Ghatippuspaschima, a new species and genus of plexippine jumping spider from the Western Ghats of India (Salticidae, Plexippini, Plexippina)

We propose a new genus of plexippine jumping spiders from the Western Ghats of India based on the new species Ghatippuspaschimagen. et sp. nov. While it bears a superficial resemblance to Pancorius in body form and Hyllus in membrane-bearing embolus, our UCE phylogenomic data-the first to resolve broad relationships within the Plexippina-as well as morphological features justify its status as a new genus. In addition to the molecular data and morphological descriptions, we provide photographs of living specimens of Ghatippuspaschimagen. et sp. nov. and information on their natural history.

Taxonomic revision of Orcevia Thorell, 1890, with description of fifteen new species (Araneae, Salticidae, Euophryini)

The Asian euophryine genus Orcevia Thorell, 1890 is revised, and fifteen new species from southern China and Southeast Asia are described: Orcevia bokoblin Yu, Maddison & Zhang, sp. nov. (), O. calcicola Yu, Maddison & Zhang, sp. nov. (), O. deelemanae Yu & Zhang, sp. nov. (), O. feitongae Yu & Zhang, sp. nov. (), O. gongae Yu & Zhang, sp. nov. (), O. jinping Yu & Zhang, sp. nov. (), O. meinei Yu, Maddison & Zhang, sp. nov. (), O. mercuryi Yu, Maddison & Zhang, sp. nov. (), O. nietzschei Yu, Maddison & Zhang, sp. nov. (), O. pakse Yu & Zhang, sp. nov. (), O. shuyuani Yu & Zhang, sp. nov. (), O. timburtoni Yu, Maddison & Zhang, sp. nov. (), O. wuliang Yu & Zhang, sp. nov. (), O. yahaha Yu, Maddison & Zhang, sp. nov. (), O. zabkai Yu, Maddison & Zhang, sp. nov. () and O. zu Yu & Zhang, sp. nov. (). Three new combinations and one new synonym are proposed: Orcevia sokoli (Prszyski & Deeleman-Reinhold, 2013) comb. nov. (transferred from Echeclus Thorell, 1890), O. sica (Wu & Yang, 2008) comb. nov. (=Laufeia longapophysis Lei & Peng, 2012 syn. nov.; transferred from Laufeia Simon, 1889), and Magyarus terrestris (Logunov, 2021) comb. nov. (transferred from Orcevia). The previously unknown females of Orcevia sica (Wu & Yang, 2008) comb. nov. and O. proszynskii (Song, Gu & Chen, 1988) are described. O. perakensis (Simon, 1901) is herein listed as a species inquirenda.

Review of Chalcovietnamicus Marusik, 1991, with description of four new species (Araneae, Salticidae, Euophryini)

The euophryine genus Chalcovietnamicus Marusik, 1991, a member of the Laufeia group of genera, is reviewed, and four new species from southern China and Southeast Asia are described with both sexes: Chalcovietnamicus logunovi Yu, Maddison & Zhang, sp. nov., C. marusiki Yu, Maddison & Zhang, sp. nov., C. terbakar Yu, Maddison & Zhang, sp. nov. and C. weihangi Yu & Zhang, sp. nov.. The monotypic genus Junxattus Prszyski & Deeleman-Reinhold, 2012 syn. nov. is considered as a junior synonym of Chalcovietnamicus Marusik, 1991, and Parvattus Zhang & Maddison, 2012 is revalidated and removed from synonymy with Chalcovietnamicus Marusik, 1991. The previously unknown female of C. vietnamensis (abka, 1985) is described based on specimens from Vietnam and Singapore. All species of Chalcovietnamicus are assigned to two species groups (daiqini-group and vietnamensis-group), except C. naga Logunov, 2020 that is herein considered as an incertae sedis.

Kelawakaju gen. nov., a new Asian lineage of marpissine jumping spiders (Araneae, Salticidae, Marpissina)

The genus Kelawakaju Maddison & Ruiz, gen. nov., is described for a lineage of bark-dwelling Asian marpissine jumping spiders that represent a dispersal to Eurasia separate from that of the Marpissa-Mendoza lineage, according to the phylogeny recovered from analysis of four gene regions. All species of Kelawakaju are new to science except Kelawakajufrenata (Simon, 1901), comb. nov., which is transferred from Ocrisiona Simon, 1901. Kelawakajufrenata is known from Hong Kong, Guangdong, Guangxi, and likely Taiwan. The five new species are Kelawakajumulu Maddison & Ruiz, sp. nov. (type species of Kelawakaju, from Sarawak, Malaysia, ♂♀), K.intexta Maddison & Ruiz, sp. nov. (from Sarawak, ♂), K.leucomelas Maddison & Ng, sp. nov. (Singapore and Johor Bahru, ♂♀), K.sahyadri Vishnudas, Maddison, & Sudhikumar, sp. nov. (India, ♂♀), and K.singapura Maddison & Ng, sp. nov. (Singapore, ♂♀).

Three new and notes on two other jumping spider species of the genus Stenaelurillus Simon, 1886 (Salticidae: Aelurillina) from the Deccan Plateau, India

We describe three new species of Stenaelurillus Simon, 1886 from the Deccan Plateau of India, and report on populations of S. sarojinae Caleb Mathai, 2014 and S. marusiki Logunov, 2001. One of the new species, S. shwetamukhi Marathe, Sanap, Maddison, sp. nov., has black-and-white markings, characteristic of several other Indian Stenaelurillus species. The other two new species, S. tamravarni Marathe Maddison, sp. nov., and S. vyaghri Sanap, Joglekar, Caleb, sp. nov., are colourful and with fringed male abdomens, like several other Indian species including S. sarojinae. The population of S. sarojinae from Mysuru, Karnataka, shows colours distinct from the population at the type locality. The female of S. marusiki is described for the first time.

