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GENIC VARIATION, SYSTEMATIC, AND BIOGEOGRAPHIC RELATIONSHIPS OF SOME GALLIFORM BIRDS R. J. GUTIERREZ,1 ROBERTM. ZINK, AND SUH Y. YANG2 Museumof VertebrateZoology, University of California,Berkeley, California 94720 USA ABSTRACT.--Starchgel electrophoresiswas used to evaluate levels and patterns of genic differentiationamong 10 speciesof galliform birds in the Phasianidae(9) and Tetraonidae (1). The phasianidsincluded an Old World quail, a partridge, a pheasant,and six species of New World quail. Measuresof within-speciesgenetic variation includedheterozygosity, percentagepolymorphic loci, and number of allelesper polymorphiclocus. These values were similar to but lower than those reported for other birds. Genetic distancesamong conspecificpopulations and among congenericspecies were low comparedto other avian results. Genetic distancesamong noncongenersboth within and between families were considerablyhigher, however, than those reported for passerinebirds. Thus, more studies of levelsof genic differentiationamong nonpasserines are required to complementthe lit- erature on genic divergenceamong passerinesand to enable us to make general statements about genic evolution in birds. Phenogramsand phylogenetictrees suggestedthat Phasianuscolchicus, Tympanuchus pal- lidicinctus,Coturnix coturnix, Alectoris chukar, and the New World quail (Odontophorinae) are genically distinct taxa. The branching sequenceamong the non-Odontophorine taxa is unresolvedby our data. The branching order among taxa in the Odontophorinaefrom a commonancestor is: Cyrtonyxmontezumae, Oreortyx pictus, Colinus virginianus, Callipepla squamata,Lophortyx gambelii, and L. californicus.The generaCyrtonyx, Oreortyx, and Colinus are clearly distinct from Callipeplaand Lophortyx,which are quite similar to each other genically. We use a fossil speciesfrom the mid-Miocene of Nebraskato calibrateour geneticdis- tances.We estimatedates of divergenceof taxain the Odontophorinaeand offer a hypothesis on their historicalbiogeography. Our analysissuggests that three east-westrange disjunc- tions could accountfor the origin of Oreortyx (12.6 MYBP), Colinus(7.0 MYBP), and Calli- pepla-Lophortyx(2.8 MYBP). We suggestthat L. californicusand L. gambeliishould be con- sidereddistinct speciesbecause of an apparentlack of panmixia in zonesof sympatry,even though the D between them is typical of that found between subspeciesof other birds. Oreortyxand Colinusshould remain as distinct genera,while our data are equivocalon the statusof Callipeplaand Lophortyx?Received 9 March 1982, accepted5 July 1982. ALLOZYMEelectrophoresis has been used less examinedavian intrafamilial relationships(e.g. frequently to examinegenetic variation within Barrowclough and Corbin 1978, Avise et al. and among groups of birds than in other ver- 1980a-c).They have found that passerinebirds tebrates (see review in Nevo 1978). Some possess considerably lower levels of genic workers have examined patterns of intraspe- (= allozymic) differentiation than other verte- cificgenic variation in passerines(e.g. Barrow- brate taxa, at comparable taxonomic levels. clough 1980,Johnson and Brown 1980, Corbin Several workers have compared the level of 1981, and references therein), and a few have genic divergence and taxonomicrank for var- ious vertebrate and invertebrate taxa (e.g. Ay- • Present address: Department of Wildlife Man- ala 1975, Avise et al. 1980b). Barrowcloughet agement, Humboldt State University, Arcata, Cali- fornia 95521 USA. al. (1981)present similar data for birds but dis- 2 Present address:Department of Biology, Inha cussreasons why comparisonsacross different University, Inchon, Korea. groups of organisms may be inappropriate; :3Lophortyx has been merged with Callipeplain the these include taxonomic artifacts [e.g. avian, Thirty-fourth Supplement to the American Orni- mammalian, and reptilian genera may not be thologists'Union check-listof North American Birds comparablebecause of the way in which tax- [Auk 99 (3, Suppl.): 5CC]. onomistspartition variation (Sibley and Ahl- 33 The Auk 100:33-47. January1983 34 GOX•gRREZ,ZINK, ANDYANG [Auk, Vol. 100 quist 1982)] and differences in rates of evolu- zygosity(/•) was definedas the numberof hetero- tion, mating systems,effective population sizes, zygous genotypesrecorded in a sample divided by recencyof common ancestry,and dispersalpa- the product of the number of loci and the number of rameters. Whether or not low levels of genic individualsassayed (see Corbin 1981for a discussion divergencetypify birds as a group is unclear, of calculating/z/).Estimates of percentagepolymor- becauseonly Barrowcloughet al. (1981)studied phismwere based on thenumber of locihaving more than one allele divided by the total number of loci