Speciation in the Hawaiian "Drosophila": Sexual Selection Appears to Play an Important Role Author(S): Kenneth Y

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Speciation in the Hawaiian "Drosophila": Sexual Selection Appears to Play an Important Role Author(s): Kenneth Y. Kaneshiro Reviewed work(s): Source: BioScience, Vol. 38, No. 4, Hawaii's Unique Biology (Apr., 1988), pp. 258-263 Published by: University of California Press on behalf of the American Institute of Biological Sciences Stable URL: http://www.jstor.org/stable/1310849 . Accessed: 19/09/2012 21:35

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http://www.jstor.org Speciationin the Hawaiian Drosophila Sexual selection appears to play an important role

Kenneth Y. Kaneshiro

t has long been recognized that the Hawaiian drosophilids included the Hawaiian Islands possess one With their often bizarre 400 species. Since then, 89 additional of the most remarkable insect fau- species have been named and de- nas on Earth and are indeed the ideal courtship patterns, scribed (Hardy and Kaneshiro 1981). natural laboratories for the study of are At least 200-250 more new species in the processes of speciation and evolu- Hawaiian Drosophila this family are already present in the tion (Hardy and Kaneshiro 1981). the of collection at the University of Hawaii Nowhere else in the world do we find birds-of-paradise but have not been described. More so many examples of explosive adap- the insect world new species are still being collected as tive radiation-the evolution of a additional sites within the islands are large number of divergent forms from sampled, and the total Hawaiian dro- a primitive ancestor. By far the most tionary phenomena. sophilid fauna may exceed 800 outstanding of these examples is the The Hawaiian drosophilids are species. Hawaiian Drosophilidae (see reviews closely associated with vegetation in The Hawaiian drosophilids have in Carson et al. 1970, Carson and the native ecosystem. Many of the not only developed a fantastic num- Kaneshiro 1976, Hardy and Kane- species are composed of extremely ber of species, but also exhibit greater shiro 1981, Kaneshiro 1983). small populations with limited distri- diversity of forms and habits than any Here, in this isolated group of Pa- bution. While it is not known how other group in this family. The bodies cific Basin islands situated more than many species might have been lost and wings are often ornately pat- 3500 kilometers from the nearest due to perturbation of native habi- terned, and unusual modifications of land mass, are found nearly one- tats, there are clear indications of the the mouthparts and legs of the males fourth of the known species in the fragility of these endemic flies. Within frequently occur (Figure 1). Many of family Drosophilidae. More than the last two decades of intensive evo- these features would be considered to 95% (484 out of 509 species in two lutionary research on these flies, sev- signify different genera among species genera) are endemic to Hawaii; they eral species are known to have be- from other areas of the world, but in are found nowhere else in the world. come extremely rare or extinct. A the Hawaiian drosophilids, these fea- Considering Hawaii's small land number of proposed and ongoing tures have been shown to be of only mass-approximately 15,500 square projects could have a major impact species group importance. Spieth kilometers-and the geological new- on a number of these rare and threat- (1966, 1974) demonstrated that these ness of the present-day high islands of ened drosophilid species. These pro- structural peculiarities in the Hawai- the Hawaiian Archipelago, the Ha- jects include the geothermal develop- ian males are manifestations of often- waiian Drosophilidae represents one ment programs within native rain times bizarre courtship patterns. The of the most striking examples of forests on the islands of Hawaii and Hawaiian drosophilids are the birds- adaptive radiation known for any Maui and a proposal to eradicate of-paradise of the insect world. group of animals anywhere, and these tephritid fruit fly species from the With the exception of the endemic islands offer a unique opportunity for State of Hawaii by applying chemical genus Titanochaeta, which preys investigating dynamic stages of evolu- pesticides, even in areas bordering upon spider eggs, the Hawaiian dro- native habitats. It will be important to sophilids are predominantly sapro- de- The larvae feed as KennethY. Kaneshirois the Director of pay close attention to potentially phytic. scavengers and occa- the Hawaiian Pro- structive projects in order to minimize on decaying bark, leaves, Evolutionary Biology on flowers and fruits of na- at the University of Hawaii in their impact on Hawaii's extremely sionally gram tive also feed on Honolulu 96822. ? 1988 American Insti- fragile ecosystems. plants. They slime tute of Biological Sciences. Hardy's (1965) taxonomic study of fluxes and fleshy fungi.

