A PHYLOGENETIC PERSPECTIVE ON ELEVATIONAL SPECIES RICHNESS PATTERNS IN MIDDLE AMERICAN TREEFROGS: WHY SO FEW SPECIES IN LOWLAND TROPICAL RAINFORESTS?

Differences in species richness at different elevations are widespread and important for conservation, but the causes of these patterns remain poorly understood. Here, we use a phylogenetic perspective to address the evolutionary and biogeographic processes that underlie elevational diversity patterns within a region. We focus on a diverse but well-studied fauna of tropical amphibians, the hylid frogs of Middle America. Middle American treefrogs show a "hump-shaped" pattern of species richness (common in many organisms and regions), with the highest regional diversity at intermediate elevations. We reconstructed phylogenetic relationships among 138 species by combining new and published sequence data from 10 genes and then used this phylogeny to infer evolutionary rates and patterns. The high species richness of intermediate elevations seems to result from two factors. First, a tendency for montane clades to have higher rates of diversification. Second, the early colonization of montane regions, leaving less time for speciation to build up species richness in lowland regions (including tropical rainforests) that have been colonized more recently. This "time-for-speciation" effect may explain many diversity patterns and has important implications for conservation. The results also imply that local-scale environmental factors alone may be insufficient to explain the high species richness of lowland tropical rainforests, and that diversification rates are lower in earth's most species-rich biome.     

DIVERSITY AND NICHE EVOLUTION ALONG ARIDITY GRADIENTS IN NORTH AMERICAN LIZARDS (PHRYNOSOMATIDAE)

Deserts occupy approximately 12% of the Earth's land surface, and are thought to have species poor but highly specialized biotas. However, few studies have examined the evolutionary origins of desert biotas and of diversity patterns along aridity gradients. Further, it is unclear if species occurring in more extreme conditions on a given niche axis (i.e., precipitation) are more specialized for those conditions (i.e., have narrower niche breadths). We address these questions here using a time‐calibrated phylogeny and climatic data for 117 species of phrynosomatid lizards. Phrynosomatids are the most species‐rich family of lizards in North America, and are found from deserts to rainforests. Surprisingly, we find that phrynosomatids have higher richness in more arid environments. This pattern occurs seemingly because they have been present in more arid habitats longer (～55 million years), and lineages in mesic environments are recently derived from more arid‐dwelling ancestors. We find little support for the hypothesis that species in more extreme environments are more specialized. Instead, many desert‐dwelling species are broadly distributed, and species in the most mesic environments have the broadest niche breadths. In summary, phrynosomatids offer a counterexample to the idea that arid regions are inhabited by a small number of recent and highly specialized lineages.     

ECOLOGICAL DIVERSIFICATION AND COMMUNITY STRUCTURE IN THE OLD WORLD LEAF WARBLERS (GENUS PHYLLOSCOPUS): A PHYLOGENETIC PERSPECTIVE

I investigated the historical basis for variation in regional species diversity. I used a molecular phylogenetic analysis within a single genus of birds (the Old World leaf warblers, genus Phylloscopus) in conjunction with ecological studies in Europe, the Himalayas, and Japan to evaluate the importance of historical events in shaping the present constellation of morphology and behavior in the three different regions. The relatively depauperate assemblages have different histories. In Japan, there was invasion of several lineages, which have more closely related species elsewhere in Asia, whereas in Europe there was also limited in situ speciation. Much of the structure of peripheral communities is attributable to invasions from species-rich Asia, with little in situ morphological diversification. Within the Phylloscopus there are several phylogenetic clades with nonoverlapping size distributions. Major ecological and morphological shifts occurred early in the history of diversification within the group, and rarely since.     

EVOLUTION OF PAEDOMORPHOSIS IN PLETHODONTID SALAMANDERS: ECOLOGICAL CORRELATES AND RE‐EVOLUTION OF METAMORPHOSIS

Life‐history modes can profoundly impact the biology of a species, and a classic example is the dichotomy between metamorphic (biphasic) and paedomorphic (permanently aquatic) life‐history strategies in salamanders. However, despite centuries of research on this system, several basic questions about the evolution of paedomorphosis in salamanders have not been addressed. Here, we use a nearly comprehensive, time‐calibrated phylogeny of spelerpine plethodontids to reconstruct the evolution of paedomorphosis and to test if paedomorphosis is (1) reversible; (2) associated with living in caves; (3) associated with relatively dry climatic conditions on the surface; and (4) correlated with limited range size and geographic dispersal. We find that paedomorphosis arose multiple times in spelerpines. We also find evidence for re‐evolution of metamorphosis after several million years of paedomorphosis in a lineage of Eurycea from the Edwards Plateau region of Texas. We also show for the first time using phylogenetic comparative methods that paedomorphosis is highly correlated with cave‐dwelling, arid surface environments, and small geographic range sizes, providing insights into both the causes and consequences of this major life history transition.     