a nonpasserinetaxon. They found higher levels (27) examined. of differentiation among some procellariiform The measuresof Nei (1978)and Rogers(1972) were taxa than those usually found among passer- used to estimate genetic distances between taxa. ines. Becausethe levelsof geneticdifferentia- Clusteranalyses, summarizing the matrixof Rogers' tion are sometimes used to make inferences D-values,were performed with boththe unweighted about evolutionaryprocesses (Avise et al. 1980c, and weighted pair-group methods,using arithmetic Templeton 1980), we clearly need additional means(UPGMA and WPGMA, respectively).The co- studies of nonpasserinesbefore we can make phenetic correlation coefficient, rcc,was used to eval- general statementsabout genic evolution in uate how well the resultant phenogramsrepresent birds. the original distancematrix. Sneathand Sokal(1973) provide details on these pheneticmethods. Phylo- The patternsof genic differencescan alsobe genetic trees, also based on Rogers'D-values, were used to infer phylogeneticrelationships (e.g. constructedaccording to the methodsof Farris (1972; Barrowcloughand Corbin 1978,Zink 1982). In Wagner trees) and Fitch and Margoliash(1967; F-M this paperwe examinelevels of genicvariation trees). The Wagner tree is an approximationof the and phylogenetic relationships among 10 most parsimonious tree. The F-M procedure con- speciesfrom 5 of 10 generaof New World quail, structsa number of treesby alteringthe branching an Old World quail, a partridge, a pheasant, structureand branch lengths. Alternative trees were and a grouse. We use our phylogenetic hy- evaluatedby the percentagestandard deviation (%SD) pothesis to construct an estimate of the evo- and by the number of negativebranches (the fewer the better). A lower %SD means a better fit of dis- lutionary history of some New World quail. tancesimplied by the tree to the original distance We also evaluateprevious statementsabout the matrix (Fitch and Margoliash 1967). A cladisticanal- taxonomic relationships of these galliform ysis, sensuHennig (1966), using alleles as character birds. states (see Wake 1981), basically corroborated the above methods. The allele in T. pallidicinctus(Te- MATERIALS AND METHODS traonidae) was considered"primitive" when com- We examined 217 specimens of galliform birds paring the pattern of allele distribution in the re- representing 10 species. Species, localities, sample maining taxa (Phasianidae),i.e.T. pallidicinctuswas sizes, and the taxonomic framework used in this pa- used as an "outgroup" to the phasianids. per are given in Appendix 1. Nomenclaturefollows the A.O.U. check-list (1957, 1973). RESULTS Liver, heart, and kidney tissuewere excisedin the field within 4 h of death and frozen in liquid nitro- Protein variation.--Twenty structural pro- gen. Tissueswere homogenizedusing the methods teins and enzymes encodedby 27 presumptive of Selander et al. (1971), and extractswere stored at genetic loci were examined in all individuals. -76øC until used for electrophoresis.Combined tis- Allelic frequenciesfor the 23 variable loci, per- sue extractswere subjectedto horizontal starch gel centagepolymorphism and heterozygosity,and electrophoresisas describedby Selanderet al. (1971). number of alleles per polymorphic locus are Gel and buffer systemsfor the loci listed in Appendix given in Appendix 2. Four loci (Mdh-1, Mdh- 2 were essentiallythe same as those describedby Yang and Patton (1981). More detailed information 2, Lap, Pt-l) were monomorphicand fixed for regardingelectmphoretic conditions is availablefrom the same electromorph acrossspecies. Seven the authors. loci (c•Gpd-1,Got-2, Udh, Gdh, Ldh-1, Ldh-2, We assumethat our electrophoreticallydetectable Pept-2) were monomorphicwithin speciesbut variants (= electromorphs)at a locus differ geneti- exhibited interspecific differences. The re- cally; hence, we refer to them as alleles.Alleles at a maining loci were polymorphicin somespecies locus were coded by their mobility from the origin. and alsoshowed interspecific fixed differences. Thg most anodal allele was designated as a, with We excludethe laboratorystrains of Coturnix slower alleles denoted as b, c, d, etc. Isozyme no- and Alectorisfrom discussionsof within-species menclaturefollows Yang and Patton (1981). Hetero- variation, becausethese levels of variation may January1983] GenicVariation in Galliforms 35 TABLE1. Matrix of geneticdistances between 17 taxa of galliform birds. Distancescomputed by methods of Nei (1978) above diagonal and Rogers(1972) below diagonal. Species Species I 2 3 4 5 6 7 1. Tympanuchuspallidicinctus -- 1.041 1.308 1.291 1.326 1.201 1.483 2. Phasianus colchicus 0.649 -- 1.446 1.282 1.310 1.172 1.654 3. Coturnix coturnix A 0.721 0.749 -- 0.064 0.059 1.185 1.340 4. C. coturnix B 0.713 0.714