258 BioScience Vol. 38 No. 4 Heed (1968) lists nine major ovipositional substrates for these flies. Al- '/ though a few species are generalists in their ovipositional behavior (e.g., Drosophila grimshawi from the Maui complex of islands will oviposit in more than ten different families of b native plants), the majority are strict r. specialists, ovipositing in one or two plant species. It seems that, at least for the picture-winged species group of Hawaiian Drosophila, the degree of specialism in larval breeding site is associated with ovipositional behav- dri ior of the females rather than the nutritional requirements of the larval rf stages (Carson and Kaneshiro 1976). After a small piece of their natural ,ii substrate stimulates gravid females of e / specialist species to oviposit, the larvae will develop fully in standard laboratory medium. g In spite of their morphological, ecological, and behavioral diversities, the Hawaiian drosophilids constitute an extremely close-knit evolutionary group. From the data to date, it appears that the entire endemic fauna could have arisen from a single successful founder. Although there are two major lineages in Hawaii, the drosophiloids and the scaptomyzoids, several lines of evidence show distinct similarities in the two groups, and only in Hawaii do these two groups intergrade. Throckmorton (1966, p. 386), on the basis of comparative anatomy of internal structures of the two groups, states ".. . Hawaii must be considered to be the only place in the world where the otherwise sharp distinctions between Scaptomyza and tend to In a Drosophila disappear." 1. Hawaiian Drosophila species exhibit great diversity in legs, mouthparts, review of the Figure major family Drosophi- heads, and wing patterns,a. Front tarsus of D. pectinitarsus(split-tarsus subgroup). lidae, Throckmorton (1975, pp. 455- b. Fronttarsus of D. expansa (bristle-tarsussubgroup). c. Fronttibia and tarsusof D. 456) further states that although "... dasycnemia (spoon-tarsussubgroup). d. D. lasiopoda (picture-winggroup), e. D. the problem of the origin of the dro- grimshawi (picture-winggroup). f. D. aethostoma (modified-mouthpartsgroup). sophiloid and scaptomyzoid lineages g. Modifiedhead of D. heteroneura.From Hardy and Kaneshiro(1981). of Hawaii remain unresolved ... the parsimonious inference from the evidence, in its present state, still favors the origin of all the Hawaiian Droso- biochemical studies). a variety of genetic techniques, in- philids from a single introduction." One of the most comprehensive cluding isozyme analyses, DNA se- The ultimate goal of the systematist methods of zoological classification quencing, chromosomal analyses, hy- is to be able to arrange any group of has been developed during the last 25 bridization, and behavioral genetics, organisms in a phylogenetic scheme years by the Hawaiian Drosophila to obtain important information on that portrays evolutionary history. It Research Project, with support from the mechanism of speciation in this is clear that such phylogenetic rela- the National Institutes of Health and group of insects. tionships must be based upon sup- the National Science Foundation. In- Nevertheless, some important portive information from many disci- vestigators in Hawaii and in labora- questions remain. Did one introduc- plines (e.g., morphology, genetics, tories in the continental United States, tion into the Hawaiian Islands really droso- ecology, behavior, physiology, and Europe, Asia, and Australia are using give rise to this large, endemic

259 April 1988 philid fauna? Which particular non- The chromosome studies on the fixed inversion differences in their Hawaiian group is the ancestor of the picture-winged species of Hawaiian banding sequence, than they are to Hawaiian drosophilids? How old is Drosophila conducted by Hampton the others in the homosequential the endemic drosophilid fauna (see L. Carson and his colleagues (Carson group. On the other hand, D. vesci- Beverley and Wilson 1985)? How and Kaneshiro 1976, Carson and seta, is closely related morphological- many drosophilid species (extant and Yoon 1981) include detailed analyses ly to another group of species, which extinct) have there been in the Hawai- of 213 inversions in 103 species. may differ from it by as many as four ian fauna? Why has there been such However, these