Phylogeny And Biogeography Of Pardosinae In The World (Araneae:Lycosidae)

The subfamily Pardosinae(Araneae:Lycosidae)is one of the most abundant subfamilies in Lycosidae.Currently,it includes 14 genera and over 630 species,among which Pardosa is the genus with the most species and the third largest genus of Araneae.Pardosinae is widely distributed in Asia,Europe,Africa,North America and Central America.According to the geographical distribution,it can be divided into seven geographical regions:Asian monsoon region,Qinghai-Tibet Plateau region,central Asian desert region,Northern Asia region,European region,Afrotropical region and American region.At present,the phylogenetic relationship of this subfamily has never been studied,and the classification boundary between Pardosinae and Pardosa is unclear,which leads to the doubt of the taxonomic position of some genera,and the monophyly of the largest Pardosa is difficult to recover.On the other hand,the history of biogeography of Pardosinae has not been studied,and the dispersal process of geographical distribution pattern is not clear.In this study,the phylogeny and the estimation of the time divergence,the origin and dispersal process,and the revision of taxonomic definition of the Pardosinae were studied using molecular phylogenetic methods based on multi-genes and morphological methods.The main results are as follows:(1)Phylogenetic relationships between Pardosinae and other subfamilies:Based on mitochondrial genes(COI,12S,16S)and nuclear genes(18S,28S,H3),164 taxa were used for molecular phylogeny.Bayesian inference and Maximum Likelihood analysis indicate that whether the controversial Pardosinae and Lycosinae should be merged was solved:Pardosinae is a monophyletic group and independently subfamily;Lycosinae which is considered as the sister group of Pardosinae,is a paraphyletic group including three monophyletic clads and the true sister group of Pardosinae is Lycosinae clade 1;the Allocosinae,the questionable Arctosinae and Hippasinae consist Lycosinae clade 3.The entire Lycosidae can be divided into three major clades:the basal clade consisting of Sosippinae and another highly supported clade;Venoniinae,Zoicinae,Evippinae,Artoriinae composed of the central large clade;Pardosinae and Lycosinae consisted the third clade.Bogdocosa(Pardosa multivaga gr.)and Evippinae are sister groups and Opisa gen.nov.(P.wuyiensis gr.)plus a uniquely "Arctosa" group and Hygrolycosa,clustered together with Sosippinae.(2)Phylogeny of Pardosa:P.lugubris gr.,which includes the type species of Pardosa,and its sister group P.amentata gr.clustered a highly supported clade,located inside the entire phylogenetic tree of Pardosinae.If followed the previous taxonomic definition,Pardosa is paraphyletic and many species groups from Pardosa are distributed throughout the molecular phylogenetic tree of Pardosinae.As for the other genera of Pardosinae,Acantholycosa and Caspicosa are located inside the node nested with P.lugubris gr..Meanwhile Bristowiella,Draposa and Wadicosa are nested with other Pardosa groups.However,the genera of Pardosinae and the species groups of Pardosa have large morphological differences from P.lugubris gr.and P.amentata gr..The species groups with similar morphology are not clustered together on the phylogeny tree,but two species groups with large morphological differences sometimes nested together with high supported value.Therefore,based on phylogenetic results and the morphological studies,Pardosa was supposed here to be restricted to the species from P.lugubris gr.and P.amentata gr..(3)Phylogeny of Pardosinae:Draposa,Bristowiella,Acantholycosa,and Caspicosa were first proved to be the monophyly and their placements were confirmed to be the members of Pardosinae by molecular phylogeny.Pardosa mongolica gr.,P.monticola gr.,P.tesquorum gr.,P.algoides gr.,P.palavula gr.,P.milvina gr.,P.bifasciata gr.,and P.nebulosa gr.were and P.astrigera gr.without P.jenisieca,P.laura gr.wothout P.sangzhiensis were monophyly.P.pseudoannulata gr.,Wadicosa,P.nebulosa gr.,P.sutherlandi gr.,P.fuscosoma gr.,Bristowiella,Draposa,P.neavioides gr.were divided earlier than other Pardosinae.Morphologically,the genital characteristics of these species are similar to Lycosinae and Pardosinae,which indicates that these species of Pardosinae may be the transitional taxa of Pardosinae(TTP).(4)Divergence time estimation of Pardosinae:In order to improve the accuracy of the results and reduce the influence of samples with only a few molecular markers,the original data set was changed to obtain a new data set with 124 taxa.The results from BEAST v.1.10 show that the earliest ancestors of Lycosidae was divided in the Eocene of 52.42Ma.The divergence time of the ancestors of the Pardosinae was estimated in the Oligocene of 31.74Ma and began to diverge in the end of the Oligocene(23.57Ma).9 genera were separated in the middle of the Miocene(16.17Ma11.53Ma).21 genera were separated in late Miocene to early Pliocene(7.92Ma-3.78).2 genera were separated in Pleistocene(1.79Ma).The transitional groups of the Pardosinae,distributed in the Afrotropical and Oriental regions,were diverged from other Pardosinae before the middle of the Miocene(21.06Ma,18.37Ma,15.7Ma).The Pardosinae groups in northern Eurasia and North America were diverged in the genera level from the late Miocene to the early Pliocene.