RECENT RADIATION OF THE PALMARIACEAE (RHODOPHYTA)1

Molecular phylogenetic studies on the evolution of the red algae indicate that this ancient division has many lineages that have recently undergone radiations. One such example is the cold–temperate family Palmariaceae. In this study, sequences from the ribosomal DNA internal transcribed spacer regions were compared among ten species in the Palmariaceae from both Atlantic and Pacific sites, Phylogenetic analyses of sequence data, in which Rhodophysema georgii Batters was used as outgroup and root, indicate a radiation into four clades, three of which contain species of “Palmaria” and the fourth species of Halosaccion. Palmaria palmata (L.) Kuntze, the type and only North Atlantic species in the genus, stands apart from all remaining species in the family and terminates the most basal branch in the rooted tree. The three more derived clades have radiated mainly in the North Pacific. Southern Ocean Palmaria and North Atlantic Devaleraea are hypothesized to have invaded from separate but closely related North Pacific ancestors. The ease with which sequences could be aligned combined with an unsaturated transition: transversion ratio and modest divergence involving predominantly point mutations suggests that the initial radiation is relatively recent (late Miocene–Pliocene) and that the Devaleraea–Palmaria clade is even more recent (late Pliocene–Pleistocene).     

危害竹子的飞虱类昆虫区系及生物地理学初探(半翅目,蜡蝉总科,飞虱科)

对世界取食、危害竹子的飞虱类昆虫的物种多样性、区系成分和分布特点进行了统计、分析,并对该类昆虫的分布格局及可能的起源与演化路径进行了初步研究。结果表明:截至目前全世界共记录竹子飞虱20属105种,均隶属于飞虱亚科,以凹距飞虱族为优势类群,有18属95种,分别占竹子飞虱属、种数的90%和90.5%,余下的为飞虱族的类群;竹子飞虱主要分布于东洋界(16属96种,占91.4%)和新热带界(6属13种,占12.4%),少数属种可渗透分布至古北界;竹子飞虱的特有属、种极为丰富,特有属13个,占竹子飞虱总属数的65%,特有种89个,比例高达84.8%;竹子飞虱可能起源于新生代第三纪的冈瓦纳古陆,东洋界的中国南部和南亚诸岛是竹子飞虱的现代分布和分化中心,新热带界的厄瓜多尔可能是竹子飞虱的又一现代分布和分化中心。     