inversions are un- fixed inversions. an explosion of species in the Hawai- evenly distributed among the species; Species relationships based on mor- ian Islands, not just in the drosophi- nearly two-thirds of the species have phology, especially that of male geni- lids but in other groups of animals as no fixed inversion differences. talia, is corroborated by analyses of well? Even among species whose banding courtship behavior and larval breed- In this article I present a brief over- patterns contain different inver:ions, ing-site ecology. Thus, it appears that view of the Hawaiian Drosophila re- the number of fixed inversion differ- similarity in chromosomal banding search group's results that illustrate ences between the most closely relat- pattern does not necessarily indicate mechanisms of species formation. I ed species is relatively small. For degree of relatedness in the Hawaiian focus on the studies of the giant poly- example, 25 species can be differenti- species. tene chromosomes found in the sali- ated from their closest relatives by no The contrast between these species' vary glands of Drosophila's last larval more than two fixed inversions. In great morphological diversity and instar, and I discuss the recent analy- contrast, morphologically similar their conservative pattern of chromo- ses of molecular structures and pat- (sibling) species of Drosophila else- somal banding indicates that chromo- terns observed in these species. Final- where in the world typically exhibit somal mutations via paracentric in- ly, I briefly discuss what appears to be several fixed inversion differences in versions have not been especially a powerful force in initiating the spe- their polytene chromosomes. For ex- important in the dynamics of the speciation process in the Hawaiian Dro- ample, Drosophila melanogaster and ciation process. Considering the new- sophila, the dynamics of the sexual its sibling species Drosophila simu- ness of the Hawaiian Islands, and selection process. lans, which are found in the continen- thus the relatively brief evolutionary tal United States, can only be distin- history of the endemic fauna, it is that the initial of Chromosomal data guished morphologically by postulated stages differences in the male genitalia, but species formation are influenced by The banding pattern of the giant they can be readily distinguished cy- factors that do not correlate with polytene chromosomes found in the tologically by more than a dozen in- chromosomal inversions. In contrast, nuclei of salivary gland cells of certain version differences. evolutionarily older species outside in the dipteran groups reflect the sequence Despite the high degree of conser- Hawaii show large differences of genes on these chromosomes. With vatism in the chromosomal banding banding pattern that correlate with proper preparation and staining, the sequences, closely related species in evolutionary distance between banding sequence of these polytene the Hawaiian drosophilids are mor- species. chromosomes lends itself to detailed phologically distinguishable. In fact, comparisons among species. Such the males of Hawaiian picture- Differentiation at the useful have second- techniques have been especially winged species striking gene level? for inferring phylogenetic relation- ary sexual structures that are easily ships among species in the cosmopoli- distinguished. While in most cases, The similiarity in the banding se- tan genus Drosophila, but the pic- species sharing banding patterns (and quences led investigators to look else- ture-winged species group of the Ha- therefore called homosequential spe- where for indicators of genetic diver- waiian Drosophila provides an out- cies) are considered to be most closely gence. In the heyday of starch-gel standing example of this technique's related, there are situations where electrophoresis, which is a technique usefulness. species identical in their chromo- used to separate proteins on the basis The banding pattern of the poly- somal banding patterns are believed of their molecular size and electrical tene chromosomes of more than a to belong to separate subgroups charge, more than 25 loci represent- hundred picture-winged species have based on male genitalia characters ing genes that code for a number of been analyzed in detail. Based on the (Kaneshiro 