Fluctuation of ecological niches and geographic range shifts along chile pepper's domestication gradient

Authors: MARTINEZ-AINSWORTH, NATALIA - Universidad Nacional Autonoma De Mexico; SCHEPPLER, HANNAH - The Ohio State University; MORENO-LETELIER, A - Universidad Nacianal Autonoma De Mexico; Bernau, Vivian; KANTAR, MICHAEL - University Of Hawaii; JARDÓN-BARBOLLA, LEV - Universidad Nacianal Autonoma De Mexico; MERCER, KRISTIN - The Ohio State University

Submitted to: Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2023
Publication Date: 11/28/2023
Citation: Martinez-Ainsworth, N.E., Scheppler, H., Moreno-Letelier, A., Bernau, V.M., Kantar, M.B., Jardón-Barbolla, L., Mercer, K.L. 2023. Fluctuation of ecological niches and geographic range shifts along chile pepper's domestication gradient. Ecology and Evolution. 13(11):e10731. https://doi.org/10.1002/ece3.10731.
DOI: https://doi.org/10.1002/ece3.10731

Interpretive Summary: Much effort has been placed on understanding how domestication changes the genetics of plants, but there has been less effort to explore the way domestication changes the geographic landscape on which the plants exist. Therefore, the goal of this study was to understand how domestication has changed the suitable geographic range of chile pepper. Capsicum annuum is a major global species whose origin has been well studied. This provides a unique opportunity to explore how the geographic range of domesticated and wild chile pepper and how they will experience climate change. We modeled the greographic range of chiles under the present day climate and in the future during 2050, 2070, and 2090. There are also clear unique environmental and geographic aspects to the ranges. However, as projections into the future are explored there is a clear asymmetric loss of habitat where wild chiles and farmer varieties (landraces) are at far greater risk than modern cultivars. While range expansion is widely associated with domestication there is little support of a constant niche expansion (either in environmental or geographical space) throughout the domestication gradient. The clear differences in environmental adaptation and future potential range for the different levels of domestication show the need to increase conservation efforts, particularly to preserve landraces and wild-like genotypes.

Technical Abstract: Domestication is an ongoing well described process. However, while much effort has been placed on understanding the changes in the genetic landscape, there has been less effort to explore the way domestication changes the geographic landscape on which the plants exist. Therefore, the goal of this study was to understand how the domestication status changed the suitable geographic space of chile pepper. Capsicum annuum is a major global species whose origin has been well studied. This provides a unique opportunity to explore how divergent the ranges of different domestication classes are and how they will experience climate change. To this end ecological niche models were created for four domestication classes (wild, arvense, landrace, modern cultivar) for present day and under two different socioeconomic pathways (SSP) for eight different general circulation models (GCM) in the future during 2050, 2070, and 2090. Considering present environmental niches there is substantial overlap in all the domestication gradient categories. There are also clear unique environmental and geographic aspects to the ranges. However, as projections into the future are explored there is a clear asymmetric loss of habitat where wild, arvense and landraces are at far greater risk than modern cultivars. While range expansion is widely associated with domestication there is little support of a constant niche expansion (either in environmental or geographical space) throughout the domestication gradient. The clear differences in environmental adaptation and future potential range for the different levels of domestication show the need to increase conservation efforts, particularly to preserve landraces and arvense genotypes.