observed levels of genetic differentiation cannot be attributed to recent population separations. Thus, the observed differences in morphological variance seem to reflect the degree of selection on each character. The less important character changed proportionately with time, but such a pattern was not observed in more important characters. These results suggest that stabilizing selection maintains morphological stasis between populations of the same species with minimal gene flow independent of divergence times.
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Imai
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Ohkubo
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Yagi
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Hasegawa
mesh_terms: D000465:Algorithms; D000818:Animals; D001000:Ants / Q000235:genetics* / Q000502:physiology*; D005075:Biological Evolution; D051456:Gene Flow; D040961:Genetic Drift; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats; D010641:Phenotype; D010802:Phylogeny; D012641:Selection, Genetic; D013045:Species Specificity