Sexual dichromatism represents a major form of phenotypic differentiation between the sexes in birds,and its evolution is likely shaped by the interplay between sexual and natural selection.The genus Ficedula,widely d...Sexual dichromatism represents a major form of phenotypic differentiation between the sexes in birds,and its evolution is likely shaped by the interplay between sexual and natural selection.The genus Ficedula,widely distributed across Eurasia,exhibits pronounced interspecific variation in both sexual dichromatism and migratory behavior,making it an ideal study system for investigating the evolutionary patterns and drivers of avian sexual dichromatism.In this study,we conducted a phylogenetic comparative analysis of plumage complexity and sexual dichromatism across 32 Ficedula species.We further explored how life-history traits influence the evolution of sexual dichromatism.Our results reveal a strong positive correlation between male plumage complexity and the degree of sexual dichromatism,with males evolving plumage complexity at significantly faster rates than females.Migratory species exhibit significantly higher levels of dichromatism.Furthermore,compared to monochromatic species,sexually dichromatic species are characterized by higher latitudinal occurrence,broader geographic distributions,and greater flight capacity.These findings demonstrated how sexual and natural selection jointly drive evolution of sexual dichromatism in Ficedula within phylogenetic constraints,advancing our understanding of the evolutionary drivers of avian sexual dichromatism.展开更多
A k coloring(not necessarily proper) of vertices of a graph is called acyclic, if for every pair of distinct colors i and j the subgraph induced by the edges whose endpoints have colors i and j is acyclic. We consider...A k coloring(not necessarily proper) of vertices of a graph is called acyclic, if for every pair of distinct colors i and j the subgraph induced by the edges whose endpoints have colors i and j is acyclic. We consider some generalized acyclic k colorings, namely, we require that each color class induces an acyclic or bounded degree graph. Mainly we focus on graphs with maximum degree 5. We prove that any such graph has an acyclic 5 coloring such that each color class induces an acyclic graph with maximum degree at most 4. We prove that the problem of deciding whether a graph G has an acyclic 2 coloring in which each color class induces a graph with maximum degree at most 3 is NP complete, even for graphs with maximum degree 5. We also give a linear time algorithm for an acyclic t improper coloring of any graph with maximum degree d assuming that the number of colors is large enough.展开更多
基金support was provided by the National Natural Sciences Foundation of China(Grant 31772444 and 31471987)。
文摘Sexual dichromatism represents a major form of phenotypic differentiation between the sexes in birds,and its evolution is likely shaped by the interplay between sexual and natural selection.The genus Ficedula,widely distributed across Eurasia,exhibits pronounced interspecific variation in both sexual dichromatism and migratory behavior,making it an ideal study system for investigating the evolutionary patterns and drivers of avian sexual dichromatism.In this study,we conducted a phylogenetic comparative analysis of plumage complexity and sexual dichromatism across 32 Ficedula species.We further explored how life-history traits influence the evolution of sexual dichromatism.Our results reveal a strong positive correlation between male plumage complexity and the degree of sexual dichromatism,with males evolving plumage complexity at significantly faster rates than females.Migratory species exhibit significantly higher levels of dichromatism.Furthermore,compared to monochromatic species,sexually dichromatic species are characterized by higher latitudinal occurrence,broader geographic distributions,and greater flight capacity.These findings demonstrated how sexual and natural selection jointly drive evolution of sexual dichromatism in Ficedula within phylogenetic constraints,advancing our understanding of the evolutionary drivers of avian sexual dichromatism.
基金supported by the Minister of Science and Higher Education of Poland (Grant No. JP2010009070)
文摘A k coloring(not necessarily proper) of vertices of a graph is called acyclic, if for every pair of distinct colors i and j the subgraph induced by the edges whose endpoints have colors i and j is acyclic. We consider some generalized acyclic k colorings, namely, we require that each color class induces an acyclic or bounded degree graph. Mainly we focus on graphs with maximum degree 5. We prove that any such graph has an acyclic 5 coloring such that each color class induces an acyclic graph with maximum degree at most 4. We prove that the problem of deciding whether a graph G has an acyclic 2 coloring in which each color class induces a graph with maximum degree at most 3 is NP complete, even for graphs with maximum degree 5. We also give a linear time algorithm for an acyclic t improper coloring of any graph with maximum degree d assuming that the number of colors is large enough.
