title: Anthropogenic habitat disturbance and ecological divergence between incipient species of the malaria mosquito Anopheles gambiae.
abstract: BACKGROUND
  Anthropogenic habitat disturbance is a prime cause in the current trend of the Earth's reduction in biodiversity. Here we show that the human footprint on the Central African rainforest, which is resulting in deforestation and growth of densely populated urban agglomerates, is associated to ecological divergence and cryptic speciation leading to adaptive radiation within the major malaria mosquito Anopheles gambiae.
  
  
  RESULTS
  In southern Cameroon, the frequency of two molecular forms--M and S--among which reproductive isolation is strong but still incomplete, was correlated to an index of urbanisation extracted from remotely sensed data, expressed as the proportion of built-up surface in each sampling unit. The two forms markedly segregated along an urbanisation gradient forming a bimodal cline of ∼6-km width: the S form was exclusive to the rural habitat, whereas only the M form was present in the core of densely urbanised settings, co-occurring at times in the same polluted larval habitats of the southern house mosquito Culex quinquefasciatus--a species association that was not historically recorded before.
  
  
  CONCLUSIONS
  Our results indicate that when humans create novel habitats and ecological heterogeneities, they can provide evolutionary opportunities for rapid adaptive niche shifts associated with lineage divergence, whose consequences upon malaria transmission might be significant.
authors: UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224), Institut de Recherche pour le Développement (IRD), Montpellier, France.
authors: Colince
authors: C
authors: Kamdem
authors: Billy
authors: B
authors: Tene Fossog
authors: Frédéric
authors: F
authors: Simard
authors: Joachim
authors: J
authors: Etouna
authors: Cyrille
authors: C
authors: Ndo
authors: Pierre
authors: P
authors: Kengne
authors: Philippe
authors: P
authors: Boussès
authors: François-Xavier
authors: FX
authors: Etoa
authors: Parfait
authors: P
authors: Awono-Ambene
authors: Didier
authors: D
authors: Fontenille
authors: Christophe
authors: C
authors: Antonio-Nkondjio
authors: Nora J
authors: NJ
authors: Besansky
authors: Carlo
authors: C
authors: Costantini
mesh_terms: D000818:Animals; D000852:Anopheles; D004463:Ecology; D017753:Ecosystem; D008288:Malaria / Q000635:transmission*