A phylogenetic and taxonomic review of baviine jumping spiders (Araneae, Salticidae, Baviini)

The systematics and taxonomy of the tropical Asian jumping spiders of the tribe Baviini is reviewed, with a molecular phylogenetic study (UCE sequence capture, traditional Sanger sequencing) guiding a reclassification of the group’s genera. The well-studied members of the group are placed into six genera: Bavia Simon, 1877, Indopadilla Caleb & Sankaran, 2019, Padillothorax Simon, 1901, Piranthus Thorell, 1895, Stagetillus Simon, 1885, and one new genus, Maripanthus Maddison, gen. nov. The identity of Padillothorax is clarified, and Bavirecta Kanesharatnam & Benjamin, 2018 synonymized with it. Hyctiota Strand, 1911 is synonymized with Stagetillus. The molecular phylogeny divides the baviines into three clades, the Piranthus clade with a long embolus (Piranthus, Maripanthus), the genus Padillothorax with a flat body and short embolus, and the Bavia clade with a higher body and (usually) short embolus (remaining genera). In general, morphological synapomorphies support or extend the molecularly delimited groups. Eighteen new species are described: Bavianessagyna, Indopadillabamilin, I.kodagura, I.nesinor, I.redunca, I.redynis, I.sabivia, I.vimedaba, Maripanthusdraconis (type species of Maripanthus), M.jubatus, M.reinholdae, Padillothoraxbadut, P.mulu, Piranthusapi, P.bakau, P.kohi, P.mandai, and Stagetillusirri, all sp. nov., with taxonomic authority W. Maddison. The distinctions between baviines and the astioid Nungia Żabka, 1985 are reviewed, leading to four species being moved into Nungia from Bavia and other genera. Fifteen new combinations are established: Baviamaurerae (Freudenschuss & Seiter, 2016), Indopadillaannamita (Simon, 1903), I.kahariana (Prószyński & Deeleman-Reinhold, 2013), I.sonsorol (Berry, Beatty & Prószyński, 1997), I.suhartoi (Prószyński & Deeleman-Reinhold, 2013), Maripanthusmenghaiensis (Cao & Li, 2016), M.smedleyi (Reimoser, 1929), Nungiahatamensis (Thorell, 1881), N.modesta (Keyserling, 1883), N.papakula (Strand, 1911), N.xiaolonghaensis (Cao & Li, 2016), Padillothoraxcasteti (Simon, 1900), P.exilis (Cao & Li, 2016), P.flavopunctus (Kanesharatnam & Benjamin, 2018), Stagetillusbanda (Strand, 1911), all comb. nov. One combination is restored, Baviacapistrata (C. L. Koch, 1846). Five of these new or restored combinations correct previous errors of placing species in genera that have superficially similar palps but extremely different body forms, in fact belonging in distantly related tribes, emphasizing that the general shape of male palps should be used with caution in determining relationships. A little-studied genus, Padillothorus Prószyński, 2018, is tentatively assigned to the Baviini. Ligdus Thorell, 1895 is assigned to the Ballini.

Sitticine jumping spiders: phylogeny, classification, and chromosomes (Araneae, Salticidae, Sitticini)

The systematics of sitticine jumping spiders is reviewed, with a focus on the Palearctic and Nearctic regions, in order to revise their generic classification, clarify the species of one region (Canada), and study their chromosomes. A genome-wide molecular phylogeny of 23 sitticine species, using more than 700 loci from the arachnid Ultra-Conserved Element (UCE) probeset, confirms the Neotropical origins of sitticines, whose basal divergence separates the new subtribeAillutticina (a group of five Neotropical genera) from the subtribe Sitticina (five genera of Eurasia and the Americas). The phylogeny shows that most Eurasian sitticines form a relatively recent and rapid radiation, which we unite into the genus Attulus Simon, 1868, consisting of the subgenera Sitticus Simon, 1901 (seven described species), Attulus (41 described species), and Sittilong Prószyński, 2017 (one species). Five species of Attulus occur natively in North America, presumably through dispersals back from the Eurasian radiation, but an additional three species were more recently introduced from Eurasia. Attuspalustris Peckham & Peckham, 1883 is considered to be a full synonym of Euophrysfloricola C. L. Koch, 1837 (not a distinct subspecies). Attussylvestris Emerton, 1891 is removed from synonymy and recognized as a senior synonym of Sitticusmagnus Chamberlin & Ivie, 1944. Thus, the five native Attulus in North America are Attulusfloricola, A.sylvestris, A.cutleri, A.striatus, and A.finschi. The other sitticines of Canada and the U.S.A. are placed in separate genera, all of which arose from a Neotropical radiation including Jollas Simon, 1901 and Tomis F.O.Pickard-Cambridge, 1901: (1) Attinella Banks, 1905 (A.dorsata, A.concolor, A.juniperi), (2) Tomis (T.welchi), and (3) Sittisax Prószyński, 2017 (S.ranieri). All Neotropical and Caribbean “Sitticus” are transferred to either Jollas (12 species total) or Tomis (14 species). Attinella (three species) and Tomis are both removed from synonymy with Sitticus; the synonymy of Sitticuscabellensis Prószyński, 1971 with Pseudattuluskratochvili Caporiacco, 1947 is restored; Pseudattulus Caporiacco, 1947 is synonymized with Tomis. Six generic names are newly synonymized with Attulus and one with Attinella. Two Neotropical species are described as new, Jollascupreussp. nov. and Tomismanabitasp. nov. Forty-six new combinations are established and three are restored. Three species synonymies are restored, one is new, and two are rejected. Across this diversity of species is a striking diversification of chromosome complements, with X-autosome fusions occurring at least four times to produce neo-Y sex chromosome systems (X₁X₂Y and X₁X₂X₃Y), some of which (Sittisaxranieri and S.saxicola) are sufficiently derived as to no longer preserve the simple traces of ancestral X material. The correlated distribution of neo-Y and a base autosome number of 28 suggests that neo-Y origins occurred preferentially in lineages with the presence of an extra pair of autosomes.

A new lapsiine jumping spider from North America, with a review of Simon’s Lapsias species (Araneae, Salticidae, Spartaeinae)

A new spider genus and species from México and Guatemala, Amilapsmayanagen. et sp. nov., is described, distinct from other members of the jumping spider tribe Lapsiini (subfamily Spartaeinae) by its four retromarginal cheliceral teeth and the large sclerite cradling the embolus. It is the first living lapsiine known outside of South America. This tribe has received attention recently for new species and genera in Ecuador and Brazil, but Simon’s original four species of Lapsias, described from Venezuela in 1900 and 1901, remain relatively poorly known. Accordingly, new illustrations of Simon’s type material are given, and a lectotype is designated for L.cyrboides Simon, 1900. The three forms of females in Simon’s material from Colonia Tovar, Aragua, are reviewed and illustrated, and they are a tentatively matched with the three male lectotypes of his species from the same location.

