Does Haldane's rule speciation within mimetic Poison frogs?

To explain how populations with distinct warning signals coexist in close parapatry, we experimentally assessed intrinsic mechanisms acting as reproductive barriers within three Ranitomeya poison-frog species. For all species, assortative mating did not occur, nor did a survival disadvantage for inter-population hybrids. However, in Ranitomeya fantastica, these hybrids of the male sex are sterile, an outcome predicted by Haldanes rule. Our results suggest a possible XY sex determinism in R. fantastica, and show that this process is associated with an extraordinary diversity, leading to speciation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/586569v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@9cd116org.highwire.dtl.DTLVardef@16303dforg.highwire.dtl.DTLVardef@19339acorg.highwire.dtl.DTLVardef@af7718_HPS_FORMAT_FIGEXP M_FIG C_FIG