POPULATION STRUCTURE AND SPECIATION IN TROPICAL SEAS: GLOBAL PHYLOGEOGRAPHY OF THE SEA URCHIN DIADEMA

Abstract.— The causes of speciation in the sea are rarely obvious, because geographical barriers are not conspicuous and dispersal abilities or marine organisms, particularly those of species with planktonic larvae, are hard to determine. The phylogenetic relations of species in cosmopolitan genera can provide information on the likely mode of their formation. We reconstructed the phylogeny of the pantropical and subtropical sea urchin genus Diadema, using sequences of mitochondrial DNA from 482 individuals collected around the world, to determine the efficacy of barriers to gene flow and to ascertain the history of possible dispersal and vicariance events that led to speciation. We also compared 22 isozyme loci between all described species except D. palmeri. The mitochondrial DNA data show that the two deepest lineages are found in the Indian and West Pacific Oceans. (Indo‐Pacific) Diadema setosum diverged first from all other extant Diadema, probably during the initiation of wide fluctuations in global sea levels in the Miocene. The D. setosum clade then split 3‐5 million years ago into two clades, one found around the Arabian Peninsula and the other in the Indo‐West Pacific. On the lineage leading to the other species of Diadema, the deepest branch is composed of D. palmeri, apparently separated when the climate of New Zealand became colder and other tropical echinoids at these islands went extinct. The next lineage to separate is composed of a currently unrecognized species of Diadema that is found at Japan and the Marshall Islands. Diadema mexicanum in the eastern Pacific separated next, whereas D. paucispinum, D. savignyi, and D. antillarum from the western and central Atlantic, and (as a separate clade) D. antillarum from the eastern Atlantic form a shallow polytomy. Apparently, Indo‐Pacific populations of Diadema maintained genetic contact with Atlantic ones around the southern tip of Africa for some time after the Isthmus of Panama was complete. Diadema paucispinum contains two lineages: D. paucispinum sensu stricto is not limited to Hawaii as previously thought, but extends to Easter Island, Pitcairn, and Okinawa; A second mitochondrial clade of D. paucispinum extends from East Africa and Arabia to the Philippines and New Guinea. A more recent separation between West Indian Ocean and West Pacific populations was detected in D. setosum. Presumably, these genetic discontinuities are the result of water flow restrictions in the straits between northern Australia and Southeast Asia during Pleistocene episodes of low sea level. Diadema savignyi is characterized by high rates of gene flow from Kiribati in the central Pacific all the way to the East African Coast. In the Atlantic, there is a biogeographic barrier between the Caribbean and Brazil, possibly caused by fresh water outflow from the Amazon and the Orinoco Rivers. Diadema antillarum populations of the central Atlantic islands of Ascension and St. Helena are genetically isolated and phylogenetically derived from Brazil. Except for its genetic separation by the mid‐Atlantic barrier, Diadema seems to have maintained connections through potential barriers to dispersal (including the Isthmus of Panama) more recently than did Eucidaris or Echinometra, two other genera of sea urchins in which phylogeography has been studied. Nevertheless, the mtDNA phylogeography of Diadema includes all stages expected from models of allopatric differentiation. There are anciently separated clades that now overlap in their geographic distribution, clades isolated in the periphery of the genus range that have remained in the periphery, clades that may have been isolated in the periphery but have since spread towards the center, closely related clades on either side of an existing barrier, and closely related monophyletic entities on either side of an historical barrier that have crossed the former barrier line, but have not attained genetic equilibrium. Except for D. paucispinum and D. savignyi, in which known hybridization may have lodged mtDNA from one species into the genome of the other, closely related clades are always allopatric, and only distantly related ones overlap geographically. Thus, the phylogenetic history and distribution of extant species of Diadema is by and large consistent with allopatric speciation.     

PATTERN,TEMPO, AND MODE OF EVOLUTIONARY AND BIOGEOGRAPHIC DIVERGENCE IN OXYSTYLIS AND WISLIZENIA (CAPPARACEAE)

Six populations of Oxystylis lutea and nine populations representing three subspecies of Wislizenia refracta were analyzed for electrophoretic variation at 18 loci. Several marker alleles differentiate O. lutea from W. refracta, although mean pair-wise genetic identity values (range, 0.53–0.64) are comparable to those found among many congeners. Oxystylis and Wislizenia share two duplicated gene loci that are not present in outgroup species in Cleome and Cleomella. Thus, they appear to be monophyletic sister taxa within a larger monophyletic group. Based on allozyme differentiation patterns, we infer a pre-Pleistocene divergence prior to differentiation within W. refracta. Subsequent anagenesis in the O. lutea lineage and cladogenesis in the W. refracta lineage have resulted in extensive morphological differentiation between Oxystylis and Wislizenia. Therefore, Oxystylis and Wislizenia are phenetically and phylogenetically distinct, and we recognize them as genera. Geographic modes of speciation predominate in the group. Variation patterns within W. refracta are consistent with recognition of three subspecies, and indicate that subsp. californica is not a historical introduction in the Central Valley of California.     

PTEROCARYOID FRUITS (JUGLANDACEAE) IN THE PALEOGENE OF NORTH AMERICA AND THEIR EVOLUTIONARY AND BIOGEOGRAPHIC SIGNIFICANCE

The Juglandaceae (walnut family) has an excellent fossil record of various organs extending back to the earliest Tertiary. Several genera which today are restricted to isolated geographic regions were widespread in the Northern Hemisphere during the Tertiary. This paper focuses upon the fossil record of the Pterocarya alliance of the subfamily Juglandoideae, tribe Juglandeae. The Pterocarya alliance includes only two modern genera, Pterocarya (five species) and Cyclocarya (one species), both restricted to Eurasia. Paleogene sediments of the Rocky Mountain Region have yielded three genera and four species referable to the Pterocarya alliance: Cyclocarya (two species), Pterocarya, and a new genus, Polyptera. Although three of the four Paleogene species described here are attributed to present day genera, each represents an extinct form, which cannot be accommodated by any single living species. These fossils, reviewed with other published reports, indicate that the Pterocarya alliance, like the Engelhardia alliance of the same family, was more diverse and much more widespread geographically in the Tertiary than it is today.     