A revision of the concept of Mago O. Pickard-Cambridge, 1882, and proposal of a new genus (Araneae: Salticidae: Amycini)

In this paper we redescribe the type species of Mago O. Pickard-Cambridge, M. intentus O. Pickard-Cambridge, and describe Mago brimodes Ruiz Maddison sp. nov. from Ecuador. Based on both morphological features and the 16SND1 gene region, we concluded that the larger spiders traditionally identified as Mago, such as Mago acutidens Simon and related species, are not closely related to the small dark M. intentus (type species) and M. brimodes. Matinta Ruiz Maddison gen. nov. is therefore proposed to hold most species previously included in Mago. The following species are transferred from Mago to the new genus: Matinta acutidens (Simon, 1900) comb. nov. (type species), Matinta apophysis (Costa Ruiz, 2017) comb. nov., Matinta balbina (Patello Ruiz, 2014) comb. nov., Matinta chickeringi (Caporiacco, 1954) comb. nov., Matinta delicata (Patello Ruiz, 2014) comb. nov., Matinta fasciata (Mello-Leitão, 1940) comb. nov., Matinta fonsecai (Soares Camargo, 1948) comb. nov., Matinta furcata (Costa Ruiz, 2017) comb. nov., Matinta jurutiensis (Patello Ruiz, 2014) comb. nov., Matinta longidens (Simon, 1900) comb. nov., Matinta mimica (Costa Ruiz, 2017) comb. nov., Matinta opiparis (Simon, 1900) comb. nov., Matinta pardo (Costa Ruiz, 2017) comb. nov., Matinta procax (Simon, 1900) comb. nov., Matinta saperda (Simon, 1900) comb. nov., Matinta silvae (Crane, 1943) comb. nov., Matinta similis (Patello Ruiz, 2014) comb. nov., Matinta steindachneri (Taczanowski, 1878) comb. nov. and Matinta vicana (Simon, 1900) comb. nov. Mago dentichelis Crane, 1949 is transferred to Noegus Simon.

Myrmarachnine jumping spiders of the new subtribe Levieina from Papua New Guinea (Araneae, Salticidae, Myrmarachnini)

A previously unreported radiation of myrmarachnine jumping spiders from New Guinea is described, which, although having few known species, is remarkably diverse in body forms. This clade is the new subtribe Levieina, represented by seven new species in three new genera. Within Levieagen. n. are three new species, L.herbertisp. n., L.lornaesp. n., and L.francesaesp. n., all of which are unusual among the myrmarachnines in appearing as typical salticids, not antlike. Papuamyrgen. n. superficially resembles Ligonipes Karsch, 1878 or Rhombonotus L. Koch, 1879 as a compact antlike spider, but lacks their laterally-compressed palp and bears an ectal spur on the paturon of the chelicera. Two species of Papuamyrgen. n. are described, Papuamyromhifosgasp. n. and P.pandorasp. n.Agorioidesgen. n., containing A.cherubinosp. n. and A.papagenasp. n., is antlike, with the carapace sunken inwards (concave) between the posterior lateral and posterior median eyes. Phylogenetic analysis of data from the 28S, 16SND1, and COI gene regions of 29 species of myrmarachnines shows that the three new genera form a clade that is sister to the subtribe Myrmarachnina (Myrmarachne sensu lato), with the subtribe Ligonipedina less closely related.

New chrysilline and aelurilline jumping spiders from Pakistan (Araneae, Salticidae)

Epocillapakhtunkhwa Ali & Maddison, sp. n. and Stenaelurillusmardanicus Ali & Maddison, sp. n. are described from Khyber Pakhtunkhwa Province, Pakistan. Noted for the first time is the presence in Epocilla of a small bump just anterior to the fovea of the carapace, of unknown functional significance, otherwise known in the unrelated Opisthoncus L. Koch, 1880 and Cocalus Pocock, 1897. In addition, the female of Menemerusnigli Wesołowska & Freudenschuss, 2012 is described for the first time.

Co-occurrence of related asexual, but not sexual, lineages suggests that reproductive interference limits coexistence

We used randomizations to analyse patterns of co-occurrence of sexual and apomictic (asexual) members of the North American Crepis agamic complex (Asteraceae). We expect strong asymmetry in reproductive interactions in Crepis: apomicts produce clonal seeds with no need for pollination and are not subject to reproductive interference from co-occurring relatives. However, because they still produce some viable pollen, apomicts can reduce reproductive success of nearby sexual relatives, potentially leading to eventual local exclusion of sexuals. Consistent with this, randomizations reveal that sexuals are over-represented in isolated sites, while apomicts freely co-occur. Incorporation of taxonomic and phylogenetic evidence indicates that this pattern is not driven by local origins of asexuals. Our evidence that patterns of local co-occurrence are structured by reproductive interference suggests an underappreciated role for these interactions in community assembly, and highlights the need for explicit tests of the relative contributions of ecological and reproductive interactions in generating patterns of limiting similarity.

Phylogeny with introgression in Habronattus jumping spiders (Araneae: Salticidae)

Background

Habronattus is a diverse clade of jumping spiders with complex courtship displays and repeated evolution of Y chromosomes. A well-resolved species phylogeny would provide an important framework to study these traits, but has not yet been achieved, in part because the few genes available in past studies gave conflicting signals. Such discordant gene trees could be the result of incomplete lineage sorting (ILS) in recently diverged parts of the phylogeny, but there are indications that introgression could be a source of conflict.

Results

To infer Habronattus phylogeny and investigate the cause of gene tree discordance, we assembled transcriptomes for 34 Habronattus species and 2 outgroups. The concatenated 2.41 Mb of nuclear data (1877 loci) resolved phylogeny by Maximum Likelihood (ML) with high bootstrap support (95-100%) at most nodes, with some uncertainty surrounding the relationships of H. icenoglei, H. cambridgei, H. oregonensis, and Pellenes canadensis. Species tree analyses by ASTRAL and SVDQuartets gave almost completely congruent results. Several nodes in the ML phylogeny from 12.33 kb of mitochondrial data are incongruent with the nuclear phylogeny and indicate possible mitochondrial introgression: the internal relationships of the americanus and the coecatus groups, the relationship between the altanus, decorus, banksi, and americanus group, and between H. clypeatus and the coecatus group. To determine the relative contributions of ILS and introgression, we analyzed gene tree discordance for nuclear loci longer than 1 kb using Bayesian Concordance Analysis (BCA) for the americanus group (679 loci) and the VCCR clade (viridipes/clypeatus/coecatus/roberti groups) (517 loci) and found signals of introgression in both. Finally, we tested specifically for introgression in the concatenated nuclear matrix with Patterson’s D statistics and D_FOIL. We found nuclear introgression resulting in substantial admixture between americanus group species, between H. roberti and the clypeatus group, and between the clypeatus and coecatus groups.

Conclusions

Our results indicate that the phylogenetic history of Habronattus is predominantly a diverging tree, but that hybridization may have been common between phylogenetically distant species, especially in subgroups with complex courtship displays.

Electronic supplementary material

The online version of this article (10.1186/s12862-018-1137-x) contains supplementary material, which is available to authorized users.