1968). protein and enzyme systems were an- similarity of banding sequences, each For example, the chromosomes of alyzed for many of the Hawaiian pic- species has been positioned on a phy- Drosophila pilimana, Drosophila gla- ture-winged species (Craddock and logenetic tree. Differences in the briapex, Drosophila vesciseta, and Johnson 1979, Johnson et al. 1975, banding sequence are almost always Drosophila aglaia are homosequen- Sene and Carson 1977). Much to the due to inversions of the paracentric tial, but the species can be divided disappointment of the molecular biol- regions (i.e., a region of chromosome into three subgroups based on differ- ogists conducting these studies, they not including the centromere is rotat- ences in male genitalia. In fact, mor- found, as in the cytological studies, an ed 1800, such that the gene sequence phological analysis indicates that D. extremely high degree of genetic simi- in the segment is reversed in relation pilimana and D. glabriapex are more larity within groups of related species. to the rest of the chromosome; see closely related to three other species, Indices of genetic similarity can be Figure 2). from which they differ by at least two calculated from the electrophoretic

260 BioScience Vol. 38 No. 4 gene-frequency data (Nei 1972, Rog- ers 1972), and the amount of genetic differentiation between different levels of evolutionary divergence has I / been classified (Ayala et al. 1974). For example, populations of the same species in different geographic loca- tions are expected to show an average similarity index (I) greater than 0.95. Sibling species give an index of approximately 0.56, while morphologi- d cally distinct species show an average tt index of about 0.35. Based on these criteria, most Ha- waiian picture-winged species would be considered subspecies rather than separate species. Even between species that are so pairs morphologically Figure 2. Banding patterns of polytene chromosome 5 (top) and chromosome 3 distinctive that even a taxonomist (bottom) of D. obscuripes,a picture-wingspecies. Chromosome5 shows the break- who does not specialize in flies could points of a single paracentricinversion e; while chromosome3 shows the breakpoints separate them without the aid of a of four paracentricinversions: m, e, r, and d. FromCarson and Stalker(1968). microscope, the similarity indices can be as high as 0.90. With the advancement of molecu- sentative Hawaiian species. The phy- ogists begun to investigate the lar technology, evolutionists have logenetic relationships determined dynamics of sexual selection in the been investigating the detailed struc- from this data do not agree with speciation process. About 10 years tures of the DNA molecule (DeSalle available morphological, behavioral, ago, mate-preference experiments be- and Giddings 1986, DeSalle et al. and ecological data. Therefore, the tween allopatric (geographically sepa- 1986a, 1986b, Dickinson 1980, Hunt suggested age of the Hawaiian species rate) pairs of closely related species and Carson 1982, Hunt et al. 1981) is questionable. Where possible, data (Kaneshiro 1976) resulted in data looking for greater resolution of phy- from as many different aspects of the indicating asymmetrical sexual isola- logenetic relationships among groups biology of the organism need to be tion (i.e., females from population A of species. For the Hawaiian droso- included in determining the evolu- discriminate strongly against the philids, these techniques have re- tionary history of a group of species. males from population B, but, in the vealed so far only minor changes at reciprocal direction, females from the molecular level between B the closely Dynamics of sexual selection population accept courtship related species. More sophisticated overtures of males from population A). sequencing of various DNA mole- What is the driving force behind the I studied the mate preference cules is now being conducted in hope speciation mechanism that has result- among four species of the planitibia of gaining the information needed to ed in genetic divergence, but with complex of Hawaiian Drosophila and measure genetic divergence between only minor differentiation in gross found that females of the species from closely related species. chromosomal morphology and spe- geologically older islands were highly Data from