Replicate patterns of species richness, historical biogeography, and phylogeny in Holarctic treefrogs

In recent decades, the field of historical biogeography has become increasingly divorced from evolutionary biology, ecology, and studies of species richness. In this paper, we explore the evolutionary causes of patterns of biogeography and species richness in Northern Hemisphere treefrogs, combining phylogenetics, ancestral area reconstruction, molecular dating methods, and ecological niche modeling. We reconstructed phylogenetic relationships among 58 hylid taxa using data from two mitochondrial genes (12S, ND1) and two nuclear genes (POMC, c-myc). We find that parallel patterns of species richness have developed in Europe, Asia, and in two separate clades of North American hylids, with the highest richness at midtemperate latitudes (30-35 degrees) on each continent. This pattern is surprising given that hylids overall show higher species richness in the New World tropics and given many standard ecological explanations for the latitudinal diversity gradient (e.g., energy, productivity, mid-domain effect). The replicate pattern in Holarctic hylids seems to reflect specialized tolerance for temperate climate regimes or possibly the effects of competition. The results also suggest that long-range dispersal between continental regions with similar climatic regimes may be easier than dispersal between geographically adjacent regions with different climatic regimes. Our results show the importance of ecology and evolution to large-scale biogeography and the importance of large-scale biogeography to understanding patterns of species richness.     

THE SPECIES RICHNESS AND DIVERSITY OF THE ARTHROPOD COMMUNITIES IN RICE FIELDS

Abstract The present paper deals with the characteristics of species richness and diversity of the arthropod communities in different rice fields and at various growing stages of rice based on the data ob tained from field surveys and the measurement of the community diversity. The field surveys were carried out in three different locations which represented three typical rice-growing habitats: mountainous, plain and hilly fields in the suburb of Fuzhou, Fujian Province in 1994. Shannon-Wiener's (1949) average information content(H), Hurlbert's(1971) probability of interspecific encounter (PIE) and Pielou's (1966) formula of equitability (E) were used to measure the diversity of the arthropod communities in the ecosystem of rice fields. The result showed that the species richness of herbivorous insects, carnivorous insects, spiders and total species in the community varied with different fields because of the influence of environmental variables in the habitats, and fluctuated with various growing stages of rice due to the variation of crop nourishment. Changes in the index values of H, PIE and E indicated that the cornmunity diversity and equitability also varied with space (habitats formed by the rice fields) and time (growing stages of rice). The author thinks that the results of the study could be applied to predict and forecast the population dynamics of rice pests, and to develop the rational program of integrated pest management in the specific rice fields. Discussions are also given in some detail on the methodology of measurement of the species richness and diversity of the arthropod communities in rice fields.     

EVOLUTION OF BREEDING DISTRIBUTIONS IN THE OLD WORLD LEAF WARBLERS (GENUS PHYLLOSCOPUS)

Among Palearctic warblers of the genus Phylloscopus those species that breed farther north occupy larger geographical ranges than those which breed farther south (Rapoport's rule). We suggest that much of this pattern is a consequence of the differential ability of species to occupy areas rendered inhospitable during the Pleistocene. In support of this suggestion, the midpoint of breeding range in a north-south direction has been an exceptionally labile trait through evolutionary time. Comparisons of ecological attributes of those species breeding in the Himalayas with close relatives in Siberia implies a role for habitat tracking in determining which species have been able to colonize northern areas; hypotheses based on climate and climatic variability have less support. In addition there is a likely role for geographic barriers and/or biotic interactions in preventing some taxa from spreading from small southern ranges.     

稻田节肢动物群落物种丰富度及多样性的研究(英文)

本文根据田间调查的资料和群落多样性指数的测定,比较了不同稻田和水稻不同生育期节肢动物群落物种丰富度及多样性。田间调查于1994年在福建省福州市郊区选择3种具有代表性的水稻种植区进行,在此基础上,作者运用Shannon－Wiener（1949）的平均信息（H）、Hurlbert（1971）的种间相遇机率（PIE）和Pielou（1966）的均匀度（E）指数来测定和分析稻田生态系统中节肢动物群落的丰富度及多样性。结果表明,由于受到稻田生境中各种环境因素及水稻不同生育期营养状况的影响,稻田节肢动物群落的丰富度及多样性不仅因田而异,而且随着水稻的生长发育过程有较大的波动。作者认为,稻田节肢动物群落丰富度及多样性的研究结果,可为水稻害虫的预测预报和综合治理提供重要的科学依据。文中还就群落丰富度及多样性的测定方法问题进行了讨论。     