A genome-wide phylogeny of jumping spiders (Araneae, Salticidae), using anchored hybrid enrichment

We present the first genome-wide molecular phylogeny of jumping spiders (Araneae: Salticidae), inferred from Anchored Hybrid Enrichment (AHE) sequence data. From 12 outgroups plus 34 salticid taxa representing all but one subfamily and most major groups recognized in previous work, we obtained 447 loci totalling 96,946 aligned nucleotide sites. Our analyses using concatenated likelihood, parsimony, and coalescent methods (ASTRAL and SVDQuartets) strongly confirm most previous results, resolving as monophyletic the Spartaeinae, Salticinae (with the hisponines sister), Salticoida, Amycoida, Saltafresia, and Simonida. The agoriines, previously difficult to place beyond subfamily, are finally placed confidently within the saltafresians as relatives of the chrysillines and hasariines. Relationships among the baviines, astioids, marpissoids, and saltafresians remain uncertain, though our analyses tentatively conclude the first three form a clade together. Deep relationships, among the seven subfamilies, appear to be largely resolved, with spartaeines, lyssomanines, and asemoneines forming a clade. In most analyses, Onomastus (representing the onomastines) is strongly supported as sister to the hisponines plus salticines. Overall, the much-improved resolution of many deep relationships despite a relatively sparse taxon sample suggests AHE is a promising technique for salticid phylogenetics.

NULL MODELS FOR THE NUMBER OF EVOLUTIONARY STEPS IN A CHARACTER ON A PHYLOGENETIC TREE

Random trees and random characters can be used in null models for testing phylogenetic hypothesis. We consider three interpretations of random trees: first, that trees are selected from the set of all possible trees with equal probability; second, that trees are formed by random speciation or coalescence (equivalent); and third, that trees are formed by a series of random partitions of the taxa. We consider two interpretations of random characters: first, that the number of taxa with each state is held constant, but the states are randomly reshuffled among the taxa; and second, that the probability each taxon is assigned a particular state is constant from one taxon to the next. Under null models representing various combinations of randomizations of trees and characters, exact recursion equations are given to calculate the probability distribution of the number of character state changes required by a phylogenetic tree. Possible applications of these probability distributions are discussed. They can be used, for example, to test for a panmictic population structure within a species or to test phylogenetic inertia in a character's evolution. Whether and how a null model incorporates tree randomness makes little difference to the probability distribution in many but not all circumstances. The null model's sense of character randomness appears more critical. The difficult issue of choosing a null model is discussed.

New species of Habronattus and Pellenes jumping spiders (Araneae, Salticidae, Harmochirina)

The harmochirine jumping spiders include the New World Habronattus, notable for their complex courtship displays, and Pellenes, found throughout the Old World and North America. Five new species of Habronattus and one new species of Pellenes are here described from North America: Habronattusaestus, sp. n., Habronattuschamelasp. n., Habronattusempyrussp. n., Habronattusluminosussp. n., Habronattusrobertisp. n., and Pellenescanadensissp. n. For each of the new species, photographs of living specimens are given, as well as notes on habitat. The new subgenus Pellenattus is described for the subgroup of Pellenes restricted to North America, with type species Pellenespeninsularis Emerton, 1925. Species placed in Pellenes (Pellenattus) are Pellenesapacheus Lowrie & Gertsch, 1955, Pellenescanadensissp. n., Pellenescrandalli Lowrie & Gertsch, 1955, Pellenesdorsalis (Banks, 1898b), Pellenesgrammaticus Chamberlin 1925, Pelleneslevii Lowrie & Gertsch, 1955, Pelleneslimatus Peckham & Peckham, 1901, Pelleneslongimanus Emerton, 1913, Pellenespeninsularis Emerton, 1925, Pellenesshoshonensis Gertsch, 1934, and Pelleneswashonus Lowrie & Gertsch, 1955. Pelleneswrighti Lowrie & Gertsch, 1955 is synonymized with Pellenespeninsularis. Attention is drawn to an undescribed species of Habronattus from Canada whose only known specimen is apparently lost.

<i>Papuaneon</i>, a new genus of jumping spiders from Papua New Guinea (Araneae: Salticidae: Neonini)

The genus Neon Simon stands alone as a phylogenetically isolated astioid jumping spider, the only member of the Neonini. The new genus Papuaneon is established for the jumping spider Papuaneon tualapa sp. nov. from Papua New Guinea. Resembling a large, hirsute Neon, it is here shown to be the sister group to Neon, based on data from the nuclear 28S and Actin 5C, and the mitochondrial 16SND1 region. Photographs of living specimens are provided.

Two new jumping spider species of the Habronattus clypeatus group (Araneae, Salticidae, Harmochirina)

Two species of the Habronattusclypeatus species group are described, Habronattusarcalorussp. n. from Texas and Colorado, and Habronattusgilaensissp. n. from New Mexico. Habronattusarcalorus males have extravagant ornamentation: a green first leg with an unusually dense lateral fringe of orange and white hairs, and a large grey triangular patella on the third leg with blue-white scales nearby. Habronattusgilaensis males are considerably more muted, lacking ornamentation on the third leg’s patella and tibia. Photographs of living specimens are given, as well as notes on habitat.

Sumakuru, a deeply-diverging new genus of lyssomanine jumping spiders from Ecuador (Araneae: Salticidae)

The lyssomanine jumping spider genus Sumakurugen. n. is here described for Sumakurubigalsp. n., from the Bigal River Biological Reserve in Ecuador. Known from a single male, the embolus of the palp takes the form of a smoothly arching curve, and appears fully mobile, being connected to the tegulum by a thin sclerite and a twisted hematodocha. Data from four gene regions (28S, 16SND1, CO1, wingless) indicate that Sumakuru is the sister group to all other sampled lyssomanines, diverging deeply on the stem lineage of the clade of other known lyssomanines. Unlike previous molecular results, the sampled species of Lyssomanes Hentz, 1845 are supported as monophyletic, with Chinoscopus Simon, 1900 as the sister to Lyssomanes.

Phylogenetic placement of the unusual jumping spider Depreissia Lessert, and a new synapomorphy uniting Hisponinae and Salticinae (Araneae, Salticidae)

The relationships of the unusual salticid spider Depreissia from central Africa and Borneo have been difficult to resolve, obscured by its highly modified ant-like body. Phylogenetic analysis of the gene 28S strongly supports its placement outside the major clade Salticinae and within the clade of cocalodines, spartaeines and lapsiines, with weaker support for a relationship with the cocalodines in particular. Excluding the genus from the Salticinae is supported also by the presence of a median apophysis on the male palp, and by the lack of a cymbial apical groove cradling the tip of embolus, which is newly presented here as a synapomorphy of Hisponinae plus Salticinae.

