Mode, tempo and pattern of evolution in subterranean mole rats of the Spalax ehrenbergi superspecies in the quaternary of Israel

The Spalax ehrenbergi superspecies in Israel involves 4 chromosomal species (2n = 52, 54, 58 and 60) displaying active ecological speciation throughout the Quaternary, matching climatic diversity. The mode of speciation was presumably peripatric, initiated chromosomally in small peripherally isolated populations. The emergence of the new chromosomal species was followed by a gradual genic accumulation of positive assortative mating, based on premating ethological species-specific isolating mechanisms involving olfaction, vocalization, seismic (vibrational), aggression and mating (through bacular variation) cues. Speciation was gradual, not punctuational, budding sequential daughter species with increasing chromosome numbers and heterozygosity, in a trend along an ecological gradient of increasing aridity towards the desert. The adaptationist programme is indispensable in understanding the evolution of Spalax ehrenbergi. The evolution of Spalax links micro- and macroevolution, corroborating the Synthetic Theory of Evolution. The evolutionary model of Spalax is potentially rich and its future advancement can enrich evolutionary theory.