THE EVOLUTION OF DIAPAUSE IN THE KILLIFISH FAMILY RIVULIDAE (ATHERINOMORPHA,CYPRINODONTIFORMES): A MOLECULAR PHYLOGENETIC AND BIOGEOGRAPHIC PERSPECTIVE

Phylogenetic relationships within the family Rivulidae (order Cyprinodontiformes) are investigated using 1972 aligned base pairs of mitochondrial DNA (mtDNA) for samples representing 66 species. Genes analyzed include those encoding the 12S ribosomal RNA; transfer RNAs for valine, glutamine, methionine, tryptophan, alanine, asparagine, cysteine, and tyrosine; complete NADH dehydrogenase subunit II; and part of cytochrome oxidase I. Parsimony analysis of the aligned mtDNA sequences results in a single most parsimonious tree. The phylogeny reveals two independent origins of developmental diapause within the family Rivulidae. It is unlikely that diapause evolved de novo in each group, suggesting that the presence or absence of diapause is the result of developmental switches between alternative stabilized pathways. Phylogeny of the family Rivulidae shows high concordance with predictions derived from the geological history of South America and Central America. Basal lineages in the rivulid phylogeny are distributed primarily on geologically old areas, whereas more nested lineages occur in geologically younger areas. However, there is little concordance between the molecular phylogeny and currently available morphological hypotheses and existing taxonomies. Based on the mtDNA phylogeny, the genera Pterolebias, Rivulus, Pituna, and Plesiolebias are considered nonmonophyletic and warrant taxonomic reassessment.     

梵争山和张家界地区蜘蛛群落结构及多样性研究

1990年8月对梵净山和张家界两个自然保护区内蜘蛛群落进行调查,结果表明:自然保护区内蜘蛛资源极为丰富,经初步鉴定,计有蜘蛛27科85属180种,其中主要成分依次为肖蛸、园蛛、狼蛛、球蛛和皿蛛等。蜘蛛发生量折合每亩为17,585—54,000头。八个不同生境类型蜘蛛群落的种类数和密度存在明显差异;各种蜘蛛分布群在群落内的比例随栖息地结构变化而改变,因而也导致蜘蛛群落的Shannon-Wiener多样性指数,Simpson优势度和均等度等参数的变化。     

中国台湾和大陆蹄盖蕨属植物的生物地理学比较

蹄盖蕨属Athyrium Roth是个典型的东亚属,全世界估计约有160种,主要分布在亚洲东部的亚热带高山,少数在温带其他地区,中国有117种,是其分布中心。台湾和大陆的蹄盖蕨属植物关系尤为密切,是研究海峡两岸植物地理关系的一个很好的材料。台湾已知共计有蹄盖蕨类植物32种,包括狭义蹄盖蕨27种,介蕨2种,蛾眉蕨1种,假蹄盖蕨1种,假冷蕨1种,即使将待查实的4种蹄盖蕨除去,至少还有28种。其中除去7种大陆不产外, 21种均和大陆共有,占75%。况且,这7种与大陆种形态相近,是否同种异名、亚种或姊妹种关系还有待进一步研究;在台湾和大陆共有的16种狭义蹄盖蕨中有7种是台湾-西南间断分布。这不仅说明了台湾的蹄盖蕨属类植物和大陆的关系密切、有着共同的起源,而且说明台湾高地的植物区系和西南高地关系最为密切。运用生物系统学和分子系统学的方法研究和测定海峡两岸共有种种内、姊妹种或近缘种之间的遗传学关系(如:遗传一致度),进一步了解并量化台湾和大陆植物区系之间的历史和地理关系是必要的。     

EVOLUTIONARY AND HISTORICAL ANALYSIS OF PROTEIN VARIATION IN THE BLOTCHED FORMS OF SALAMANDERS OF THE ENSATINA COMPLEX (AMPHIBIA: PLETHODONTIDAE)