molecular studies have cific structural genes? For a clue, look discriminant against males from geo- also been useful for determining for a once again at the morphological di- logically younger islands. On the oth- variety of organisms the time since versity in these species. Spieth (1966, er hand, females from the younger divergence of related species (i.e., the 1968) first reported that the tremen- islands accepted males from the older "molecular clock"). However, it is dous morphological diversity in these islands oftentimes even better than necessary to exercise caution in inter- species is a manifestation of the males from their own population preting such data from single pro- males' elaborate mating dance. (Mor- (Kaneshiro 1976). I proposed that teins. For example, in a recent study phological differentiation is more evi- courtship requirements are simplified by Beverley and Wilson (1985), it was dent in the males, while females of during the early stages of a founder proposed that the ancestor of the closely related species are, for the event, when the population size is Hawaiian drosophilids may have ar- most part, nearly indistinguishable.) small (Kaneshiro 1976, 1980, 1983). rived in the islands as long as 40 Spieth showed that all the sometimes In the newly established population, million years ago--when only part of bizarre secondary sexual characters there is strong selection for less dis- the Emperor Seamounts of the Ha- found in the males are used in some criminating females. Highly discrimi- waiian Chain was in existence and way during their complex sexual dis- nating females may never encounter long before Kauai, the oldest of the plays. Sexual selection clearly plays males that are able to satisfy their present high islands, rose above sea an extremely important role in the courtship requirements. Females that level. This study was based on the speciation pattern of this remarkable are less discriminating will be most analysis of a single protein, the larval group of organisms. likely to mate and leave progeny. hemolymph protein, in a few repre- Only recently, however, have biol- During the subsequent flush/crash cy-

April 1988 261 cles (Carson 1968, 1971), there may because it is even less likely that high- mony to the significant role sexual be a shift in the distribution of female ly discriminant females would en- selection has played in the speciation mating types towards those that are counter males able to satisfy their process. While the forces of natural less discriminating. Such a shift in the courtship requirements. selection are still considered to be mating system may become fixed in The differential selection model al- important in directing the course of the new population. I have now ex- lows plasticity, permitting shifts in evolution in a population, adaptive tended my model to explore the role the distribution of mating types in the shifts in response to changes in the of sexual selection in the most dy- population. This characteristic is external environment occur over a namic stages of the speciation process most important in the explanation of much longer period of time than ad- (Kaneshiro in press, Kaneshiro and asymmetrical mating isolation be- justments to the mating system (i.e., Giddings 1987). tween populations. Also, if other the sexual environment), which are Within a population, some males parts of the genome are affected pleio- believed to occur during the initial, are highly successful in mating with tropically by the sexual selection most dynamic stages of the speciation the majority of the females, but other process, then sexual selection may be process. males are less successful in satisfying a mechanism for maintaining levels of most females' courtship require- genetic variability in the population. ments. There are also females who While the Hawaiian Drosophila is Acknowledgments show little discrimination in mate an outstanding example of explosive The research reported here was sup- choice, while others are highly dis- adaptive radiation, the studies of the ported by NSF Grant Nos. DEB- criminant and they mate with only mating systems in these species sug- 8206773 and BSR-8600120. males of superior courtship ability. gest that adaptive shifts into novel Classical sexual selection theory environments may not be the primary References cited states that there should be strong mechanism by which speciation oc- selection those individuals curs in this shifts with- Ayala, E J., M. L. Tracey, D. Hedgecock, and against group. Rather, R. C. Richmond. whose deviate in the "sexual environment" a 1974. Genetic differentia- mating phenotypes play tion during the speciation process in Dro- from the mean. But I suggest that dominant role in the initial stages of sophila. Evolution 28: 576-606. instead, there is differential selection species formation. While genetic Beverley, S. M., and A. C. Wilson. 