The new Andean jumping spider genus Urupuyu and its placement within a revised classification of the Amycoida (Araneae: Salticidae)

Urupuyu gen. nov. is described for three new species of small black jumping spiders from the cloud forests of Ecuador: Urupuyu antisana sp. nov. (type species), U. edwardsi sp. nov., and U. occidentale sp. nov. Phylogenetic analyses with DNA sequences (28S, actin 5C, wingless, 16SND1 and CO1) indicate Urupuyu is closely related to the huriine amycoids Hurius and Scoturius, a placement also supported by morphological traits. Our phylogenetic analysis serves to clarify the relationships within the Amycoida in general, leading to our proposing a revised classification for the group, with subfamilies Gophoinae, Sitticinae, Bredinae subfam. nov., Scopocirinae, Thiodininae, Sarindinae, Huriinae, Simonellinae, and Amycinae. We confirm the marpissine-like Breda belongs within the Amycoida. The phylogeny implies that ant mimicry has evolved at least twice (simonellines and sarindines) and probably a third time (Atomosphyrus in the thiodinines) within the Amycoida. The following new synonymies are proposed for suprageneric names: Hyetusseae Simon, 1903 and Arachnomureae Mello-Leitão, 1917 = Thiodininae Simon, 1901; Zunigeae Simon, 1901 = Sarindinae Simon, 1901; Synemosynae Banks, 1892 = Simonellinae Peckham, Peckham & Wheeler, 1888; Magoninae Petrunkevitch, 1928 = Amycinae F.O.P.-Cambridge, 1900.

The jumping spider genus Thiodina Simon, 1900 reinterpreted, and revalidation of Colonus F.O.P-Cambridge, 1901 and Nilakantha Peckham & Peckham, 1901 (Araneae: Salticidae: Amycoida)

In this paper we call attention to the identity of the type species of Thiodina Simon, 1900, T. nicoleti Roewer, 1951. When Simon proposed the genus, he characterized it based on morphological features found in species he described, but not found in the type species he designated, and whose type specimens, apparently, he had not examined. Nicolet's original description makes it clear that the type species is not closely related to the more familiar species placed in the genus. This misinterpretation was followed by contemporary researchers and survives until today. Here we designate and describe a neotype for T. nicoleti. We revalidate Colonus F.O.P.-Cambridge, 1901 and Nilakantha Peckham & Peckham, 1901 to transfer most species formerly placed in Thiodina. The combinations Colonus puerperus (Hentz, 1846), Nilakantha cockerelli Peckham & Peckham, 1901 and N. peckhami Bryant, 1940 are restored. The following new combinations are established: Colonus branicki (Taczanowski, 1871) new comb., C. candidus (Mello-Leitão, 1922) new comb., C. germaini (Simon, 1900) new comb., C. hesperus (Richman & Vetter, 2004) new comb., C. melanogaster (Mello-Leitão, 1917) new comb., C. pallidus (C.L. Koch, 1846) new comb., C. pseustes (Chamberlin & Ivie, 1936) new comb., C. punctulatus (Mello-Leitão, 1917) new comb., C. rishwani (Makhan, 2006) new comb., C. robustus (Mello-Leitão, 1945) new comb., C. sylvanus (Hentz, 1846) new comb., C. vaccula (Simon, 1900) new comb., C. vellardi (Soares & Camargo, 1948) new comb., Nilakantha beugelorum (Wolff, 1990) new comb., N. crucifera (F.O.P.-Cambridge, 1901) new comb., and N. inerma (Bryant, 1940) new comb. Thiodina setosa Mello-Leitão, 1947 is tentatively transferred to Cotinusa Simon, 1900.

Genera of euophryine jumping spiders (Araneae: Salticidae), with a combined molecular-morphological phylogeny

Morphological traits of euophryine jumping spiders were studied to clarify generic limits in the Euophryinae and to permit phylogenetic classification of genera lacking molecular data. One hundred and eight genera are recognized within the subfamily. Euophryine generic groups and the delimitation of some genera are reviewed in detail. In order to explore the effect of adding formal morphological data to previous molecular phylogenetic studies, and to find morphological synapomorphies, eighty-two morphological characters were scored for 203 euophryine species and seven outgroup species. The morphological dataset does not perform as well as the molecular dataset (genes 28S, Actin 5C; 16S-ND1, COI) in resolving the phylogeny of Euophryinae, probably because of frequent convergence and reversal. The formal morphological data were mapped on the phylogeny in order to seek synapomorphies, in hopes of extending the phylogeny to include taxa for which molecular data are not available. Because of homoplasy, few globally-applicable morphological synapomorphies for euophryine clades were found. However, synapomorphies that are unique locally in subclades still help to delimit euophryine generic groups and genera. The following synonyms of euophryine genera are proposed: Maeotella with Anasaitis; Dinattus with Corythalia; Paradecta with Compsodecta; Cobanus, Chloridusa and Wallaba with Sidusa; Tariona with Mopiopia; Nebridia with Amphidraus; Asaphobelis and Siloca with Coryphasia; Ocnotelus with Semnolius; Palpelius with Pristobaeus; Junxattus with Laufeia; Donoessus with Colyttus; Nicylla, Pselcis and Thianitara with Thiania. The new genus Saphrys is erected for misplaced species from southern South America.

Insights to the mating strategies of Habronattus americanus jumping spiders from natural behaviour and staged interactions in the wild

We documented natural behaviour and staged intersexual interactions ofHabronattusamericanusjumping spiders in the wild in order to clarify three aspects of their mating strategies: (1) Do males invest more than females in locomotory mate search? (2) Do females exert strong mate choice? (3) Do direct contests occur among males? Males apparently invested heavily in mate search, travelling more than females yet eating nothing. Conversely, females frequently hunted and spent 10% of their time feeding. Females encountered one male per hour, likely affording them a high degree of choice among prospective mates. Accordingly, they promoted the termination of each interaction and ultimately rejected nearly all courting males. Male–male interactions were brief and did not feature direct antagonism. Our findings suggest that mate competition inH. americanusis characterized by male scramble competition for dispersed females, and that female mate choice may exert strong selection on male sexual display traits.

The deep phylogeny of jumping spiders (Araneae, Salticidae)

In order to resolve better the deep relationships among salticid spiders, we compiled and analyzed a molecular dataset of 169 salticid taxa (and 7 outgroups) and 8 gene regions. This dataset adds many new taxa to previous analyses, especially among the non-salticoid salticids, as well as two new genes – wingless and myosin heavy chain. Both of these genes, and especially the better sampled wingless, confirm many of the relationships indicated by other genes. The cocalodines are placed as sister to lapsiines, in a broader clade with the spartaeines. Cocalodines, lapsiines, and spartaeines are each supported as monophyletic, though the first two have no known morphological synapomorphies. The lyssomanines appear to be non-monophyletic, of three separate groups: (1) Lyssomanes plus Chinoscopus, (2) Onomastus, and (3) the remainder of Old World species. Several previously-inferred relationships continue to be supported: hisponines as sister to the Salticoida, Amycoida as sister to the remaining Salticoida, and Saltafresia as monophyletic. The relationship of Salticus with Philaeus and relatives is now considered well enough corroborated to move the latter into the subfamily Salticinae. A new clade consisting of the Plexippoida + Aelurilloida + Leptorchesteae + Salticinae is recognized. Nungia is found to be an astioid, and Echeclus, Gedea and Diplocanthopoda to be hasariines. The euophryines are corroborated as monophyletic. The agoriines Agorius and Synagelides are salticoids, within the sister group to amycoids, but their further placement is problematical, perhaps because of their nuclear ribosomal genes’ high GC bias, as also seen in the similarly problematic Eupoa.

