Evolution of the Realized Climatic Niche in the Genus: Arabidopsis (Brassicaceae)

Abstract

The evolution of the realized climatic niche in the genus Arabidopsis was studied using an almost complete phylogenetic tree based on DNA sequences of the ribosomal internal transcribed spacers. The realized climatic niche (climate space) was determined by the intersections of the distribution ranges of the taxa with climate data and is presented in temperature/precipitation diagrams. A positive correlation exists between the climate spaces of the taxa and their range sizes. The diagrams revealed a core climate; that is, a climate space in which all taxa co‐exist. This core climate is almost identical to the most parsimonious reconstruction of the genus' ancestral climate space and may be considered an ancestral state of these characters. Mapping the evolutionary changes occurring in the realized climatic space on the phylogenetic tree from the core climate proved to be the most parsimonious procedure. The character complex is homoplastic; that is, many parallel evolutionary events have occurred in the subclades. With the exception of A. thaliana, which is sister to the other species of the genus and occupies a very large climate space, the late‐diverged taxa of the other subclades experienced great evolutionary changes whereas the realized climate space of the taxa that diverged earlier resembles the core climate. The latter also show some parallel contractions in the climate space. It is hypothesized that the diversification of Arabidopsis may have started from small to midsized ranges in a temperate climate.

Multiple FLC haplotypes defined by independent cis-regulatory variation underpin life history diversity in Arabidopsis thaliana

“…Use of FLC genomic sequence from a close relative, Arabidopsis lyrata, did not help define which of the haplotypes are ancestral because of the high sequence divergence and large number of indels in the functionally important intronic regions. However, rapid vernalization might have arisen through selection pressure on the length of the plant life cycle due to high mortality from drought (Hoffmann 2005;Satake 2010), herbivory (Parachnowitsch and Lajeunesse 2012), pathogens (Kemen et al 2011), agriculture, or human disturbance. The broader climate envelope of A. thaliana compared with its close relatives, which extends beyond the cool temperate regions into more Mediterranean climates, argues that faster vernalization could have increased the A. thaliana range (Hoffmann 2005).…”

Quantitative divergence of the bacterial root microbiota in Arabidopsis thaliana relatives

“…Cardamine hirsuta diverged from the Arabidopsis species ∼35 Mya and often shares the same habitat with A. thaliana. A. thaliana has a cosmopolitan distribution whereas the other species occur in spatially restricted populations or developed even endemic subspecies, indicative of their adaptation to specific ecological niches (6). The two diploid species, A. halleri and A. lyrata, co-occur in Eurasia, but, in contrast to A. lyrata (Northern rock-cress), the geographical distribution of A. halleri rarely extends into northern latitudes.…”

Cis-regulatory Evolution of Chalcone-Synthase Expression in the Genus Arabidopsis

“…These experiments were conducted with A. halleri and A. lyrata, two self-incompatible species that differ substantially in their ecology (Mitchell-Olds 2001). In central Europe, A. halleri grows in highly competitive open meadows, whereas A. lyrata is restricted to low-competition habitats on exposed rocks (Hoffmann 2005). We compared our findings to data from the model species A. thaliana (de Meaux et al 2005), which differs from other species in the genus by its self-compatibility and low specieswide levels of diversity (Wright et al 2003;Schmid et al 2005).…”