1985. An- in the two sexes for the opposite ends changes resulting from such shifts in cient origin for Hawaii Drosophilidae in- of the distribution. the can occur I ferred from protein comparisons. Proc. Natl. mating type mating system rapidly, Acad. Sci. 82: 4753-4757. I that sexual do propose selection fa- not suggest that the speciation Carson, H. L. 1968. The population flush and vors both males that are highly suc- process is completed in a relatively its genetic consequences. Pages 123-137 in cessful in mating and females that are short period of time, as in the punctu- R. C. Lewontin, ed. Population Biology and Evolution. not highly discriminant. It selects ated equilibrium model of speciation. Syracuse University Press, Syra- males that are unsuccessful in within the sexual environ- cuse, NY. against Changes 1971. Speciation and the founder prin- mating and females that are highly ment may be the entering "wedge" ciple. Stadler Symp. 3: 51-70. discriminating in mate choice. This for the speciation process; other ge- Carson, H. L., D. E. Hardy, H. T. Spieth, and differential selection between the two netic changes within the population W. S. Stone. 1970. The evolutionary biology sexes can act as the accumulate much more of the Hawaiian Drosophilidae. Pages 437- stabilizing agent slowly. 543 in M. K. Hecht and W. C. Steere, eds. for the sexual selection process. Mat- Essays in Evolution and Genetics in Honor ings between a male with superior Conclusions of Theodosius Dobzhansky. Appleton-Cen- behavioral qualities and a female that tury Crofts, New York. is less discriminant will result in off- After more than 20 of research Carson, H. L., and K. Y. Kaneshiro. 1976. years of Hawaii: and eco- the normal distri- on the Hawaiian it is Drosophila systematics spring representing Drosophilidae, logical genetics. Annu. Rev. Ecol. Syst. 7: bution of mating types in the popula- now apparent that comparatively 311-345. tion. Unlike classical sexual selection small amounts of detectable genetic Carson, H. L., and H. D. Stalker. 1968. Poly- theory, my hypothesis avoids run- changes, as can be measured by cyto- tene chromosome relationships in Hawaiian or molecular species of Drosophila. II. The D. planitibia away processes (Fisher 1930)-sexu- logical, electrophoretic, subgroup. Univ. Texas Publ. 6818: 355- ally selected characters that develop techniques, have occurred between 365. into features reducing the survivabili- species. Two explanations are possi- Carson, H. L., and J. S. Yoon. 1981. Genetics of individuals. sexual selec- ble for these observations. these and evolution of Hawaiian Drosophila. ty Thus, First, M. tion itself maintains a balanced mate- be of such recent Pages 298-344 in Ashburner, H. L. Car- species may origin son, and J. N. Thompson, eds. The Genetics recognition system in the population. that their brief evolutionary history and Biology of Drosophila, vol. 3b. Academ- This differential selection model has not permitted the accumulation ic Press, London, UK. portrays sexual selection as a dynam- of significant genetic differences Craddock, E. M., and W. E. Johnson. 1979. Genetic variation in Hawaiian Drosophila. ic system. For example, when a popu- among related species. Second, fac- V. Chromosomal and in lation is small because the environ- tors allozymic diversity other than those that involve Drosophila silvestris and its homosequential ment is hostile, the distribution of chromosomal or allozymic changes species. Evolution 33: 137-155. female mating types may shift in or- may be involved in the dynamic DeSalle, R., and L. V. Giddings. 1986. Mito- der that the survive the of the in this chondrial DNA phylogeny of four chromo- population stages speciation process of Hawaiian stress. under these condi- fauna. somally homosequential species Selection, Drosophila. Proc. Natl. Acad. Sci. 83: 6902- tions, would even more strongly favor Studies of the elaborate mating sys- 6906. females that are less discriminating, tem in these flies provide strong testi- DeSalle, R., L. V. Giddings, and K. Y. Kane-

