Evolution in action: adaptation and incipient sympatric speciation with gene flow across life at “Evolution Canyon”, Israel

Abstract

Various major evolutionary problems are still open, controversial or unsettled. These include even the basic evolutionary processes of adaptation and speciation. The “Evolution Canyon” model is a microscale natural laboratory that can highlight some of the basic problems requiring clarification (Nevo list of “Evolution Canyon” publications athttp://evolution.haifa.ac.il). This is especially true if an interdisciplinary approach is practiced including ecological functional genomics, transcriptomics, proteomics, metabolomics and phenomics. Here I overview and reanalyze theincipient sympatric adaptive ecological speciationof five model organisms at “Evolution Canyon”, across life: the soil bacterium,Bacillus simplex; wild barley, the progenitor of cultivated barley,Hordeum spontaneum; the tiny beetleOryzaephilus surinamensis; the cosmopolitan fruit-fly,Drosophila melanogaster, and the Africa-originated spiny mouse,Acomys cahirinus. All five models of organisms displayevolution in action of microclimatic adaptation and incipient sympatric adaptive ecological speciationon the tropical and temperate abutting slopes, separated on average by only 250 meters. Some distant species converge in theirmicro-climatic adaptations to the hot and dry “African”, south-facing slope (SFS or AS) and to the cool and humid “European”, north-facing slope (NSF or ES). Natural selection overrules ongoing inter-slope gene-flow between the free interbreeding populations within and between slopes, and leads toadaptive incipient sympatric ecological speciationon the dramatically opposite abutting xeric savannoid and mesic forested slopes.