02246nas a2200277   4500008004100000245006100041210006000102260000900162300001400171490000800185520149200193653000901685653001601694653001101710653001201721653001701733653001201750653000901762653001501771653001401786100002201800700002501822700002101847700001901868856008101887       1999                        eng d00aReciprocal natural selection on host-parasite phenotypes0 aReciprocal natural selection on hostparasite phenotypes  c1999  a261 - 2700 v1543 a<p>Coevolution is evolution in one species in response to selection imposed by a second species, followed by evolution in the second species in response to reciprocal selection imposed by the first species. Although reciprocal selection is a prerequisite of coevolution, it has seldom been documented in natural populations. We examined the feasibility of reciprocal selection in a simple host-parasite system consisting of feral pigeons (Columba livia) and their Ischnoceran feather lice (Phthiraptera: Insecta). We tested for a selective effect of parasites on hosts with experimentally altered defenses and for a selective effect of host defense on a component of parasite escape. Previous work indicates that pigeons control lice through efficient preening, while lice escape from preening using complex avoidance behavior. Our results show that feral pigeons with impaired preening, owing to slight bill deformities, have higher louse loads than pigeons with normal bills. We use a controlled experiment to show that high louse loads reduce the survival of pigeons, suggesting that lice select for efficient preening and against bill deformities. In a reciprocal experiment, we demonstrate that preening with a normal bill selects for small body size in lice, which may facilitate their escape From preening. The results of this study verify a crucial element of coevolutionary theory by identifying likely targets of reciprocal phenotypic selection between host and parasite.</p>
10abird10acoevolution10acuckoo10aCuculus10aectoparasite10afitness10alice10arock doves10avirulence1 aClayton, Dale, H.1 aLee, Patricia, L. M.1 aTompkins, D., M.1 aBrodie, E., D.  uhttps://phthiraptera.myspecies.info/sites/phthiraptera.info/files/1224_0.pdf