262 BioScience Vol. 38 No. 4 shiro. 1986a. Mitochondrial DNA variabili- 1976. Ethological isolation and phy- 1A.4, ty in natural populations of Hawaiian Dro- logeny in the planitibia subgroup of Hawai- sophila. II. Genetic and phylogenetic ian Drosophila. Evolution 30: 740-745. relationship of natural populations of D. 1980. Sexual isolation, speciation and silvestris and D. heteroneura. Heredity 56: the direction of evolution. Evolution 34: 87-96. 437-444. DeSalle, R., L. V. Giddings, and A. R. Temple- 1983. Sexual selection, and direction HEN THERE ton. 1986b. Mitochondrial DNA variability of Evolution in the biosystematics of Hawai- in natural populations of Hawaiian Dro- ian Drosophilidae. Annu. Rev. Entomol. 28: of 161-178. sophila. I. Methods and levels variability WILL BE in D. silvestris and D. heteroneura. Heredity . In press. The dynamics of sexual selec- 56: 75-85. tion and founder effects in species formation. Dickinson, W. J. 1980. Evolution of patterns of In L. V. Giddings, K. Y. Kaneshiro, and gene expression in Hawaiian picture winged W. W. Anderson, eds. Genetics, Speciation, NO Drosophila. J. Mol. Evol. 16: 73-94. and the Founder Principle. Oxford Universi- LONELINESS, Fisher, R. A. 1930. The Genetical Theory of ty Press, New York. Natural Selection. Oxford University Press, Kaneshiro, K. Y., and L. V. Giddings. 1987. Oxford, UK. The significance of asymmetrical sexual iso- NO DESTITUTION', Hardy, D. E. 1965. Insects of Hawaii, vol. 12. lation and the formation of new species. Diptera: Cyclorrhapha, II. Series Schizo- Pages 29-43 in M. K. Hecht, B. Wallace, phora, Section Acalypterae, I. Family Droso- and G. T. Prance, eds. Evolutionary Biology, philidae. University of Hawaii Press, vol. 21. Plenum Publ. Corp., New York. NO SICKNESS, Honolulu. Nei, M. 1972. Genetic distances between popu- Hardy, D. E., and K. Y. Kaneshiro. 1981. Dro- lations. Am. Nat. 106: 283-292. sophilidae of Pacific Oceania. Pages 309- Rogers, J. S. 1972. Measures of genetic similar- 348 in M. Ashburner, H. L. Carson, and ity and genetic distance. Univ. Texas Publ. NO WAR, J. N. Thompson, eds. Genetics and Biology 7213: 145-153. of Drosophila, vol. 3a. Academic Press, Sene, E M., and H. L. Carson. 1977. Genetic London. variation in Hawaiian Drosophila. IV. Allo- Heed, W. B. 1968. Ecology of the Hawaiian zymic similarity between D. silvestris and D. ONLY THEN Drosophilidae. Univ. Texas Publ. 6818: heteroneura from the Island of Hawaii. Ge- 387-419. netics 86: 187-198. Hunt, J. A., and H. L. Carson. 1982. Evolu- Spieth, H. T. 1966. Courtship behavior of tionary relationships of four species of Ha- endemic Hawaiian Drosophila. Univ. Texas WILL THERE waiian Drosophila as measured by DNA Publ. 6615: 245-313. reassociation. Genetics 104: 353-364. . 1968. Evolutionary implications of the Hunt, J. A., T. J. Hall, and R. J. Britten.1981. mating behavior of the species of Antopo- Evolutionary distances in Hawaiian Dro- cerus (Drosophilidae) in Hawaii. Univ. Texas BE NO NEED sophila measured by DNA reassociation. J. Publ. 6818: 319-333. Mol. Evol. 17: 361-367. . 1974. Mating behavior and evolution Johnson, W. E., H. L. Carson, K. Y. Kaneshiro, of the Hawaiian Drosophila. Pages 94-101 W. W. M. Steiner, and M. M. Cooper. 1975. in M. J. D. White, ed. Genetic Mechanisms FOR THE Genetic variation in Hawaiian Drosophila. of Speciation in Insects. Australia and New II. Allozymic differentiation in the D. planiti- Zealand Book Co., Sydney. bia subgroup. Pages 563-583 in C. L. Mar- Throckmorton, L. H. 1966. The relationships kert, ed. Isozymes IV. Genetics and Evolu- of the endemic Hawaiian Drosophilidae. AMERICAN tion. Academic Press, New York. Univ. Texas Publ. 6615: 335-396. Kaneshiro, K. Y. 1968. A study of the relation- . 1975. The phylogeny, ecology and ships of Hawaiian Drosophila species based geography of Drosophila. Pages 431-469 in on external male genitalia. Univ. Texas Publ. R. C. King, ed. Handbook of Genetics, vol 3. RED CROSS. 6918: 55-70. Plenum Publ. Corp., New York.

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