Jerzego, a new hisponine jumping spider from Borneo (Araneae: Salticidae)

A new genus and species of hisponine jumping spider from Sarawak, Jerzego corticicola Maddison sp. nov. are described, representing one of the few hisponine jumping spiders known from Asia, and the only whose male is known. Although similar to the primarily-Madagascan genus Hispo in having an elongate and flat body, sequences of 28s and 16sND1 genes indicate that Jerzego is most closely related to Massagris and Tomomingi, a result consistent with morphology. Females of Jerzego and other genera of Hisponinae were found to have an unusual double copulatory duct, which appears to be a synapomorphy of the subfamily. Two species are transferred from Hispo, Jerzego bipartitus (Simon) comb. nov. and Jerzego alboguttatus (Simon) comb. nov. Diagnostic illustrations and photographs of living spiders are provided. 

Tisaniba, a new genus of marpissoid jumping spiders from Borneo (Araneae: Salticidae)

Six new species of marpissoid jumping spiders from Sarawak, Borneo, are described in the new genus Tisaniba Zhang & Maddison. They are the type species, T. mulu Zhang & Maddison sp. nov., as well as the species T. bijibijan Zhang & Maddison sp. nov., T. dik Zhang & Maddison sp. nov., T. kubah Zhang & Maddison sp. nov., T. selan Zhang & Maddison sp. nov., and T. selasi Zhang & Maddison sp. nov. The spiders are small and brown to black, living in leaf litter in the tropical forest. Phylogenetic analyses based on 28s and 16sND1 genes indicate that they are a distinctive group within the marpissoids. Diagnostic illustrations and photographs of living spiders are provided for all species.

Multiple origins of sex chromosome fusions correlated with chiasma localization in Habronattus jumping spiders (Araneae: Salticidae)

Entelegyne spiders rarely show fusions yielding neo-Y chromosomes, which M. J. D. White attributed to a constraint in spiders, namely their proximal chiasma localization acting to upset meiotic segregation in males with fusions. Of the 75 taxa of Habronattus and outgroups studied, 47 have X1 X2 0 sex chromosomes in males, 10 have X1 X2 Y, 15 have X1 X2 X3 Y, 2 have X0, and one has both X1 X2 0 and X1 X2 X3 Y. Chromosome numbers and behavior suggest neo-Ys formed by an autosome-X fusion to make X1 X2 Y, with a second fusion to an autosome to make X1 X2 X3 Y. Phylogeny shows at least 8-15 gains (or possibly some losses) of neo-Y (i.e., X-autosome fusions), a remarkable number for such a small clade. In contrast to the many X-autosome fusions, at most one autosome-autosome fusion is indicated. Origins of neo-Y are correlated significantly with distal localization of chiasmata, supporting White's hypothesis that evolution of neo-Y systems is facilitated by looser pairing (distal chiasmata) at meiosis. However, an alternative (or contributing) explanation for the correlation is that X-autosome fusions were selected to permit isolation of male-favored alleles to the neo-Y chromosome, aided by distal chiasmata limiting recombination. This intralocus sexual conflict hypothesis could explain both the many X-autosome fusions, and the stunning complexity of male Habronattus courtship displays.

Molecular phylogeny, divergence times and biogeography of spiders of the subfamily Euophryinae (Araneae: Salticidae)

We investigate phylogenetic relationships of the jumping spider subfamily Euophryinae, diverse in species and genera in both the Old World and New World. DNA sequence data of four gene regions (nuclear: 28S, Actin 5C; mitochondrial: 16S-ND1, COI) were collected from 263 jumping spider species. The molecular phylogeny obtained by Bayesian, likelihood and parsimony methods strongly supports the monophyly of a Euophryinae re-delimited to include 85 genera. Diolenius and its relatives are shown to be euophryines. Euophryines from different continental regions generally form separate clades on the phylogeny, with few cases of mixture. Known fossils of jumping spiders were used to calibrate a divergence time analysis, which suggests most divergences of euophryines were after the Eocene. Given the divergence times, several intercontinental dispersal events are required to explain the distribution of euophryines. Early transitions of continental distribution between the Old and New World may have been facilitated by the Antarctic land bridge, which euophryines may have been uniquely able to exploit because of their apparent cold tolerance. Two hot-spots of diversity of euophryines are discovered: New Guinea and the Caribbean Islands. Implications of the molecular phylogeny on the taxonomy of euophryines, and on the evolution of unusual genitalic forms and myrmecophagy, are also briefly discussed.

Loss of genetic variability in social spiders: genetic and phylogenetic consequences of population subdivision and inbreeding

The consequences of population subdivision and inbreeding have been studied in many organisms, particularly in plants. However, most studies focus on the short-term consequences, such as inbreeding depression. To investigate the consequences of both population fragmentation and inbreeding for genetic variability in the longer term, we here make use of a natural inbreeding experiment in spiders, where sociality and accompanying population subdivision and inbreeding have evolved repeatedly. We use mitochondrial and nuclear data to infer phylogenetic relationships among 170 individuals of Anelosimus spiders representing 23 species. We then compare relative mitochondrial and nuclear genetic variability of the inbred social species and their outbred relatives. We focus on four independently derived social species and four subsocial species, including two outbred–inbred sister species pairs. We find that social species have 50% reduced mitochondrial sequence divergence. As inbreeding is not expected to reduce genetic variability in the maternally inherited mitochondrial genome, this suggests the loss of variation due to strong population subdivision, founder effects, small effective population sizes (colonies as individuals) and lineage turnover. Social species have < 10% of the nuclear genetic variability of the outbred species, also suggesting the loss of genetic variability through founder effects and/or inbreeding. Inbred sociality hence may result in reduction in variability through various processes. Sociality in most Anelosimus species probably arose relatively recently (0.1–2 mya), with even the oldest social lineages having failed to diversify. This is consistent with the hypothesis that inbred spider sociality represents an evolutionary dead end. Heterosis underlies a species potential to respond to environmental change and/or disease. Inbreeding and loss of genetic variability may thus limit diversification in social Anelosimus lineages and similarly pose a threat to many wild populations subject to habitat fragmentation or reduced population sizes.

