02250nas a2200277   4500008004100000245008100041210006900122300001000191490000800201520140800209653001401617653001901631653001601650653001401666653002701680653002101707653002901728100002401757700002401781700001901805700002101824700001701845700002301862700002101885856006601906       2004                        eng d00aParasite escape mechanisms drive morphological diversification in avian lice0 aParasite escape mechanisms drive morphological diversification i  a12 pp0 v2913 a<p>Organisms that have repeatedly evolved similar morphologies owing to the same selective pressures provide excellent cases in which to examine specific morphological changes and their relevance to the ecology and evolution of taxa. Hosts of permanent parasites act as an independent evolutionary experiment, as parasites on these hosts are thought to be undergoing similar selective pressures. Parasitic feather lice have repeatedly diversified into convergent ecomorphs in different microhabitats on their avian hosts. We quantified specific morphological characters to determine (i) which traits are associated with each ecomorph, (ii) the quantitative differences between these ecomorphs, and (iii) if there is evidence of displacement among co-occurring lice as might be expected under louse&ndash;louse competition on the host. We used nano-computed tomography scan data of 89 specimens, belonging to four repeatedly evolved ecomorphs, to examine their mandibular muscle volume, limb length and three-dimensional head shape data. Here, we find evidence that lice repeatedly evolve similar morphologies as a mechanism to escape host defences, but also diverge into different ecomorphs related to the way they escape these defences. Lice that co-occur with other genera on a host exhibit greater morphological divergence, indicating a potential role of competition in evolutionary divergence.</p>
10aBird lice10aco-adaptations10aCT scanning10aEvolution10aGuimaraesiella antiqua10amicro-morphology10aNeopsittaconirmus bushae1 aKOLENCIK, STANISLAV1 aStanley, Edward, L.1 aPunnath, Aswaj1 aGrant, Avery, R.1 aDoña, Jorge1 aJohnson, Kevin, P.1 aAllen, Julie, M.  uhttps://royalsocietypublishing.org/doi/10.1098/rspb.2023.2665