Researchers claim to have found possible example of sympatric speciation

first_imgMiddle East Blind Mole Rat or Palestine Mole Rat (Nannospalax ehrenbergi or Spalax ehrenbergi). Credit: Wikipedia. Citation: Researchers claim to have found possible example of sympatric speciation (2013, January 30) retrieved 18 August 2019 from https://phys.org/news/2013-01-sympatric-speciation.html Journal information: Proceedings of the National Academy of Sciences (Phys.org)—A research team working in Israel has found what might possibly be an example of evolutionary divergence in action – and it’s not due to a natural barrier. In their paper published in the Proceedings of the National Academy of Sciences, the researchers describe how blind mole rats living nearly side-by-side in the Upper Galilee Mountains, have been found to possess a difference in their mitochondrial DNA, of up to 40 percent. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: Possible incipient sympatric ecological speciation in blind mole rats (Spalax), PNAS, Published online before print January 28, 2013, doi: 10.1073/pnas.1222588110AbstractSympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2n = 52). The study microsite (0.04 km2) is sharply subdivided geologically, edaphically, and ecologically into abutting barrier-free ecologies divergent in rock, soil, and vegetation types. The Pleistocene Alma basalt abuts the Cretaceous Senonian Kerem Ben Zimra chalk. Only 28% of 112 plant species were shared between the soils. We examined mitochondrial DNA in the control region and ATP6 in 28 mole rats from basalt and in 14 from chalk habitats. We also sequenced the complete mtDNA (16,423 bp) of four animals, two from each soil type. Remarkably, the frequency of all major haplotype clusters (HC) was highly soil-biased. HCI and HCII are chalk biased. HC-III was abundant in basalt (36%) but absent in chalk; HC-IV was prevalent in basalt (46.5%) but was low (20%) in chalk. Up to 40% of the mtDNA diversity was edaphically dependent, suggesting constrained gene flow. We identified a homologous recombinant mtDNA in the basalt/chalk studied area. Phenotypically significant divergences differentiate the two populations, inhabiting different soils, in adaptive oxygen consumption and in the amount of outside-nest activity. This identification of a possible incipient sympatric adaptive ecological speciation caused by natural selection indirectly refutes the allopatric alternative. Sympatric ecological speciation may be more prevalent in nature because of abundant and sharply abutting divergent ecologies.last_img read more