01698nas a2200181   4500008004100000245009900041210006900140260001400209300001400223490000700237520114200244653002701386653001401413653000801427100002201435700002201457856003701479       2009                        eng d00aCharacter Displacement: Ecological and Reproductive Responses to a Common Evolutionary Problem0 aCharacter Displacement Ecological and Reproductive Responses to   cSeptember  a253–2760 v843 adoi: 10.1086/605079 ABSTRACT Character displacement is the process by which traits evolve in response to selection to lessen resource competition or reproductive interactions between species. Although character displacement has long been viewed as an important mechanism for enabling closely related species to coexist, the causes and consequences of character displacement have not been fully explored. Moreover, character displacement in traits associated with resource use (ecological character displacement) has been largely studied independently of that in traits associated with reproduction (reproductive character displacement). In this review, we underscore the commonalities of these two forms of character displacement and discuss how they interact. We focus on the causes of character displacement and explore how character displacement can have downstream effects ranging from speciation to extinction. In short, understanding how organisms respond to competitive and reproductive interactions with heterospecifics offers key insights into the evolutionary causes and consequences of species coexistence and diversification.10acharacter-displacement10aevolution10arcd1 aPfennig, Karin, s1 aPfennig, David, w  uhttp://dx.doi.org/10.1086/60507901669nas a2200217   4500008004100000245007300041210006900114260000800183300001600191490000800207520103300215653001701248653001001265653002701275653001401302653001001316100003101326700002601357700002201383856004601405       2009                        eng d00aCharacter displacement of song and morphology in African tinkerbirds0 aCharacter displacement of song and morphology in African tinkerb  cMay  a8256–82610 v1063 a10.1073/pnas.0810124106 Divergence in acoustic signals between populations of animals can lead to species recognition failure, reproductive isolation, and speciation. Character displacement may facilitate coexistence of species in natural communities, yet evidence for character displacement in acoustic signals is scant. Here, we find evidence of character displacement in song as well as body size and bill size of 2 related African tinkerbirds. Playback experiments indicate that related species' songs are perceived differently in sympatry than in allopatry. We suggest character displacement occurs in phenotypic traits facilitating species recognition, which has important implications for understanding the processes that lead to speciation and diversification. Because many of the sites where the 2 species coexist are areas where pristine rainforest has been degraded, results also suggest that anthropogenic pressures resulting from deforestation may be a contributing cause of character displacement in these species.10abioacoustics10abirds10acharacter-displacement10aevolution10asongs1 aKirschel, Alexander, N. G.1 aBlumstein, Daniel, T.1 aSmith, Thomas, B.  uhttp://dx.doi.org/10.1073/pnas.0810124106