@article{fdi:010049780,
  title = {{L}iving at the edge: biogeographic patterns of habitat segregation conform to speciation by niche expansion in {A}nopheles gambiae},
  author = {{C}ostantini, {C}arlo and {A}yala, {D}iego and {G}uelbeogo, {W}.{M}. and {P}ombi, {M}. and {S}ome, {C}.{Y}. and {B}assole, {I}.{HN}. and {O}se, {K}enji and {F}otsing, {J}ean-{M}arie and {S}agnon, {N}. and {F}ontenille, {D}idier and {B}esansky, {N}.{J}. and {S}imard, {F}r{\'e}d{\'e}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground; {O}ngoing lineage splitting within the {A}frican malaria mosquito {A}nopheles gambiae is compatible with ecological speciation, the evolution of reproductive isolation by divergent natural selection acting on two populations exploiting alternative resources. {D}ivergence between two molecular forms ({M} and {S}) identified by fixed differences in r{DNA}, and characterized by marked, although incomplete, reproductive isolation is occurring in {W}est and {C}entral {A}frica. {T}o elucidate the role that ecology and geography play in speciation, we carried out a countrywide analysis of {A}n. gambiae {M} and {S} habitat requirements, and that of their chromosomal variants, across {B}urkina {F}aso. {R}esults; {M}aps of relative abundance by geostatistical interpolators produced a distinct pattern of distribution: the {M}-form dominated in the northernmost arid zones, the {S}-form in the more humid southern regions. {M}aps of habitat suitability, quantified by {E}cological {N}iche {F}actor {A}nalysis based on 15 eco-geographical variables revealed less contrast among forms. {M} was peculiar as it occurred proportionally more in habitat of marginal quality. {M}easures of ecological niche breadth and overlap confirmed the mismatch between the fundamental and realized patterns of habitat occupation: forms segregated more than expected from the extent of divergence of their environmental envelope - a signature of niche expansion. {C}lassification of chromosomal arm 2{R} karyotypes by multilocus genetic clustering identified two clusters loosely corresponding to molecular forms, with 'mismatches' representing admixed individuals due to shared ancestral polymorphism and/or residual hybridization. {I}n multivariate ordination space, these karyotypes plotted in habitat of more marginal quality compared to non-admixed, 'typical', karyotypes. {T}he distribution of 'typical' karyotypes along the main eco-climatic gradient followed a consistent pattern within and between forms, indicating an adaptive role of inversions at this geographical scale. {C}onclusion; {E}cological segregation between {M} and {S} is consistent with niche expansion into marginal habitats by chromosomal inversion variants during early lineage divergence; presumably, this process is promoted by inter-karyotype competition in the higher-quality core habitat. {W}e propose that the appearance of favourable allelic combinations in other regions of suppressed recombination (e.g. pericentromeric portions defining speciation islands in {A}n. gambiae) fosters development of reproductive isolation to protect linkage between separate chromosomal regions.},
  keywords = {{PALUDISME} ; {VECTEUR} ; {MOUSTIQUE} ; {REPARTITION} {GEOGRAPHIQUE} ; {SPECIATION} ; {FACTEUR} {ECOLOGIQUE} ; {NICHE} {ECOLOGIQUE} ; {HABITAT} ; {ABONDANCE} ; {POLYMORPHISME} {GENETIQUE} ; {STRUCTURE} {GENETIQUE} ; {STRUCTURE} {DE} {POPULATION} ; {CHROMOSOME} ; {INVERSION} ; {CARYOTYPE} ; {EVOLUTION} ; {BURKINA} {FASO}},
  booktitle = {},
  journal = {{BMC} {E}cology},
  volume = {9},
  numero = {16},
  pages = {1--27},
  ISSN = {1472-6785},
  year = {2009},
  DOI = {10.1186/1472-6785-9-16},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049780},
}