(5)Historical biogeographical of Pardosinae:the biogeographical history of Pardosinae was analyzed in RASP based on BioGeoBEARS package,statistical dispersal-vicariance analysis(S-DIVA)and Bayesian binary MCMC model to reconstruct ancestral distribution area using the tree files generated from BEAST.The results reveal that with the close of Tethys sea in the Paleocene,the Eurasian continent and the African continent gradually approached.The ancestors of Pardosinae may have been widely distributed from Africa to southern Asia during the Oligocene and divided to two clades at 18.37Ma for some reason.Before that,P.pseudoannulata gr.was diverged firstly.In the Miocene the earth began to become colder,and the formation of ice sheets at the north and south poles caused a global drought.The precipitation in East Africa was greatly reduced,and the expansion of deserts in the Middle East formed a geographical barrier.Meanwhile,the sea lanes between Asia and Africa reopened in the Middle Miocene,and the Red Sea expanded in the late Miocene completely isolating the species dispersal between Africa and Asia.These affairs may cause the divergence of the African Pardosinae genera in the two clades around 16Ma.Then,with the dramatic uplift of the Qinghai-Tibet Plateau in the Miocene period,the two clades of Pardosinae were isolated further by the mountains and the weather changes.One of clade is the ancestor of the transitional groups between Lycosinae and Pardosinae.On the one hand,morphologically,they reserved the genital characteristics of the common ancestor of Lycosinae and Pardosinae.On the other hand,with the global cooling and drying,they might share the same favorite habitus for wet and warm environment with their ancestors,so they lived and dispersed in the monsoon region formed by the uplift of the Qinghai-Tibet Plateau.About 10Ma,the Tibetan Plateau has reached its current height.Another clade of Pardosinae may had adapted to the colder and drier conditions by living on the Tibetan Plateau and gradually be able to expand northward.One clade was diverged and then experienced the rapid radiation in the Hengduan Mountains in the southeast of the Tibetan Plateau,and some species of this clade continue to spread eastward to southern China together with the species from transitional groups forming the distribution patter in eastern Asia.The ancestor of the rest Pardosinae continued to spread north:the westward dispersal into Central Asia adapting dry and hot climate there and into Europe;the eastward dispersal in Northern Asia divided into a palaearctic clade and a holarctic clade;at least in 7Ma,two clades of Pardosinae had dispersed to North America,which coincides with the appearance time of Bering Land Bridge(7.5Ma).The Pleistocene glacial activity caused some species from Northern Asia clade living in the northern temperate zone to retreat southward to the northern temperate refuge in the Hengduan Mountains and radiated rapidly after the ice age.(6)Redefinitions of Pardosinae and Pardosa:Based on phylogenetic results and morphological study,the definitions of Pardosinae and Pardosa were revised.Pardosinae:the sclerosed Median Apophysis with upper and lower arms on the male palp located in the middle of the bulb;the embolic division having a developed palea;Lateral Apophysis on the ventral surface of the palea;Terminal Apophysis is the first process from apital-retrolateral edge of palea;Conductor is the second process from that order.Terminal Apophysis,Conductor,and Lateral Apophysis can be dignosed according to the position of their origins.Pardosa:on the male palp,the long upper arm of Median Apophysis curved and sharped distally;the lower arm extended retrolaterally with a ventral hook;the long Conductor and the abrupt Terminal Apophysis lamellar;on the female,epigyne with one or two hoods;the stalk of Median Septum narrow and the base of it wider than the height procurved laterally;the height of the atrium lower than 1/2 that of Median septum;the height of septal base lower than 1/2 that of the atrium;the atrium oval.Pardosa is limited to Pardosa lugubris gr.,P.amentata gr.,and P.abagensis gr..(7)Taxonomy of Pardosinae:taxonomic studies describe a total of 115 species of 44 species related to Pardosinae,including 9 known genera and 33 new genera(32 of Pardosinae)There are 19 new species,5 new species,6 new species with different names,79 new combinations,and 4 new sexual descriptions.The specimens described are from Eurasia,North America,and Africa.The taxonomic revision is based on morphological observations and molecular phylogenetic studies.