Niche divergence among closely related taxa provides insight on evolutionary patterns of ticks

CUERVO PF; FLORES FS; VENZAL JM; NAVA S

JOURNAL OF BIOGEOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021

0305-0270

Aim: Understanding the degree to which closely related taxa diverge in their nichetraits could provide insight on their evolutionary patterns, as well as shed some lighton the mechanisms underpinning broad-scale biogeographic patterns. The evolutionof ticks was thought to be driven by hosts. However, recent evidence suggests thattick evolution is more likely to be driven by habitat conditions. The Amblyomma macu-latum group of ticks provides a good example to test the former, as its incipient specia-tion raises the possibility of a very rapid adaptation to slightly different environments.Location: The Americas.Taxa: Ticks from the Amblyomma maculatum Koch, 1844 (Acari: Ixodidae) group (A.tigrinum, A. triste s.s., A. maculatum s.s. and two intermediate morphs).Methods: We analysed the distribution of each tick morphotype with ecological nichemodels. Next, we explored the question of whether these closely related taxa inhabitenvironments that are more different or more similar than expected by comparingniches overlap in environmental space.Results: We addressed the question of whether the differentiation of taxa within thisgroup results from ecological factors, either maintaining a similar ecological niche(conservatism) or by occupying distinct niches (divergence). We found evidence forniche differentiation, showing that the members of the Amblyomma maculatum groupexist in and respond to aspects of different environments, leading to geographicalvariation.Main conclusions: The analysis of the ecological niches of the Amblyomma maculatumgroup of ticks indicates niche conservatism for the pairs A. tigrinum?A. maculatums.s. and A. triste s.s.?A. maculatum s.s, traditionally associated to allopatric speciation;while incipient niche divergence is suggested for the rest of comparisons. These find-ings add additional evidence to the study of the evolution of ticks, giving support tothe hypothesis of habitat conditions driving the evolution of taxa with no strict hostspecificity.