Global ecological niche conservatism and evolution in Olea species

Uzma Ashraf; A Townsend Peterson; Muhammad Nawaz Chaudhry; Marlon E Cobos

doi:10.1016/j.sjbs.2022.103500

Global ecological niche conservatism and evolution in Olea species

Saudi J Biol Sci. 2023 Jan;30(1):103500. doi: 10.1016/j.sjbs.2022.103500. Epub 2022 Nov 11.

Authors

Uzma Ashraf^{1

2

3}, A Townsend Peterson⁴, Muhammad Nawaz Chaudhry³, Marlon E Cobos⁴

Affiliations

¹ Department of Land, Air and Water Resources, University of California, Davis, USA.
² Wild Energy Initiative, Institute of the Environment, University of California, Davis, USA.
³ Department of Environmental Sciences and Policy, Lahore School of Economics, Lahore, Punjab, Pakistan.
⁴ Biodiversity Institute, University of Kansas, Lawrence, KS, USA.

Abstract

Background and aims: Climate is an important parameter in delimiting coarse-grained aspects of fundamental ecological niches of species; evolution of these niches has been considered a key component in biological diversification. We assessed phylogenetic niche conservatism and evolution in 24 species of the family Oleaceae in relation to temperature and precipitation variables. We studied niches of 17 Olea species and 7 species from other genera of Oleaceae globally.

Methods: We used nuclear ribosomal and plastid DNA to reconstruct an evolutionary tree for the family. We used an approach designed specifically to incorporate uncertainty and incomplete knowledge of species' ecological niche limits. We performed parsimony- and likelihood-based reconstructions of ancestral states on two independent phylogenetic hypotheses for the family. After detailed analysis, species' niches were classified into warm and cold niches, wet and dry niches, and broad and narrow niches.

Key results: Given that full estimates of fundamental niches are difficult, we explore the alternative approach of explicit incorporation of knowledge of gaps in the information available, which allows avoidance of overestimation of amounts of evolutionary change. The result is a first synthetic view of evolutionary dynamics of ecological niches and distributional potential in a widespread plant family. Temperate regions of the Earth were occupied only by lineages that could derive with cold and dry niches; Southeast Asia held species with warm and wet niches; and parts of Africa held only species with dry niches.

Conclusions: High temperature in Lutetian (Oligocene) and low temperature in Rupelian (Eocene) with major desertification events play important role for niche retraction and expansion in the history for Oleaceae clades. Associations between environmental niche characteristics and phylogeny reconstruction play an important role in understanding ecological niche conservatism, the overall picture was relatively slow or conservative niche evolution in this group.

Keywords: Ancestral reconstruction; Climate change; Evolution; Niche evolution in olives; Oleaceae; Olives; Phylogeny.

Associated data

Dryad/10.5061/dryad.s2v81