Tagged: Adaptive divergence

Plasticity to drought and ecotypic differentiation in populations of a crop wild relative

Plant functional traits often vary across space, particularly when species encounter contrasting environmental conditions throughout their range. Such phenotypic variation is determined by both genetic and environmental effects. Understanding their relative contribution to trait variation and how they influence plant adaptation are central questions in evolutionary ecology. Yet, they are also of potential importance to agriculture, particularly if variation is observed in functional traits in natural populations of crop wild relatives. In a new study published in AoBP, Matesanz et al. assessed adaptive differentiation and phenotypic plasticity in populations of Lupinus angustifolius, a Mediterranean crop wild relative, from two regions...

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Differential adaptation and species diversification between two Melastoma species and their F1 hybrid

In speciation, the formation of new lineages can be driven by two basic evolutionary processes—lineage divergence and lineage fusion. Lineage divergence can happen through differential adaptation or genetic drift, with the former expected to proceed more rapidly when the effective population size is large.Lineage fusion through hybridization, on the other hand, can provide raw material for adaptation to various habitats by creating new allelic combinations and phenotypes. When the two drivers of speciation take effect on a single group of taxa, rapid species radiation can occur. Variation in gene expression has been shown to promote adaptive divergence, and can lead...

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Flower of Iris atropurpurea in NET population and distribution map of I. atropurpurea.

Intra-species ecological divergence in irises

Speciation is often described as a continuum, from minor divergence of populations to complete reproductive isolation between species. Within-species population divergence can shed light on the first steps of speciation and the mechanisms underlying it. Yardeni et al. show that ecological divergence of Iris atropurpurea populations is associated with partial reproductive isolation. They find no spatial pattern of reproductive isolation, suggesting that ecological differentiation is predominant over isolation by distance and reduced gene flow in this species. These findings also have implications for conservation management and genetic rescue of the highly fragmented and endangered I. atropurpurea.

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