NeXML: rich, extensible, and verifiable representation of comparative data and metadata

In scientific research, integration and synthesis require a common understanding of where data come from, how much they can be trusted, and what they may be used for. To make such an understanding computer-accessible requires standards for exchanging richly annotated data. The challenges of conveying reusable data are particularly acute in regard to evolutionary comparative analysis, which comprises an ever-expanding list of data types, methods, research aims, and subdisciplines. To facilitate interoperability in evolutionary comparative analysis, we present NeXML, an XML standard (inspired by the current standard, NEXUS) that supports exchange of richly annotated comparative data. NeXML defines syntax for operational taxonomic units, character-state matrices, and phylogenetic trees and networks. Documents can be validated unambiguously. Importantly, any data element can be annotated, to an arbitrary degree of richness, using a system that is both flexible and rigorous. We describe how the use of NeXML by the TreeBASE and Phenoscape projects satisfies user needs that cannot be satisfied with other available file formats. By relying on XML Schema Definition, the design of NeXML facilitates the development and deployment of software for processing, transforming, and querying documents. The adoption of NeXML for practical use is facilitated by the availability of (1) an online manual with code samples and a reference to all defined elements and attributes, (2) programming toolkits in most of the languages used commonly in evolutionary informatics, and (3) input-output support in several widely used software applications. An active, open, community-based development process enables future revision and expansion of NeXML.

Complete separation along matrilines in a social spider metapopulation inferred from hypervariable mitochondrial DNA region

The distribution and quantity of genetic diversity may be profoundly influenced by the emergence and dynamics of social groups. Permanent social living in spiders has resulted in the subdivision of their populations in more or less isolated colony lineages that grow, proliferate and become extinct without mixing with one another. A newly discovered hypervariable mitochondrial DNA region allowed us to examine the fine scale metapopulation structure in the social Anelosimus eximius. We sampled 39 colonies in Ecuador and French Guiana and identified 25 haplotypes. The majority of colonies contained one haplotype. Additional haplotypes occurred in approximately 15% of the colonies, and were always closely related to the common colony haplotype. Our findings confirm that colonies consist of single matrilines, with within-colony variation explained by mutations within the matriline. We thus found no evidence of mixing of matrilines. Likewise, colonies in a cluster often shared a haplotype, implying common colony ancestry. In few cases, however, haplotypes were shared between more distant colonies, providing evidence for occasional longer distance dispersal and/or widespread colony lineages. The geographical localities of colonies were incongruent with phylogenetic trees and haplotype networks, showing that some areas contained two or more matrilines. Hence, females do not migrate into foreign colonies, but faithfully remain within their own colony lineage, even when they disperse into new areas. These results indicate that the fine scale metapopulation structure of pure matrilines is maintained over the long term and that colony turnover is not extensive or radical enough to homogenize entire geographical areas. Genetic diversity is thus preserved to some extent at the metapopulation level.

Arctic-alpine distributions--metapopulations on a continental scale?

Cold-adapted species in the Northern Hemisphere frequently show arctic-alpine discontinuous ranges at high latitudes and on mountains farther south, but area connectivity through current and historical gene flow remains unclear. We used the coalescent-based program IMa (Isolation with Migration-analytic) to test for migration among disjunct European areas of arctic-alpine wolf spiders of the Pardosa saltuaria group. Mitochondrial (ND1) and nuclear (ITS1, 5.8S rDNA, ITS2) markers were analyzed simultaneously. Gene flow was unidirectional from Scandinavia to the Alps and the Carpathians, complex with respect to intermediate relict areas in central Europe, and very limited in outlying areas in the Balkans and Pyrenees. Population connectivity may have been greater during glacial events that might alternatively account for the inferred arctic-alpine links. A simulation study under various demographic histories (using a new module in the Mesquite package, which models episodic migration) showed that the empirical results are equally consistent with moderate levels of ongoing (continuous) migration or, alternatively, with strong migration bursts at the last glacial maximum but not at earlier times. Habitat connectivity was probably maximal during glacial events, illustrating the potential influence of ecology and life history on organismal responses to past climatic change.

Estimating trait-dependent speciation and extinction rates from incompletely resolved phylogenies

Species traits may influence rates of speciation and extinction, affecting both the patterns of diversification among lineages and the distribution of traits among species. Existing likelihood approaches for detecting differential diversification require complete phylogenies; that is, every extant species must be present in a well-resolved phylogeny. We developed 2 likelihood methods that can be used to infer the effect of a trait on speciation and extinction without complete phylogenetic information, generalizing the recent binary-state speciation and extinction method. Our approaches can be used where a phylogeny can be reasonably assumed to be a random sample of extant species or where all extant species are included but some are assigned only to terminal unresolved clades. We explored the effects of decreasing phylogenetic resolution on the ability of our approach to detect differential diversification within a Bayesian framework using simulated phylogenies. Differential diversification caused by an asymmetry in speciation rates was nearly as well detected with only 50% of extant species phylogenetically resolved as with complete phylogenetic knowledge. We demonstrate our unresolved clade method with an analysis of sexual dimorphism and diversification in shorebirds (Charadriiformes). Our methods allow for the direct estimation of the effect of a trait on speciation and extinction rates using incompletely resolved phylogenies.

Converting endangered species categories to probabilities of extinction for phylogenetic conservation prioritization

Background

Categories of imperilment like the global IUCN Red List have been transformed to probabilities of extinction and used to rank species by the amount of imperiled evolutionary history they represent (e.g. by the Edge of Existence programme). We investigate the stability of such lists when ranks are converted to probabilities of extinction under different scenarios.

Methodology and Principal Findings

Using a simple example and computer simulation, we show that preserving the categories when converting such list designations to probabilities of extinction does not guarantee the stability of the resulting lists.

Significance

Care must be taken when choosing a suitable transformation, especially if conservation dollars are allocated to species in a ranked fashion. We advocate routine sensitivity analyses.

Estimating a Binary Character's Effect on Speciation and Extinction

Determining whether speciation and extinction rates depend on the state of a particular character has been of long-standing interest to evolutionary biologists. To assess the effect of a character on diversification rates using likelihood methods requires that we be able to calculate the probability that a group of extant species would have evolved as observed, given a particular model of the character's effect. Here we describe how to calculate this probability for a phylogenetic tree and a two-state (binary) character under a simple model of evolution (the "BiSSE" model, binary-state speciation and extinction). The model involves six parameters, specifying two speciation rates (rate when the lineage is in state 0; rate when in state 1), two extinction rates (when in state 0; when in state 1), and two rates of character state change (from 0 to 1, and from 1 to 0). Using these probability calculations, we can do maximum likelihood inference to estimate the model's parameters and perform hypothesis tests (e.g., is the rate of speciation elevated for one character state over the other?). We demonstrate the application of the method using simulated data with known parameter values.