Geographic variation in 23 to 29 protein-encoding genetic loci was examined in 48 populations of the Ensatina complex, a “ring species” distributed around the Central Valley of California. The samples span two critical links in the chain of morphologically distinct units: the transition from the unblotched to blotched color pattern types in the vicinity of Lassen Peak, northeastern California, and a geographic gap in the range of the complex in the San Gabriel Mountains, southern California. A general pattern of isolation by distance with a regular buildup of genetic distance correlated with increases in geographic distance characterizes the populations studied, with the exception of a little-differentiated group of populations in the northern Sierra Nevada; this region is postulated to be a zone of genetic reticulation characterized by relatively high gene flow. An adaptively significant color pattern is thought to have spread into the northern Sierra Nevada from the south, but protein variants have been introduced both from the north and the south. Genetic distances across the San Gabriel Mountain gap match expectations from the pattern of buildup of genetic distance as a function of geographic distance elsewhere in the complex. A phylogenetic analysis of the protein data supports the reticulation hypothesis; whereas the southernmost populations currently do constitute a monophyletic assemblage, an “extinction experiment” demonstrates that the distinction could be the result of the recent extinction of populations in a present gap in our sampling. The Ensatina complex appears to be a dynamic entity representing several stages in the evolution of species. It is a ring species, and whereas various taxonomic arrangements are possible, no taxonomic changes are proposed.     

EVOLUTIONARY HISTORY OF THE MATING SYSTEM IN AMSINCKIA (BORAGINACEAE)

A survey of restriction site variation in the chloroplast genome of the annual plant genus Amsinckia, together with estimation of outcrossing rates, was conducted to analyze the evolutionary history of the mating system. Species, and in some cases populations within species, differ markedly in their mating system. Five taxa are distylous and predominantly outcrossing, or show mixed mating systems, while the remaining taxa are homostylous and predominantly self-fertilizing. Reconstruction of the molecular phylogeny of the group places different distylous and homostylous taxa at four separate branch tips. When distyly is treated as ancestral in the group, or when the loss of distyly is assumed to be more common than its gain, the results of the phylogenetic analysis support the hypothesis that the self-fertilizing taxa are of recent origin from outcrossing relatives. These findings are discussed with respect to theory for the evolution and breakdown of distyly and the probability of extinction of selfing lineages.     

EVOLUTIONARY PATTERNS OF ALTERED BEHAVIOR AND SUSCEPTIBILITY IN PARASITIZED HOSTS

Adaptation is the usual context for interpreting parasite-host interactions. For example, altered host behavior is often interpreted as a parasite adaptation, because in some cases it enhances parasite transmission. Resistance to parasites also has obvious adaptive value for hosts. However, it is difficult to evaluate the adaptive significance of host-parasite interactions without considering the historical context in which these traits have evolved and if they can be predicted by host (or parasite) phylogeny. We examined the influence of host phylogeny on patterns of altered behavior and resistance to parasitism in a cockroach-acanthocephalan system. A consensus cladogram for cockroach subfamilies was produced from the morphological data of McKittrick. We used this cladogram to predict patterns of altered host behavior in seven cockroach host species. Each species was experimentally infected with a single species of acanthocephalan, Moniliformis moniliformis, a parasite that is transmitted when cockroaches are eaten by rodent final hosts. Activity patterns, substrate choices, and responses to light were measured for control and infected animals. These data were recoded into a behavioral matrix of discrete characters. We determined the most parsimonious distribution of the behavioral characters on the tree obtained from McKittrick's data. We then measured the concordance between the behavioral data and the cockroach cladogram with the consistency index (CI). We compared the observed CI to the expected value based on a randomization of observed character states. For three different models of evolutionary character change, there was no evidence of strong concordance (significantly large CI) between altered host behavior and host relationships. Parsimony analysis of the interior nodes of the phylogenetic reconstruction suggested that unaltered behavior was the ancestral state for most host behaviors. We also compared host phylogeny to a data set on the susceptibility of 29 cockroach species to infection with M. moniliformis. At the species level, there was a significant concordance between susceptibility and host phylogeny. This pattern was consistent with the finding that susceptibility of species varied significantly among different subfamilies. However, at the subfamily level, susceptibility was not strongly concordant with phylogeny. We predict that, given enough time, resistance should be lost in subfamilies that are currently resistant to parasitism. In spite of the potential importance of phylogeny in the evolution of behavior and susceptibility, we found little evidence for phylogenetic effects in this system. We conclude that changes in the behavioral responses of hosts to parasites and, to a lesser extent, changes in susceptibility are more frequent than cockroach speciation events in different cockroach lineages. This finding strengthens the assertion that at least some of the altered behaviors are adaptive for host and/or parasite.