Linking of Digital Images to Phylogenetic Data Matrices Using a Morphological Ontology

Images are paramount in documentation of morphological data. Production and reproduction costs have traditionally limited how many illustrations taxonomy could afford to publish, and much comparative knowledge continues to be lost as generations turn over. Now digital images are cheaply produced and easily disseminated electronically but pose problems in maintenance, curation, sharing, and use, particularly in long-term data sets involving multiple collaborators and institutions. We propose an efficient linkage of images to phylogenetic data sets via an ontology of morphological terms; an underlying, fine-grained database of specimens, images, and associated metadata; fixation of the meaning of morphological terms (homolog names) by ostensive references to particular taxa; and formalization of images as standard views. The ontology provides the intellectual structure and fundamental design of the relationships and enables intelligent queries to populate phylogenetic data sets with images. The database itself documents primary morphological observations, their vouchers, and associated metadata, rather than the conventional data set cell, and thereby facilitates data maintenance despite character redefinition or specimen reidentification. It minimizes reexamination of specimens, loss of information or data quality, and echoes the data models of web-based repositories for images, specimens, and taxonomic names. Confusion and ambiguity in the meanings of technical morphological terms are reduced by ostensive definitions pointing to features in particular taxa, which may serve as reference for globally unique identifiers of characters. Finally, the concept of standard views (an image illustrating one or more homologs in a specific sex and life stage, in a specific orientation, using a specific device and preparation technique) enables efficient, dynamic linkage of images to the data set and automatic population of matrix cells with images independently of scoring decisions.

Sociality in theridiid spiders: repeated origins of an evolutionary dead end

Evolutionary "dead ends" result from traits that are selectively advantageous in the short term but ultimately result in lowered diversification rates of lineages. In spiders, 23 species scattered across eight families share a social system in which individuals live in colonies and cooperate in nest maintenance, prey capture, and brood care. Most of these species are inbred and have highly female-biased sex ratios. Here we show that in Theridiidae this social system originated eight to nine times independently among 11 to 12 species for a remarkable 18 to 19 origins across spiders. In Theridiidae, the origins cluster significantly in one clade marked by a possible preadaptation: extended maternal care. In most derivations, sociality is limited to isolated species: social species are sister to social species only thrice. To examine whether sociality in spiders represents an evolutionary dead end, we develop a test that compares the observed phylogenetic isolation of social species to the simulated evolution of social and non-social clades under equal diversification rates, and find that sociality in Theridiidae is significantly isolated. Because social clades are not in general smaller than their nonsocial sister clades, the "spindly" phylogenetic pattern-many tiny replicate social clades-may be explained by extinction rapid enough that a nonsocial sister group does not have time to diversify while the social lineage remains extant. In this case, this repeated origin and extinction of sociality suggests a conflict between the short-term benefits and long-term costs of inbred sociality. Although benefits of group living may initially outweigh costs of inbreeding (hence the replicate origins), in the long run the subdivision of the populations in relatively small and highly inbred colony lineages may result in higher extinction, thus an evolutionary dead end.

The phylogeny of the social Anelosimus spiders (Araneae: Theridiidae) inferred from six molecular loci and morphology

We use fragments of three nuclear genes (Histone 3, 18SrDNA, and 28SrDNA) and three mitochondrial genes (16SrDNA, ND1, and COI) totalling approximately 4.5kb, in addition to morphological data, to estimate the phylogenetic relationships among Anelosimus spiders, well known for their sociality. The analysis includes 67 individuals representing 23 of the 53 currently recognized Anelosimus species and all species groups previously recognized by morphological evidence. We analyse the data using Bayesian, maximum likelihood, and parsimony methods, considering the genes individually as well as combined (mitochondrial, nuclear, and both combined) in addition to a 'total evidence' analysis including morphology. Most of the data partitions are congruent in agreeing on several fundamental aspects of the phylogeny, and the combined molecular data yield a tree broadly similar to an existing morphological hypothesis. We argue that such congruence among data partitions is an important indicator of support that may go undetected by standard robustness estimators. Our results strongly support Anelosimus monophyly, and the monophyly of the recently revised American 'eximius lineage', although slightly altered by excluding A. pacificus. There was consistent support for the scattering of American Anelosimus species in three clades suggesting intercontinental dispersal. Several recently described species are reconstructed as monophyletic, supporting taxonomic decisions based on morphology and behaviour in this taxonomically difficult group. Corroborating previous results from morphology, the molecular data suggest that social species are scattered across the genus and thus that sociality has evolved multiple times, a significant finding for exploring the causes and consequences of social evolution in this group of organisms.

Confounding asymmetries in evolutionary diversification and character change

Studies of character evolution often assume that a phylogeny's shape is determined independently of the characters, which then evolve as mere passengers along the tree's branches. However, if the characters help shape the tree, but this is not considered, biased inferences can result. Simulations of asymmetrical speciation (i.e., one character state conferring a higher rate of speciation than another) result in data that are interpreted to show a higher rate of change toward the diversification-enhancing state, even though the rates to and from this state were in fact equal. Conversely, simulations of asymmetrical character change yield data that could be misinterpreted as showing asymmetrical rates of speciation. Studies of biased diversification and biased character change need to be unified by joint models and estimation methods, although how successfully the two processes can be teased apart remains to be seen.

Inferring phylogeny despite incomplete lineage sorting

It is now well known that incomplete lineage sorting can cause serious difficulties for phylogenetic inference, but little attention has been paid to methods that attempt to overcome these difficulties by explicitly considering the processes that produce them. Here we explore approaches to phylogenetic inference designed to consider retention and sorting of ancestral polymorphism. We examine how the reconstructability of a species (or population) phylogeny is affected by (a) the number of loci used to estimate the phylogeny and (b) the number of individuals sampled per species. Even in difficult cases with considerable incomplete lineage sorting (times between divergences less than 1 N(e) generations), we found the reconstructed species trees matched the "true" species trees in at least three out of five partitions, as long as a reasonable number of individuals per species were sampled. We also studied the tradeoff between sampling more loci versus more individuals. Although increasing the number of loci gives more accurate trees for a given sampling effort with deeper species trees (e.g., total depth of 10 N(e) generations), sampling more individuals often gives better results than sampling more loci with shallower species trees (e.g., depth = 1 N(e)). Taken together, these results demonstrate that gene sequences retain enough signal to achieve an accurate estimate of phylogeny despite widespread incomplete lineage sorting. Continued improvement in our methods to reconstruct phylogeny near the species level will require a shift to a compound model that considers not only nucleotide or character state substitutions, but also the population genetics processes of lineage sorting. [Coalescence; divergence; population; speciation.].